We can simplify the code in the stats functions using buffer_feed_chunk()
instead of buffer_write_chunk(). Let's start with this function. This
patch also fixed an issue where we could dump past the end of the capture
buffer if it is shorter than the captured request.
In old versions, before 1.3.16, we had to refresh the timeouts after
each call to process_session() because the stream socket handler did
not do it. Now that the sockets can exchange data for a long period
without calling process_session(), we can detect an old activity and
refresh a timeout long after the last activity, causing too late a
detection of some timeouts.
The fix simply consists in not checking for activity anymore in
stream_sock_data_finish() but only set a timeout if it was not
previously set.
Calling buffer_shutw() marks the buffer as closed but if it was already
closed in the other direction, the stream interface is not marked as
closed, causing infinite loops.
We took this opportunity to completely remove buffer_shutw() and buffer_shutr()
which have no reason to be used at all and which will always cause trouble
when directly called. The stats occurrence was the last one.
By default, when data is sent over a socket, both the write timeout and the
read timeout for that socket are refreshed, because we consider that there is
activity on that socket, and we have no other means of guessing if we should
receive data or not.
While this default behaviour is desirable for almost all applications, there
exists a situation where it is desirable to disable it, and only refresh the
read timeout if there are incoming data. This happens on sessions with large
timeouts and low amounts of exchanged data such as telnet session. If the
server suddenly disappears, the output data accumulates in the system's
socket buffers, both timeouts are correctly refreshed, and there is no way
to know the server does not receive them, so we don't timeout. However, when
the underlying protocol always echoes sent data, it would be enough by itself
to detect the issue using the read timeout. Note that this problem does not
happen with more verbose protocols because data won't accumulate long in the
socket buffers.
When this option is set on the frontend, it will disable read timeout updates
on data sent to the client. There probably is little use of this case. When
the option is set on the backend, it will disable read timeout updates on
data sent to the server. Doing so will typically break large HTTP posts from
slow lines, so use it with caution.
During troubleshooting, it's often useful to get the list of supported
pollers but until now it was required to have a working configuration
first. Since the pollers are known before main() is called, let's list
them with the build options.
The "static-rr" is just the old round-robin algorithm. It is still
in use when a hash algorithm is used and the data to hash is not
present, but it was impossible to configure it explicitly. This one
is cheaper in terms of CPU and supports unlimited numbers of servers,
so it makes sense to be able to use it.
LB algo macros were composed of the LB algo by itself without any indication
of the method to use to look up a server (the lb function itself). This
method was implied by the LB algo, which was not very convenient to add
more algorithms. Now we have several fields in the LB macros, some to
describe what to look for in the requests, some to describe how to transform
that (kind of algo) and some to describe what lookup function to use.
The next patch will make it possible to factor out some code for all algos
which rely on a map.
The lbprm structure has moved to backend.h, where it should be, and
all algo-specific types and declarations have moved to their specific
files. The proxy struct is now much more readable.
This patch implements "description" (proxy and global) and "node" (global)
options, removes "node-name" and adds "show-node" & "show-desc" options
for "stats". It also changes the way the header lines (with proxy name) and
the statistics are displayed, so stats no longer look so clumsy with very
long names.
Instead of "node-name" it is possible to use show-node/show-desc with
an optional parameter that overrides a default node/description.
backend cust-0045
# report specific values for this customer
stats show-node Europe
stats show-desc Master node for Europe, Asia, Africa
We need to remove hash map accesses out of backend.c if we want to
later support new hash methods. This patch separates the hash computation
method from the server lookup. It leaves the lookup function to lb_map.c
and calls it with the result of the hash.
It was becoming painful to have all the LB algos in backend.c.
Let's move them to their own files. A few hashing functions still
need be broken in two parts, one for the contents and one for the
map position.
The code was duplicated serveral times, let's use
server_status_printf() instead.
text data bss dec hex filename
263504 5800 64224 333528 516d8 haproxy-old
262944 5800 64224 332968 514a8 haproxy-new
Depends on "struct chunk rework" and
"Health check reporting code rework + health logging, v3"
Check if rise/fall has an argument and it is > 0 or bad things may happen
in the health checks. ;)
Now it is verified and the code no longer allows for such condition:
backend bad
(...)
server o-f0 192.168.129.27:80 check inter 4000 source 0.0.0.0 rise 0
server o-r0 192.168.129.27:80 check inter 4000 source 0.0.0.0 fall 0
server o-f1 192.168.129.27:80 check inter 4000 source 0.0.0.0 rise
server o-r1 192.168.129.27:80 check inter 4000 source 0.0.0.0 fall
[ALERT] 269/161830 (24136) : parsing [../git/haproxy.cfg:98]: 'rise' has to be > 0.
