This patch adds pointer to a struct server to peer structure which
is initialized after having parsed a remote "peer" line.
After having parsed all peers section we run ->prepare_srv to initialize
all SSL/TLS stuff of remote perr (or server).
Remaining thing to do to completely support peer protocol over SSL/TLS:
make "bind" keyword be supported in "peers" sections to make SSL/TLS
incoming connections to local peers work.
May be backported to 1.5 and newer.
With this patch "default-server" lines are supported in "peers" sections
to setup the default settings of peers which are from now setup
when parsing both "peer" and "server" lines.
May be backported to 1.5 and newer.
Even if not already the case, we suppose that the frontend "peers" section
may have been already initialized outside of "peer" line, we seperate
their initializations from their binding initializations.
May be backported to 1.5 and newer.
Use ->local "peers" struct member to flag a "peers" section frontend
has being initialized. This is to be able to initialize the frontend
of "peers" sections on lines different from "peer" lines.
May be backported to 1.5 and newer.
Create init_peers_frontend() function to allocate and initialize
the frontend of "peers" sections (->peers_fe) so that to reuse it later.
May be backported to 1.5 and newer.
This one is a proxy option which can be inherited from defaults even
if the LB algo changes. Move it out of the lb_chash struct so that we
don't need to keep anything separate between these structs. This will
allow us to merge them into an union later. It even takes less room
now as it fills a hole and removes another one.
In session, don't keep an infinite number of connection that can idle.
Add a new frontend parameter, "max-session-srv-conns" to set a max number,
with a default value of 5.
Instead of the old "idle-timeout" mechanism, add a new option,
"pool-purge-delay", that sets the delay before purging idle connections.
Each time the delay happens, we destroy half of the idle connections.
Add a new command, "pool-max-conn" that sets the maximum number of connections
waiting in the orphan idling connections list (as activated with idle-timeout).
Using "-1" means unlimited. Using pools is now dependant on this.
Change the default for http-reuse from "never" to "safe", as it has been
the recommended setting for a few versions now and backend H2 makes little
sense without it.
Some warnings were removed from the config parser since it can dynamically
be disabled depending on the server's configuration, so there's no need to
disable it on a whole backend just for one server.
Currently a mux may be forced on a bind or server line by specifying the
"proto" keyword. The problem is that the mux may depend on the proxy's
mode, which is not known when parsing this keyword, so a wrong mux could
be picked.
Let's simply update the mux entry while checking its validity. We do have
the name and the side, we only need to see if a better mux fits based on
the proxy's mode. It also requires to remove the side check while parsing
the "proto" keyword since a wrong mux could be picked.
This way it becomes possible to declare multiple muxes with the same
protocol names and different sides or modes.
Wrong variable was used to know if we need to call the callback
post_section_parser() or not. We must use 'cs' and not 'pcs'.
This patch must be backported in 1.8 with the commit 7805e2b ("BUG/MINOR:
cfgparse: Fix transition between 2 sections with the same name").
When a section's parser is registered, it can also define a post section
callback, called at the end of the section parsing. But when 2 sections with the
same name followed each other, the transition between them was missed. This
induced 2 bugs. First, the call to the post section callback was skipped. Then,
the parsing of the second section was mixed with the first one.
This patch must be backported in 1.8.
In some situations, especially when dealing with low latency on processors
supporting a variable frequency or when running inside virtual machines,
each time the process waits for an I/O using the poller, the processor
goes back to sleep or is offered to another VM for a long time, and it
causes excessively high latencies.
A solution to this provided by this patch is to enable busy polling using
a global option. When busy polling is enabled, the pollers never sleep and
loop over themselves waiting for an I/O event to happen or for a timeout
to occur. On multi-processor machines it can significantly overheat the
processor but it usually results in much lower latencies.
A typical test consisting in injecting traffic over a single connection at
a time over the loopback shows a bump from 4640 to 8540 connections per
second on forwarded connections, indicating a latency reduction of 98
microseconds for each connection, and a bump from 12500 to 21250 for
locally terminated connections (redirects), indicating a reduction of
33 microseconds.
It is only usable with epoll and kqueue because select() and poll()'s
API is not convenient for such usages, and the level of performance they
are used in doesn't benefit from this anyway.
The option, which obviously remains disabled by default, can be turned
on using "busy-polling" in the global section, and turned off later
using "no busy-polling". Its status is reported in "show info" to help
troubleshooting suspicious CPU spikes.
