Instead of calling the data layer wake callback function, we now first try
to wake it up. If the data layer is subscribed for receives or for sends,
its tasklet is woken up. The wake callback function is only called as the
last chance to notify the data layer.
Because si_cs_process() is also the SI wake callback function, it may be
called from the mux layer. Thus, in such cases, it is performed outside any
I/O event and si_cs_recv() is not called. If a read0 is reported by the mux,
via the CS_FL_EOS flag, the event is not handled, because only si_cs_recv()
take care of this flag for now.
It is not a bug, because this does not happens for now. All muxes set this
flag when the data layer retrieve data (via mux->rcv_buf()). But it is safer
to be prepared to handle it from the wake callback. And in fact, it will be
useful to fix the HTTP upgrades of TCP connections (especially TCP>H1>H2
upgrades).
To be sure to not handle the same event twice, it is only handled if the
shutr is not already set on the input channel.
The reuse of idle connections should only happen for a proxy with the
http mode. In case of a backend with the tcp mode, the reuse selection
and insertion in session list are skipped.
This behavior is present since commit :
MEDIUM: connection: Add private connections synchronously in session server list
It could also be further exagerated by :
MEDIUM: backend: add reused conn to sess if mux marked as HOL blocking
It can be backported up to 2.3.
A bug was introduced by the early insertion of idle connections at the
end of connect_server. It is possible to reuse a connection not yet
ready waiting for an handshake (for example with proxy protocol or ssl).
A wrong duplicate xprt_handshake_io_cb tasklet is thus registered as a
side-effect.
This triggers the BUG_ON statement of xprt_handshake_subscribe :
BUG_ON(ctx->subs && ctx->subs != es);
To counter this, a check is now present in session_get_conn to only
return a connection without the flag CO_FL_WAIT_XPRT. This might cause
sometimes the creation of dedicated server connections when in theory
reuse could have been used, but probably only occurs rarely in real
condition.
This behavior is present since commit :
MEDIUM: connection: Add private connections synchronously in session server list
It could also be further exagerated by :
MEDIUM: backend: add reused conn to sess if mux marked as HOL blocking
It can be backported up to 2.3.
NOTE : This bug seems to be only reproducible with mode tcp, for an
unknown reason. However, reuse should never happen when not in http
mode. This improper behavior will be the subject of a dedicated patch.
This bug can easily be reproducible with the following config (a
webserver is required to accept proxy protocol on port 31080) :
global
defaults
mode tcp
timeout connect 1s
timeout server 1s
timeout client 1s
listen li
bind 0.0.0.0:4444
server bla1 127.0.0.1:31080 check send-proxy-v2
with the inject client :
$ inject -u 10000 -d 10 -G 127.0.0.1:4444
This should fix the github issue #1058.
Use chunk_inistr() for a chunk initialisation in
ssl_sock_load_sctl_from_file() instead of a manual initialisation which
was not initialising head.
Fix issue #1073.
Must be backported as far as 2.2
The new ckch_inst_new_load_srv_store() function which mimics the
ckch_inst_new_load_store() function includes some dead code which was
used only in the former function.
Fix issue #1081.
The previous patch was pushed too quickly (399bf72f6 "BUG/MINOR: stats:
Remove a break preventing ST_F_QCUR to be set for servers"). It was not an
extra break but a misplaced break statement. Thus, now a break statement
must be added after filling the ST_F_MODE field in stats_fill_sv_stats().
No backport needed except if the above commit is backported.
There is an extra break statement wrongly placed in stats_fill_sv_stats()
function, just before filling the ST_F_QCUR field. It prevents this field to
be set to the right value for servers.
No backport needed except if commit 3a9a4992 ("MEDIUM: stats: allow to
select one field in `stats_fill_sv_stats`") is backported.