[ALERT] 269/161830 (24136) : parsing [../git/haproxy.cfg:99]: 'fall' has to be > 0.
[ALERT] 269/161830 (24136) : parsing [../git/haproxy.cfg:100]: 'rise' expects an integer argument.
[ALERT] 269/161830 (24136) : parsing [../git/haproxy.cfg:101]: 'fall' expects an integer argument.
Also add endline in the custom id checking code.
This patch adds health logging so it possible to check what
was happening before a crash. Failed healt checks are logged if
server is UP and succeeded healt checks if server is DOWN,
so the amount of additional information is limited.
I also reworked the code a little:
- check_status_description[] and check_status_info[] is now
joined into check_statuses[]
- set_server_check_status updates not only s->check_status and
s->check_duration but also s->result making the code simpler
Changes in v3:
- for now calculate and use local versions of health/rise/fall/state,
it is a slow path, no harm should be done. One day we may centralize
processing of the checks and remove the duplicated code.
- also log checks that are restoring current state
- use "conditionally succeeded" for 404 with disable-on-404
There is no reason to inline functions which are used to grab a server
depending on an LB algo. They are large and used at several places.
Uninlining them saves 400 bytes of code.
Due to a misplaced call to stream_int_retnclose(), the stats output
buffer was erased before each call to produce_content(), resulting
in missing pieces in the stats output if the connection was not
fast enough between haproxy and the client.
Released version 1.4-dev3 with the following main changes :
- [BUILD] compilation of haproxy-1.4-dev2 on FreeBSD
- [MEDIUM] Collect & show information about last health check, v3
- [MINOR] export the hostname variable so that all the code can access it
- [MINOR] stats: add a new node-name setting
- [MEDIUM] remove old experimental tcpsplice option
- [BUILD] fix build for systems without SOL_TCP
- [MEDIUM] move connection establishment from backend to the SI.
- [MEDIUM] make the global stats socket part of a frontend
- [MEDIUM] session: account per-listener connections
- [MINOR] session: switch to established state if no connect function
- [MEDIUM] make the unix stats sockets use the generic session handler
- [CLEANUP] unix: remove uxst_process_session()
- [CLEANUP] move remaining stats sockets code to dumpstats
- [MINOR] move the initial task's nice value to the listener
- [MINOR] cleanup set_session_backend by using pre-computed analysers
- [MINOR] set s->srv_error according to the analysers
- [MEDIUM] set rep->analysers from fe and be analysers
- [MEDIUM] replace BUFSIZE with buf->size in computations
- [MEDIUM] make it possible to change the buffer size in the configuration
- [MEDIUM] report error on buffer writes larger than buffer size
- [MEDIUM] stream_interface: add and use ->update function to resync
- [CLEANUP] remove ifdef MSG_NOSIGNAL and define it instead
- [MEDIUM] remove TCP_CORK and make use of MSG_MORE instead
- [BUG] tarpit did not work anymore
- [MINOR] acl: add support for hdr_ip to match IP addresses in headers
- [MAJOR] buffers: fix misuse of the BF_SHUTW_NOW flag
- [MINOR] buffers: provide more functions to handle buffer data
- [MEDIUM] buffers: provide new buffer_feed*() function
- [MINOR] buffers: add peekchar and peekline functions for stream interfaces
- [MINOR] buffers: provide buffer_si_putchar() to send a char from a stream interface
- [BUG] buffer_forward() would not correctly consider data already scheduled
- [MINOR] buffers: add buffer_cut_tail() to cut only unsent data
- [MEDIUM] stream_interface: make use of buffer_cut_tail() to report errors
- [MAJOR] http: add support for HTTP 1xx informational responses
- [MINOR] buffers: inline buffer_si_putchar()
- [MAJOR] buffers: split BF_WRITE_ENA into BF_AUTO_CONNECT and BF_AUTO_CLOSE
- [MAJOR] buffers: fix the BF_EMPTY flag's meaning
- [BUG] stream_interface: SI_ST_CLO must have buffers SHUT
- [MINOR] stream_sock: don't set SI_FL_WAIT_DATA if BF_SHUTW_NOW is set
- [MEDIUM] add support for infinite forwarding
- [BUILD] stream_interface: fix conflicting declaration
- [BUG] buffers: buffer_forward() must not always clear BF_OUT_EMPTY
- [BUG] variable buffer size ignored at initialization time
- [MINOR] ensure that buffer_feed() and buffer_skip() set BF_*_PARTIAL
- [BUG] fix buffer_skip() and buffer_si_getline() to correctly handle wrap-arounds
- [MINOR] stream_interface: add SI_FL_DONT_WAKE flag
- [MINOR] stream_interface: add iohandler callback
- [MINOR] stream_interface: add functions to support running as internal/external tasks
- [MEDIUM] session: call iohandler for embedded tasks (applets)
- [MINOR] add a ->private member to the stream_interface
- [MEDIUM] stats: prepare the connection for closing before dumping
- [MEDIUM] stats: replace the stats socket analyser with an SI applet
We can get rid of the stats analyser by moving all the stats code
to a stream interface applet. Above being cleaner, it provides new
advantages such as the ability to process requests and responses
from the same function and work only with simple state machines.
