If the "close-spread-time" option is set to "infinite", active
connection closing during a soft-stop can be disabled. The 'connection:
close' header or the GOAWAY frame will not be added anymore to the
server's response and active connections will only be closed once the
clients disconnect. Idle connections will not be closed all at once when
the soft-stop starts anymore, and each idle connection will follow its
own timeout based on the multiple timeouts set in the configuration (as
is the case during regular execution).
This feature request was described in GitHub issue #1614.
This patch should be backported to 2.5. It depends on 'MEDIUM: global:
Add a "close-spread-time" option to spread soft-stop on time window'.
There were plenty of leftovers from old code that were never removed
and that are not needed at all since these files do not use any
definition depending on fcntl.h, let's drop them.
Almost all of our hash-based LB algorithms are implemented as special
cases of something that can now be achieved using sample expressions,
and some of them have adopted some options to adapt their behavior in
ways that could also be achieved using converters.
There are users who want to hash other parameters that are combined
into variables, and who set headers from these values and use
"balance hdr(name)" for this.
Instead of constantly implementing specific options and having users
hack around when they want a real hash, let's implement a native hash
mode that applies to a standard sample expression. This way, any
fetchable element (including variables) may be used to construct the
hash, even modified by any converter if desired.
Since the 2.5, it is possible to define TCP/HTTP ruleset in defaults
sections. However, rules defining a capture in defaults sections was not
properly handled because they was not shared with the proxies inheriting
from the defaults section. This led to crash when haproxy tried to store a
new capture.
So now, to fix the issue, when a new proxy is created, the list of captures
points to the list of its defaults section. It may be NULL or not. All new
caputres are prepended to this list. It is not a problem to share the same
defaults section between several proxies, because it is not altered and we
take care to not release it when corresponding proxies are freed but only
when defaults proxies are freed. To do so, defaults proxies are now
unreferenced at the end of free_proxy() function instead of the beginning.
This patch should fix the issue #1674. It must be backported to 2.5.
Remaining flags and associated functions are move in the conn-stream
scope. These flags are added on the endpoint and not the conn-stream
itself. This way it will be possible to get them from the mux or the
applet. The functions to get or set these flags are renamed accordingly with
the "cs_" prefix and updated to manipualte a conn-stream instead of a
stream-interface.
Flag to consider a stream as indepenent is now handled at the conn-stream
level. Thus SI_FL_INDEP_STR stream-int flag is replaced by CS_FL_INDEP_STR
conn-stream flags.
At many places, we now use the new CS functions to get a stream or a channel
from a conn-stream instead of using the stream-interface API. It is the
first step to reduce the scope of the stream-interfaces. The main change
here is about the applet I/O callback functions. Before the refactoring, the
stream-interface was the appctx owner. Thus, it was heavily used. Now, as
far as possible,the conn-stream is used. Of course, it remains many calls to
the stream-interface API.
The new 'close-spread-time' global option can be used to spread idle and
active HTTP connction closing after a SIGUSR1 signal is received. This
allows to limit bursts of reconnections when too many idle connections
are closed at once. Indeed, without this new mechanism, in case of
soft-stop, all the idle connections would be closed at once (after the
grace period is over), and all active HTTP connections would be closed
by appending a "Connection: close" header to the next response that goes
over it (or via a GOAWAY frame in case of HTTP2).
This patch adds the support of this new option for HTTP as well as HTTP2
connections. It works differently on active and idle connections.
On active connections, instead of sending systematically the GOAWAY
frame or adding the 'Connection: close' header like before once the
soft-stop has started, a random based on the remainder of the close
window is calculated, and depending on its result we could decide to
keep the connection alive. The random will be recalculated for any
subsequent request/response on this connection so the GOAWAY will still
end up being sent, but we might wait a few more round trips. This will
ensure that goaways are distributed along a longer time window than
before.
On idle connections, a random factor is used when determining the expire
field of the connection's task, which should naturally spread connection
closings on the time window (see h2c_update_timeout).
This feature request was described in GitHub issue #1614.
This patch should be backported to 2.5. It depends on "BUG/MEDIUM:
mux-h2: make use of http-request and keep-alive timeouts" which
refactorized the timeout management of HTTP2 connections.
Log servers are a real mess because:
- entries are duplicated using memcpy() without their strings being
reallocated, which results in these ones not being freeable every
time.
- a new field, ring_name, was added in 2.2 by commit 99c453df9
("MEDIUM: ring: new section ring to declare custom ring buffers.")
but it's never initialized during copies, causing the same issue
- no attempt is made at freeing all that.
Of course, running "haproxy -c" under ASAN quickly notices that and
dumps a core.