Building with `"DEBUG=-DDEBUG_STRICT=1 -DDEBUG_USE_ABORT=1"` previously emitted the warning:
In file included from include/haproxy/api.h:35:0,
from src/mux_pt.c:13:
include/haproxy/buf.h: In function ‘br_init’:
include/haproxy/bug.h:42:90: warning: implicit declaration of function ‘abort’ [-Wimplicit-function-declaration]
#define ABORT_NOW() do { extern void ha_backtrace_to_stderr(); ha_backtrace_to_stderr(); abort(); } while (0)
^
include/haproxy/bug.h:56:21: note: in expansion of macro ‘ABORT_NOW’
#define CRASH_NOW() ABORT_NOW()
^
include/haproxy/bug.h:68:4: note: in expansion of macro ‘CRASH_NOW’
CRASH_NOW(); \
^
include/haproxy/bug.h:62:35: note: in expansion of macro ‘__BUG_ON’
#define _BUG_ON(cond, file, line) __BUG_ON(cond, file, line)
^
include/haproxy/bug.h:61:22: note: in expansion of macro ‘_BUG_ON’
#define BUG_ON(cond) _BUG_ON(cond, __FILE__, __LINE__)
^
include/haproxy/buf.h:875:2: note: in expansion of macro ‘BUG_ON’
BUG_ON(size < 2);
^
This patch fixes that issue. The `DEBUG_USE_ABORT` option exists for use with
static analysis tools. No backport needed.
This patch makes things more consistent between the bind_conf functions
and the server ones:
- ssl_sock_load_srv_ckchs() loads the SSL_CTX in the server
(ssl_sock_load_ckchs() load the SNIs in the bind_conf)
- add the server parameter to ssl_sock_load_srv_ckchs()
- changes made to the ckch_inst are done in
ckch_inst_new_load_srv_store()
Since the server SSL_CTX is now stored in the ckch_inst, it is not
needed anymore to pass an SSL_CTX to ckch_inst_new_load_srv_store() and
ssl_sock_load_srv_ckchs().
The new feature allowing the change of server side certificates
introduced duplicated free code. Rework the code in
cli_io_handler_commit_cert() to be more consistent.
The client_crt member is not used anymore since the server's ssl context
initialization now behaves the same way as the bind lines one (using
ckch stores and instances).
When trying to update a backend certificate, we should find a
server-side ckch instance thanks to which we can rebuild a new ssl
context and a new ckch instance that replace the previous ones in the
server structure. This way any new ssl session will be built out of the
new ssl context and the newly updated certificate.
This resolves a subpart of GitHub issue #427 (the certificate part)
In order for the backend server's certificate to be hot-updatable, it
needs to fit into the implementation used for the "bind" certificates.
This patch follows the architecture implemented for the frontend
implementation and reuses its structures and general function calls
(adapted for the server side).
The ckch store logic is kept and a dedicated ckch instance is used (one
per server). The whole sni_ctx logic was not kept though because it is
not needed.
All the new functions added in this patch are basically server-side
copies of functions that already exist on the frontend side with all the
sni and bind_cond references removed.
The ckch_inst structure has a new 'is_server_instance' flag which is
used to distinguish regular instances from the server-side ones, and a
new pointer to the server's structure in case of backend instance.
Since the new server ckch instances are linked to a standard ckch_store,
a lookup in the ckch store table will succeed so the cli code used to
update bind certificates needs to be covered to manage those new server
side ckch instances.
Split the server's ssl context initialization into the general ssl
related initializations and the actual initialization of a single
SSL_CTX structure. This way the context's initialization will be
usable by itself from elsewhere.
Reorganize the conditions for the reuse of idle/safe connections :
- reduce code by using variable to store reuse mode and idle/safe conns
counts
- consider that idle/safe/avail lists are properly allocated if
max_idle_conns not null. An allocation failure prevents haproxy
startup.
It is only a problem on the response path because the request payload length
it always known. But when a filter is registered to analyze the response
payload, the filtering may hang if the server closes just after the headers.
The root cause of the bug comes from an attempt to allow the filters to not
immediately forward the headers if necessary. A filter may choose to hold
the headers by not forwarding any bytes of the payload. For a message with
no payload but a known payload length, there is always a EOM block to
forward. Thus holding the EOM block for bodyless messages is a good way to
also hold the headers. However, messages with an unknown payload length,
there is no EOM block finishing the message, but only a SHUTR flag on the
channel to mark the end of the stream. If there is no payload when it
happens, there is no payload at all to forward. In the filters API, it is
wrongly detected as a condition to not forward the headers.