There's no need for any hijack hack anymore.
The direct advantage for the user are the interactive mode and the
ability to chain several commands delimited by a semi-colon. Now if
the user types "prompt", he gets a prompt from which he can send
as many requests as he wants. All outputs are terminated by a
blank line followed by a new prompt, so this can be used from
external tools too.
The code is not very clean, it needs some rework, but some part
of the dirty parts are due to the remnants of the hijack mode used
in the old functions we call.
The old AN_REQ_STATS_SOCK analyser flag is now unused and has been
removed.
We will need to modify the stats dump functions so that they can
be used in interactive mode. For this, we want their caller to
prepare the connection for a close, not themselves to do it.
Let's simply move the stream_int_retnclose() out.
iohandlers will need to store some form of context and for this will
need a way to find their call context. We add the ->private as well
as ->st0 and ->st1 for that purpose. Most likely ->private will be
initialized to the current session and ->st0 and ->st1 will be used
to maintain any form of internal state between calls.
Currently, it's up to process_session() to call the internal tasks
if any are associated to the task being processed. If such a task
is referenced, we don't use ->update() in process_session(), but
only ->iohandler(), which itself is free to use ->update() to
complete its work.
It it also important to understand that an I/O handler may wake the
task up again, for instance because it tries to send data to the
other stream interface, which itself will wake the task up. So
after returning from ->iohandler(), we must check if the task has
been sent back to the runqueue, and if so, immediately return.
It will soon be necessary to have stream interfaces running as part of
the current task, or as independant tasks. For instance when we want to
implement compression or SSL. It will also be used for applets running
as stream interfaces.
These new functions are used to perform exactly that. Note that it's
still not easy to write a simple echo applet and more functions will
likely be needed.
When stream interfaces will embedded applets running as part as their
holding task, we'll need a new callback to process them from the
session processor.
We had to add a new stream_interface flag : SI_FL_DONT_WAKE. This flag
is used to indicate that a stream interface is being updated and that
no wake up should be sent to its owner. This will be required for tasks
embedded into stream interfaces. Otherwise, we could have the
owner task send wakeups to itself during status updates, thus
preventing the state from converging. As long as a stream_interface's
status is being monitored and adjusted, there is no reason to wake it
up again, as we know its changes will be seen and considered.
Those two functions did not correctly deal with full buffers and/or
buffers that wrapped around. Buffer_skip() was even able to incorrectly
set buf->w further than the end of buffer if its len argument was wrong,
and buffer_si_getline() was able to incorrectly return a length larger
than the effective buffer data available.
It's important that these functions set these flags themselves, otherwise
the callers will always have to do this, and there is no valid reason for
not doing it.
Commit 27a674efb8 introduced the ability
to configure buffer sizes. Unfortunately, the pool was created before
the conf was read, so that is was always set to the default size.
In order to fix that, we delay the call to init_buffer(), which is not
a problem since nothing uses it during the initialization.
Collect information about last health check result,
including L7 code if possible (for example http or smtp
return code) and time took to finish last check.
Health check info is provided on both stats pages (html & csv)
and logged when a server is marked UP or DOWN. Currently active
check are marked with an asterisk, but only in html mode.
Currently there are 14 status codes:
UNK -> unknown
INI -> initializing
SOCKERR -> socket error
L4OK -> check passed on layer 4, no upper layers testing enabled
L4TOUT -> layer 1-4 timeout
L4CON -> layer 1-4 connection problem, for example "Connection refused"
(tcp rst) or "No route to host" (icmp)
L6OK -> check passed on layer 6
L6TOUT -> layer 6 (SSL) timeout
L6RSP -> layer 6 invalid response - protocol error
L7OK -> check passed on layer 7
L7OKC -> check conditionally passed on layer 7, for example
404 with disable-on-404
L7TOUT -> layer 7 (HTTP/SMTP) timeout
L7RSP -> layer 7 invalid response - protocol error
L7STS -> layer 7 response error, for example HTTP 5xx
In TCP, we don't want to forward chunks of data, we want to forward
indefinitely. This patch introduces a special value for the amount
of data to be forwarded. When buffer_forward() is called with
BUF_INFINITE_FORWARD, it configures the buffer to never stop
forwarding until the end.
