Commit Graph

134 Commits

Author SHA1 Message Date
Willy Tarreau
58393e103f [MEDIUM] acl: get rid of dummy values in always_true/always_false
make use of last change in order to get rid of dummy values in
always_true/always_false.
2008-07-20 10:39:22 +02:00
Willy Tarreau
c6317703ce [MINOR] acl: add REQ_CONTENT to the list of default acls
With content inspection, checking the presence of data in the
request buffer is very important. It's getting boring to always
add such an ACL, so let's add it by default.
2008-07-20 09:29:50 +02:00
Willy Tarreau
62644770cf [DOC] document the new "tcp-request" keyword and associated ACLs
The update concerns :
  - tcp-request inspect-delay
  - tcp-request accept
  - tcp-request reject
  - acl ... req_len
  - acl ... req_ssl_ver
2008-07-16 18:36:06 +02:00
Willy Tarreau
e5c5ce970f [DOC] documentation for the "retries" parameter was missing. 2008-06-20 17:27:19 +02:00
Willy Tarreau
b463dfb2de [MEDIUM] add support for conditional HTTP redirection
A new "redirect" keyword adds the ability to send an HTTP 301/302/303
redirection to either an absolute location or to a prefix followed by
the original URI. The redirection is conditionned by ACL rules, so it
becomes very easy to move parts of a site to another site using this.

This work was almost entirely done at Exceliance by Emeric Brun.

A test-case has been added in the tests/ directory.
2008-06-07 23:08:56 +02:00
Krzysztof Piotr Oledzki
efe3b6f524 [MINOR] Allow to specify a domain for a cookie
This patch allows to specify a domain used when inserting a cookie
providing a session stickiness. Usefull for example with wildcard domains.

The patch adds one new variable to the struct proxy: cookiedomain.
When set the domain is appended to a Set-Cookie header.

Domain name is validated using the new invalid_domainchar() function.
It is basically invalid_char() limited to [A-Za-z0-9_.-]. Yes, the test
is too trivial and does not cover all wrong situations, but the main
purpose is to detect most common mistakes, not intentional abuses.

