The internal tick clock was used to export the timestamp int the token
on retry packets. Doing this in cluster mode the nodes don't
understand the timestamp from tokens generated by others.
This patch re-work this using the the real current date (wall-clock time).
Timestamp are also now considered in secondes instead of milleseconds.
This patch should be backported until v2.6
sink_write() currently relies on sink->maxlen to know when to stop
writing a given payload.
But it could be useful to pass a smaller, explicit value to sink_write()
to stop before the ring maxlen, for instance if the ring is shared between
multiple feeders.
sink_write() now takes an optional maxlen parameter:
if maxlen is > 0, then sink_write will stop writing at maxlen if maxlen
is smaller than ring->maxlen, else only ring->maxlen will be considered.
[for haproxy <= 2.7, patch must be applied by hand: that is:
__sink_write() and sink_write() should be patched to take maxlen into
account and function calls to sink_write() should use 0 as second argument
to keep original behavior]
Thierry Fournier reported an annoying side-effect when using the debug()
converter.
Consider the following examples:
[1] http-request set-var(txn.test) bool(true),ipmask(24)
[2] http-request redirect location /match if { bool(true),ipmask(32) }
When starting haproxy with [1] example we get:
config : parsing [test.conf:XX] : error detected in frontend 'fe' while parsing 'http-request set-var(txn.test)' rule : converter 'ipmask' cannot be applied.
With [2], we get:
config : parsing [test.conf:XX] : error detected in frontend 'fe' while parsing 'http-request redirect' rule : error in condition: converter 'ipmask' cannot be applied in ACL expression 'bool(true),ipmask(32)'.
Now consider the following examples which are based on [1] and [2]
but with the debug() sample conv inserted in-between those incompatible
sample types:
[1*] http-request set-var(txn.test) bool(true),debug,ipmask(24)
[2*] http-request redirect location /match if { bool(true),debug,ipmask(32) }
According to the documentation, "it is safe to insert the debug converter
anywhere in a chain, even with non-printable sample types".
Thus we don't expect any side-effect from using it within a chain.
However in current implementation, because of debug() returning SMP_T_ANY
type which is a pseudo type (only resolved at runtime), the sample
compatibility checks performed at parsing time are completely uneffective.
(haproxy will start and no warning will be emitted)
The indesirable effect of this is that debug() prevents haproxy from
warning you about impossible type conversions, hiding potential errors
in the configuration that could result to unexpected evaluation or logic
while serving live traffic. We better let haproxy warn you about this kind
of errors when it has the chance.
With our previous examples, this could cause some inconveniences. Let's
say for example that you are testing a configuration prior to deploying
it. When testing the config you might want to use debug() converter from
time to time to check how the conversion chain behaves.
Now after deploying the exact same conf, you might want to remove those
testing debug() statements since they are no longer relevant.. but
removing them could "break" the config and suddenly prevent haproxy from
starting upon reload/restart. (this is the expected behavior, but it
comes a bit too late because of debug() hiding errors during tests..)
To fix this, we introduce a new output type for sample expressions:
SMP_T_SAME - may only be used as "expected" out_type (parsing time)
for sample converters.
As it name implies, it is a way for the developpers to indicate that the
resulting converter's output type is guaranteed to match the type of the
sample that is presented on the converter's input side.
(converter may alter data content, but data type must not be changed)
What it does is that it tells haproxy that if switching to the converter
(by looking at the converter's input only, since outype is SAME) is
conversion-free, then the converter type can safely be ignored for type
compatibility checks within the chain.
debug()'s out_type is thus set to SMP_T_SAME instead of ANY, which allows
it to fully comply with the doc in the sense that it does not impact the
conversion chain when inserted between sample items.
Co-authored-by: Thierry Fournier <thierry.f.78@gmail.com>
SMP_T_ADDR support was added in b805f71 ("MEDIUM: sample: let the cast
functions set their output type").
According to the above commit, it is made clear that the ADDR type is
a pseudo/generic type that may be used for compatibility checks but
that cannot be emitted from a fetch or converter.
With that in mind, all conversions from ADDR to other types were
explicitly disabled in the compatibility matrix.
But later, when map_*_ip functions were updated in b2f8f08 ("MINOR: map:
The map can return IPv4 and IPv6"), we started using ADDR as "expected"
output type for converters. This still complies with the original
description from b805f71, because it is used as the theoric output
type, and is never emitted from the converters themselves (only "real"
types such as IPV4 or IPV6 are actually being emitted at runtime).
But this introduced an ambiguity as well as a few bugs, because some
compatibility checks are being performed at config parse time, and thus
rely on the expected output type to check if the conversion from current
element to the next element in the chain is theorically supported.
However, because the compatibility matrix doesn't support ADDR to other
types it is currently impossible to use map_*_ip converters in the middle
of a chain (the only supported usage is when map_*_ip converters are
at the very end of the chain).
To illustrate this, consider the following examples:
acl test str(ok),map_str_ip(test.map) -m found # this will work
acl test str(ok),map_str_ip(test.map),ipmask(24) -m found # this will raise an error
Likewise, stktable_compatible_sample() check for stick tables also relies
on out_type[table_type] compatibility check, so map_*_ip cannot be used
with sticktables at the moment:
backend st_test
stick-table type string size 1m expire 10m store http_req_rate(10m)
frontend fe
bind localhost:8080
mode http
http-request track-sc0 str(test),map_str_ip(test.map) table st_test # raises an error
To fix this, and prevent future usage of ADDR as expected output type
(for either fetches or converters) from introducing new bugs, the
ADDR=>? part of the matrix should follow the ANY type logic.
That is, ADDR, which is a pseudo-type, must be compatible with itself,
and where IPV4 and IPV6 both support a backward conversion to a given
type, ADDR must support it as well. It is done by setting the relevant
ADDR entries to c_pseudo() in the compatibility matrix to indicate that
the operation is theorically supported (c_pseudo() will never be executed
because ADDR should not be emitted: this only serves as a hint for
compatibility checks at parse time).
This is what's being done in this commit, thanks to this the broken
examples documented above should work as expected now, and future
usage of ADDR as out_type should not cause any issue.
This function is used for ANY=>!ANY conversions in the compatibility
matrix to help differentiate between real NOOP (c_none) and pseudo
conversions that are theorically supported at config parse time but can
never occur at runtime,. That is, to explicit the fact that actual related
runtime operations (e.g.: ANY->IPV4) are not NOOP since they might require
some conversion to be performed depending on the input type.
When checking the conf we don't know the effective out types so
cast[pseudo type][pseudo type] is allowed in the compatibility matrix,
but at runtime we only expect cast[real type][(real type || pseudo type)]
because fetches and converters may not emit pseudo types, thus using
c_none() everywhere was too ambiguous.
The process will crash if c_pseudo() is invoked to help catch bugs:
crashing here means that a pseudo type has been encountered on a
converter's input at runtime (because it was emitted earlier in the
chain), which is not supported and results from a broken sample fetch
or converter implementation. (pseudo types may only be used as out_type
in sample definitions for compatibility checks at parsing time)
Both sample_parse_expr() and parse_acl_expr() implement some code
logic to parse sample conv list after respective fetch or acl keyword.
(Seems like the acl one was inspired by the sample one historically)
But there is clearly code duplication between the two functions, making
them hard to maintain.
Hopefully, the parsing logic between them has stayed pretty much the
same, thus the sample conv parsing part may be moved in a dedicated
helper parsing function.
This is what's being done in this commit, we're adding the new function
sample_parse_expr_cnv() which does a single thing: parse the converters
that are listed right after a sample fetch keyword and inject them into
an already existing sample expression.
Both sample_parse_expr() and parse_acl_expr() were adapted to now make
use of this specific parsing function and duplicated code parts were
cleaned up.
Although sample_parse_expr() remains quite complicated (numerous function
arguments due to contextual parsing data) the first goal was to get rid of
code duplication without impacting the current behavior, with the added
benefit that it may allow further code cleanups / simplification in the
future.
This patch allows the low level packet parser to drop packets with type for discarded
packet number spaces. Furthermore, this prevents it from reallocating new encryption
levels and packet number spaces already released/discarded. When a packet number space
is discarded, it MUST NOT be reallocated.
As the packet number space discarding is done asap the type of packet received is
known, some packet number space discarding check may be safely removed from qc_try_rm_hp()
and qc_qel_may_rm_hp() which are called after having parse the packet header, and
is type.
As the packet number spaces and encryption level are dynamically allocated,
the information about the packet number space discarded status must be kept
somewhere else than in these objects.
quic_tls_discard_keys() is no more useful.
Modify quic_pktns_discard() to do the same job: flag the quic_conn object
has having discarded packet number space.
Implement quic_tls_pktns_is_disarded() to check if a packet number space is
discarded. Note the Application data packet number space is never discarded.
The maximum length of the secrets derived by the TLS stack is 384 bits.
This reduces the size of the objects provided by the "quic_tls_secret" pool by
16 bytes.
Should be backported as far as 2.6
Replace ->els static array of encryption levels by 4 pointers into the QUIC
connection object, quic_conn struct.
->iel denotes the Initial encryption level,
->eel the Early-Data encryption level,
->hel the Handshaske encryption level and
->ael the Application Data encryption level.
Add ->qel_list to this structure to list the encryption levels after having been
allocated. Modify consequently the encryption level object itself (quic_enc_level
struct) so that it might be added to ->qel_list QUIC connection list of
encryption levels.
Implement qc_enc_level_alloc() to initialize the value of a pointer to an encryption
level object. It is used to initialized the pointer newly added to the quic_conn
structure. It also takes a packet number space pointer address as argument to
initialize it if not already initialized.
Modify quic_tls_ctx_reset() to call it from quic_conn_enc_level_init() which is
called by qc_enc_level_alloc() to allocate an encryption level object.
