Thanks to previous commits, it is possible to use small buffers at different
places: to store the request when a connection is queued or when L7 retries
are enabled, or for health-checks requests. However, there was no
configuration parameter to fine tune small buffer use.
It is now possible, thanks to the proxy option "use-small-buffers".
Documentation was updated accordingly.
When healthchecks were configured for a proxy, an enum-like was used to
sepcify the check's type. The idea was to reserve some values for futur
types of healthcheck. But it is overkill. I doubt we will ever have
something else than tcp and external checks. So corresponding PR_O2 flags
were slightly reviewed and a hole was filled.
Thanks to this change, some bits were released in options2 bitfield.
If support for small buffers is enabled, we now try to use them for
healthcheck requests. First, we take care the tcpcheck ruleset may use small
buffers. Send rules using LF strings or too large data are excluded. The
ability to use small buffers or not are set on the ruleset. All send rules
of the ruleset must be compatible. This info is then transfer to server's
healthchecks relying on this ruleset.
Then, when a healthcheck is running, when a send rule is evaluated, if
possible, we try to use small buffers. On error, the ability to use small
buffers is removed and we retry with a regular buffer. It means on the first
error, the support is disabled for the healthcheck and all other runs will
use regular buffers.
In the same way support for large chunks was added to properly work with
large buffers, we are now adding supports for small chunks because it is
possible to process small buffers.
So a dedicated memory pool is added to allocate small
chunks. alloc_small_trash_chunk() must be used to allocate a small
chunk. alloc_trash_chunk_sz() and free_trash_chunk() were uppdated to
support small chunks.
In addition, small trash buffers are also created, using the same mechanism
than for regular trash buffers. So three thread-local trash buffers are
created. get_small_trash_chunk() must be used to get a small trash buffer.
And get_trash_chunk_sz() was updated to also deal with small buffers.
htx_move_to_small_buffer()/htx_move_to_large_buffer() and
htx_copy_to_small_buffer()/htx_copy_to_large_buffer() functions can now be
used to move or copy blocks from a default buffer to a small or large
buffer. The destination buffer is allocated and then each blocks are
transferred into it.
These funtions relies in htx_xfer() function.
htx_xfer() function should replace htx_xfer_blks(). It will be a bit easier to
maintain and to use. The behavior of htx_xfer() can be changed by calling it
with specific flags:
* HTX_XFER_KEEP_SRC_BLKS: Blocks from the source message are just copied
* HTX_XFER_PARTIAL_HDRS_COPY: It is allowed to partially xfer headers or trailers
* HTX_XFER_HDRS_ONLY: only headers are xferred
By default (HTX_XFER_DEFAULT or 0), all blocks from the source message are moved
into to the destination mesage. So copied in the destination messageand removed
from the source message.
The caller must still define the maximum amount of data (including meta-data)
that can be xferred.
It is no longer necessary to specify a block type to stop the copy. Most of
time, with htx_xfer_blks(), this parameter was set to HTX_BLK_UNUSED. And
otherwise it was only specified to transfer headers.
It is important to not that the caller is responsible to verify the original
HTX message is well-formated. Especially, it must be sure headers part and
trailers part are complete (finished by EOH/EOT block).
For now, htx_xfer_blks() is not removed for compatiblity reason. But it is
deprecated.
Because small buffers were only used by QUIC streams, the pool used to alloc
these buffers was located in the quic code. However, their usage will be
extended to other parts. So, the small buffers pool was moved into the
dynbuf part.
Function proxy_check_errors() is used when configuration parsing is
over. This patch splits it in two newly named ones.
The first function is named proxy_check_http_errors(). It is responsible
to check for the validity of any "errorfiles" directive which could
reference non-existent http-errors section or code not defined in such
section. This function is now called via proxy_finalize().
The second function is named proxy_finalize_http_errors(). It converts
each conf_errors type used during parsing in a proper http_reply type
for runtime usage. This function is still called via post-proxy-check,
after proxy_finalize().
This patch does not bring any functional change. However, it will become
necessary to ensure http-errors can be used as expected with dynamic
backends.
In conf_errors struct, arbitrary integer values were used for both
<type> field and <status> array. This renders the code difficult to
follow.