The underscore ("_") character is not RFC-valid but as it is
often (mis)used so I decided to allow it.
2008-05-25 10:09:02 +02:00
Marek Majkowski
9c30fc161f [MEDIUM] add support for URI hash depth and length limits
This patch adds two optional arguments "len" and "depth" to
"balance uri". They are used to limit the length in characters
of the analysis, as well as the number of directory components
it applies to.
2008-04-28 00:43:55 +02:00
Willy Tarreau
7b4c5aee55 [RELEASE] Released version 1.3.15
Released version 1.3.15 with the following main changes :
    - [BUILD] Added support for 'make install'
    - [BUILD] Added 'install-man' make target for installing the man page
    - [BUILD] Added 'install-bin' make target
    - [BUILD] Added 'install-doc' make target
    - [BUILD] Removed "/" after '$(DESTDIR)' in install targets
    - [BUILD] Changed 'install' target to install the binaries first
    - [BUILD] Replace hardcoded 'LD = gcc' with 'LD = $(CC)'
    - [MEDIUM]: Inversion for options
    - [MEDIUM]: Count retries and redispatches also for servers, fix redistribute_pending, extend logs, %d->%u cleanup
    - [BUG]: Restore clearing t->logs.bytes
    - [MEDIUM]: rework checks handling
    - [DOC] Update a "contrib" file with a hint about a scheme used for formathing subjects
    - [MEDIUM] Implement "track [<backend>/]<server>"
    - [MINOR] Implement persistent id for proxies and servers
    - [BUG] Don't increment server connections too much + fix retries
    - [MEDIUM]: Prevent redispatcher from selecting the same server, version #3
    - [MAJOR] proto_uxst rework -> SNMP support
    - [BUG] appsession lookup in URL does not work
    - [BUG] transparent proxy address was ignored in backend
    - [BUG] hot reconfiguration failed because of a wrong error check
    - [DOC] big update to the configuration manual
    - [DOC] large update to the configuration manual
    - [DOC] document more options
    - [BUILD] major rework of the GNU Makefile
    - [STATS] add support for "show info" on the unix socket
    - [DOC] document options forwardfor to logasap
    - [MINOR] add support for the "backlog" parameter
    - [OPTIM] introduce global parameter "tune.maxaccept"
    - [MEDIUM] introduce "timeout http-request" in frontends
    - [MINOR] tarpit timeout is also allowed in backends
    - [BUG] increment server connections for each connect()
    - [MEDIUM] add a turn-around state of one second after a connection failure
    - [BUG] fix typo in redispatched connection
    - [DOC] document options nolinger to ssl-hello-chk
    - [DOC] added documentation for "option tcplog" to "use_backend"
    - [BUG] connect_server: server might not exist when sending error report
    - [MEDIUM] support fully transparent proxy on Linux (USE_LINUX_TPROXY)
    - [MEDIUM] add non-local bind to connect() on Linux
    - [MINOR] add transparent proxy support for balabit's Tproxy v4
    - [BUG] use backend's source and not server's source with tproxy
    - [BUG] fix overlapping server flags
    - [MEDIUM] fix server health checks source address selection
    - [BUG] build failed on CONFIG_HAP_LINUX_TPROXY without CONFIG_HAP_CTTPROXY
    - [DOC] added "server", "source" and "stats" keywords
    - [DOC] all server parameters have been documented
    - [DOC] document all req* and rsp* keywords.
    - [DOC] added documentation about HTTP header manipulations
    - [BUG] log response byte count, not request
    - [BUILD] code did not build in full debug mode
    - [BUG] fix truncated responses with sepoll
    - [MINOR] use s->frt_addr as the server's address in transparent proxy
    - [MINOR] fix configuration hint about timeouts
    - [DOC] minor cleanup of the doc and notice to contributors
    - [MINOR] report correct section type for unknown keywords.
    - [BUILD] update MacOS Makefile to build on newer versions
    - [DOC] fix erroneous "useallbackups" option in the doc
    - [DOC] applied small fixes from early readers
    - [MINOR] add configuration support for "redir" server keyword
    - [MEDIUM] completely implement the server redirection method
    - [TESTS] add a test case for the server redirection mechanism
    - [DOC] add a configuration entry for "server ... redir <prefix>"
    - [BUILD] backend.c and checks.c did not build without tproxy !
    - Revert "[BUILD] backend.c and checks.c did not build without tproxy !"
    - [BUILD] backend.c and checks.c did not build without tproxy !
    - [OPTIM] used unsigned ints for HTTP state and message offsets
    - [OPTIM] GCC4's builtin_expect() is suboptimal
    - [BUG] failed conns were sometimes incremented in the frontend!
    - [BUG] timeout.check was not pre-set to eternity
    - [TESTS] add test-pollers.cfg to easily report pollers in use
    - [BUG] do not apply timeout.connect in checks if unset
    - [BUILD] ensure that makefile understands USE_DLMALLOC=1
    - [MINOR] silent gcc for a wrong warning
    - [CLEANUP] update .gitignore to ignore more temporary files
    - [CLEANUP] report dlmalloc's source path only if explictly specified
    - [BUG] str2sun could leak a small buffer in case of error during parsing
    - [BUG] option allbackups was not working anymore in roundrobin mode
    - [MAJOR] implementation of the "leastconn" load balancing algorithm
    - [BUILD] ensure that users don't build without setting the target anymore.
    - [DOC] document the leastconn LB algo
    - [MEDIUM] fix stats socket limitation to 16 kB
    - [DOC] fix unescaped space in httpchk example.
    - [BUG] fix double-decrement of server connections
    - [TESTS] add a test case for port mapping
    - [TESTS] add a benchmark for integer hashing
    - [TESTS] add new methods in ip-hash test file
    - [MAJOR] implement parameter hashing for POST requests
2008-04-19 21:25:12 +02:00
matt.farnsworth@nokia.com
1c2ab96be5 [MAJOR] implement parameter hashing for POST requests
This patch extends the "url_param" load balancing method by introducing
the "check_post" option. Using this option enables analysis of the beginning
of POST requests to search for the specified URL parameter.

The patch also fixes a few minor typos in comments that were discovered
during code review.
2008-04-15 15:30:41 +02:00
Willy Tarreau
ebaf21af95 [DOC] fix unescaped space in httpchk example.
Lars Braeuer reported a missing space in the example which drives
readers in wrong direction.
2008-03-21 20:18:01 +01:00
Willy Tarreau
2d2a7f8fbc [DOC] document the leastconn LB algo 2008-03-17 12:08:13 +01:00
Krzysztof Piotr Oledzki
2c6962c3c0 [MAJOR] proto_uxst rework -> SNMP support
Currently there is a ~16KB limit for a data size passed via unix socket.
It is caused by a trivial bug ttat is going to fixed soon, however
in most cases there is no need to dump a full stats.