Implement 2 new helper functions:
- ssl_to_qel_addr() to match and pointer address to a quic_encryption level
attached to a quic_conn object with a TLS encryption level enum value;
- qc_quic_enc_level() to match a pointer to a quic_encryption level attached
to a quic_conn object with an internal encryption level enum value.
This functions are useful to be called from ->set_encryption_secrets() and
->add_handshake_data() TLS stack called which takes a TLS encryption enum
as argument (enum ssl_encryption_level_t).
Replace all the use of the qc->els[] array element values by one of the newly
added ->[ieha]el quic_conn struct member values.
Very simple patch to define and declare a pool for the QUIC TLS encryptions levels.
It will be used to dynamically allocate such objects to be attached to the
QUIC connection object (quic_conn struct) and to remove from quic_conn struct the
static array of encryption levels (see ->els[]).
Add a pool to dynamically handle the memory used for the QUIC TLS packet number spaces.
Remove the static array of packet number spaces at QUIC connection level (struct
quic_conn) and add three new members to quic_conn struc as pointers to quic_pktns
struct, one by packet number space as follows:
->ipktns for Initial packet number space,
->hpktns for Handshake packet number space and
->apktns for Application packet number space.
Also add a ->pktns_list new member (struct list) to quic_conn struct to attach
the list of the packet number spaces allocated for the QUIC connection.
Implement ssl_to_quic_pktns() to map and retrieve the addresses of these pointers
from TLS stack encryption levels.
Modify quic_pktns_init() to initialize these members.
Modify ha_quic_set_encryption_secrets() and ha_quic_add_handshake_data() to
allocate the packet numbers and initialize the encryption level.
Implement quic_pktns_release() which takes pointers to pointers to packet number
space objects to release the memory allocated for a packet number space attached
to a QUIC connection and reset their address values.
Modify qc_new_conn() to allocation only the Initial packet number space and
Initial encryption level.
Modify QUIC loss detection API (quic_loss.c) to use the new ->pktns_list
list attached to a QUIC connection in place of a static array of packet number
spaces.
Replace at several locations the use of elements of an array of packet number
spaces by one of the three pointers to packet number spaces
haproxy/quic_tls-t.h is the correct place to quic_enc_level structure
definition.
Should be backported as far as 2.6 to ease any further backport to come.
In some cases it may be desirable for latency reasons to forcefully
flush the queue even if it results in suboptimal compression. In our
case the queue might contain up to almost 4 bytes, which need an EOB
and a switch to literal mode, followed by 4 bytes to encode an empty
message. This means that each call can add 5 extra bytes in the ouput
stream. And the flush may also result in the header being produced for
the first time, which can amount to 2 or 10 bytes (zlib or gzip). In
the worst case, a total of 19 bytes may be emitted at once upon a flush
with 31 pending bits and a gzip header.
This is libslz upstream commit cf8c4668e4b4216e930b56338847d8d46a6bfda9.
This patch introduces the "client-sigalgs" keyword for the server line,
which allows to configure the list of server signature algorithms
negociated during the handshake. Also available as
"ssl-default-server-client-sigalgs" in the global section.
This patch introduces the "sigalgs" keyword for the server line, which
allows to configure the list of server signature algorithms negociated
during the handshake. Also available as "ssl-default-server-sigalgs" in
the global section.
This bug arrived with this commit:
MINOR: quic: Remove pool_zalloc() from qc_new_conn()
Missing initialization of largest packet number received during a keyupdate phase.
This prevented the keyupdate feature from working and made the keyupdate interop
tests to fail for all the clients.
Furthermore, ->flags from quic_tls_ctx was also not initialized. This could
also impact the keyupdate feature at least.
No backport needed.
qc_new_conn() is ued to initialize QUIC connections with quic_conn struct objects.
This function calls quic_conn_release() when it fails to initialize a connection.
quic_conn_release() is also called to release the memory allocated by a QUIC
connection.
Replace pool_zalloc() by pool_alloc() in this function and initialize
all quic_conn struct members which are referenced by quic_conn_release() to
prevent use of non initialized variables in this fonction.
The ebtrees, the lists attached to quic_conn struct must be initialized.
The tasks must be reset to their NULL default values to be safely destroyed
by task_destroy(). This is all the case for all the TLS cipher contexts
of the encryption levels (struct quic_enc_level) and those for the keyupdate.
The packet number spaces (struct quic_pktns) must also be initialized.
->prx_counters pointer must be initialized to prevent quic_conn_prx_cntrs_update()
from dereferencing this pointer.
->latest_rtt member of quic_loss struct must also be initialized. This is done
by quic_loss_init() called by quic_path_init().
->tx.pto_probe member of quic_pktns struct was not initialized by quic_pktns_init().
This bug never occured because all quic_pktns structs are attached to quic_conn
structs which are always pool_zalloc()'ed.
Must be backported as far as 2.6.
proxy default-server is a specific type of server that is not allocated
using new_server(): it is directly stored within the parent proxy
structure. However, since it may contain some default config options that
may be inherited by regular servers, it is also subject to dynamic members
(strings, structures..) that needs to be deallocated when the parent proxy
is cleaned up.
Unfortunately, srv_drop() may not be used directly from p->defsrv since
this function is meant to be used on regular servers only (those created
using new_server()).
To circumvent this, we're splitting srv_drop() to make a new function
called srv_free_params() that takes care of the member cleaning which
originally takes place in srv_drop(). This function is exposed through
server.h, so it may be called from outside server.c.
Thanks to this, calling srv_free_params(&p->defsrv) from free_proxy()
prevents any memory leaks due to dynamic parameters allocated when
parsing a default-server line from a proxy section.
This partially fixes GH #2173 and may be backported to 2.8.
[While it could also be relevant for other stable versions, the patch
won't apply due to architectural changes / name changes between 2.4 => 2.6
and then 2.6 => 2.8. Considering this is a minor fix that only makes
memory analyzers happy during deinit paths (at least for <= 2.8), it might
not be worth the trouble to backport them any further?]
Historically the client-fin and server-fin timeouts were made to allow
a connection closure to be effective quickly if the last data were sent
down a socket and the client didn't close, something that can happen
when the peer's FIN is lost and retransmits are blocked by a firewall
for example. This made complete sense in 1.5 for TCP and HTTP in close
mode. But nowadays with muxes, it's not done at the right layer anymore
and even the description doesn't match what is being done, because what
happens is that the stream will abort the whole transfer after it's done
sending to the mux and this timeout expires.
We've seen in GH issue 2095 that this can happen with very short timeout
values, and while this didn't trigger often before, now that the muxes
(h2 & quic) properly report an end of stream before even the first
sc_conn_sync_recv(), it seems that it can happen more often, and have
two undesirable effects:
- logging a timeout when that's not the case
- aborting the request channel, hence the server-side conn, possibly
before it had a chance to be put back to the idle list, causing
this connection to be closed and not reusable.
Unfortunately for TCP (mux_pt) this remains necessary because the mux
doesn't have a timeout task. So here we're adding tests to only do
this through an HTX mux. But to be really clean we should in fact
completely drop all of this and implement these timeouts in the mux
itself.
This needs to be backported to 2.8 where the issue was discovered,
and maybe carefully to older versions, though that is not sure at
all. In any case, using a higher timeout or removing client-fin in
HTTP proxies is sufficient to make the issue disappear.
As seen in commits 33a4461fa ("BUG/MINOR: stats: Fix Lua's `get_stats`
function") and a46b142e8 ("BUG/MINOR: Missing stat_field_names (since
f21d17bb)") it seems frequent to omit to update stats_fields[] when
adding a new ST_F_xxx entry. This breaks Lua's get_stats() and shows
a "(null)" in the header of "show stat", but that one is not detectable
to the naked eye anymore.
Let's add a reminder above the enum declaration about this, and a small
reg tests checking for the absence of "(null)". It was verified to fail
before the last patch above.
This patch is similar to the previous one but for QUIC mux functions
used inside the mux code itself or application layer. Replace all
occurences of qc_* prefix by qcc_* or qcs_*. This should help to better
differentiate code between quic_conn and MUX.
This should be backported up to 2.7.
There was a misnaming in stats counter for *_BLOCKED frames in regard to
QUIC rfc convention. This patch fixes it to prevent future ambiguity :
- STREAMS_BLOCKED -> STREAM_DATA_BLOCKED
- STREAMS_DATA_BLOCKED_BIDI -> STREAMS_BLOCKED_BIDI
- STREAMS_DATA_BLOCKED_UNI -> STREAMS_BLOCKED_UNI
This should be backported up to 2.7.
Remove nb_streams field from qcc. It was not used outside of a BUG_ON()
statement to ensure we never have a negative count of streams. However
this is already checked with other fields.
This should be backported up to 2.7.
The Linux kernel maintains data structures to track a processes' open file
descriptors, and it expands these structures as necessary when FD usage grows
(at every FD=2^X starting at 64). However when threading is in use, during
expansion the kernel will pause (observed up to 47ms) while it waits for thread
synchronization (see https://bugzilla.kernel.org/show_bug.cgi?id=217366).
This change addresses the issue and avoids the random pauses by opening the
maximum file descriptor during initialization, so that expansion will not occur
while processing traffic.
TCC silently ignores the weak and section attributes, which ruins the
initcalls. Technically we're exactly in the same situation as with an
obsolete linker. Let's just automatically set the flag if TCC is
detected, this avoids surprises where the program compiles but does
not start.
No backport is needed.
TCC doesn't knoow about __attribute__((weak)), it silently ignores it.
We could add a "static" modifier there in this case but we already have
an alternate portable mode that is based on a slightly larger literal
for obsolete linkers (and non-ELF systems) which choke on weak. Let's
just add the test for tcc there and use it in this case.
No backport is needed.
