Commit 200b0fa ("MEDIUM: Add support for updating TLS ticket keys via
socket") introduced support for updating TLS ticket keys from the CLI,
but missed a small corner case : if multiple bind lines reference the
same tls_keys file, the same reference is used (as expected), but during
the clean shutdown, it will lead to a double free when destroying the
bind_conf contexts since none of the lines knows if others still use
it. The impact is very low however, mostly a core and/or a message in
the system's log upon old process termination.
Let's introduce some basic refcounting to prevent this from happening,
so that only the last bind_conf frees it.
Thanks to Janusz Dziemidowicz and Thierry Fournier for both reporting
the same issue with an easy reproducer.
This fix needs to be backported from 1.6 to 1.8.
By default, HAProxy's DNS resolution at runtime ensure that there is no
IP address duplication in a backend (for servers being resolved by the
same hostname).
There are a few cases where people want, on purpose, to disable this
feature.
This patch introduces a couple of new server side options for this purpose:
"resolve-opts allow-dup-ip" or "resolve-opts prevent-dup-ip".
This patch adds a warning if an http-(request|reponse) (add|set)-header
rewrite fails to change the respective header in a request or response.
This usually happens when tune.maxrewrite is not sufficient to hold all
the headers that should be added.
There's no real reason to have a specific scheduler for applets anymore, so
nuke it and just use tasks. This comes with some benefits, the first one
being that applets cannot induce high latencies anymore since they share
nice values with other tasks. Later it will be possible to configure the
applets' nice value. The second benefit is that the applet scheduler was
not very thread-friendly, having a big lock around it in prevision of this
change. Thus applet-intensive workloads should now scale much better with
threads.
Some more improvement is possible now : some applets also use a task to
handle timers and timeouts. These ones could now be simplified to use only
one task.
Introduce tasklets, lightweight tasks. They have no notion of priority,
they are just run as soon as possible, and will probably be used for I/O
later.
For the moment they're used to replace the temporary thread-local list
that was used in the scheduler. The first part of the struct is common
with tasks so that tasks can be cast to tasklets and queued in this list.
Once a task is in the tasklet list, it has its leaf_p set to 0x1 so that
it cannot accidently be confused as not in the queue.
Pure tasklets are identifiable by their nice value of -32768 (which is
normally not possible).
In preparation for thread-specific runqueues, change the task API so that
the callback takes 3 arguments, the task itself, the context, and the state,
those were retrieved from the task before. This will allow these elements to
change atomically in the scheduler while the application uses the copied
value, and even to have NULL tasks later.
The function hlua_ctx_resume return less text message and more error
code. These error code allow the caller to return appropriate
message to the user.
The polled_mask is only used in the pollers, and removing it from the
struct fdtab makes it fit in one 64B cacheline again, on a 64bits machine,
so make it a separate array.
With the old model, any fd shared by multiple threads, such as listeners
or dns sockets, would only be updated on one threads, so that could lead
to missed event, or spurious wakeups.
To avoid this, add a global list for fd that are shared, using the same
implementation as the fd cache, and only remove entries from this list
when every thread as updated its poller.
[wt: this will need to be backported to 1.8 but differently so this patch
must not be backported as-is]
For large farms where servers are regularly added or removed, picking
a random server from the pool can ensure faster load transitions than
when using round-robin and less traffic surges on the newly added
servers than when using leastconn.
This commit introduces "balance random". It internally uses a random as
the key to the consistent hashing mechanism, thus all features available
in consistent hashing such as weights and bounded load via hash-balance-
factor are usable. It is extremely convenient because one common concern
when using random is what happens when a server is hammered a bit too
much. Here that can trivially be avoided, like in the configuration below :
backend bk0
balance random
hash-balance-factor 110
server-template s 1-100 127.0.0.1:8000 check inter 1s
Note that while "balance random" internally relies on a hash algorithm,
it holds the same properties as round-robin and as such is compatible with
reusing an existing server connection with "option prefer-last-server".