This patch adds the missing strdup() and initialization where required,
adds a new free_logsrv() function to cleanly free() such a structure,
calls it from the proxy when iterating over logsrvs instead of silently
leaking their file names and ring names, and adds the same logsrv loop
to the proxy_free_defaults() function so that we don't leak defaults
sections on exit.
It looks a bit entangled, but it comes as a whole because all this stuff
is inter-dependent and was missing.
It's probably preferable not to backport this in the foreseable future
as it may reveal other jokes if some obscure parts continue to memcpy()
the logsrv struct.
The server_id_hdr_name is already processed as an ist in various locations lets
also just store it as such.
see 0643b0e7e ("MINOR: proxy: Make `header_unique_id` a `struct ist`") for a
very similar past commit.
The orgto_hdr_name is already processed as an ist in `http_process_request`,
lets also just store it as such.
see 0643b0e7e ("MINOR: proxy: Make `header_unique_id` a `struct ist`") for a
very similar past commit.
The fwdfor_hdr_name is already processed as an ist in `http_process_request`,
lets also just store it as such.
see 0643b0e7e ("MINOR: proxy: Make `header_unique_id` a `struct ist`") for a
very similar past commit.
The monitor_uri is already processed as an ist in `http_wait_for_request`, lets
also just store it as such.
see 0643b0e7e ("MINOR: proxy: Make `header_unique_id` a `struct ist`") for a
very similar past commit.
The unsafe conn-stream API (__cs_*) is now used when we are sure the good
endpoint or application is attached to the conn-stream. This avoids compiler
warnings about possible null derefs. It also simplify the code and clear up
any ambiguity about manipulated entities.
As reported by Coverity in issue #1568, a missing initialization of the
error message pointer in parse_new_proxy() may result in displaying garbage
or crashing in case of memory allocation error when trying to create a new
proxy on startup.
This should be backported to 2.4.
Since recent changes related to the conn-stream/stream-interface
refactoring, GCC reports potential null pointer dereferences when we get the
appctx, the stream or the stream-interface from the conn-strem. Of course,
depending on the time, these entities may be null. But at many places, we
know they are defined and it is safe to get them without any check. Thus, we
use ALREADY_CHECKED() macro to silent these warnings.
Note that the refactoring is unfinished, so it is not a real issue for now.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the proxy part.
Because appctx is now an endpoint of the conn-stream, there is no reason to
still have the stream-interface as appctx owner. Thus, the conn-stream is
now the appctx owner.
Thanks to previous changes, it is now possible to set an appctx as endpoint
for a conn-stream. This means the appctx is no longer linked to the
stream-interface but to the conn-stream. Thus, a pointer to the conn-stream
is explicitly stored in the stream-interface. The endpoint (connection or
appctx) can be retrieved via the conn-stream.
Create a new structure li_per_thread. This is uses as an array in the
listener structure, with an entry allocated per thread. The new function
li_init_per_thr is responsible of the allocation.
For now, li_per_thread contains fields only useful for QUIC listeners.
As such, it is only allocated for QUIC listeners.
Avoid closing idle connections if a soft stop is in progress.
By default, idle connections will be closed during a soft stop. In some
environments, a client talking to the proxy may have prepared some idle
connections in order to send requests later. If there is no proper retry
on write errors, this can result in errors while haproxy is reloading.
Even though a proper implementation should retry on connection/write
errors, this option was introduced to support back compat with haproxy <
v2.4. Indeed before v2.4, we were waiting for a last request to be able
to add a "connection: close" header and advice the client to close the
connection.
In a real life example, this behavior was seen in AWS using the ALB in
front of a haproxy. The end result was ALB sending 502 during haproxy
reloads.
This patch was tested on haproxy v2.4, with a regular reload on the
process, and a constant trend of requests coming in. Before the patch,
we see regular 502 returned to the client; when activating the option,
the 502 disappear.
This patch should help fixing github issue #1506.
In order to unblock some v2.3 to v2.4 migraton, this patch should be
backported up to v2.4 branch.
Signed-off-by: William Dauchy <wdauchy@gmail.com>
[wt: minor edits to the doc to mention other options to care about]
Signed-off-by: Willy Tarreau <w@1wt.eu>
It is now possible to have TCP/HTTP rules and ACLs defined in defaults
sections. So we must try to release corresponding lists when a default proxy
is destroyed.
No backport needed.
TCP and HTTP rules can now be defined in defaults sections, but only those
with a name. Because these rules may use conditions based on ACLs, ACLs can
also be defined in defaults sections.
However there are some limitations:
* A defaults section defining TCP/HTTP rules cannot be used by a defaults
section
* A defaults section defining TCP/HTTP rules cannot be used bu a listen
section
* A defaults sections defining TCP/HTTP rules cannot be used by frontends
and backends at the same time
* A defaults sections defining 'tcp-request connection' or 'tcp-request
session' rules cannot be used by backends
* A defaults sections defining 'tcp-response content' rules cannot be used
by frontends
The TCP request/response inspect-delay of a proxy is now inherited from the
defaults section it uses. For now, these rules are only parsed. No evaluation is
performed.