Because it is not the most used feature and not the obvious one, this patch
introduces another way to hold the message headers at the begining of the
forwarding. A filter flag is added to explicitly says the headers should be
hold. A filter may choose to set the STRM_FLT_FL_HOLD_HTTP_HDRS flag and not
forwad anything to hold the headers. This flag is removed at each call, thus
it must always be explicitly set by filters. This flag is only evaluated if
no byte has ever been forwarded because the headers are forwarded with the
first byte of the payload.
reg-tests/filters/random-forwarding.vtc reg-test is updated to also test
responses with unknown payload length (with and without payload).
This patch must be backported as far as 2.0.
use `stats_fill_sv_stats` when possible to avoid duplicating code.
the following metrics have a change of behaviour:
haproxy_server_limit_sessions
haproxy_server_queue_limit
haproxy_server_check_failures_total
haproxy_server_check_up_down_total
haproxy_server_downtime_seconds_total
haproxy_server_current_throttle
haproxy_server_idle_connections_limit
depending on cases, if the limit was not configured or enabled, NaN is
returned instead. It should not be an issue for users, even better than
before as it provides more precise info.
Signed-off-by: William Dauchy <wdauchy@gmail.com>
prometheus approach requires to output all values for a given metric
name; meaning we iterate through all metrics, and then iterate in the
inner loop on all objects for this metric.
In order to allow more code reuse, adapt the stats API to be able to
select one field or fill them all otherwise.
This patch follows what has already been done on frontend and backend
side.
From this patch it should be possible to remove most of the duplicate
code on prometheuse side for the server.
A few things to note though:
- state require prior calculation, so I moved that to a sort of helper
`stats_fill_be_stats_computestate`.
- all ST_F*TIME fields requires some minor compute, so I moved it at te
beginning of the function under a condition.
Signed-off-by: William Dauchy <wdauchy@gmail.com>
use `stats_fill_be_stats` when possible to avoid duplicating code; make
use of field selector to get the needed field only.
the only difference is on `haproxy_backend_downtime_seconds_total` as
stats.c is testing `px->srv`. This behaviour is present since commit
7344f47893 ("MINOR: stats: only report
backend's down time if it has servers"). The end result is a NaN instead
of a zero when no server are present.
Signed-off-by: William Dauchy <wdauchy@gmail.com>
prometheus approach requires to output all values for a given metric
name; meaning we iterate through all metrics, and then iterate in the
inner loop on all objects for this metric.
In order to allow more code reuse, adapt the stats API to be able to
select one field or fill them all otherwise.
This patch follows what has already been done on frontend side.
From this patch it should be possible to remove most of the duplicate
code on prometheuse side for the backend
A few things to note though:
- status and uweight field requires prior compute, so I moved that to a
sort of helper `stats_fill_be_stats_computesrv`.
- all ST_F*TIME fields requires some minor compute, so I moved it at te
beginning of the function under a condition.
Signed-off-by: William Dauchy <wdauchy@gmail.com>
GitHub issue #796 notes that many administrators miss the fact that the `hdr()`
fetch (without the `f`) splits the header value at commas. This is only
mentioned at the end of a long paragraph.
This patch attempts to improve the documentation by:
- Explaning the "comma issue" as early as possible.
- Adding newlines to split the explanation into distinct sections.
- Reducing duplication by making the `res` siblings refer to their `req`
counterparts.
This patch may be backported as long as it applies cleanly. During the
refactoring I needed to adjust several explanations for consistency and not all
of them might be available in older branches.
while working on backend/servers I realised I could have written that in
a better way and avoid one extra break. This is slightly improving
readiness.
also while being here, fix function declaration which was not 100%
accurate.
this patch does not change the behaviour of the code.
Signed-off-by: William Dauchy <wdauchy@gmail.com>
Not necessarily mandatory but I saw a few prometheus client parsing only
`NaN`. Also most librarries do output `NaN`
Signed-off-by: William Dauchy <wdauchy@gmail.com>
In stats_fill_fe_stats(), some fields are conditionnal (ST_F_HRSP_* for
instance). But unlike unimplemented fields, for those fields, the <metric>
variable is used to fill the <stats> array, but it is not initialized. This
bug as no impact, because these fields are not used. But it is better to fix
it now to avoid future bugs.