Because the HTX is still experimental, we must add special cases during the
configuration check to be sure it is not enabled on a proxy with incompatible
options. Here, for HTX proxies, when a mux protocol is specified on a bind line
or a server line, we must force the HTX mode (PROTO_MODE_HTX).
Concretely, H2 is the only mux protocol that can be forced. And it doesn't yet
support the HTX. So forcing the H2 on an HTX proxy will always fail.
This was the largest function of the whole file, taking a rough second
to build alone. Let's move it to a distinct file along with a few
dependencies. Doing so saved about 2 seconds on the total build time.
The config parser is the largest file to build and its build dominates
the total project's build time. Let's start to split it into multiple
smaller pieces by extracting the "global" section parser into a new
file called "cfgparse-global.c". This removes 1/4th of the file's build
time.
To be used, error messages declared in a default section must be copied when the
parsing of a proxy section starts. But this was only done for frontends.
This patch may be backported to older versions.
In 1.8, commit 45a66cc ("MEDIUM: config: ensure that tune.bufsize is at
least 16384 when using HTTP/2") tried to avoid an annoying issue making
H2 fail when haproxy is built with default buffer sizes smaller than 16kB,
which used to be the case for a very long time. Sadly, the test only sees
when NPN/ALPN exactly match "h2" and not when it's combined like
"h2,http/1.1" nor "http/1.1,h2". We can safely use strstr() there because
the string is prefixed by the token's length (0x02) which is unambiguous
as it cannot be part of any other token.
This fix should be backported to 1.8 as a safety guard against bad
configurations.
This patch implements analysers for parsing the CLI and extra features
for the master's CLI.
For each command (sent alone, or separated by ; or \n) the request
analyser will determine to which server it should send the request.
The 'mode cli' proxy is able to parse a prefix for each command which is
used to select the apropriate server. The prefix start by @ and is
followed by "master", the PID preceded by ! or the relative PID. (e.g.
@master, @1, @!1234). The servers are not round-robined anymore.
The command is sent with a SHUTW which force the server to close the
connection after sending its response. However the proxy allows a
keepalive connection on the client side and does not close.
The response analyser does not do much stuff, it only reinits the
connection when it received a close from the server, and forward the
response. It does not analyze the response data.
The only guarantee of the end of the response is the close of the
server, we can't rely on the double \n since it's not send by every
command.
This could be reimplemented later as a filter.
This option makes a proxy use only HTX-compatible muxes instead of the
HTTP-compatible ones for HTTP modes. It must be set on both ends, this
is checked at parsing time.
peers_init_sync() doesn't check task_new()'s return value and doesn't
return any result to indicate success or failure. Let's make it return
an int and check it from the caller.
This can be backported as far as 1.6.
Since keep-alive mode is the default mode, the passive close has disappeared,
and in the code, httpclose and forceclose options are handled the same way:
connections with the client and the server are closed as soon as the request and
the response are received and missing "Connection: close" header is added in
each direction.
So to make things clearer, forceclose is now an alias for httpclose. And
httpclose is explicitly an active close. So the old passive close does not exist
anymore. Internally, the flag PR_O_HTTP_PCL has been removed and PR_O_HTTP_FCL
has been replaced by PR_O_HTTP_CLO. In HTTP analyzers, the checks done to find
the right mode to use, depending on proxies options and "Connection: " header
value, have been simplified.
This should only be a cleanup and no changes are expected.
This option is frontends specific, so there is no reason to support it on
backends. So now, it is ignored if it is set on a backend and a warning is
emitted during the startup. The change is quite trivial, but the commit is
tagged as MEDIUM because it is a small breakage with previous versions and
configurations using this options could emit a warning now.
This option is backends specific, so there is no reason to support it on
frontends. So now, it is ignored if it is set on a frontend and a warning is
emitted during the startup. The change is quite trivial, but the commit is
tagged as MEDIUM because it is a small breakage with previous versions and
configurations using this options could emit a warning now.
These ones are mostly called from cfgparse.c for the parsing and do
not depend on the HTTP representation. The functions's prototypes
were moved to proto/http_rules.h, making this file work exactly like
tcp_rules. Ideally we should stop calling these functions directly
from cfgparse and register keywords, but there are a few cases where
that wouldn't work (stats http-request) so it's probably not worth
trying to go this far.
This protocol is based on the uxst one, but it uses socketpair and FD
passing insteads of a connect()/accept().