TCC is upset by the declaration looking like:
const unsigned char ist_lc[256] __attribute__((weak)) = ((const unsigned char[256]){ ... });
It was written like this because it's expanded from the _IST_LC macro
but it's never used as-is, it's only used from ist_lc, which should be
the one containing the cast so that the macro only contains the list of
bytes that can be used in both places. And this assigns more consistent
roles to the lower and upper case macro/variable now, one is typed and
the other one not. No backport is needed.
Add ->sent_pkt counter to quic_conn struct to count the packet at QUIC connection
level. Then, when the connection is released, the ->sent_pkt counter value
is added to the one for the listener.
Must be backported to 2.7.
Add some statistical counters to quic_conn struct from quic_counters struct which
are used at listener level to handle them at QUIC connection level. This avoid
calling atomic functions. Furthermore this will be useful soon when a counter will
be added for the total number of packets which have been sent which will be very
often incremented.
Some counters were not added, espcially those which count the number of QUIC errors
by QUIC error types. Indeed such counters would be incremented most of the time
only one time at QUIC connection level.
Implement quic_conn_prx_cntrs_update() which accumulates the QUIC connection level
statistical counters to the listener level statistical counters.
Must be backported to 2.7.
Thierry Fournier reported a build breakage with the ubiquitous make
3.81, LDFLAGS were ignored. This is caused by the declaration of the
collect_opt_flags macro that is defined with an "=" sign, something
that only appeared in 3.82 and that is not necessary. With it removed,
the build now works fine at least from 3.80 to 4.3.
No backport is needed since this makefile cleanup appeared in 2.8.
During a code audit of the various situations that promote ERR_PENDING to
ERROR, it appeared that:
- all muxes use se_fl_set_error() to set it, which chooses either based
on EOI/EOS presence ;
- EOI/EOS that arrive late after ERR_PENDING were not systematically
upgraded to ERROR
This results in confusion about how such ERROR or ERR_PENDING ought to
be handled, which is not quite desirable.
This patch adds a test to se_fl_set() to detect if we're setting EOI or
EOS while ERR_PENDING is present, or the other way around so that any
sequence of EOI/EOS <-> ERR_PENDING results in ERROR being set. This
way there will no longer be possible situations where ERROR is missing
while the other ones are set.
quic_aead_iv_build() should never fail unless we call it with buffers of
different size. This never happens in the code as every input buffers
are of size QUIC_TLS_IV_LEN.
Remove the return value and add a BUG_ON() to prevent future misusage.
This is especially useful to remove one error handling on the sending
patch via quic_packet_encrypt().
This should be backported up to 2.7.
Right now there's no way to enforce a specific value of now_ms upon
startup in order to compensate for the time it takes to load a config,
specifically when dealing with the health check startup. For this we'd
need to force the now_offset value to compensate for the last known
value of the current date. This patch exposes a function to do exactly
this.
Just like we have the uptime in "show info", let's add the boot time.
It's trivial to collect as it's just the difference between the ready
date and the start date, and will allow users to monitor this element
in order to take action before it starts becoming problematic. Here
the boot time is reported in milliseconds, so this allows to even
observe sub-second anomalies in startup delays.
Some huge configs take a significant amount of time to start and this
can cause some trouble (e.g. health checks getting delayed and grouped,
process not responding to the CLI etc). For example, some configs might
start fast in certain environments and slowly in other ones just due to
the use of a wrong DNS server that delays all libc's resolutions. Let's
first start by measuring it by keeping a copy of the most recently known
ready date, once before calling check_config_validity() and then refine
it when leaving this function. A last call is finally performed just
before deciding to split between master and worker processes, and it covers
the whole boot. It's trivial to collect and even allows to get rid of a
call to clock_update_date() in function check_config_validity() that was
used in hope to better schedule future events.
Uninline and move qc_attach_sc() function to implementation source file.
This will be useful for next commit to add traces in it.
This should be backported up to 2.7.
MUX is responsible to put EOS on stream when read channel is closed.
This happens if underlying connection is closed or a RESET_STREAM is
received. FIN STREAM is ignored in this case.
For connection closure, simply check for CO_FL_SOCK_RD_SH.
For RESET_STREAM reception, a new flag QC_CF_RECV_RESET has been
introduced. It is set when RESET_STREAM is received, unless we already
received all data. This is conform to QUIC RFC which allows to ignore a
RESET_STREAM in this case. During RESET_STREAM processing, input buffer
is emptied so EOS can be reported right away on recv_buf operation.
This should be backported up to 2.7.
Fix the openssl build with older openssl version by disabling the new
ssl_c_r_dn fetch.
This also disable the ssl_client_samples.vtc file for OpenSSL version
older than 1.1.1
This patch addresses #1514, adds the ability to fetch DN of the root
ca that was in the chain when client certificate was verified during SSL
handshake.
qc_stream_buf_alloc() can fail for two reasons :
* limit of Tx buffer per connection reached
* allocation failure
The first case is properly treated. A flag QC_CF_CONN_FULL is set on the
connection to interrupt emission. It is cleared when a buffer became
available after in order ACK reception and the MUX tasklet is woken up.
The allocation failure was handled with the same mechanism which in this
case is not appropriate and could lead to a connection transfer freeze.
Instead, prefer to close the connection with a QUIC internal error code.
To differentiate the two causes, qc_stream_buf_alloc() API was changed
to return the number of available buffers to the caller.
This must be backported up to 2.6.
Remove QUIC MUX function qcs_http_handle_standalone_fin(). The purpose
of this function was only used when receiving an empty STREAM frame with
FIN bit. Besides, it was called by each application protocol which could
have different approach and render the function purpose unclear.
Invocation of qcs_http_handle_standalone_fin() have been replaced by
explicit code in both H3 and HTTP/0.9 module. In the process, use
htx_set_eom() to reliably put EOM on the HTX message.
This should be backported up to 2.7, along with the previous patch which
introduced htx_set_eom().
Implement a new HTX utility function htx_set_eom(). If the HTX message
is empty, it will first add a dummy EOT block. This is a small trick
needed to ensure readers will detect the HTX buffer as not empty and
retrieve the EOM flag.
Replace the H2 code related by a htx_set_eom() invocation. QUIC also has
the same code which will be replaced in the next commit.
This should be backported up to 2.7 before the related QUIC patch.
This provides more consistency between the master and the worker. When
"prompt timed" is passed on the master, the timed mode is toggled. When
enabled, for a master it will show the master process' uptime, and for
a worker it will show this worker's uptime. Example:
master> prompt timed
[0:00:00:50] master> show proc
#<PID> <type> <reloads> <uptime> <version>
11940 master 1 [failed: 0] 0d00h02m10s 2.8-dev11-474c14-21
# workers
11955 worker 0 0d00h00m59s 2.8-dev11-474c14-21
# old workers
11942 worker 1 0d00h02m10s 2.8-dev11-474c14-21
# programs
[0:00:00:58] master> @!11955
[0:00:01:03] 11955> @!11942
[0:00:02:17] 11942> @
[0:00:01:10] master>
Entering "prompt timed" toggles reporting of the process' uptime in
the prompt, which will report days, hours, minutes and seconds since
it was started. As discussed with Tim in issue #2145, this can be
convenient to roughly estimate the time between two outputs, as well
as detecting that a process failed to be reloaded for example.
Adding http_free_redirect_rule() function to free a single redirect rule
since it may be required to free rules outside of free_proxy() function.
This patch is required for an upcoming bugfix.
[for 2.2, free_proxy function did not exist (first seen in 2.4), thus
http_free_redirect_rule() needs to be deducted from haproxy.c deinit()
function if the patch is required]
A xref is added between the endpoint descriptors. It is created when the
server endpoint is attached to the SC and it is destroyed when an endpoint
is detached.
This xref is not used for now. But it will be useful to retrieve info about
an endpoint for the opposite side. It is also the warranty there is still a
endpoint attached on the other side.
When "optioon socket-stats" is used in a frontend, its listeners have
their own stats and will appear in the stats page. And when the stats
page has "stats show-legends", then a tooltip appears on each such
socket with ip:port and ID. The problem is that since QUIC arrived, it
was not possible to distinguish the TCP listeners from the QUIC ones
because no protocol indication was mentioned. Now we add a "proto"
legend there with the protocol name, so we can see "tcp4" or "quic6"
and figure how the socket is bound.
Following previous patch, error notification from quic_conn has been
adjusted to rely on standard connection flags. Most notably, CO_FL_ERROR
on the connection instance when a fatal error is detected.
Check for CO_FL_ERROR is implemented by qc_send(). If set the new flag
QC_CF_ERR_CONN will be set for the MUX instance. This flag is similar to
the local error flag and will abort most of the futur processing. To
ensure stream upper layer is also notified, qc_wake_some_streams()
called by qc_process() will put the stream on error if this new flag is
set.
This should be backported up to 2.7.
When an error is detected at quic-conn layer, the upper MUX must be
notified. Previously, this was done relying on quic_conn flag
QUIC_FL_CONN_NOTIFY_CLOSE set and the MUX wake callback called on
connection closure.
Adjust this mechanism to use an approach more similar to other transport
layers in haproxy. On error, connection flags are updated with
CO_FL_ERROR, CO_FL_SOCK_RD_SH and CO_FL_SOCK_WR_SH. The MUX is then
notified when the error happened instead of just before the closing. To
reflect this change, qc_notify_close() has been renamed qc_notify_err().
This function must now be explicitely called every time a new error
condition arises on the quic_conn layer.
To ensure MUX send is disabled on error, qc_send_mux() now checks
CO_FL_SOCK_WR_SH. If set, the function returns an error. This should
prevent the MUX from sending data on closing or draining state.
To complete this patch, MUX layer must now check for CO_FL_ERROR
explicitely. This will be the subject of the following commit.
This should be backported up to 2.7.
Add traces for when an upper layer stream is woken up by the MUX. This
should help to diagnose frozen stream issues.
