Implement a new CLI command 'del server'. It can be used to removed a
dynamically added server. Only servers in maintenance mode can be
removed, and without pending/active/idle connection on it.
Add a new reg-test for this feature. The scenario of the reg-test need
to first add a dynamic server. It is then deleted and a client is used
to ensure that the server is non joinable.
The management doc is updated with the new command 'del server'.
cli_parse_add_server can be executed in parallel by several CLI
instances and so must be thread-safe. The critical points of the
function are :
- server duplicate detection
- insertion of the server in the proxy list
The mode of operation has been reversed. The server is first
instantiated and parsed. The duplicate check has been moved at the end
just before the insertion in the proxy list, under the thread isolation.
Thus, the thread safety is guaranteed and server allocation is kept
outside of locks/thread isolation.
Config information has been added into the logsrv struct. The filename
is duplicated and should be freed on exit.
Introduced in the current release.
This does not need to be backported.
The current "ADD" vs "ADDQ" is confusing because when thinking in terms
of appending at the end of a list, "ADD" naturally comes to mind, but
here it does the opposite, it inserts. Several times already it's been
incorrectly used where ADDQ was expected, the latest of which was a
fortunate accident explained in 6fa922562 ("CLEANUP: stream: explain
why we queue the stream at the head of the server list").
Let's use more explicit (but slightly longer) names now:
LIST_ADD -> LIST_INSERT
LIST_ADDQ -> LIST_APPEND
LIST_ADDED -> LIST_INLIST
LIST_DEL -> LIST_DELETE
The same is true for MT_LISTs, including their "TRY" variant.
LIST_DEL_INIT keeps its short name to encourage to use it instead of the
lazier LIST_DELETE which is often less safe.
The change is large (~674 non-comment entries) but is mechanical enough
to remain safe. No permutation was performed, so any out-of-tree code
can easily map older names to new ones.
The list doc was updated.
This improves the use of local variables in sample_conv_json_query:
- Use the enum type for the return value of `mjson_find`.
- Do not use single letter variables.
- Reduce the scope of variables that are only needed in a single branch.
- Add missing newlines after variable declaration.
The test in srv_alloc_lb() to allocate the lb_nodes[] array used in the
consistent hash was incorrect, it wouldn't do it for consistent hash and
could do it for regular random.
No backport is needed as this was added for dynamic servers in 2.4-dev by
commit f99f77a50 ("MEDIUM: server: implement 'add server' cli command").
Amaury noticed that I managed to break the build of DEBUG_FAIL_ALLOC
for the second time with 207c09509 ("MINOR: pools: move the fault
injector to __pool_alloc()"). The joy of endlessly reworking patch
sets... No backport is needed, that was in the just merged cleanup
series.
This function has become too big (251 bytes) and is now hurting
performance a lot, with up to 4% request rate being lost over the last
pool changes. Let's move it to pool.c as a regular function. Other
attempts were made to cut it in half but it's still inefficient. Doing
this results in saving ~90kB of object code, and even 112kB since the
pool changes, with code that is even slightly faster!
Conversely, pool_get_from_cache(), which remains half of this size, is
still faster inlined, likely in part due to the immediate use of the
returned pointer afterwards.
Till now it used to call it only if there were not too many objects into
the local cache otherwise would send the latest one directly into the
shared cache. Now it always sends to the local cache and it's up to the
local cache to free its oldest objects. From a cache freshness perspective
it's better this way since we always evict cold objects instead of hot
ones. From an API perspective it's better because it will help make the
shared cache invisible to the public API.
Till now we could only evict oldest objects from all local caches using
pool_evict_from_local_caches() until the cache size was satisfying again,
but there was no way to evict excess objects from a single cache, which
is the reason why pool_put_to_cache() used to refrain from putting into
the local cache and would directly write to the shared cache, resulting
in massive writes when caches were full.
Let's add this new function now. It will stop once the number of objects
in the local cache is no higher than 16+total/8 or the cache size is no
more than 75% full, just like before.
For now the function is not used.
Continuing the unification of local and shared pools, now the usage of
pools is governed by CONFIG_HAP_POOLS without which allocations and
releases are performed directly from the OS using pool_alloc_nocache()
and pool_free_nocache().
There are two levels of freeing to the OS:
- code that wants to keep the pool's usage counters updated uses
pool_free_area() and handles the counters itself. That's what
pool_put_to_shared_cache() does in the no-global-pools case.
- code that does not want to update the counters because they were
already updated only calls pool_free_area().
Let's extract these calls to establish the symmetry with pool_get_from_os()
and pool_alloc_nocache(), resulting in pool_put_to_os() (which only updates
the allocated counter) and pool_free_nocache() (which also updates the used
counter). This will later allow to simplify the generic code.
A part of the code cannot be factored out because it still uses non-atomic
inc/dec for pool->used and pool->allocated as these are located under the
pool's lock. While it can make sense in terms of bus cycles, it does not
make sense in terms of code normalization. Further, some operations were
still performed under a lock that could be totally removed via the use of
atomic ops.