Replaces these values with proper enums type. Two new types are defined
for each of these fields. The first one represents the directive type,
derived from the keyword used (errorfile vs errorfiles). This directly
represents which part of <info> union should be manipulated.
The second enum is used for errorfiles directive with a reference on a
http-errors section. It indicates whether or not if a status code should
be imported from this section, and if this import is explicit or
implicit.
There's always a risk that some tasks run multiple times if they wake
each other up. Now we include the loop counter in the task struct and
stop processing the queue it's in when meeting a task that has already
run. We only pick 16 bits since that's only what remains free in the
task common part, so from time to time (once every 65536) it will be
possible to wrongly match a task as having already run and stop evaluating
its queue, but it's rare enough that we don't care, because this will
be OK on the next iteration.
We anticipated that the do-log action should be expanded with optional
arguments at some point. Now that we heard of multiple use-cases
that could be achieved with do-log action, but that are limitated by the
fact that all do-log statements inherit from the implicit log-profile
defined on the logger, we need to provide a way for the user to specify
that custom log-profile that could be used per do-log actions individually
This is what we try to achieve in this commit, by leveraging the
prerequisite work performed by the last 2 commits.
The new field th_ctx->rq_tot_peak contains the computed peak run queue
length averaged over the last 512 calls. This is computed when entering
process_runnable_tasks. It will not take into account new tasks that are
created or woken up during this round nor those which are evicted, which
is the reason why we're using a peak measurement to increase chances to
observe transient high values. Tests have shown that 512 samples are good
to provide a relatively smooth average measurement while still fading
away in a matter of milliseconds at high loads. Since this value is
only updated once per round, it cannot be used as a statistic and
shouldn't be exposed, it's only for internal use (self-regulation).
Sometimes it's desirable to observe fading away peak values, where a new
value that is higher than the historical one instantly replaces it,
otherwise contributes to it. It is convenient when trying to observe
certain phenomenons like peak queue sizes. The new function
swrate_add_peak_local() does that to a private variable (no atomic ops
involved as it's not worth the cost since such use cases are typically
local).
When "set-dumpable" is set to "libs", in addition to marking the process
dumpable, haproxy also reads the binary and shared objects into memory as
a tar archive in a page-aligned location so that these files are easily
extractable from a future core dump. The goal here is to always have
access to the exact same binary and libs as those which caused the core
to happen. It's indeed very frequent to miss some of these, or to get
mismatching files due to a local update that didn't experience a reload,
or to get those of a host system instead of the container.
The in-memory tar file presents everything under a directory called
"core-%d" where %d corresponds to the PID of the worker process. In
order to ease the finding of these data in the core dump, the memory
area is contiguous and surrounded by PROT_NONE pages so that it appears
in its own segment in the core file. The total size used by this is a
few tens of MB, which is not a problem on large systems.
New function load_file_into_tar() concatenates a file into an in-memory
tar archive and grows its size. Only the base name and a provided prefix
are used to name the faile. If the file cannot be loaded, it's added as
size zero and permissions 0 to show that it failed to load. This will
be used to load post-mortem information so it needs to remain simple.
The purpose here is to create a tar file header in memory from a known
file name, prefix, size and mode. It will be used to prepare archives
of libs in use for improved debugging, but may probably be useful for
other purposes due to its simplicity.
We no longer rely on now_offset stored in the shm-stats-file. Instead
haproxy automatically computes the now_offset relative to the monotonic
clock and the shared global clock.
Indeed, the previous model based on static now_offset when monotonic
clock is available proved to be insufficient when used in
combination with shm-stats-file (that is when monotonic clock is shared
between multiple co-processes). In ideal situation co-processes would
correctly apply the offset to their local monotonic clock and end up
with consistent now_ns. But when restarting from an existing
shm-stats-file from a previous session (ie: prior to reboot), then the
local monotonic clock would no longer be consistent with the one used
to update the file previously, so applying a static offset would fail
to restore clock consistency.
For this specific issue, a workaround was brought by 09bf116
("BUG/MEDIUM: stats-file: detect and fix inconsistent shared clock when resuming from shm-stats-file")
but the solution implemented there was deemed too fragile, because there
is a 60sec window where the fix would fail to detect inconsistent clock
and would leave haproxy with a broken clock ranging from 0 to 60 seconds,
which can be huge..