This should be backported up to 2.7.
As discussed a few times over the years, it's quite difficult to know
how often we stop accepting connections because the global maxconn was
reached. This is not easy to know because when we reach the limit we
stop accepting but we don't know if incoming connections are pending,
so it's not possible to know how many were delayed just because of this.
However, an interesting equivalent metric consist in counting the number
of times an accepted incoming connection resulted in the limit being
reached. I.e. "we've accepted the last one for now". That doesn't imply
any other one got delayed but it's a factual indicator that something
might have been delayed. And by counting the number of such events, it
becomes easier to know whether some limits need to be adjusted because
they're reached often, or if it's exceptionally rare.
The metric is reported as a counter in show info and on the stats page
in the info section right next to "maxconn".
Now in "show info" we have a TotalWarnings field that reports the total
number of warnings issued since the process started. It's also reported
in the the stats page next to the uptime.
LIST_DELETE doesn't affect the previous pointers of the stored element.
This can sometimes hide bugs when such a pointer is reused by accident
in a LIST_NEXT() or equivalent after having been detached for example, or
ia another LIST_DELETE is performed again, something that LIST_DEL_INIT()
is immune to. By compiling with -DDEBUG_LIST, we'll replace a freshly
detached list element with two invalid pointers that will cause a crash
in case of accidental misuse. It's not enabled by default.
->others member of tp_version_information structure pointed to a buffer in the
TLS stack used to parse the transport parameters. There is no garantee that this
buffer is available until the connection is released.
Do not dump the available versions selected by the client anymore, but displayed the
chosen one (selected by the client for this connection) and the negotiated one.
Must be backported to 2.7 and 2.6.
A recent series of patch were introduced to streamline error generation
by QUIC MUX. However, a regression was introduced : every error
generated by the MUX was built as CONNECTION_CLOSE_APP frame, whereas it
should be only for H3/QPACK errors.
Fix this by adding an argument <app> in qcc_set_error. When false, a
standard CONNECTION_CLOSE is used as error.
This bug was detected by QUIC tracker with the following tests
"stop_sending" and "server_flow_control" which requires a
CONNECTION_CLOSE frame.
This must be backported up to 2.7.
The comment for the stconn structure was still referencing the SHUTR/SHUTW
flags. These flags were replaced and we now use ABRT/SHUT flags in
comments. The comment itself was slightly updated to be accurate.
When sc_need_room() is called, the caller cannot request more free space
than a minimum value to be sure it is always possible to unblock it. it is a
safety guard to not freeze any SC on NEED_ROOM condition. At worse it will
lead to some wakeups un excess at the edge.
To keep things simple, the following minimum is used:
(global.tune.bufsize - global.tune.maxrewrite - sizeof(struct htx))
Most of the function in quic_frame.c and quic_frame.h manipulate <buf> buffer
position variables which have nothing to see with struct buffer variables.
Rename them to <pos>
Should be backported to 2.7.
Commit e83f937cc ("MEDIUM: quic: use a global CID trees list") uses a
local variable "tree" used only for locks, but when threads are disabled
it spews a warning about this unused variable.
The function that cpu-map uses to parse CPU sets, parse_cpu_set(), was
etended in 2.4 with commit a80823543 ("MINOR: cfgparse: support the
comma separator on parse_cpu_set") to support commas between ranges.
But since it was quite late in the development cycle, by then it was
decided not to add a last-minute surprise and not to magically support
commas in cpu-map, hence the "comma_allowed" argument.
Since then we know that it was not the best choice, because the comma
is silently ignored in the cpu-map syntax, causing all sorts of
surprises in field with threads running on a single node for example.
In addition it's quite common to copy-paste a taskset line and put it
directly into the haproxy configuration.
This commit relaxes this rule an finally allows cpu-map to support
commas between ranges. It simply consists in removing the comma_allowed
argument in the parse_cpu_set() function. The doc was updated to
reflect this.
Exposing a new hlua function, available from body or init contexts, that
forcefully disables the sending of email alerts even if the mailers are
defined in haproxy configuration.
This will help for sending email directly from lua.
(prevent legacy email sending from intefering with lua)
Adding a new event type: SERVER_CHECK.
This event is published when a server's check state ought to be reported.
(check status change or check result)
SERVER_CHECK event is provided as a server event with additional data
carrying relevant check's context such as check's result and health.
Adding a new SERVER event in the event_hdl API.
SERVER_ADMIN is implemented as an advanced server event.
It is published each time the administrative state changes.
(when s->cur_admin changes)
SERVER_ADMIN data is an event_hdl_cb_data_server_admin struct that
provides additional info related to the admin state change, but can
be casted as a regular event_hdl_cb_data_server struct if additional
info is not needed.
Adding a new SERVER event in the event_hdl API.
SERVER_STATE is implemented as an advanced server event.
It is published each time the server's effective state changes.
(when s->cur_state changes)
SERVER_STATE data is an event_hdl_cb_data_server_state struct that
provides additional info related to the server state change, but can
be casted as a regular event_hdl_cb_data_server struct if additional
info is not needed.
sc_need_room() now takes the required free space to receive more data as
parameter. All calls to this function are updated accordingly. For now, this
value is set but not used. When we are waiting for a buffer, 0 is used. So
we expect to be unblocked ASAP. However this must be reviewed because
SC_FL_NEED_BUF is probably enough in this case and this flag is already set
if the input buffer allocation fails.
When the SC is blocked because it is waiting for room in the input buffer,
it will be responsible to specify the minimum free space required to
progress. In this commit, we only introduce the field in the stconn
structure that will be used to store this value. It is a signed value with
the following meaning:
* -1: The SC is waiting for room but not based on the buffer state. It
will be typically used during splicing when the pipe is full. In
this case, only a successful send can unblock the SC.
* >= 0; The minimum free space in the input buffer to unblock the SC. 0 is
a special value to specify the SC must be unblocked ASAP, by the
stream, at the end of process_stream() or when output data are
consumed on the opposite side.
stats_putchk() is updated to use the applet API instead of the channel API
to write data. To do so, the appctx is passed as parameter instead of the
channel. This way, the applet does not need to take care to request more
room it it fails to put data into the channel's buffer.
This commit introduces the keyword "client-sigalgs" for the bind line,
which does the same as "sigalgs" but for the client authentication.
"ssl-default-bind-client-sigalgs" allows to set the default parameter
for all the bind lines.
This patch should fix issue #2081.
This patch introduces the "sigalgs" keyword for the bind line, which
allows to configure the list of server signature algorithms negociated
during the handshake. Also available as "ssl-default-bind-sigalgs" in
the default section.
This patch was originally written by Bruno Henc.
The thread dump mechanism that is used by "show threads" and by the
panic dump is overly complicated due to an initial misdesign. It
firsts wakes all threads, then serializes their dumps, then releases
them, while taking extreme care not to face colliding dumps. In fact
this is not what we need and it reached a limit where big machines
cannot dump all their threads anymore due to buffer size limitations.
What is needed instead is to be able to dump *one* thread, and to let
the requester iterate on all threads.
That's what this patch does. It adds the thread_dump_buffer to the
struct thread_ctx so that the requester offers the buffer to the
thread that is about to be dumped. This buffer also serves as a lock.
A thread at rest has a NULL, a valid pointer indicates the thread is
using it, and 0x1 (NULL+1) is used by the dumped thread to tell the
requester it's done. This makes sure that a given thread is dumped
once at a time. In addition to this, the calling thread decides
whether it accesses the thread by itself or via the debug signal
handler, in order to get a backtrace. This is much saner because the
calling thread is free to do whatever it wants with the buffer after
each thread is dumped, and there is no dependency between threads,
once they've dumped, they're free to continue (and possibly to dump
for another requester if needed). Finally, when the THREAD_DUMP
feature is disabled and the debug signal is not used, the requester
accesses the thread by itself like before.
For now we still have the buffer size limitation but it will be
addressed in future patches.
NS_TO_TV helper was implemented in 591fa59 ("MINOR: time: add conversions
to/from nanosecond timestamps")
Due to NS_TO_TV being implemented as a macro and not a function, we must
take extra care when manipulating user input.
In current implementation, 't' argument is not isolated within the macro.
Because of this, NS_TO_TV(1 + 1) will expand to:
((const struct timeval){ .tv_sec = 1 + 1 / 1000000000ULL, .tv_usec = (1 + 1 % 1000000000ULL) / 1000U })
Instead of:
((const struct timeval){ .tv_sec = 2 / 1000000000ULL, .tv_usec = (2 % 1000000000ULL) / 1000U })
As such, NS_TO_TV usage in hlua_now() is currently incorrect and this
results in unexpected values being passed to lua.
In this patch, we're adding an extra parenthesis around 't' in NS_TO_TV()
macro to make it safe against such usages. (that is: ensure proper
argument expansion as if NS_TO_TV was implemented as a function)
This is a 2.8 specific bug, no backport needed.
When a fatal error is detected by the QUIC MUX or H3 layer, the
connection should be closed with a CONNECTION_CLOSE with an error code
as the reason.
Previously, a direct call was used to the quic_conn layer to try to
close the connection. This API was adjusted to be more flexible. Now,
when an error is detected, the function qcc_set_error() is called. This
set the flag QC_CF_ERRL with the error code stored by the MUX. The
connection will be closed soon so most of the operations are not
conducted anymore. Connection is then finally closed during qc_send()
via quic_conn layer if QC_CF_ERRL is set. This will set the flag
QC_CF_ERRL_DONE which indicates that the MUX instance can be freed.
This model is cleaner and brings the following improvments :
- interaction with quic_conn layer for closure is centralized on a
single function
- CO_FL_ERROR is not set anymore. This was incorrect as this should be
reserved to errors reported by the transport layer to be similar with
other haproxy components. As a consequence, qcc_is_dead() has been
adjusted to check for QC_CF_ERRL_DONE to release the MUX instance.