There is still one occurrence in pool_put_to_shared_cache() in the locked
code where pool_free_area() is called under the lock, which must absolutely
be fixed.
Now there's one part dealing with the allocation itself and keeping
counters up to date, and another one on top of it to return such an
allocated pointer to the user and update the use count and stats.
This is in anticipation for being able to group cache-related parts.
The release code is still done at once.
Till now it was limited to objects allocated from the OS which means
it had little use as soon as pools were enabled. Let's move it upper
in the layers so that any code can benefit from fault injection. In
addition this allows to pass a new flag POOL_F_NO_FAIL to disable it
if some callers prefer a no-failure approach.
ha_random() is quite heavy and uses atomic ops or even a lock on some
architectures. Here we don't seek good randoms, just statistical ones,
so let's use the statistical prng instead.
Now the multi-level cache becomes more visible:
pool_get_from_local_cache()
pool_put_to_local_cache()
pool_get_from_shared_cache()
pool_put_to_shared_cache()
The functions were rightfully called from/to_cache when the thread-local
cache was considered as the only cache, but this is getting terribly
confusing. Let's call them from/to local_cache to make it clear that
it is not related with the shared cache.
As a side note, since pool_evict_from_cache() used not to work for a
particular pool but for all of them at once, it was renamed to
pool_evict_from_local_caches() (plural form).
They were strictly equivalent, let's remerge them and rename them to
pool_alloc_nocache() as it's the call which performs a real allocation
which does not check nor update the cache. The only difference in the
past was the former taking the lock and not the second but now the lock
is not needed anymore at this stage since the pool's list is not touched.
In addition, given that the "avail" argument is no longer used by the
function nor by its callers, let's drop it.
Now we don't loop anymore trying to refill multiple items at once, and
an allocated object is directly returned to the requester instead of
being stored into the shared pool. This has multiple benefits. The
first one is that no locking is needed anymore on the allocation path
and the second one is that the loop will no longer cause latency spikes.
This is a first step towards unifying all the fallback code. Right now
these two functions are the only ones which do not update the needed_avg
rate counter since there's currently no shared pool kept when using them.
But their code is similar to what could be used everywhere except for
this one, so let's make them capable of maintaining usage statistics.
As a side effect the needed field in "show pools" will now be populated.
The mem_should_fail() call enabled by DEBUG_FAIL_ALLOC used to be placed
only in the no-cache version of the allocator. Now we can generalize it
to all modes and remove the exclusive test on CONFIG_HAP_NO_GLOBAL_POOLS.
We're going to make the local pool always present unless pools are
completely disabled. This means that pools are always enabled by
default, regardless of the use of threads. Let's drop this notion
of "local" pools and make it just "pool". The equivalent debug
option becomes DEBUG_NO_POOLS instead of DEBUG_NO_LOCAL_POOLS.
For now this changes nothing except the option and dropping the
dependency on USE_THREAD.
Initially per-thread pool caches were stored into a fixed-size array.
But this was a bit ugly because the last allocated pools were not able
to benefit from the cache at all. As a work around to preserve
performance, a size of 64 cacheable pools was set by default (there
are 51 pools at the moment, excluding any addon and debugging code),
so all in-tree pools were covered, at the expense of higher memory
usage.
In addition an index had to be calculated for each pool, and was used
to acces the pool cache head into that array. The pool index was not
even stored into the pools so it was required to determine it to access
the cache when the pool was already known.
This patch changes this by moving the pool cache head into the pool
head itself. This way it is certain that each pool will have its own
cache. This removes the need for index calculation.
The pool cache head is 32 bytes long so it was aligned to 64B to avoid
false sharing between threads. The extra cost is not huge (~2kB more
per pool than before), and we'll make better use of that space soon.
The pool cache head contains the size, which should probably be removed
since it's already in the pool's head.
When building with DEBUG_FAIL_ALLOC we call a random generator to decide
whether the pool alloc should succeed or fail, and there was a preliminary
debugging mechanism to keep sort of a history of the previous decisions. But
it was never used, enforces a lock during the allocation, and forces to use
static variables, all of which are limiting the ability to pursue the pools
cleanups with no real benefit. Let's get rid of them now.
Since recent commit ae07592 ("MEDIUM: pools: add CONFIG_HAP_NO_GLOBAL_POOLS
and CONFIG_HAP_GLOBAL_POOLS") the pre-allocation of all desired reserved
buffers was not done anymore on systems not using the shared cache. This
basically has no practical impact since these ones will quickly be refilled
by all the ones used at run time, but it may confuse someone checking if
they're allocated in "show pools".
That's only 2.4-dev, no backport is needed.