The PR_FL_READY flags must now be set on a proxy at the end of the
configuration validity check to notify it is fully configured and may be
safely used.
For now there is no real usage of this flag. But it will be usefull for
referenced default proxies to finish their configuration only once.
This patch is mandatory to support TCP/HTTP rules in defaults sections.
A proxy may now references the defaults section it is used. To do so, a
pointer on the default proxy was added in the proxy structure. And a
refcount must be used to track proxies using a default proxy. A default
proxy is destroyed iff its refcount is equal to zero and when it drops to
zero.
All this stuff must be performed during init/deinit staged for now. All
unreferenced default proxies are removed after the configuration parsing.
This patch is mandatory to support TCP/HTTP rules in defaults sections.
This change is required to support TCP/HTTP rules in defaults sections. The
'disabled' bitfield in the proxy structure, used to know if a proxy is
disabled or stopped, is replaced a generic bitfield named 'flags'.
PR_DISABLED and PR_STOPPED flags are renamed to PR_FL_DISABLED and
PR_FL_STOPPED respectively. In addition, everywhere there is a test to know
if a proxy is disabled or stopped, there is now a bitwise AND operation on
PR_FL_DISABLED and/or PR_FL_STOPPED flags.
.disabled field in the proxy structure is documented to be a bitfield. So
use it as a bitfield. This change was introduced to the 2.5, by commit
8e765b86f ("MINOR: proxy: disabled takes a stopping and a disabled state").
No backport is needed except if the above commit is backported.
The last 3 fields were 3 list heads that are per-thread, and which are:
- the pool's LRU head
- the buffer_wq
- the streams list head
Moving them into thread_ctx completes the removal of dynamic elements
from the struct thread_info. Now all these dynamic elements are packed
together at a single place for a thread.
We'll need to improve the API to pass other arguments in the future, so
let's start to adapt better to the current use cases. task_new() is used:
- 18 times as task_new(tid_bit)
- 18 times as task_new(MAX_THREADS_MASK)
- 2 times with a single bit (in a loop)
- 1 in the debug code that uses a mask
This patch provides 3 new functions to achieve this:
- task_new_here() to create a task on the calling thread
- task_new_anywhere() to create a task to be run anywhere
- task_new_on() to create a task to run on a specific thread
The change is trivial and will allow us to later concentrate the
required adaptations to these 3 functions only. It's still possible
to call task_new() if needed but a comment was added to encourage the
use of the new ones instead. The debug code was not changed and still
uses it.
In ticket #1348 some users expressed some concerns regarding the removal
of the "grace" directive from the proxies. Their use case very closely
mimmicks the original intent of the grace keyword, which is, let haproxy
accept traffic for some time when stopping, while indicating an external
LB that it's stopping.
This is implemented here by starting a task whose expiration triggers
the soft-stop for real. The global "stopping" variable is immediately
set however. For example, this below will be sufficient to instantly
notify an external check on port 9999 that the service is going down,
while other services remain active for 10s:
global
grace 10s
frontend ext-check
bind :9999
monitor-uri /ext-check
monitor fail if { stopping }
This option can be used to define a specific log format that will be
used in case of error, timeout, connection failure on a frontend... It
will be used for any log line concerned by the log-separate-errors
option. It will also replace the format of specific error messages
decribed in section 8.2.6.
If no "error-log-format" is defined, the legacy error messages are still
emitted and the other error logs keep using the regular log-format.
This option will be replaced by a "error-log-format" that enables to use
a dedicated log-format for connection error messages instead of the
regular log-format (in which most of the fields would be invalid in such
a case).
The "log-error-via-logformat" mechanism will then be replaced by a test
on the presence of such an error log format or not. If a format is
defined, it is used for connection error messages, otherwise the legacy
error log format is used.
Patch 211c967 ("MINOR: httpclient: add the server to the proxy") broke
the reg-tests that do a "show servers state".
Indeed the servers of the proxies flagged with PR_CAP_INT are dumped in
the output of this CLI command.
This patch fixes the issue par ignoring the PR_CA_INT proxies in the
dump.
In a future patch, it will be possible to remove at runtime every
servers, both static and dynamic. This requires to extend the server
refcount for all instances.
First, refcount manipulation functions have been renamed to better
express the API usage.
* srv_refcount_use -> srv_take
The refcount is always initialize to 1 on the server creation in
new_server. It's also incremented for each check/agent configured on a
server instance.