This should be backported up to 2.7.
Add a dedicated trace event QMUX_EV_QCC_ERR. This is used for locally
detected error when a CONNECTION_CLOSE should be emitted.
This should be backported up to 2.7.
Now that "now" is no more a timeval, there's no point keeping a copy
of it as a timeval, let's also switch start_time to nanoseconds, it
simplifies operations.
This puts an end to the occasional confusion between the "now" date
that is internal, monotonic and not synchronized with the system's
date, and "date" which is the system's date and not necessarily
monotonic. Variable "now" was removed and replaced with a 64-bit
integer "now_ns" which is a counter of nanoseconds. It wraps every
585 years, so if all goes well (i.e. if humanity does not need
haproxy anymore in 500 years), it will just never wrap. This implies
that now_ns is never nul and that the zero value can reliably be used
as "not set yet" for a timestamp if needed. This will also simplify
date checks where it becomes possible again to do "date1<date2".
All occurrences of "tv_to_ns(&now)" were simply replaced by "now_ns".
Due to the intricacies between now, global_now and now_offset, all 3
had to be turned to nanoseconds at once. It's not a problem since all
of them were solely used in 3 functions in clock.c, but they make the
patch look bigger than it really is.
The clock_update_local_date() and clock_update_global_date() functions
are now much simpler as there's no need anymore to perform conversions
nor to round the timeval up or down.
The wrapping continues to happen by presetting the internal offset in
the short future so that the 32-bit now_ms continues to wrap 20 seconds
after boot.
The start_time used to calculate uptime can still be turned to
nanoseconds now. One interrogation concerns global_now_ms which is used
only for the freq counters. It's unclear whether there's more value in
using two variables that need to be synchronized sequentially like today
or to just use global_now_ns divided by 1 million. Both approaches will
work equally well on modern systems, the difference might come from
smaller ones. Better not change anyhting for now.
One benefit of the new approach is that we now have an internal date
with a resolution of the nanosecond and the precision of the microsecond,
which can be useful to extend some measurements given that timestamps
also have this resolution.
Instead we're using ns_to_sec(tv_to_ns(&now)) which allows the tv_sec
part to disappear. At this point, "now" is only used as a timeval in
clock.c where it is updated.
Let's get rid of timeval in storage of internal timestamps so that they
are no longer mistaken for wall clock time. These were exclusively used
subtracted from each other or to/from "now" after being converted to ns,
so this patch removes the tv_to_ns() conversion to use them natively. Two
occurrences of tv_isge() were turned to a regular wrapping subtract.
Instead of operating on {sec, usec} now we convert both operands to
ns then subtract them and convert to ms. This is a first step towards
dropping timeval from these timestamps.
Interestingly, tv_ms_elapsed() and tv_ms_remain() are no longer used at
all and could be removed.
In order to ease the transition away from the timeval used in internal
timestamps, let's first create a few functions and macro to return a
counter from a timeval and conversely, as well as ease the conversions
to/from ns/us/ms/sec to save the user from having to count zeroes and
to think about appending ULL in conversions.
SC_FL_SND_NEVERWAIT and SC_FL_SND_EXP_MORE flags have the same value. It is
not critical because these flags are only used to know if MSG_MORE flag must
be set on a send().
No backport needed.
It is possible to start too many applets on sporadic burst of events after
an inactivity period. It is due to the way we estimate if a new applet must
be created or not. It is based on a frequency counter. We compare the events
processing rate against the number of events currently processed (in
progress or waiting to be processed). But we should also take care of the
number of idle applets.
We already track the number of idle applets, but it is global and not
per-thread. Thus we now also track the number of idle applets per-thread. It
is not a big deal because this fills a hole in the spoe_agent structure.
Thanks to this counter, we can refrain applets creation if there is enough
idle applets to handle currently processed events.
This patch should be backported to every stable versions.
During accept, a quic-conn is rebind to a new thread. This process is
done in two times :
* first on the original thread via qc_set_tid_affinity()
* then on the newly assigned thread via qc_finalize_affinity_rebind()
Most quic_conn operations (I/O tasklet, task and quic_conn FD socket
read) are reactivated ony after the second step. However, there is a
possibility that datagrams are handled before it via quic_dgram_parse()
when using listener sockets. This does not seem to cause any issue but
this may cause unexpected behavior in the future.
To simplify this, qc_finalize_affinity_rebind() will be called both by
qc_xprt_start() and quic_dgram_parse(). Only one invocation will be
performed thanks to the new flag QUIC_FL_CONN_AFFINITY_CHANGED.
This should be backported up to 2.7.
Some HTX responses may not always contain a EOM block. For example this
is the case if content-length header is missing from the HTTP server
response. Stream termination is thus signaled to QUIC mux via shutw
callback. However, this is interpreted inconditionnally as an early
close by the mux with a RESET_STREAM emission. Most of the times, QUIC
clients report this as an error.
To fix this, check if htx.extra is set to HTX_UNKOWN_PAYLOAD_LENGTH for
a qcs instance. If true, shutw will never be used to emit a
RESET_STREAM. Instead, the stream will be closed properly with a FIN
STREAM frame. If all data were already transfered, an empty STREAM frame
is sent.
This fix may help with the github issue #2004 where chrome browser stop
to use QUIC after receiving RESET_STREAM frames.
This issue was reported by Vladimir Zakharychev. Thanks to him for his
help and testing. It was also reproduced locally using httpterm with the
query string "/?s=1k&b=0&C=1".
This should be backported up to 2.7.
On aarch64 there's also a guaranted invalid instruction, called UDF, and
which even supports an optional 16-bit immediate operand:
https://developer.arm.com/documentation/ddi0596/2021-12/Base-Instructions/UDF--Permanently-Undefined-?lang=en
It's conveniently encoded as 4 zeroes (when the operand is zero). It's
unclear when support for it was added into GAS, if at all; even a
not-so-old 2.27 doesn't know about it. Let's byte-encode it.
Tested on an A72 and works as expected.
BUG_ON() calls currently trigger a segfault. This is more convenient
than abort() as it doesn't rely on any function call nor signal handler
and never causes non-unwindable stacks when opening cores. But it adds
quite some confusion in bug reports which are rightfully tagged "segv"
and do not instantly allow to distinguish real segv (e.g. null derefs)
from code asserts.
Some CPU architectures offer various crashing methods. On x86 we have
INT3 (0xCC), which stops into the debugger, and UD0/UD1/UD2. INT3 looks
appealing but for whatever reason (maybe signal handling somewhere) it
loses the last call point in the stack, making backtraces unusable. UD2
has the merit of being only 2 bytes and causing an invalid instruction,
which almost never happens normally, so it's easily distinguishable.
Here it was defined as a macro so that the line number in the core
matches the one where the BUG_ON() macro is called, and the debugger
shows the last frame exactly at its calligg point.
E.g. when calling "debug dev bug":
Program terminated with signal SIGILL, Illegal instruction.
#0 debug_parse_cli_bug (args=<optimized out>, payload=<optimized out>, appctx=<optimized out>, private=<optimized out>) at src/debug.c:408
408 BUG_ON(one > zero);
[Current thread is 1 (Thread 0x7f7a660cc1c0 (LWP 14238))]
(gdb) bt
#0 debug_parse_cli_bug (args=<optimized out>, payload=<optimized out>, appctx=<optimized out>, private=<optimized out>) at src/debug.c:408
#1 debug_parse_cli_bug (args=<optimized out>, payload=<optimized out>, appctx=<optimized out>, private=<optimized out>) at src/debug.c:402
#2 0x000000000061a69f in cli_parse_request (appctx=appctx@entry=0x181c0160) at src/cli.c:832
#3 0x000000000061af86 in cli_io_handler (appctx=0x181c0160) at src/cli.c:1035
#4 0x00000000006ca2f2 in task_run_applet (t=0x181c0290, context=0x181c0160, state=<optimized out>) at src/applet.c:449
Rename all frame variables with the suffix _frm. This helps to
differentiate frame instances from other internal objects.
This should be backported up to 2.7.
Each frame type used in quic_frame union has been renamed with the
following prefix "qf_". This helps to differentiate frame instances from
other internal objects.
This should be backported up to 2.7.
This new setting accepts "by-process", "by-group" and "by-thread" and
will dictate how listeners will be sharded by default when nothing is
specified. While the default remains "by-process", "by-group" should be
much more efficient with many threads, while not changing anything for
single-group setups.
When testing if a protocol supports SO_REUSEPORT, we're now able to
verify if the OS does really support it. While it may be supported at
build time, it may possibly have been blocked in a container for
example so we'd rather know what it's like.
The new function _sock_supports_reuseport() will be used to check if a
protocol type supports SO_REUSEPORT or not. This will be useful to verify
that shards can really work.
The new function protocol_supports_flag() checks the protocol flags
to verify if some features are supported, but will support being
extended to refine the tests. Let's use it to check for REUSEPORT.
Some protocol support SO_REUSEPORT and others not. Some have such a
limitation in the kernel, and others in haproxy itself (e.g. sock_unix
cannot support multiple bindings since each one will unbind the previous
one). Also it's really protocol-dependent and not just family-dependent
because on Linux for some time it was supported for TCP and not UDP.
Let's move the definition to the protocols instead. Now it's preset in
tcp/udp/quic when SO_REUSEPORT is defined, and is otherwise left unset.
The enabled() config condition test validates IPv4 (generally sufficient),
and -dR / noreuseport all protocols at once.
We'll use these flags to know if some protocols are supported, and if
so, with what options/extensions. Reuseport will move there for example.
Two functions were added to globally set/clear a flag.
What used to be only two lines to apply a mask in a loop in
check_config_validity() grew into a 130-line block that performs deeply
listener-specific operations that do not have their place there anymore.