To fix it, the metric is now defined and initialized into the for loop.
The bug was introduced by the commit 0ef54397 ("MEDIUM: stats: allow to
select one field in `stats_fill_fe_stats`"). No backport is needed except if
the above commit is backported. It fixes the issue #1063.
A regression was introduced by the commit 0ef54397b ("MEDIUM: stats: allow
to select one field in `stats_fill_fe_stats`"). stats_fill_fe_stats()
function fails on unimplemented metrics for frontends. However, not all
stats metrics are used by frontends. For instance ST_F_QCUR. As a
consequence, the frontends stats are always skipped.
To fix the bug, we just skip unimplemented metric for frontends. An error is
triggered only if a specific field is given and is unimplemented.
No backport is needed except if the above commit is backported.
Released version 2.4-dev6 with the following main changes :
- MINOR: converter: adding support for url_enc
- BUILD: SSL: guard TLS13 ciphersuites with HAVE_SSL_CTX_SET_CIPHERSUITES
- BUILD: ssl: guard EVP_PKEY_get_default_digest_nid with ASN1_PKEY_CTRL_DEFAULT_MD_NID
- BUILD: ssl: guard openssl specific with SSL_READ_EARLY_DATA_SUCCESS
- BUILD: Makefile: exclude broken tests by default
- CLEANUP: cfgparse: replace "realloc" with "my_realloc2" to fix to memory leak on error
- BUG/MINOR: hlua: Fix memory leak in hlua_alloc
- MINOR: contrib/prometheus-exporter: export build_info
- DOC: fix some spelling issues over multiple files
- CLEANUP: Fix spelling errors in comments
- SCRIPTS: announce-release: fix typo in help message
- CI: github: add a few more words to the codespell ignore list
- DOC: Add maintainers for the Prometheus exporter
- BUG/MINOR: sample: fix concat() converter's corruption with non-string variables
- BUG/MINOR: server: Memory leak of proxy.used_server_addr during deinit
- CLEANUP: sample: remove uneeded check in json validation
- MINOR: reg-tests: add a way to add service dependency
- BUG/MINOR: sample: check alloc_trash_chunk return value in concat()
- BUG/MINOR: reg-tests: fix service dependency script
- MINOR: reg-tests: add base prometheus test
- Revert "BUG/MINOR: dns: SRV records ignores duplicated AR records"
- BUG/MINOR: sample: Memory leak of sample_expr structure in case of error
- BUG/MINOR: check: Don't perform any check on servers defined in a frontend
- BUG/MINOR: init: enforce strict-limits when using master-worker
- MINOR: contrib/prometheus-exporter: avoid connection close header
- MINOR: contrib/prometheus-exporter: use fill_info for process dump
- BUG/MINOR: init: Use a dynamic buffer to set HAPROXY_CFGFILES env variable
- MINOR: config: Add failifnotcap() to emit an alert on proxy capabilities
- MINOR: server: Forbid server definitions in frontend sections
- BUG/MINOR: threads: Fixes the number of possible cpus report for Mac.
- CLEANUP: pattern: rename pat_ref_commit() to pat_ref_commit_elt()
- MINOR: pattern: add the missing generation ID manipulation functions
- MINOR: peers: Add traces for peer control messages.
- BUG/MINOR: dns: SRV records ignores duplicated AR records (v2)
- BUILD: peers: fix build warning about unused variable
- BUG/MEDIUM: stats: add missing INF_BUILD_INFO definition
- MINOR: cache: Do not store responses with an unknown encoding
- BUG/MINOR: peers: Possible appctx pointer dereference.
- MINOR: build: discard echoing in help target
- MINOR: cache: Remove the `hash` part of the accept-encoding secondary key
- CLEANUP: cache: Use proper data types in secondary_key_cmp()
- CLEANUP: Rename accept_encoding_hash_cmp to accept_encoding_bitmap_cmp
- BUG/MINOR: peers: Wrong "new_conn" value for "show peers" CLI command.
- MINOR: contrib: Make the wireshark peers dissector compile for more distribs.