* free_server -> srv_drop
This decrements the refcount and if null, the server is freed, so code
calling it must not use the server reference after it. As a bonus, this
function now returns the next server instance. This is useful when
calling on the server loop without having to save the next pointer
before each invocation.
In these functions, remove the checks that prevent refcount on
non-dynamic servers. Each reference to "dynamic" in variable/function
naming have been eliminated as well.
As a convenience, return the next server instance from servers list on
free_server.
This is particularily useful when using this function on the servers
list without having to save of the next pointer before calling it.
This patch splits the disabled state of a proxy into a PR_DISABLED and a
PR_STOPPED state.
The first one is set when the proxy is disabled in the configuration
file, and the second one is set upon a stop_proxy().
Rename the 'dontloglegacyconnerr' option to 'log-error-via-logformat'
which is much more self-explanatory and readable.
Note: only legacy keywords don't use hyphens, it is recommended to
separate words with them in new keywords.
In case of connection failure, a dedicated error message is output,
following the format described in section "Error log format" of the
documentation. These messages cannot be configured through a log-format
option.
This patch adds a new option, "dontloglegacyconnerr", that disables
those error logs when set, and "replaces" them by a regular log line
that follows the configured log-format (thanks to a call to sess_log in
session_kill_embryonic).
The new fc_conn_err sample fetch allows to add the legacy error log
information into a regular log format.
This new option is unset by default so the logging logic will remain the
same until this new option is used.
This patch renames the proxy capability "LUA" to "INT" so it could be
used for any internal proxy.
Every proxy that are not user defined should use this flag.
This option had always been broken in HTX, which means that the first
breakage appeared in 1.9, that it was broken by default in 2.0 and that
no workaround existed starting with 2.1. The way this option works is
praticularly unfit to the rest of the configuration and to the internal
architecture. It had some uses when it was introduced 14 years ago but
nowadays it's possible to do much better and more reliable using a
set of "http-request set-dst" and "http-request set-uri" rules, which
additionally are compatible with DNS resolution (via do-resolve) and
are not exclusive to normal load balancing. The "option-http_proxy"
example config file was updated to reflect this.
The option is still parsed so that an error message gives hints about
what to look for.
A queue is specific to a server or a proxy, so we don't need to place
this distinction inside all pendconns, it can be in the queue itself.
This commit adds the relevant fields "px" and "sv" into the struct
queue, and initializes them accordingly.
Till now whenever a server or proxy's queue was touched, this server
or proxy's lock was taken. Not only this requires distinct code paths,
but it also causes unnecessary contention with other uses of these locks.
This patch adds a lock inside the "queue" structure that will be used
the same way by the server and the proxy queuing code. The server used
to use a spinlock and the proxy an rwlock, though the queue only used
it for locked writes. This new version uses a spinlock since we don't
need the read lock part here. Tests have not shown any benefit nor cost
in using this one versus the rwlock so we could change later if needed.
The lower contention on the locks increases the performance from 362k
to 374k req/s on 16 threads with 20 servers and leastconn. The gain
with roundrobin even increases by 9%.
This is tagged medium because the lock is changed, but no other part of
the code touches the queues, with nor without locking, so this should
remain invisible.
This reverts commit fcb8bf8650.
The recent changes since 5304669e1 MEDIUM: queue: make
pendconn_process_next_strm() only return the pendconn opened a tiny race
condition between stream_free() and process_srv_queue(), as the pendconn
is accessed outside of the lock, possibly while it's being freed. A
different approach is required.
Till now whenever a server or proxy's queue was touched, this server
or proxy's lock was taken. Not only this requires distinct code paths,
but it also causes unnecessary contention with other uses of these locks.
This patch adds a lock inside the "queue" structure that will be used
the same way by the server and the proxy queuing code. The server used
to use a spinlock and the proxy an rwlock, though the queue only used
it for locked writes. This new version uses a spinlock since we don't
need the read lock part here. Tests have not shown any benefit nor cost
in using this one versus the rwlock so we could change later if needed.
The lower contention on the locks increases the performance from 491k
to 507k req/s on 16 threads with 20 servers and leastconn. The gain
with roundrobin even increases by 6%.
The performance profile changes from this:
13.03% haproxy [.] fwlc_srv_reposition
8.08% haproxy [.] fwlc_get_next_server
3.62% haproxy [.] process_srv_queue
1.78% haproxy [.] pendconn_dequeue
1.74% haproxy [.] pendconn_add
to this:
11.95% haproxy [.] fwlc_srv_reposition
7.57% haproxy [.] fwlc_get_next_server
3.51% haproxy [.] process_srv_queue
1.74% haproxy [.] pendconn_dequeue
1.70% haproxy [.] pendconn_add
At this point the differences are mostly measurement noise.
This is tagged medium because the lock is changed, but no other part of
the code touches the queues, with nor without locking, so this should
remain invisible.