In addition it's worth noting that the peers code still doesn't support
shards nor being bound to more than one group, which is a second reason
for moving that code to its own function. Nothing was changed except
recreating the missing variables from the bind_conf itself (the fe only).
This field forces an unaligned hole between two list heads. Let's move
it up where it will be more easily combined with other fields. In
addition, turn it to unsigned while it's still not used.
There's a two-byte hole in proto_fam after sock_family, let's move the
l3_addrlen there as a ushort. Note that contrary to what the comment
says, it's still not used by hash algorithms though it could.
One limitation of the current thread index mechanism is that if the
values are assigned multiple times to the same thread and the index
loops, it can match again the old value, which will not prevent a
competing thread from finishing its CAS and assigning traffic to a
thread that's not the optimal one. The probability is low but the
solution is simple enough and consists in implementing an update
counter in the high bits of the index to force a mismatch in this
case (assuming we don't try to cover for extremely unlikely cases
where the update counter loops while the index remains equal). So
let's do that. In order to improve the situation a little bit, we
now set the index to a ulong so that in 32 bits we have 8 bits of
counter and in 64 bits we have 40 bits.
There has always been a race when checking the length of an accept queue
to determine which one is more loaded that another, because the head and
tail are read at two different moments. This is not required, we can merge
them as two 16 bit numbers inside a single 32-bit index that is always
accessed atomically. This way we read both values at once and always have
a consistent measurement.
The purpose of this new flag will be to mark that some listeners
duplicate their reference's FD instead of trying to setup a completely
new listener from scratch. This will be used when multiple groups want
to listen to the same socket, via multiple FDs.
In order to create multiple receivers for one multi-group shard, we'll
need some more info about the shard. Here we store:
- the number of groups (= number of receivers)
- the number of threads (will be used for accept LB)
- pointer to the reference rx (to get the FD and to find all threads)
- pointers to the other members (to iterate over all threads)
For now since there's only one group per shard it remains simple. The
listener deletion code already takes care of removing the current
member from its shards list and moving others' reference to the last
one if it was their reference (so as to avoid o(n^2) updates during
ordered deletes).
Since the vast majority of setups will not use multi-group shards, we
try to save memory usage by only allocating the shard_info when it is
needed, so the principle here is that a receiver shard_info==NULL is
alone and doesn't share its socket with another group.
Various approaches were considered and tests show that the management
of the listeners during boot makes it easier to just attach to or
detach from a shard_info and automatically allocate it if it does not
exist, which is what is being done here.
For now the attach code is not called, but detach is already called
on delete.
This new algorithm for rebalancing incoming connections to multiple
threads is simpler and instead of considering the threads load, it will
only cycle through all of them, offering a fair share of the traffic to
each thread. It may be well suited for short-lived connections but is
also convenient for very large thread counts where it's not always certain
that the least loaded thread will always be found.
There's a li_per_thread array in each listener for use with QUIC
listeners. Since thread groups were introduced, this array can be
allocated too large because global.nbthread is allocated for each
listener, while only no more than MIN(nbthread,MAX_THREADS_PER_GROUP)
may be used by a single listener. This was because the global thread
ID is used as the index instead of the local ID (since a listener may
only be used by a single group). Let's just switch to local ID and
reduce the allocated size.
When migrating a quic_conn to another thread, we may need to also
switch the listener if the thread belongs to another group. When
this happens, the freshly created connection will already have the
target listener, so let's just pick it from the connection and use
it in qc_set_tid_affinity(). Note that it will be the caller's
responsibility to guarantee this.
Operational and administrative state change causes are not propagated
through srv_update_status(), instead they are directly consumed within
the function to provide additional info during the call when required.
Thus, there is no valid reason for keeping adm and op causes within
server struct. We are wasting space and keeping uneeded complexity.
We now exlicitly pass change type (operational or administrative) and
associated cause to srv_update_status() so that no extra storage is
needed since those values are only relevant from srv_update_status().
This one is greatly inspired by "MINOR: server: change adm_st_chg_cause storage type".
While looking at current srv_op_st_chg_cause usage, it was clear that
the struct needed some cleanup since some leftovers from asynchronous server
state change updates were left behind and resulted in some useless code
duplication, and making the whole thing harder to maintain.
Two observations were made:
- by tracking down srv_set_{running, stopped, stopping} usage,
we can see that the <reason> argument is always a fixed statically
allocated string.
- check-related state change context (duration, status, code...) is
not used anymore since srv_append_status() directly extracts the
values from the server->check. This is pure legacy from when
the state changes were applied asynchronously.
To prevent code duplication, useless string copies and make the reason/cause
more exportable, we store it as an enum now, and we provide
srv_op_st_chg_cause() function to fetch the related description string.
HEALTH and AGENT causes (check related) are now explicitly identified to
make consumers like srv_append_op_chg_cause() able to fetch checks info
from the server itself if they need to.
srv_append_status() has become a swiss-knife function over time.
It is used from server code and also from checks code, with various
inputs and distincts code paths, making it very hard to guess the
actual behavior of the function (resulting string output).
To simplify the logic behind it, we're dividing it in multiple contextual
functions that take simple inputs and do explicit things, making them
more predictable and easier to maintain.
Even though it doesn't look like it at first glance, this is more like
a cleanup than an actual code improvement:
Given that srv->adm_st_chg_cause has been used to exclusively store
static strings ever since it was implemented, we make the choice to
store it as an enum instead of a fixed-size string within server
struct.
This will allow to save some space in server struct, and will make
it more easily exportable (ie: event handlers) because of the
reduced memory footprint during handling and the ability to later get
the corresponding human-readable message when it's explicitly needed.
For advanced async handlers only
(Registered using EVENT_HDL_ASYNC_TASK() macro):
event->when is provided as a struct timeval and fetched from 'date'
haproxy global variable.
Thanks to 'when', related event consumers will be able to timestamp
events, even if they don't work in real-time or near real-time.
Indeed, unlike sync or normal async handlers, advanced async handlers
could purposely delay the consumption of pending events, which means
that the date wouldn't be accurate if computed directly from within
the handler.
Add the ability to provide a cleanup function for event data passed
via the publishing function.
One use case could be the need to provide valid pointers in the safe
section of the data struct.
Cleanup function will be automatically called with data (or copy of data)
as argument when all handlers consumed the event, which provides an easy
way to release some memory or decrement refcounts to ressources that were
provided through the data struct.
data in itself may not be freed by the cleanup function, it is handled
by the API.
This would allow passing large (allocated) data blocks through the data
struct while keeping data struct size under the EVENT_HDL_ASYNC_EVENT_DATA
size limit.
To do so, when publishing an event, where we would currently do:
struct event_hdl_cb_data_new_family event_data;
/* safe data, available from both sync and async contexts
* may not use pointers to short-living resources
*/
event_data.safe.my_custom_data = x;
/* unsafe data, only available from sync contexts */
event_data.unsafe.my_unsafe_data = y;
/* once data is prepared, we can publish the event */
event_hdl_publish(NULL,
EVENT_HDL_SUB_NEW_FAMILY_SUBTYPE_1,
EVENT_HDL_CB_DATA(&event_data));
We could do:
struct event_hdl_cb_data_new_family event_data;
/* safe data, available from both sync and async contexts
* may not use pointers to short-living resources,
* unless EVENT_HDL_CB_DATA_DM is used to ensure pointer
* consistency (ie: refcount)
*/
event_data.safe.my_custom_static_data = x;
event_data.safe.my_custom_dynamic_data = malloc(1);
/* unsafe data, only available from sync contexts */
event_data.unsafe.my_unsafe_data = y;
/* once data is prepared, we can publish the event */
event_hdl_publish(NULL,
EVENT_HDL_SUB_NEW_FAMILY_SUBTYPE_1,
EVENT_HDL_CB_DATA_DM(&event_data, data_new_family_cleanup));
With data_new_family_cleanup func which would look like this:
void data_new_family_cleanup(const void *data)
{
const struct event_hdl_cb_data_new_family *event_data = ptr;
/* some data members require specific cleanup once the event
* is consumed
*/
free(event_data.safe.my_custom_dynamic_data);
/* don't ever free data! it is not ours */
}
Not sure if this feature will become relevant in the future, so I prefer not
to mention it in the doc for now.
But given that the implementation is trivial and does not put a burden
on the existing API, it's a good thing to have it there, just in case.
ESUB_INDEX(n) index macro is used exclusively with n > 0
Fixing it so that it starts numbering at 1 instead of 2.
This way, we don't waste a subtype slot in event_hdl_sub_type
struct, and we comply with the structure comments about max
supported event subtypes (currently set at 16).
If 68e692da0 ("MINOR: event_hdl: add event handler base api")
is being backported, then this commit should be backported with it.
This commit does nothing that ought to be mentioned, except that
it adds missing comments and slighty moves some function calls
out of "sensitive" code in preparation of some server code refactors.
Expose proxy_uuid variable in event_hdl_cb_data_server struct to
overcome proxy_name fixed length limitation.
proxy_uuid may be used by the handler to perform proxy lookups.
This should be preferred over lookups relying proxy_name.
(proxy_name is suitable for printing / logging purposes but not for
ID lookups since it has a maximum fixed length)
Since this commit:
BUG/MINOR: quic: Possible wrapped values used as ACK tree purging limit.
There are more chances that ack ranges may be removed from their trees when
building a packet. It is preferable to impose a limit to these trees. This
will be the subject of the a next commit to come.
For now on, it is sufficient to stop deleting ack range from their trees.
Remove quic_ack_frm_reduce_sz() and quic_rm_last_ack_ranges() which were
there to do that.
Make qc_frm_len() support ACK frames and calls it to ensure an ACK frame
may be added to a packet before building it.
Must be backported to 2.6 and 2.7.