In order to use arbitrary data in the CLI (multiple lines or group of words
that must be considered as a whole, for example), it is now possible to add a
payload to the commands. To do so, the first line needs to end with a special
pattern: <<\n. Everything that follows will be left untouched by the CLI parser
and will be passed to the commands parsers.
Per-command support will need to be added to take advantage of this
feature.
Signed-off-by: Aurélien Nephtali <aurelien.nephtali@corp.ovh.com>
In addition to metrics about time spent in the SPOE, following counters have
been added:
* applets : number of SPOE applets.
* idles : number of idle applets.
* nb_sending : number of streams waiting to send data.
* nb_waiting : number of streams waiting for a ack.
* nb_processed : number of events/groups processed by the SPOE (from the
stream point of view).
* nb_errors : number of errors during the processing (from the stream point of
view).
Log messages has been updated to report these counters. Following pattern has
been added at the end of the log message:
... <idles>/<applets> <nb_sending>/<nb_waiting> <nb_error>/<nb_processed>
Now it is possible to configure a logger in a spoe-agent section using a "log"
line, as for a proxy. "no log", "log global" and "log <address> ..." syntaxes
are supported.
With "log global" line, the global list of loggers are copied into the proxy's
struct. The list coming from the default section is also copied when a frontend
or a backend section is parsed. So it is possible to have duplicate entries in
the proxy's list. For instance, with this following config, all messages will be
logged twice:
global
log 127.0.0.1 local0 debug
daemon
defaults
mode http
log global
option httplog
frontend front-http
log global
bind *:8888
default_backend back-http
backend back-http
server www 127.0.0.1:8000
"set-process-time" and "set-total-time" options have been added to store
processing times in the transaction scope, at each event and group processing,
the current one and the total one. So it is possible to get them.
TODO: documentation
Following metrics are added for each event or group of messages processed in the
SPOE:
* processing time: the delay to process the event or the group. From the
stream point of view, it is the latency added by the SPOE
processing.
* request time : It is the encoding time. It includes ACLs processing, if
any. For fragmented frames, it is the sum of all fragments.
* queue time : the delay before the request gets out the sending queue. For
fragmented frames, it is the sum of all fragments.
* waiting time: the delay before the reponse is received. No fragmentation
supported here.
* response time: the delay to process the response. No fragmentation supported
here.
* total time: (unused for now). It is the sum of all events or groups
processed by the SPOE for a specific threads.
Log messages has been updated. Before, only errors was logged (status_code !=
0). Now every processing is logged, following this format:
SPOE: [AGENT] <TYPE:NAME> sid=STREAM-ID st=STATUC-CODE reqT/qT/wT/resT/pT
where:
AGENT is the agent name
TYPE is EVENT of GROUP
NAME is the event or the group name
STREAM-ID is an integer, the unique id of the stream
STATUS_CODE is the processing's status code
reqT/qT/wT/resT/pT are delays descrive above
For all these delays, -1 means the processing was interrupted before the end. So
-1 for the queue time means the request was never dequeued. For fragmented
frames it is harder to know when the interruption happened.
For now, messages are logged using the same logger than the backend of the
stream which initiated the request.
This function will be called from the CLI's "show fd" command to append some
extra mux-specific information that only the mux handler can decode. This is
supposed to help collect various hints about what is happening when facing
certain anomalies.
This patch add option crc32c (PP2_TYPE_CRC32C) to proxy protocol v2.
It compute the checksum of proxy protocol v2 header as describe in
"doc/proxy-protocol.txt".
The management of the servers and the proxies queues was not thread-safe at
all. First, the accesses to <strm>->pend_pos were not protected. So it was
possible to release it on a thread (for instance because the stream is released)
and to use it in same time on another one (because we redispatch pending
connections for a server). Then, the accesses to stream's information (flags and
target) from anywhere is forbidden. To be safe, The stream's state must always
be updated in the context of process_stream.