The "sockpair@" prefix has been implemented for both bind and server
keywords.
When HAProxy wants to connect through a sockpair@, it creates 2 new
sockets using the socketpair() syscall and pass one of the socket
through the FD specified on the server line.
On the bind side, haproxy will receive the FD, and will use it like it
was the FD of an accept() syscall.
This protocol was designed for internal communication within HAProxy
between the master and the workers, but it's possible to use it
externaly with a wrapper and pass the FD through environment variabls.
When threads are disabled, some variables such as tid and tid_bit are
still checked everywhere, the MAX_THREADS_MASK macro is ~0UL while
MAX_THREADS is 1, and the all_threads_mask variable is replaced with a
macro forced to zero. The compiler cannot optimize away all this code
involving checks on tid and tid_bit, and we end up in special cases
where all_threads_mask has to be specifically tested for being zero or
not. It is not even certain the code paths are always equivalent when
testing without threads and with nbthread 1.
Let's change this to make sure we always present a single thread when
threads are disabled, and have the relevant values declared as constants
so that the compiler can optimize all the tests away. Now we have
MAX_THREADS_MASK set to 1, all_threads_mask set to 1, tid set to zero
and tid_bit set to 1. Doing just this has removed 4 kB of code in the
no-thread case.
A few checks for all_threads_mask==0 have been removed since it never
happens anymore.
The "process" directive on "bind" lines supports process references and
thread references. No check is performed on the thread number validity,
so that if a listener is only bound to non-existent threads, the traffic
will never be processed. It easily happens when setting one bind line per
thread with an incorrect (or reduced) thread count. No warning appears
and some random connections are never served. It also happens when setting
thread references with threads support disabled at build time.
This patch makes use of the all_threads_mask variable to detect if some
referenced threads don't exist, to emit a warning and fix this.
This patch needs to be backported to 1.8, just like the previous one which
it depends on (MINOR: threads: move "nbthread" parsing to hathreads.c).
The purpose is to make sure that all variables which directly depend
on this nbthread argument are set at the right moment. For now only
all_threads_mask needs to be set. It used to be set while calling
thread_sync_init() which is called too late for certain checks. The
same function handles threads and non-threads, which removes the need
for some thread-specific knowledge from cfgparse.c.
Thierry discovered that the following config crashes haproxy while
parsing the config (it's probably the smallest crasher) :
defaults
stick-table type ip size 1M
And indeed it does because it looks for the current proxy's name which it
does not have as it's the default one. This affects all versions since 1.6.
This fix must be backported to all versions back to 1.6.
Chunks are only a subset of a buffer (a non-wrapping version with no head
offset). Despite this we still carry a lot of duplicated code between
buffers and chunks. Replacing chunks with buffers would significantly
reduce the maintenance efforts. This first patch renames the chunk's
fields to match the name and types used by struct buffers, with the goal
of isolating the code changes from the declaration changes.
Most of the changes were made with spatch using this coccinelle script :
@rule_d1@
typedef chunk;
struct chunk chunk;
@@
- chunk.str
+ chunk.area
@rule_d2@
typedef chunk;
struct chunk chunk;
@@
- chunk.len
+ chunk.data
@rule_i1@
typedef chunk;
struct chunk *chunk;
@@
- chunk->str
+ chunk->area
@rule_i2@
typedef chunk;
struct chunk *chunk;
@@
- chunk->len
+ chunk->data
Some minor updates to 3 http functions had to be performed to take size_t
ints instead of ints in order to match the unsigned length here.
This introduces a new directive for the `resolvers` section:
`parse-resolv-conf`. When present, it will attempt to add any
nameservers in `/etc/resolv.conf` to the list of nameservers
for the current `resolvers` section.
[Mailing list thread][1].
[1]: https://www.mail-archive.com/haproxy@formilux.org/msg29600.html
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.
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".
Louis Chanouha reported an inappropriate warning when http-reuse is
present in a defaults section while a TCP proxy accidently inherits
it and finds a conflict with other options like the use of the PROXY
protocol. To fix this patch removes the http-reuse option for TCP
proxies.
This fix needs to be backported to 1.8, 1.7 and possibly 1.6.
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
Now, the function parse_logsrv should be used to parse a "log" line. This
function will update the list of loggers passed in argument. It can release all
log servers when "no log" line was parsed (by the caller) or it can parse "log
global" or "log <address> ... " lines. It takes care of checking the caller
context (global or not) to prohibit "log global" usage in the global section.