By simply recomputing the now_offset each time we learn from another
process (through the shared map by reading global_now_ns), we simply
recompute our local offset (difference between OUR monotonic clock
and the SHARED one). Also, in clock_update_global_date(), we make
sure we always recompute the now_offset as now_ms may have been
updated from shared clock if shared clock was ahead of us.
Thanks to that new logic, interrupted processes, resumed processes,
processed started with shm-stats-file from previous session now
correctly recover from those various situations and multiple
co-processes with diverting clocks on startup end up converging to
the same values.
Since it is no longer relevant to save now_offset in the map, it was
removed but to prevent shm-stats-file incompatibility with previous
versions, 8-byte hole was forced, and we didn't bump the shm-stats-file
version on purpose.
This patch may be backported in 3.3 after a solid period of observation
to ensure we didn't break things.
We defer processing of the "-dt" options until after the configuration
file has been read. This will be useful if we ever allow trace sources
to be registered later, for instance with LUA.
No backport needed.
Keywords registered out of an initcall will have a TH_EX_CTX_CLI_KWL
execution context pointing to the keyword list. The report will indicate
the 5 first words of the first command of the list, e.g.:
exec_ctx: cli kwl starting with 'debug counters '
This should also work for CLI keywords registered in Lua.
Now CLI keywords registered via an initcall will be tracked during
execution, by keeping a link to their initcall location. "show threads"
now shows "exec_ctx: kw registered at @debug.c:3093" which indeed
corresponds to the initcall for the debugging commands.
Till now the CLI didn't know what keyword was being processed after it
was parsed. In order to report the execution context, we'll need to
store it. And this may even help for post-mortem analysis to know the
exact keyword being processed, so let's store the pointer in the cli_ctx
part of the appctx.
It allows to know when a thread is currnetly running inside an applet.
For example now "show threads" will show "applet '<CLI>'" for the thread
issuing this command.
It now appears almost everywhere due to callbacks (e.g. ssl_sock_io_cb).
Muxes also become visible now on memory profiling. A small test on h1+ssl
yields 838 lines of statistics. The number of buckets should definitely
be increased, and more grouping criteria should be added.
A performance test was conducted to observe the possible effect of
setting the execution context on each task switch, and it didn't change
at all, remaining at about 1.01 billion ctxsw/s on a 128-thread EPYC.
Most calls to mux ops were instrumented with a CALL_MUX_WITH_RET() or
CALL_MUX_NO_RET() macro in order to make the current thread's context
point to the called mux and be able to track its allocations. Only
a bunch of harmless mux_ctl() and ->subscribe/unsubscribe calls were
left untouched since useless. But destroy/detach/shut/init/snd_buf
and rcv_buf are now tracked.
It will not show allocations performed in IO callback via tasklet
wakeups however.
In order to ease reading of the output, cmp_memprof_ctx() knows about
muxes and sorts based on the .subscribe function address instead of
the mux_ops address so as to keep various callers grouped.
Doing this allows to report the allocations/releases performed by filters
when running with memory profiling enabled. The flt_conf pointer is kept
and the report shows the filter name.
A bit similar to what was done for sample fetch functions and converters,
we now store with each action keyword the location of the initcall when
they're registered this way. Since there are many functions only calling
a LIST_APPEND() (one per ruleset), we now implement a dedicated function
to store the context in all keywords before doing the append.
However that's not sufficient, because keywords are not mandatory for
actions, so we cannot safely rely on rule->kw. Thus we then set the
exec_ctx per rule when they are all scanned in check_action_rules(),
based on the keyword if it exists, otherwise we make a context from
the action_ptr function if it is set (it should).
Finally at all call points we now check rule->exec_ctx.
The purpose here is to be able to spot certain callbacks, such as the
SSL message callbacks, which are difficult to associate to anything.
Thus we introduce a new context type, TH_EX_CTX_FUNC, for which the
context is just the function pointed to by the void *pointer. One
difficulty with callbacks is that the allocation and release contexts
will likely be different, so the code should be properly structured
to allow proper tracking, either by instrumenting all calls, or by
making sure that the free calls are easy to spot in a report.