An abort during a connect would go to the SI_ST_CLO state without
the buffers shut. This was causing some sessions to never end if
they would abort before the connect request was initiated. This
bug has been introduced after 1.4-dev2.
The doc has been extended to reflect that too.
The BF_EMPTY flag was once used to indicate an empty buffer. However,
it was used half the time as meaning the buffer is empty for the reader,
and half the time as meaning there is nothing left to send.
"nothing to send" is only indicated by "->send_max=0 && !pipe". Once
we fix this, we discover that the flag is not used anymore. So the
flags has been renamed BF_OUT_EMPTY and means exactly the condition
above, ie, there is nothing to send.
Doing so has allowed us to remove some unused tests for emptiness,
but also to uncover a certain amount of situations where the flag
was not correctly set or tested.
The BF_WRITE_ENA buffer flag became very complex to deal with, because
it was used to :
- enable automatic connection
- enable close forwarding
- enable data forwarding
The last point was not very true anymore since we introduced ->send_max,
but still the test remained everywhere. This was causing issues such as
impossibility to connect without forwarding data, impossibility to prevent
closing when data was forwarded, etc...
This patch clarifies the situation by getting rid of this multi-purpose
flag and replacing it with :
- data forwarding based only on ->send_max || ->pipe ;
- a new BF_AUTO_CONNECT flag to allow automatic connection and only
that ;
- ability to perform an automatic connection when ->send_max or ->pipe
indicate that data is waiting to leave the buffer ;
- a new BF_AUTO_CLOSE flag to let the producer automatically set the
BF_SHUTW_NOW flag when it gets a BF_SHUTR.
During this cleanup, it was discovered that some tests were performed
twice, or that the BF_HIJACK flag was still tested, which is not needed
anymore since ->send_max replcaed it. These places have been fixed too.
These cleanups have also revealed a few areas where the other flags
such as BF_EMPTY are not cleanly used. This will be an opportunity for
a second patch.
By inlining this function and slightly reordering it, we can double
the getchar/putchar test throughput, and reduce its footprint by about
40 bytes. Also, it was the only non-inlined char-based function, which
now makes it more consistent this time.
HTTP supports status codes 100 and 101 to report protocol indications,
which are followed by the requests's response. Till now, haproxy would
only see those responses without parsing subsequent ones. That means
that cookie additions were only performed on 1xx messages for instance,
which does not work since headers must be ignored with 1xx messages.
Also, logs were not terribly useful with the common 100 status code
in response to "Expect: 100-continue" during POST some requests.
This change adds support for such messages. Now haproxy sees them,
forwards them and skips them until it finds a correct response, which
it logs and processes. As an exception, header removal/rewriting still
work on 1xx responses in order to be able to strip out sensible
information that may have accidentely been left by another equipment
(possibly an older haproxy itself). But headers addition are disabled
however.
This change brings the ability to loop on response without data, which
is a starting point to support keepalive. The change is marked as major
as a few fixes had to be performed in the HTTP message parser.
The stream_int_return() function used to call buffer_erase() on the response
buffer, which completely wipes it without taking care about whatever could
have been there. Now we more carefully strip only data not scheduled to be
sent.
This function is used to cut the "tail" of a buffer, which means strip it
to the length of unsent data only, and kill any remaining unsent data. Any
scheduled forwarding is stopped. This is mainly to be used to send error
messages after existing data. It does the same as buffer_erase() for buffers
without pending outgoing data.
The computations in buffer_forward() were only valid if buffer_forward()
was used on a buffer which had no more data scheduled for forwarding.
This is always the case right now so this bug is not yet triggered but
it will soon be. Now we correctly discount the bytes to be forwarded
from the data already present in the buffer.
This function works like a traditional putchar() except that it
can return 0 if the output buffer is full.
Now a basic character-based echo function would look like this, from
a stream interface :
while (1) {
c = buffer_si_peekchar(req);
if (c < 0)
break;
if (!buffer_si_putchar(res, c)) {
si->flags |= SI_FL_WAIT_ROOM;
break;
}
buffer_skip(req, 1);
req->flags |= BF_WRITE_PARTIAL;
res->flags |= BF_READ_PARTIAL;
}