- BUG/MINOR: mux_h2: missing space between "st" and ".flg" in the "show fd" helper
- CLEANUP: tools: make resolve_sym_name() take a const pointer
- CLEANUP: cli: make "show fd" use a const connection to access other fields
- MINOR: cli: make "show fd" also report the xprt and xprt_ctx
- MINOR: xprt: add a new show_fd() helper to complete some "show fd" dumps.
- MINOR: ssl: provide a "show fd" helper to report important SSL information
- MINOR: xprt/mux: export all *_io_cb functions so that "show fd" resolves them
- MINOR: mux-h2: make the "show fd" helper also decode the h2s subscriber when known
- MINOR: mux-h1: make the "show fd" helper also decode the h1s subscriber when known
- MINOR: mux-fcgi: make the "show fd" helper also decode the fstrm subscriber when known
- CI: Pin VTest to a known good commit
- MINOR: cli: give the show_fd helpers the ability to report a suspicious entry
- MINOR: cli/show_fd: report some easily detectable suspicious states
- MINOR: ssl/show_fd: report some FDs as suspicious when possible
- MINOR: mux-h2/show_fd: report as suspicious an entry with too many calls
- MINOR: mux-h1/show_fd: report as suspicious an entry with too many calls
- BUG/MINOR: mworker: define _GNU_SOURCE for strsignal()
- BUG/MEDIUM: tcpcheck: Don't destroy connection in the wake callback context
- BUG/MEDIUM: mux-h2: Xfer rxbuf to the upper layer when creating a front stream
- MINOR: http: Add HTTP 501-not-implemented error message
- MINOR: muxes: Add exit status for errors about not implemented features
- MINOR: mux-h1: Be prepared to return 501-not-implemented error during parsing
- MEDIUM: mux-h1: Return a 501-not-implemented for upgrade requests with a body
- DOC: Remove space after comma in converter signature
- DOC: Rename '<var name>' to '<var>' in converter signature
- MINOR: stats: duplicate 3 fields in bytes in info
- MINOR: stats: add new start time field
- MINOR: contrib/prometheus-exporter: merge info description from stats
- MEDIUM: stats: allow to select one field in `stats_fill_fe_stats`
- MINOR: contrib/prometheus-exporter: use fill_fe_stats for frontend dump
- MINOR: contrib/prometheus-exporter: Don't needlessly set empty label for metrics
- MINOR: contrib/prometheus-exporter: Split the PROMEX_FL_STATS_METRIC flag
- MINOR: contrib/prometheus-exporter: Add promex_metric struct defining a metric
- MEDIUM: contrib/prometheus-exporter: Rework matrices defining Promex metrics
- BUG/MINOR: stream: Don't update counters when TCP to H2 upgrades are performed
- BUG/MEDIUM: mux-h2: fix read0 handling on partial frames
- MINOR: debug: always export the my_backtrace function
- MINOR: debug: extract the backtrace dumping code to its own function
- MINOR: debug: create ha_backtrace_to_stderr() to dump an instant backtrace
- MEDIUM: debug: now always print a backtrace on CRASH_NOW() and friends
- MINOR: debug: let ha_dump_backtrace() dump a bit further for some callers
- BUILD: debug: fix build warning by consuming the write() result
- MINOR: lua: remove unused variable
- BUILD/MINOR: lua: define _GNU_SOURCE for LLONG_MAX
Lua requires LLONG_MAX defined with __USE_ISOC99 which is set by
_GNU_SOURCE, not necessarely defined by default on old compiler/glibc.
$ make V=1 TARGET=linux-glibc-legacy USE_THREAD= USE_ACCEPT4= USE_PCRE=1 USE_OPENSSL=1 USE_ZLIB=1 USE_LUA=1
..