When running with CONFIG_HAP_NO_GLOBAL_POOLS, it's theoritically possible
to keep an incorrect count of allocated entries in a pool because the
allocated counter was used as a cumulated counter of alloc calls instead
of a number of currently allocated items (it's possible the meaning has
changed over time). The only impact in this mode essentially is that
"show pools" will report incorrect values. But this would only happen on
limited pools, which is not even certain still exist.
This was added by recent commit 0bae07592 ("MEDIUM: pools: add
CONFIG_HAP_NO_GLOBAL_POOLS and CONFIG_HAP_GLOBAL_POOLS") so no backport
is needed.
This patch renames all existing uri-normalizers into a more consistent naming
scheme:
1. The part of the URI that is being touched.
2. The modification being performed as an explicit verb.
This normalizer merges `../` path segments with the predecing segment, removing
both the preceding segment and the `../`.
Empty segments do not receive special treatment. The `merge-slashes` normalizer
should be executed first.
See GitHub Issue #714.
When the session is aborted before any connection attempt to any server, the
number of connection retries reported in the logs is wrong. It happens
because when the retries counter is not strictly positive, we consider the
max number of retries was reached and the backend retries value is used. It
is obviously wrong when no connectioh was performed.
In fact, at this stage, the retries counter is initialized to 0. But the
backend stream-interface is in the INI state. Once it is set to SI_ST_REQ,
the counter is set to the backend value. And it is the only possible state
transition from INI state. Thus it is safe to rely on it to fix the bug.
This patch must be backported to all stable versions.
The http_get_stline() was designed to be called from HTTP analyzers. Thus
before any data forwarding. To prevent any invalid usage, two BUG_ON()
statements were added. However, it is not a good idea because it is pretty
hard to be sure no HTTP sample fetch will never be called outside the
analyzers context. Especially because there is at least one possible area
where it may happens. An HTTP sample fetch may be used inside the unique-id
format string. On the normal case, it is generated in AN_REQ_HTTP_INNER
analyzer. But if an error is reported too early, the id is generated when
the log is emitted.
So, it is safer to remove the BUG_ON() statements and consider the normal
behavior is to return NULL if the first block is not a start-line. Of
course, this means all calling functions must test the return value or be
sure the start-line is really there.
This patch must be backported as far as 2.0.
This patch adds 4 new sample fetches to get the source and the destination
info (ip address and port) of the backend connection :
* bc_dst : Returns the destination address of the backend connection
* bc_dst_port : Returns the destination port of the backend connection
* bc_src : Returns the source address of the backend connection
* bc_src_port : Returns the source port of the backend connection
The configuration manual was updated accordingly.
When method sample fetch is called, if an exotic method is found
(HTTP_METH_OTHER), when smp_prefetch_htx() is called, we must be sure the
start-line is still there. Otherwise, HAproxy may crash because of a NULL
pointer dereference, for instance if the method sample fetch is used inside
a unique-id format string. Indeed, the unique id may be generated when the
log message is emitted. At this stage, the request channel is empty.
This patch must be backported as far as 2.0. But the bug exists in all
stable versions for the legacy HTTP mode too. Thus it must be adapted to the
legacy HTTP mode and backported to all other stable versions.
For all ssl_bc_* sample fetches, the test on the keyword when called from a
health-check is inverted. We must be sure the 5th charater is a 'b' to
retrieve a connection.
This patch must be backported as far as 2.2.
bc_http_major sample fetch now works when it is called from a
tcp-check. When it happens, the session origin is a check. The backend
connection is retrieved from the conn-stream attached to the check.
If required, this path may easily be backported as far as 2.2.
fc_http_major and bc_http_major sample fetches return the major digit of the
HTTP version used, respectively, by the frontend and the backend
connections, based on the mux. However, in reality, "2" is returned if the
H2 mux is detected, otherwise "1" is inconditionally returned, regardless
the mux used. Thus, if called for a raw TCP connection, "1" is returned.
To fix this bug, we now get the multiplexer flags, if there is one, to be
sure MX_FL_HTX is set.
I guess it was made this way on purpose when the H2 multiplexer was
introduced in the 1.8 and with the legacy HTTP mode there is no other
solution at the connection level. Thus this patch should be backported as
far as 2.2. For the 2.0, it must be evaluated first because of the legacy
HTTP mode.
When a log-format string is built from an health-check, the session origin
is the health-check itself and not a connection. In addition, there is no
stream. It means for now some formats are not supported: %s, %sc, %b, %bi,
%bp, %si and %sp.
Thanks to this patch, the session origin is converted to a check. So it is
possible to retrieve the backend and the backend connection. Note this
session have no listener, thus %ft format must be guarded.
This patch is light and standalone, thus it may be backported as far as 2.2
if required. However, because the error is human, it is probably better to
wait a bit to be sure everything is properly protected.
The dummy frontend used to create the session of the tcp-checks is
initialized without identifier. However, it is required because this id may
be used without any guard, for instance in log-format string via "%f" or
when fe_name sample fetch is called. Thus, an unset id may lead to crashes.
This patch must be backported as far as 2.2.