Not all hlua "time" variables use the same time logic.
hlua->wake_time relies on ticks since its meant to be used in conjunction
with task scheduling. Thus, it should be stored as a signed int and
manipulated using the tick api.
Adding a few comments about that to prevent mixups with hlua internal
timer api which doesn't rely on the ticks api.
For non yieldable lua handlers (converters, fetches or yield
incompatible lua functions), current timeout detection relies on now_ms
thread local variable.
But within non-yieldable contexts, now_ms won't be updated if not by us
(because we're momentarily stuck in lua context so we won't
re-enter the polling loop, which is responsible for clock updates).
To circumvent this, clock_update_date(0, 1) was manually performed right
before now_ms is being read for the timeout checks.
But this fails to work consistently, because if no other concurrent
threads periodically run clock_update_global_date(), which do happen if
we're the only active thread (nbthread=1 or low traffic), our
clock_update_date() call won't reliably update our local now_ms variable
Moreover, clock_update_date() is not the right tool for this anyway, as
it was initially meant to be used from the polling context.
Using it could have negative impact on other threads relying on now_ms
to be stable. (because clock_update_date() performs global clock update
from time to time)
-> Introducing hlua multipurpose timer, which is internally based on
now_cpu_time_fast() that provides per-thread consistent clock readings.
Thanks to this new hlua timer API, hlua timeout logic is less error-prone
and more robust.
This allows the timeout detection to work as expected for both yieldable
and non-yieldable lua handlers.
This patch depends on commit "MINOR: clock: add now_cpu_time_fast() function"
While this could theorically be backported to all stable versions,
it is advisable to avoid backports unless we're confident enough
since it could cause slight behavior changes (timing related) in
existing setups.
Same as now_cpu_time(), but for fast queries (less accurate)
Relies on now_cpu_time() and now_mono_time_fast() is used
as a cache expiration hint to prevent now_cpu_time() from being
called too often since it is known to be quite expensive.
Depends on commit "MINOR: clock: add now_mono_time_fast() function"
Same as now_mono_time(), but for fast queries (less accurate)
Relies on coarse clock source (also known as fast clock source on
some systems).
Fallback to now_mono_time() if coarse source is not supported on the system.
Remove the receiver RX_F_LOCAL_ACCEPT flag. This was used by QUIC
protocol before thread rebinding was supported by the quic_conn layer.
This should be backported up to 2.7 after the previous patch has also
been taken.
When a quic_conn instance is rebinded on a new thread its tasks and
tasklet are destroyed and new ones created. Its socket is also migrated
to a new thread which stop reception on it.
To properly reactivate a quic_conn after rebind, wake up its tasks and
tasklet if they were active before thread rebind. Also reactivate
reading on the socket FD. These operations are implemented on a new
function qc_finalize_affinity_rebind().
This should be backported up to 2.7 after a period of observation.
Implement a new function qc_set_tid_affinity(). This function is
responsible to rebind a quic_conn instance to a new thread.
This operation consists mostly of releasing existing tasks and tasklet
and allocating new instances on the new thread. If the quic_conn uses
its owned socket, it is also migrated to the new thread. The migration
is finally completed with updated the CID TID to the new thread. After
this step, the connection is thus accessible to the new thread and
cannot be access anymore on the old one without risking race condition.
To ensure rebinding is either done completely or not at all, tasks and
tasklet are pre-allocated before all operations. If this fails, an error
is returned and rebiding is not done.
To destroy the older tasklet, its context is set to NULL before wake up.
In I/O callbacks, a new function qc_process() is used to check context
and free the tasklet if NULL.
The thread rebinding can cause a race condition if the older thread
quic_dghdlrs::dgrams list contains datagram for the connection after
rebinding is done. To prevent this, quic_rx_pkt_retrieve_conn() always
check if the packet CID is still associated to the current thread or
not. In the latter case, no connection is returned and the new thread is
returned to allow to redispatch the datagram to the new thread in a
thread-safe way.
This should be backported up to 2.7 after a period of observation.
When QUIC handshake is completed on our side, some frames are prepared
to be sent :
* HANDSHAKE_DONE
* several NEW_CONNECTION_ID with CIDs allocated
This step was previously executed in quic_conn_io_cb() directly after
CRYPTO frames parsing. This patch delays it to be completed after
accept. Special care have been taken to ensure it is still functional
with 0-RTT activated.
For the moment, this patch should have no impact. However, when
quic_conn thread migration on accept will be implemented, it will be
easier to remap only one CID to the new thread. New CIDs will be
allocated after migration on the new thread.
This should be backported up to 2.7 after a period of observation.
Define a new protocol callback set_affinity. This function is used
during listener_accept() to notify about a rebind on a new thread just
before pushing the connection on the selected thread queue. If the
callback fails, accept is done locally.
This change will be useful for protocols with state allocated before
accept is done. For the moment, only QUIC protocol is concerned. This
will allow to rebind the quic_conn to a new thread depending on its
load.
This should be backported up to 2.7 after a period of observation.
CIDs were moved from a per-thread list to a global list instance. The
TID-encoded is thus non needed anymore.
This should be backported up to 2.7 after a period of observation.
Previously, quic_connection_id were stored in a per-thread tree list.
Datagram were first dispatched to the correct thread using the encoded
TID before a tree lookup was done.
Remove these trees and replace it with a global trees list of 256
entries. A CID is using the list index corresponding to its first byte.
On datagram dispatch, CID is lookup on its tree and TID is retrieved
using new member quic_connection_id.tid. As such, a read-write lock
protects each list instances. With 256 entries, it is expected that
contention should be reduced.
A new structure quic_cid_tree served as a tree container associated with
its read-write lock. An API is implemented to ensure lock safety for
insert/lookup/delete operation.
This patch is a step forward to be able to break the affinity between a
CID and a TID encoded thread. This is required to be able to migrate a
quic_conn after accept to select thread based on their load.
This should be backported up to 2.7 after a period of observation.
Remove <tid> member in quic_conn. This is moved to quic_connection_id
instance.
For the moment, this change has no impact. Indeed, qc.tid reference
could easily be replaced by tid as all of this work was already done on
the connection thread. However, it is planified to support quic_conn
thread migration in the future, so removal of qc.tid will simplify this.
This should be backported up to 2.7.
ODCID are never stored in the CID tree. Instead, we store our generated
CID which is directly derived from the CID using a hash function. This
operation is done via quic_derive_cid().
Previously, generated CID was returned as a 64-bits integer. However,
this is cumbersome to convert as an array of bytes which is the most
common CID representation. Adjust this by modifying return type to a
quic_cid struct.
This should be backported up to 2.7.
qc_parse_hd_form() is the function used to parse the first byte of a
packet and return its type and version. Its API has been simplified with
the following changes :
* extra out paremeters are removed (long_header and version). All infos
are now stored directly in quic_rx_packet instance
* a new dummy version is declared in quic_versions array with a 0 number
code. This can be used to match Version negotiation packets.
* a new default packet type is defined QUIC_PACKET_TYPE_UNKNOWN to be
used as an initial value.
Also, the function has been exported to an include file. This will be
useful to be able to reuse on quic-sock to parse the first packet of a
datagram.
This should be backported up to 2.7.
Two different structs exists for QUIC connection ID :
* quic_connection_id which represents a full CID with its sequence
number
* quic_cid which is just a buffer with a length. It is contained in the
above structure.
To better differentiate them, rename all quic_connection_id variable
instances to "conn_id" by contrast to "cid" which is used for quic_cid.
This should be backported up to 2.7.
QUIC_LOCK label is never used. Indeed, lock usage is minimal on QUIC as
every connection is pinned to its owned thread.
This should be backported up to 2.7.
SC_FL_EOS flag is added to report the end-of-stream at the SC level. It will
be used to distinguish end of stream reported by the endoint, via the
SE_FL_EOS flag, and the abort triggered by the stream, via the
SC_FL_ABRT_DONE flag.
In this patch, the flag is defined and is systematically tested everywhere
SC_FL_ABRT_DONE is tested. It should be safe because it is never set.
The flag SC_FL_ERROR is added to ack errors on the endpoint. When
SE_FL_ERROR flag is detected on the SE descriptor, the corresponding is set
on the SC. Idea is to avoid, as far as possible, to manipulated the SE
descriptor in upper layers and know when an error in the endpoint is handled
by the SC.
For now, this flag is only set and cleared but never tested.
Here again, it is just a flag renaming. In SC flags, there is no longer
shutdown for reads but aborts. For now this flag is set when a read0 is
detected. It is of couse not accurate. This will be changed later.
After the flag renaming, it is now the turn for the channel function to be
renamed and moved in the SC scope. channel_shutw_now() is replaced by
sc_schedule_shutdown(). The request channel is replaced by the front SC and
the response is replace by the back SC.
Because shutowns for reads are now considered as aborts, the shudowns for
writes can now be considered as shutdowns. Here it is just a flag
renaming. SC_FL_SHUTW_NOW is renamed SC_FL_SHUT_WANTED.
After the flag renaming, it is now the turn for the channel function to be
renamed and moved in the SC scope. channel_shutr_now() is replaced by
sc_schedule_abort(). The request channel is replaced by the front SC and the
response is replace by the back SC.
Most of calls to channel_abort() are associated to a call to
channel_auto_close(). Others are in areas where the auto close is the
default. So, it is now systematically enabled when an abort is performed on
a channel, as part of channel_abort() function.
Add the number of packet losts and the maximum congestion control window computed
by the algorithms to "show quic".
Same thing for the traces of existent congestion control algorithms.
Must be backported to 2.7 and 2.6.
Instead of artificially setting the shards count to MAX_THREAD when
"by-thread" is used, let's reserve special values for symbolic names
so that we can add more in the future. For now we use value -1 for
"by-thread", which requires to turn the type to signed int but it was
already used as such everywhere anyway.
fd_migrate_on() can be used to migrate an existing FD to any thread, even
one belonging to a different group from the current one and from the
caller's. All that is needed is to make sure the FD is still valid when
the operation is performed (which is the case when such operations happen).