cc -Iinclude -O2 -g -Wall -Wextra -Wdeclaration-after-statement -fwrapv -Wno-strict-aliasing -Wno-unused-label -Wno-sign-compare -Wno-unused-parameter -Wno-missing-field-initializers -DUSE_EPOLL -DUSE_NETFILTER -DUSE_PCRE -DUSE_POLL -DUSE_TPROXY -DUSE_LINUX_TPROXY -DUSE_LINUX_SPLICE -DUSE_LIBCRYPT -DUSE_CRYPT_H -DUSE_GETADDRINFO -DUSE_OPENSSL -DUSE_LUA -DUSE_FUTEX -DUSE_ZLIB -DUSE_CPU_AFFINITY -DUSE_DL -DUSE_RT -DUSE_PRCTL -DUSE_THREAD_DUMP -I/usr/include/openssl101e/ -DUSE_PCRE -I/usr/include -DCONFIG_HAPROXY_VERSION=\"2.4-dev5-73246d-83\" -DCONFIG_HAPROXY_DATE=\"2021/01/21\" -c -o src/hlua.o src/hlua.c
In file included from /usr/local/include/lua.h:15,
from /usr/local/include/lauxlib.h:15,
from src/hlua.c:16:
/usr/local/include/luaconf.h:581:2: error: #error "Compiler does not support 'long long'. Use option '-DLUA_32BITS' or '-DLUA_C89_NUMBERS' (see file 'luaconf.h' for details)"
..
cc -Iinclude -O2 -g -Wall -Wextra -Wdeclaration-after-statement -fwrapv -Wno-strict-aliasing -Wno-unused-label -Wno-sign-compare -Wno-unused-parameter -Wno-missing-field-initializers -DUSE_EPOLL -DUSE_NETFILTER -DUSE_PCRE -DUSE_POLL -DUSE_TPROXY -DUSE_LINUX_TPROXY -DUSE_LINUX_SPLICE -DUSE_LIBCRYPT -DUSE_CRYPT_H -DUSE_GETADDRINFO -DUSE_OPENSSL -DUSE_LUA -DUSE_FUTEX -DUSE_ZLIB -DUSE_CPU_AFFINITY -DUSE_DL -DUSE_RT -DUSE_PRCTL -DUSE_THREAD_DUMP -I/usr/include/openssl101e/ -DUSE_PCRE -I/usr/include -DCONFIG_HAPROXY_VERSION=\"2.4-dev5-73246d-83\" -DCONFIG_HAPROXY_DATE=\"2021/01/21\" -c -o src/hlua_fcn.o src/hlua_fcn.c
In file included from /usr/local/include/lua.h:15,
from /usr/local/include/lauxlib.h:15,
from src/hlua_fcn.c:17:
/usr/local/include/luaconf.h:581:2: error: #error "Compiler does not support 'long long'. Use option '-DLUA_32BITS' or '-DLUA_C89_NUMBERS' (see file 'luaconf.h' for details)"
..
Cc: Thierry Fournier <tfournier@arpalert.org>
hlua_init() uses 'idx' only in openssl related code, while 'i' is used
in shared code and is safe to be reused. This commit replaces the use of
'idx' with 'i'
$ make V=1 TARGET=linux-glibc USE_LUA=1 USE_OPENSSL=
..
cc -Iinclude -O2 -g -Wall -Wextra -Wdeclaration-after-statement -fwrapv -Wno-address-of-packed-member -Wno-unused-label -Wno-sign-compare -Wno-unused-parameter -Wno-clobbered -Wno-missing-field-initializers -Wno-cast-function-type -Wtype-limits -Wshift-negative-value -Wshift-overflow=2 -Wduplicated-cond -Wnull-dereference -DUSE_EPOLL -DUSE_NETFILTER -DUSE_POLL -DUSE_THREAD -DUSE_BACKTRACE -DUSE_TPROXY -DUSE_LINUX_TPROXY -DUSE_LINUX_SPLICE -DUSE_LIBCRYPT -DUSE_CRYPT_H -DUSE_GETADDRINFO -DUSE_LUA -DUSE_FUTEX -DUSE_ACCEPT4 -DUSE_CPU_AFFINITY -DUSE_TFO -DUSE_NS -DUSE_DL -DUSE_RT -DUSE_PRCTL -DUSE_THREAD_DUMP -I/usr/include/lua5.3 -I/usr/include/lua5.3 -DCONFIG_HAPROXY_VERSION=\"2.4-dev5-37286a-78\" -DCONFIG_HAPROXY_DATE=\"2021/01/21\" -c -o src/hlua.o src/hlua.c
src/hlua.c: In function 'hlua_init':
src/hlua.c:9145:6: warning: unused variable 'idx' [-Wunused-variable]
9145 | int idx;
| ^~~
When writing commit a8459b28c ("MINOR: debug: create
ha_backtrace_to_stderr() to dump an instant backtrace") I just forgot
that some distros are a bit extremist about the syscall return values.
src/debug.c: In function `ha_backtrace_to_stderr':
src/debug.c:147:3: error: ignoring return value of `write', declared with attribute warn_unused_result [-Werror=unused-result]
write(2, b.area, b.data);
^~~~~~~~~~~~~~~~~~~~~~~~
CC src/h1_htx.o
Let's apply the usual tricks to shut them up. No backport is needed.