>From the very first day of force-persist and ignore-persist features,
they only applied to backends, except that the documentation stated it
could also be applied to frontends.
In order to make it clear, the documentation is updated and the parser
will raise a warning if the keywords are used in a frontend section.
This patch should be backported up to the 1.5 branch.
Martin Brauer reported an unexpected warning when some parts of the
global stats are defined but not the listening address, like below :
global
#stats socket run/admin.sock mode 660 level admin
stats timeout 30s
Then haproxy complains :
[WARNING] 334/150131 (23086) : config : frontend 'GLOBAL' has no
'bind' directive. Please declare it as a backend if this was intended.
This is because of the check for a bind-less frontend (the global section
creates a frontend for the stats). There's no clean fix for this one, so
here we're simply checking that the frontend is not the global stats one
before emitting the warning.
This patch should be backported to all stable versions.
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.
Commit 4cfede87a3 removed
`exit-on-failure` in favor of `no-exit-on-failure`, but failed
to update references to the former in user facing messages.
This should be backported to haproxy 1.8.
"monitor-uri" may rely on "monitor fail" rules, which are processed
very early, immediately after the HTTP request is parsed and before
any http rulesets. It's not reported by the config parser when this
ruleset is misplaces, causing some configurations not to work like
users would expect. Let's just add the warning for a misplaced rule.
This patch changes the behavior of the master during the exit of a
worker.
When a worker exits with an error code, for example in the case of a
segfault, all workers are now killed and the master leaves.
If you don't want this behavior you can use the option
"master-worker no-exit-on-failure".
During the migration to the second version of the pools, the new
functions and pool pointers were all called "pool_something2()" and
"pool2_something". Now there's no more pool v1 code and it's a real
pain to still have to deal with this. Let's clean this up now by
removing the "2" everywhere, and by renaming the pool heads
"pool_head_something".
Rename the global variable "proxy" to "proxies_list".
There's been multiple proxies in haproxy for quite some time, and "proxy"
is a potential source of bugs, a number of functions have a "proxy" argument,
and some code used "proxy" when it really meant "px" or "curproxy". It worked
by pure luck, because it usually happened while parsing the config, and thus
"proxy" pointed to the currently parsed proxy, but we should probably not
rely on this.
[wt: some of these are definitely fixes that are worth backporting]
Now, it is possible to bind CPU at the thread level instead of the process level
by defining a thread set in "cpu-map" directives. Thus, its format is now:
cpu-map [auto:]<process-set>[/<thread-set>] <cpu-set>...
where <process-set> and <thread-set> must follow the format:
all | odd | even | number[-[number]]
Having a process range and a thread range in same time with the "auto:" prefix
is not supported. Only one range is supported, the other one must be a fixed
number. But it is allowed when there is no "auto:" prefix.
Because it is possible to define a mapping for a process and another for a
thread on this process, threads will be bound on the intersection of their
mapping and the one of the process on which they are attached. If the
intersection is null, no specific binding will be set for the threads.
It was a temporary directive used for development purpose. Now, CPU mapping for
at the thread level should be done using the cpu-map directive. This feature
will be added in a next commit.
Now, processa and CPU ranges can be partially defined. The higher bound can be
omitted. In such case, it is replaced by the corresponding maximum value, 32 or
64 depending on the machine's word size.
By extension, It is also true for the "bind-process" directive and "process"
parameter on a "bind" or a "stats socket" line.
The prefix "auto:" can be added before the process set to let HAProxy
automatically bind a process to a CPU by incrementing process and CPU sets. To
be valid, both sets must have the same size. No matter the declaration order of
the CPU sets, it will be bound from the lower to the higher bound.
Examples:
# all these lines bind the process 1 to the cpu 0, the process 2 to cpu 1
# and so on.
cpu-map auto:1-4 0-3
cpu-map auto:1-4 0-1 2-3
cpu-map auto:1-4 3 2 1 0
# bind each process to exaclty one CPU using all/odd/even keyword
cpu-map auto:all 0-63
cpu-map auto:even 0-31
cpu-map auto:odd 32-63
# invalid cpu-map because process and CPU sets have different sizes.
cpu-map auto:1-4 0 # invalid
cpu-map auto:1 0-3 # invalid
Now, this function returns a status code to indicate a success (0) or a failure
(1) and the error message in set in <err> parameter. And the result of the parsing
is set in <proc> parameter.