So to fix these issues, the queue module has been refactored. A lock has been
added in the pendconn structure. And now, when we try to dequeue a pending
connection, we start by unlinking it from the server/proxy queue and we wake up
the stream. Then, it is the stream reponsibility to really dequeue it (or
release it). This way, we are sure that only the stream can create and release
its <pend_pos> field.
However, be careful. This new implementation should be thread-safe
(hopefully...). But it is not optimal and in some situations, it could be really
slower in multi-threaded mode than in single-threaded one. The problem is that,
when we try to dequeue pending connections, we process it from the older one to
the newer one independently to the thread's affinity. So we need to wait the
other threads' wakeup to really process them. If threads are blocked in the
poller, this will add a significant latency. This problem happens when maxconn
values are very low.
This patch must be backported in 1.8.
This patch implement proxy protocol v2 options related to crypto information:
ssl-cipher (PP2_SUBTYPE_SSL_CIPHER), cert-sig (PP2_SUBTYPE_SSL_SIG_ALG) and
cert-key (PP2_SUBTYPE_SSL_KEY_ALG).
Private key information is used in switchctx to implement native multicert
selection (ecdsa/rsa/anonymous). This patch extract and store full pkey
information: dsa type and pkey size in bits. This can be used for switchctx
or to report pkey informations in ppv2 and log.
A TLS ticket keys file can be updated on the CLI and used in same time. So we
need to protect it to be sure all accesses are thread-safe. Because updates are
infrequent, a R/W lock has been used.
This patch must be backported in 1.8
An fd cache entry might be removed and added at the end of the list, while
another thread is parsing it, if that happens, we may miss fd cache entries,
to avoid that, add a new field in the struct fdtab, "added_mask", which
contains a mask for potentially affected threads, if it is set, the
corresponding thread will set its bit in fd_cache_mask, to avoid waiting in
poll while it may have more work to do.
Create a local, per-thread, fdcache, for file descriptors that only belongs
to one thread, and make the global fd cache mostly lockless, as we can get
a lot of contention on the fd cache lock.
Instead of looking for CO_FL_EARLY_DATA to know if we have to try to wake
up a stream, because it is waiting for a SSL handshake, instead add a new
conn_stream flag, CS_FL_WAIT_FOR_HS. This way we don't have to rely on
CO_FL_EARLY_DATA, and we will only wake streams that are actually waiting.
Instead of using a list of applets with idle ones in front, we now use an
ebtree. Aapplets in the tree are idle by definition. And the key is the applet's
weight. When a new frame is queued, the first idle applet (with the lowest
weight) is woken up and its weight is increased by one. And when an applet sends
a frame to a SPOA, its weight is decremented by one.
This is empirical, but it should avoid to overuse a very few number of applets
and increase the balancing between idle applets.
So it is easier to respect the max_fpa value. This is no more the maximum frames
processed by an applet at each loop but the maximum frames waiting for an ack
for a specific applet.
The function spoe_handle_processing_appctx has been rewritten accordingly.
sending_rate was a counter used to evaluate the SPOE capacity to process
frames. Because it was not really accurrate, it has been replaced by a frequency
counter representing the number of frames handled by the SPOE per second. We
just check this counter is higher than the number of streams waiting for a
reply. If not, a new applet is created.
The calculation of a minimal number of active applets was really empirical and
finally useless. On heavy load, there are always many active applets (most of
time, more than the minimal required) and when the load is low, there is no
reason to keep unused applets opened.
Because of this change, the flag SPOE_APPCTX_FL_PERSIST is now unused. So it has
been removed.
Since only select() and poll() still make use of maxfd, let's move
its computation right there in the pollers themselves, and only
during each fd update pass. The computation doesn't need a lock
anymore, only a few atomic ops. It will be accurate, be done much
less often and will not be required anymore in the FD's fast patch.