The dump state is now passed to the function so that the caller can adjust
the behavior. A new series of 4 values allow to stop *after* dumping main
instead of before it or any of the usual loops. This allows to also report
BUG_ON() that could happen very high in the call graph (e.g. startup, or
the scheduler itself) while still understanding what the call path was.
The purpose is to enable the dumping of a backtrace on BUG_ON(). While
it's very useful to know that a condition was met, very often some
caller context is missing to figure how the condition could happen.
From now on, on systems featuring backtrace, a backtrace of the calling
thread will also be dumped to stderr in addition to the unexpected
condition. This will help users of DEBUG_STRICT as they'll most often
find this backtrace in their logs even if they can't find their core
file.
A new "debug dev bug" expert-mode CLI command was added to test the
feature.
This function calls the ha_dump_backtrace() function with a locally
allocated buffer and sends the output slightly indented to fd #2. It's
meant to be used as an emergency backtrace dump.
The backtrace dumping code was located into the thread dump function
but it looks particularly convenient to be able to call it to produce
a dump in other situations, so let's move it to its own function and
make sure it's called last in the function so that we can benefit from
tail merging to save one entry.
In order to simplify the code and remove annoying ifdefs everywhere,
let's always export my_backtrace() and make it adapt to the situation
and return zero if not supported. A small update in the thread dump
function was needed to make sure we don't use its results if it fails
now.
Since commit aade4edc1 ("BUG/MEDIUM: mux-h2: Don't handle pending read0
too early on streams"), we've met a few cases where an early connection
close wouldn't be properly handled if some data were pending in a frame
header, because the test now considers the buffer's contents before
accepting to report the close, but given that frame headers or preface
are consumed at once, the buffer cannot make progress when it's stuck
at intermediary lengths.
In order to address this, this patch introduces two flags in the h2c
connection to store any reported shutdown and failed parsing. The idea
is that we cannot rely on conn_xprt_read0_pending() in the parser since
it wouldn't consider data pending in the buffer nor intermediary layers,
but we know for certain that after a read0 is reported by the transport
layer in presence of an RD_SH on the connection, no more progress will
be made there. This alone is not sufficient to decide to end processing,
we can only do this once these final data have been submitted to a parser.
Therefore, now when a parser fails on missing data, we check if a read0
has already been reported on this connection, and if so we set a new
END_REACHED flag on the connection to indicate a failure to process the
final data. The h2c_read0_pending() function now simply reports this
flag's status. This way we're certain that the input shutdown is only
considered after the demux attempted to parse the last frame.
Maybe over the long term the subscribe() API should be improved to
synchronously fail when trying to subscribe for an even that will not
happen. This may be an elegant solution that could possibly work across
multiple layers and even muxes, and be usable at a few specific places
where that's needed.
Given the patch above was backported as far as 2.0, this one should be
backported there as well. It is possible that the fcgi mux has the same
issue, but this was not analysed yet.
Thanks to Pierre Cheynier for providing detailed traces allowing to
quickly narrow the problem down, and to Olivier for his analysis.
When a TCP to H2 upgrade is performed, the SF_IGNORE flag is set on the
stream before killing it. This happens when a TCP/SSL client connection is
routed to a HTTP backend and the h2 alpn detected. The SF_IGNORE flag was
added for this purpose, to skip some processing when the stream is aborted
before a mux upgrade. Some counters updates were skipped this way. But some
others are still updated.
Now, all counters update at the end of process_stream(), before releasing
the stream, are ignored if SF_IGNORE flag is set. Note this stream is
aborted because we switch from a mono-stream to a multi-stream
multiplexer. It works differently for TCP to H1 upgrades.
This patch should be backported as far as 2.0 after some observation period.