Now, you can define processes concerned by a cpu-map line using a range. For
instance, the following line binds the first 32 processes on CPUs 0 to 3:
cpu-map 1-32 0-3
HTTP/2 mandates the support of 16384 bytes frames by default, so we need
a large enough buffer to process them. Till now if tune.bufsize was too
small, H2 connections were simply rejected during their establishment,
making it quite hard to troubleshoot the issue.
Now we detect when HTTP/2 is enabled on an HTTP frontend and emit an
error if tune.bufsize is not large enough, with the appropriate
recommendation.
At the end of the master initialisation, a call to protocol_unbind_all()
was made, in order to close all the FDs.
Unfortunately, this function closes the inherited FDs (fd@), upon reload
the master wasn't able to reload a configuration with those FDs.
The create_listeners() function now store a flag to specify if the fd
was inherited or not.
Replace the protocol_unbind_all() by mworker_cleanlisteners() +
deinit_pollers()
By default, no affinity is set for threads. To bind threads on CPU, you must
define a "thread-map" in the global section. The format is the same than the
"cpu-map" parameter, with a small difference. The process number must be
defined, with the same format than cpu-map ("all", "even", "odd" or a number
between 1 and 31/63).
A thread will be bound on the intersection of its mapping and the one of the
process on which it is attached. If the intersection is null, no specific bind
will be set for the thread.
A lock is used to protect accesses to a peer structure.
A the lock is taken in the applet handler when the peer is identified
and released living the applet handler.
In the scheduling task for peers section, the lock is taken for every
listed peer and released at the end of the process task function.
The peer 'force shutdown' function was also re-worked.
A lock for LB parameters has been added inside the proxy structure and atomic
operations have been used to update server variables releated to lb.
The only significant change is about lb_map. Because the servers status are
updated in the sync-point, we can call recalc_server_map function synchronously
in map_set_server_status_up/down function.
2 global locks have been added to protect, respectively, the run queue and the
wait queue. And a process mask has been added on each task. Like for FDs, this
mask is used to know which threads are allowed to process a task.
For many tasks, all threads are granted. And this must be your first intension
when you create a new task, else you have a good reason to make a task sticky on
some threads. This is then the responsibility to the process callback to lock
what have to be locked in the task context.
Nevertheless, all tasks linked to a session must be sticky on the thread
creating the session. It is important that I/O handlers processing session FDs
and these tasks run on the same thread to avoid conflicts.
Email alerts relies on checks to send emails. The link between a mailers section
and a proxy was resolved during the configuration parsing, But initialization was
done when the first alert is triggered. This implied memory allocations and
tasks creations. With this patch, everything is now initialized during the
configuration parsing. So when an alert is triggered, only the memory required
by this alert is dynamically allocated.
Moreover, alerts processing had a flaw. The task handler used to process alerts
to be sent to the same mailer, process_email_alert, was designed to give back
the control to the scheduler when an alert was sent. So there was a delay
between the sending of 2 consecutives alerts (the min of
"proxy->timeout.connect" and "mailer->timeout.mail"). To fix this problem, now,
we try to process as much queued alerts as possible when the task is woken up.
This is a huge patch with many changes, all about the DNS. Initially, the idea
was to update the DNS part to ease the threads support integration. But quickly,
I started to refactor some parts. And after several iterations, it was
impossible for me to commit the different parts atomically. So, instead of
adding tens of patches, often reworking the same parts, it was easier to merge
all my changes in a uniq patch. Here are all changes made on the DNS.
First, the DNS initialization has been refactored. The DNS configuration parsing
remains untouched, in cfgparse.c. But all checks have been moved in a post-check
callback. In the function dns_finalize_config, for each resolvers, the
nameservers configuration is tested and the task used to manage DNS resolutions
is created. The links between the backend's servers and the resolvers are also
created at this step. Here no connection are kept alive. So there is no needs
anymore to reopen them after HAProxy fork. Connections used to send DNS queries
will be opened on demand.
Then, the way DNS requesters are linked to a DNS resolution has been
reworked. The resolution used by a requester is now referenced into the
dns_requester structure and the resolution pointers in server and dns_srvrq
structures have been removed. wait and curr list of requesters, for a DNS
resolution, have been replaced by a uniq list. And Finally, the way a requester
is removed from a DNS resolution has been simplified. Now everything is done in
dns_unlink_resolution.
srv_set_fqdn function has been simplified. Now, there is only 1 way to set the
server's FQDN, independently it is done by the CLI or when a SRV record is
resolved.