This provides a small performance increase of about 1% in connection
rate when using epoll since we get rid of this computation which was
performed under a lock.
The incorrect comment was introduced in commit:
2ac5718dbd
v1.5-dev9 is the first tag containing this comment, the fix
should be backported to haproxy 1.5 and newer.
Some pollers like epoll() need to know if the fd is already known or
not in order to compute the operation to perform (add, mod, del). For
now this is performed based on the difference between the previous FD
state and the new state but this will not be usable anymore once threads
become responsible for their own polling.
Here we come with a different approach : a bitmask is stored with the
fd to indicate which pollers already know it, and the pollers will be
able to simply perform the add/mod/del operations based on this bit
combined with the new state.
This patch only adds the bitmask declaration and initialization, it
is it not yet used. It will be needed by the next two fixes and will
need to be backported to 1.8.
Since the fd update tables are per-thread, we need to have a bit per
thread to indicate whether an update exists, otherwise this can lead
to lost update events every time multiple threads want to update the
same FD. In practice *for now*, it only happens at start time when
listeners are enabled and ask for polling after facing their first
EAGAIN. But since the pollers are still shared, a lost event is still
recovered by a neighbor thread. This will not reliably work anymore
with per-thread pollers, where it has been observed a few times on
startup that a single-threaded listener would not always accept
incoming connections upon startup.
It's worth noting that during this code review it appeared that the
"new" flag in the fdtab isn't used anymore.
This fix should be backported to 1.8.
A number of counters have been added at special places helping better
understanding certain bug reports. These counters are maintained per
thread and are shown using "show activity" on the CLI. The "clear
counters" commands also reset these counters. The output is sent as a
single write(), which currently produces up to about 7 kB of data for
64 threads. If more counters are added, it may be necessary to write
into multiple buffers, or to reset the counters.
To backport to 1.8 to help collect more detailed bug reports.
This one allows not to inflate some structures when threads are
disabled. Now struct global is 1.4 kB instead of 33 kB.
Should be backported to 1.8 for ease of backporting of upcoming
patches.
The "thread" part is 32kB long, better move it at the end of the
structure since it's only used during initialization, to keep the
rest grouped together.
Should be backported to 1.8 to ease backporting of upcoming patches,
no functional impact.
In addition to "option force-set-var", recently added, this directive can be
used to selectivelly register unknown variable names, without totally relaxing
their registration during the runtime, like "option force-set-var" does.
So there is no way for a malicious agent to exhaust memory by defining a too
high number of variable names. In other hand, you need to enumerate all
variable names. This could be painfull in some circumstances.
Remember, this directive is only usefull when the variable names are not
referenced anywhere in the HAProxy configuration or the SPOE one.
Thanks to Etienne Carrière for his help on this part.
A SRV record weight can range from 0 to 65535, while haproxy weight goes
from 0 to 256, so we have to divide it by 256 before handing it to haproxy.
Also, a SRV record with a weight of 0 doesn't mean the server shouldn't be
used, so use a minimum weight of 1.
This should probably be backported to 1.8.
The new function check_request_for_cacheability() is used to check if
a request may be served from the cache, and/or allows the response to
be stored into the cache. For this it checks the cache-control and
pragma header fields, and adjusts the existing TX_CACHEABLE and a new
TX_CACHE_IGNORE flags.
For now, just like its response side counterpart, it only checks the
first value of the header field. These functions should be reworked to
improve their parsers and validate all elements.
By copying the info in the stream interface that the mux cleanly reports
aborts, we'll have the ability to check this flag wherever needed regardless
of the presence of a mux or not.
This new field will be used to describe certain properties of some
muxes. For now we only add MX_FL_CLEAN_ABRT to indicate that a mux
is able to unambiguously report aborts using CS_FL_ERROR contrary
to others who may only report it via a read0. This will be used to
improve handling of the abortonclose option with H2. Other flags
may come later to report multiplexing capabilities or not, support
of client/server sides etc.