This is potentially slightly expensive since it locks the tgid during the
delicate operation, but it is normally performed only from an owning
thread to offer the FD to another one (e.g. reassign a better thread upon
accept()).
In order to permit to migrate FDs from one thread group to another,
we'll need to be able to set a TGID that is compatible with no other
thread group. Either we use a special value or we dedicate a special
bit. Given that we already have way more bits than needed, let's just
sacrifice the topmost one to serve as a lock bit, indicating the tgid
is not valid anymore. This will make all fd_grab_tgid() fail to grab
it.
The new fd_lock_tgid() function now tries to assign a locked tgid to
an idle FD, and fd_unlock_tgid() simply drops the lock bit, revealing
the target tgid.
For now it's still unused so it must not have any effect.
fd_claim_tgid() uses a CAS to set the desired TGID on the FD. It's only
called from fd_insert() where in the vast majority of cases, the tgid
and refcount are zero before the call. However the loop was optimized
for the case where it was equal to the desired TGID, systematically
causing one extra round in the loop there. Better start assuming a
zero value.
We're only checking for 0, 1, or >1 groups enabled there, and we'll soon
need to be more precise and know quickly which groups are non-empty.
Let's just replace the count with a mask of enabled groups. This will
allow to quickly spot the presence of any such group in a set.
Alert when the len argument of a stick table type contains incorrect
characters.
Replace atol by strtol.
Could be backported in every maintained versions.
Once in a while we introduce an sprintf() or strncat() function by
accident. These ones are particularly dangerous and must never ever
be used because the only way to use them safely is at least as
complicated if not more, than their safe counterparts. By redefining
a few of these functions with an attribute_warning() we can deliver a
message to the developer who is tempted to use them. This commit does
it for strcat(), strcpy(), strncat(), sprintf(), vsprintf(). More could
come later if needed, such as strtok() and maybe a few others, but these
are less common.
__attribute__((deprecated)) is convenient to discourage from using
something deprecated, but gcc >= 4.3 provides __attribute__((warning(x)))
that allows to display a specific warning if something is used. This is
particularly convenient to give indications when some API parts need to
be adapted. Let's just define it as a macro that falls back to the older
deprecated attribute when not available.
It's supported on clang 14 as well but works differently and errors
out when redefined (while the main purpose precisely is to add such a
redefinition). Thus instead on clang we use deprecated(msg) which is
OK. See https://github.com/llvm/llvm-project/issues/56519
It appeared that __has_attribute() doesn't work on gcc 4.4 and older
because the concatenation of __has_attribute##x isn't resolved as a one
before being passed to __equals_1() which immediately concatenates it to
comma_for_one. We first need to pass it through an extra layer to resolve
this name to a value. The new version was tested with gcc 4.2 to 11.3.
This may be backported though it's pretty minor.
Add code so that compression can be used for requests as well.
New compression keywords are introduced :
"direction" that specifies what we want to compress. Valid values are
"request", "response", or "both".
"type-req" and "type-res" define content-type to be compressed for
requests and responses, respectively. "type" is kept as an alias for
"type-res" for backward compatibilty.
"algo-req" specifies the compression algorithm to be used for requests.
Only one algorithm can be provided.
"algo-res" provides the list of algorithm that can be used to compress
responses. "algo" is kept as an alias for "algo-res" for backward
compatibility.
Make provision for being able to store both compression algorithms and
content-types to compress for both requests and responses. For now only
the responses one are used.
Make provision for storing the compression algorithm and the compression
context twice, one for requests, and the other for responses. Only the
response ones are used for now.
In the commit 2954bcc1e (BUG/MINOR: http-ana: Don't switch message to DATA
when waiting for payload), the HTTP message flags were extended and don't
fit anymore in an unsigned char. So, we must use an unsigned integer now. It
is not a big deal because there was already a 6-bytes hole in the structure,
just after the flags. Now, there are a 3-bytes hold before.
This patch should fix the issue #2105. It is 2.8-specific, no backport
needed.
Previously, ODCID were concatenated with the client address. This was
done to prevent a collision between two endpoints which used the same
ODCID.
Thanks to the two previous patches, first connection generated CID is
now directly derived from the client ODCID using a hash function which
uses the client source address from the same purpose. Thus, it is now
unneeded to concatenate client address to <odcid> quic-conn member.
This change allows to simplify the quic_cid structure management and
reduce its size which is important as it is embedded several times in
various structures such as quic_conn and quic_rx_packet.
This should be backported up to 2.7.
First connection CID generation has been altered. It is now directly
derived from client ODCID since previous commit :
commit 162baaff7a
MINOR: quic: derive first DCID from client ODCID
This patch removes the ODCID tree which is now unneeded. On connection
lookup via CID, if a DCID is not found the hash derivation is performed
for an INITIAL/0-RTT packet only. In case a client has used multiple
times an ODCID, this will allow to retrieve our generated DCID in the
CID tree without storing the ODCID node.
The impact of this two combined patch is that it may improve slightly
haproxy memory footprint by removing a tree node from quic_conn
structure. The cpu calculation induced by hash derivation should only be
performed only a few times per connection as the client will start to
use our generated CID as soon as it received it.
This should be backported up to 2.7.
HTTP_MSGF_EXPECT_CHECKED is now set on the request message to know the
"Expect: " header was already handled, if any. The flag is set from the
moment we try to handle the header to send a "100-continue" response,
whether it was found or not.
This way, when we are waiting for the request payload, thanks to this flag,
we only try to handle "Expect: " header only once. Before it was performed
by changing the message state from BODY to DATA. But this has some side
effects and it is no accurate. So, it is better to rely on a flag to do so.
Now that the event handler API is pretty mature, we can expose it in
the lua API.
Introducing the core.event_sub(<event_types>, <cb>) lua function that
takes an array of event types <event_types> as well as a callback
function <cb> as argument.
The function returns a subscription <sub> on success.
Subscription <sub> allows you to manage the subscription from anywhere
in the script.
To this day only the sub->unsub method is implemented.
The following event types are currently supported:
- "SERVER_ADD": when a server is added
- "SERVER_DEL": when a server is removed from haproxy
- "SERVER_DOWN": server states goes from up to down
- "SERVER_UP": server states goes from down to up
As for the <cb> function: it will be called when one of the registered
event types occur. The function will be called with 3 arguments:
cb(<event>,<data>,<sub>)
<event>: event type (string) that triggered the function.
(could be any of the types used in <event_types> when registering
the subscription)
<data>: data associated with the event (specific to each event family).
For "SERVER_" family events, server details such as server name/id/proxy
will be provided.
If the server still exists (not yet deleted), a reference to the live
server is provided to spare you from an additionnal lookup if you need
to have direct access to the server from lua.
<sub> refers to the subscription. In case you need to manage it from
within an event handler.
(It refers to the same subscription that the one returned from
core.event_sub())
Subscriptions are per-thread: the thread that will be handling the
event is the one who performed the subscription using
core.event_sub() function.
Each thread treats events sequentially, it means that if you have,
let's say SERVER_UP, then SERVER_DOWN in a short timelapse, then your
cb function will first be called with SERVER_UP, and once you're done
handling the event, your function will be called again with SERVER_DOWN.
This is to ensure event consitency when it comes to logging / triggering
logic from lua.
Your lua cb function may yield if needed, but you're pleased to process
the event as fast as possible to prevent the event queue from growing up
To prevent abuses, if the event queue for the current subscription goes
over 100 unconsumed events, the subscription will pause itself
automatically for as long as it takes for your handler to catch up.
This would lead to events being missed, so a warning will be emitted in
the logs to inform you about that. This is not something you want to let
happen too often, it may indicate that you subscribed to an event that
is occurring too frequently or/and that your callback function is too
slow to keep up the pace and you should review it.
If you want to do some parallel processing because your callback
functions are slow: you might want to create subtasks from lua using
core.register_task() from within your callback function to perform the
heavy job in a dedicated task and allow remaining events to be processed
more quickly.
Please check the lua documentation for more information.
Adding alternative findserver() functions to be able to perform an
unique match based on name or puid and by leveraging revision id (rid)
to make sure the function won't match with a new server reusing the
same name or puid of the "potentially deleted" server we were initially
looking for.
For example, if you were in the position of finding a server based on
a given name provided to you by a different context:
Since dynamic servers were implemented, between the time the name was
picked and the time you will perform the findserver() call some dynamic
server deletion/additions could've been performed in the mean time.
In such cases, findserver() could return a new server that re-uses the
name of a previously deleted server. Depending on your needs, it could
be perfectly fine, but there are some cases where you want to lookup
the original server that was provided to you (if it still exists).
While working on event handling from lua, the need for a pause/resume
function to temporarily disable a subscription was raised.
We solve this by introducing the EHDL_SUB_F_PAUSED flag for
subscriptions.
The flag is set via _pause() and cleared via _resume(), and it is
checked prior to notifying the subscription in publish function.
Pause and Resume functions are also available for via lookups for
identified subscriptions.
If 68e692da0 ("MINOR: event_hdl: add event handler base api")
is being backported, then this commit should be backported with it.
Use event_hdl_async_equeue_size() in advanced async task handler to
get the near real-time event queue size.
By near real-time, you should understand that the queue size is not
updated during element insertion/removal, but shortly before insertion
and shortly after removal, so the size should reflect the approximate
queue size at a given time but should definitely not be used as a
unique source of truth.
If 68e692da0 ("MINOR: event_hdl: add event handler base api")
is being backported, then this commit should be backported with it.
Add event_hdl_async_equeue_isempty() to check is the event queue is
empty from an advanced async task handler.
If 68e692da0 ("MINOR: event_hdl: add event handler base api")
is being backported, then this commit should be backported with it.