The static DNS resolutions pool has been replaced by a dynamoc pool. The part
has been modified by Baptiste Assmann.
The way the DNS resolutions are triggered by the task or by a health-check has
been totally refactored. Now, all timeouts are respected. Especially
hold.valid. The default frequency to wake up a resolvers is now configurable
using "timeout resolve" parameter.
Now, as documented, as long as invalid repsonses are received, we really wait
all name servers responses before retrying.
As far as possible, resources allocated during DNS configuration parsing are
releases when HAProxy is shutdown.
Beside all these changes, the code has been cleaned to ease code review and the
doc has been updated.
Allow to register a function which will be called after the
configuration file parsing, at the end of the check_config_validity().
It's useful fo checking dependencies between sections or for resolving
keywords, pointers or values.
This commit implements a post section callback. This callback will be
used at the end of a section parsing.
Every call to cfg_register_section must be modified to use the new
prototype:
int cfg_register_section(char *section_name,
int (*section_parser)(const char *, int, char **, int),
int (*post_section_parser)());
This function is used to create a series of listeners for a specific
address and a port range. It automatically calls the matching protocol
handlers to add them to the relevant lists. This way cfgparse doesn't
need to manipulate listeners anymore. As an added bonus, the memory
allocation is checked.
cfgparse has no business directly calling each individual protocol's 'add'
function to create a listener. Now that they're all registered, better
perform a protocol lookup on the family and have a standard ->add method
for all of them.
It's a shame that cfgparse() has to make special cases of each protocol
just to cast the port to the target address family. Let's pass the port
in argument to the function. The unix listener simply ignores it.
During the configuration parsing, log buffers are reallocated when
global.max_syslog_len is updated. This can be done serveral time. So, instead of
doing it serveral time, we do it only once after the configuration parsing.
Now, we use init_log_buffers and deinit_log_buffers to, respectively, initialize
and deinitialize log buffers used for syslog messages.
These functions have been introduced to be used by threads, to deal with
thread-local log buffers.
Trash buffers are reallocated when "tune.bufsize" parameter is changed. Here, we
just move the realloc after the configuration parsing.
Given that the config parser doesn't rely on the trash size, it should be
harmless.
Now, we use init_trash_buffers and deinit_trash_buffers to, respectively,
initialize and deinitialize trash buffers (trash, trash_buf1 and trash_buf2).
These functions have been introduced to be used by threads, to deal with
thread-local trash buffers.
Historically listeners used to have a handler depending on the upper
layer. But now it's exclusively process_stream() and nothing uses it
anymore so it can safely be removed.
Since commit 9d8dbbc ("MINOR: dns: Maximum DNS udp payload set to 8192") it's
possible to specify a packet size, but passing too large a size or a negative
size is not detected and results in memset() being performed over a 2GB+ area
upon receipt of the first DNS response, causing runtime crashes.
We now check that the size is not smaller than the smallest packet which is
the DNS header size (12 bytes).
No backport is needed.
Following up DNS extension introduction, this patch aims at making the
computation of the maximum number of records in DNS response dynamic.
This computation is based on the announced payload size accepted by
HAProxy.
The "hold obsolete" timer is used to prevent HAProxy from moving a server to
an other IP or from considering the server as DOWN if the IP currently
affected to this server has not been seen for this period of time in DNS
responses.
That said, historically, HAProxy used to update servers as soon as the IP
has disappeared from the response. Current default timeout break this
historical behavior and may change HAProxy's behavior when people will
upgrade to 1.8.
This patch changes the default value to 0 to keep backward compatibility.
Edns extensions may be used to negotiate some settings between a DNS
client and a server.
For now we only use it to announce the maximum response payload size accpeted
by HAProxy.
This size can be set through a configuration parameter in the resolvers
section. If not set, it defaults to 512 bytes.
Make it so for each server, instead of specifying a hostname, one can use
a SRV label.
When doing so, haproxy will first resolve the SRV label, then use the
resulting hostnames, as well as port and weight (priority is ignored right
now), to each server using the SRV label.
It is resolved periodically, and any server disappearing from the SRV records
will be removed, and any server appearing will be added, assuming there're
free servers in haproxy.
As DNS servers may not return all IPs in one answer, we want to cache the
previous entries. Those entries are removed when considered obsolete, which
happens when the IP hasn't been returned by the DNS server for a time
defined in the "hold obsolete" parameter of the resolver section. The default
is 30s.