With the two new context types TH_EX_CTX_SMPF/CONV, we can now also
report contexts corresponding to direct calls to sample_register_fetches()
and sample_register_convs(). In this case, the first word of the keyword
list is reported.
Now keywords are registered with an exec_ctx and this one is passed
when calling ->process. The ctx is of type INITCALL when passed via
an initcall where we know the file name and line number.
This was tested with and extra "malloc(15)" added in smp_fetch_path()
which shows that it works:
$ socat /tmp/sock1 - <<< "show profiling memory"|grep via
Calls | Tot Bytes | Caller and method [via]
1893399 0 60592592 0| 0x78b2ec task_run_applet+0x3339c malloc(32) [via initcall @http_fetch.c:2416]
When the execution context is set to TH_EX_CTX_INITCALL, the pointer
points to a valid initcall, and the decoder will show "kw registered
at %s:%d" with file and line number of the initcall declaration. It's
up to the caller to make the initcall pointer point to the one that was
set during the initcall. The purpose here is to be able to preserve and
pass that knowledge of an initcall down the chain so that future calls
to functions registered via the initcall are still assigned to it.
The INITCALL macros will now store the file and line number where they
are declared into the initcall struct, and RUN_INITCALLS() will assign
them to the global caller_file and caller_line variables, and will even
set caller_initcall to the current initall so that at any instant such
functions know where their caller declared them. This will help with
error messages and traces where a bit of context will be welcome.
The new function chunk_append_thread_ctx() appends to a buffer the given
execution context based on its type and pointer. The goal is to easily
use it in profiling output and thread dumps. For now it only handles
TH_EX_CTX_NONE (which prints nothing) and TH_EX_CTX_OTHER (which indicates
"other ctx" followed by the pointer). It will be extended by new types as
they arrive.
This now allows to report the same function in multiple bins based on the
th_ctx's exec_ctx discriminant. It's also worth noting that the context is
not atomically committed, but this shouldn't be a problem since a single
entry can get it. In the worst case, a second thread trying to create the
same context in parallel would create a different bin just for this call,
which is harmless. The same situation already exists with the caller
pointer.
We have the struct made of a type and a pointer in the th_ctx and a
function to switch it for the current thread. Two macros are provided
to enclose a callee within a temporary context. For now only type OTHER
is supported (only a generic pointer).
The purpose here is to combine two pointers and a long argument instead
of having the caller perform the mixing. Also it's cleaner and more
efficient this was as the arg is mixed after the multiplications, and
modern processors are efficient at multiplying then adding.
We'll need to further extend the pointer hashing code to pass extra
parameters and to retrieve the dropped bits, so let's first split the
part that hashes the pointer from the part that reduces the hash to
the desired size.
Starting with OpenSSL 4.0, X509_get_subject_name(), X509_get_issuer_name(),
and X509_CRL_get_issuer() return a const-qualified X509_NAME pointer.
Similarly, X509_NAME_get_entry() returns a const X509_NAME_ENTRY *, and
X509_NAME_ENTRY_get_data() returns a const ASN1_STRING *.
Introduce the __X509_NAME_CONST__ macro (defined to 'const' for OpenSSL
>= 4.0.0, empty for WolfSSL and older OpenSSL version which lacks const
on these APIs) and use it to qualify X509_NAME * variables and the
parameters of the three DN helper functions ssl_sock_get_dn_entry(),
ssl_sock_get_dn_formatted(), and ssl_sock_get_dn_oneline(). This avoids
both const-qualifier warnings on OpenSSL 4.0 and discarded-qualifier
warnings on WolfSSL, without needing explicit casts at call sites.
In ssl_sock.c (ssl_get_client_ca_file) and ssl_gencert.c
(ssl_sock_do_create_cert), a __X509_NAME_CONST__ X509_NAME * variable was
being reused to store the result of X509_NAME_dup() and then passed to
mutating functions (X509_NAME_add_entry_by_txt, X509_NAME_free). Introduce
separate X509_NAME * variables (xn_dup, subject) to hold the mutable
duplicate.
Original patch from Alexandr Nedvedicky <sashan@openssl.org>:
https://www.mail-archive.com/haproxy@formilux.org/msg46696.html