This patch makes possible to select a scope of dumped data by extending
current "show stat" to "show stat [<iid> <type> <sid>]":
 - iid is a proxy id, -1 to dump all proxies
 - type selects type of dumpable objects: 1 for frontend, 2 for backend, 4 for
   server, -1 for all types. Values can be ORed, for example:
     1+2=3   -> frontend+backend.
     1+2+4=7 -> frontend+backend+server.
 - sid is a service id, -1 to dump everything from the selected proxy.

To do this I implemented a new session flag (SN_STAT_BOUND), added three
variables in data_ctx.stats (iid, type, sid), modified dumpstats.c and
completely revorked the process_uxst_stats: now it waits for a "\n"
terminated string, splits args and uses them. BTW: It should be quite easy
to add new commands, for example to enable/disable servers, the only problem
I can see is a not very lucky config name (*stats* socket). :|

During the work I also fixed two bug:
 - s->flags were not initialized for proto_uxst
 - missing comma if throttling not enabled (caused by a stupid change in
     "Implement persistent id for proxies and servers")

Other changes:
 - No more magic type valuse, use STATS_TYPE_FE/STATS_TYPE_BE/STATS_TYPE_SV
 - Don't memset full s->data_ctx (it was clearing s->data_ctx.stats.{iid/type/sid},
    instead initialize stats.sv & stats.sv_st (stats.px and stats.px_st were already
    initialized)

With all that changes it was extremely easy to write a short perl plugin
for a perl-enabled net-snmp (also included in this patch).

29385 is my PEN (Private Enterprise Number) and I'm willing to donate
the SNMPv2-SMI::enterprises.29385.106.* OIDs for HAProxy if there
is nothing assigned already.
2008-03-04 06:32:16 +01:00
Krzysztof Piotr Oledzki
f58a962247 [MINOR] Implement persistent id for proxies and servers
This patch adds a possibility to set a persistent id for a proxy/server.
Now, even if some proxies/servers are inserted/deleted/moved, iids and
sids can be still used reliable.

Some people add servers with tricky names (BACKEND or FRONTEND for example).
So I also added one more field ('type') to distinguish between a
backend (0), frontend (1) and server (2) without complicated logic:
if name==BACKEND and sid==0 then type is BACKEND else type is SERVER,
etc for a FRONTEND. It also makes possible to have one frontend with more
than one IP (a patch coming soon) with independed stats - for example to
differs between remote and local traffic.

Finally, I added documentation about the CSV format.

This patch depends on '[MEDIUM] Implement "track [<backend>/]<server>"'
2008-02-28 17:23:59 +01:00
Krzysztof Piotr Oledzki
c8b16fc948 [MEDIUM] Implement "track [<backend>/]<server>"
This patch implements ability to set the current state of one server
by tracking another one. It:
 - adds two variables: *tracknext, *tracked to struct server
 - implements findserver(), similar to findproxy()
 - adds "track" keyword accepting both "proxy/server" and "server" (assuming current proxy)
 - verifies if both checks and tracking is not enabled at the same time
 - changes set_server_down() to notify tracking server
 - creates set_server_up(), set_server_disabled(), set_server_enabled() by
   moving the code from process_chk() and adding notifications
 - changes stats to show a name of tracked server instead of Chk/Dwn/Dwntime(html)
   or by adding new variable (csv)

Changes from the previuos version:
 - it is possibile to track independently of the declaration order
 - one extra comma bug is fixed
 - new condition to check if there is no disable-on-404 inconsistency
2008-02-27 10:39:53 +01:00
Willy Tarreau
21d2af3e9f Revert "[BUILD] backend.c and checks.c did not build without tproxy !"
This reverts commit 3c3c0122f8.
This commit was buggy as it also removed previous tproxy changes !
2008-02-14 20:25:24 +01:00
Willy Tarreau
3c3c0122f8 [BUILD] backend.c and checks.c did not build without tproxy !
missing #ifdefs.
2008-02-13 22:22:56 +01:00
Willy Tarreau
5c7bf79814 [DOC] add a configuration entry for "server ... redir <prefix>" 2008-02-13 01:07:57 +01:00
Willy Tarreau
d2a4aa2c09 [DOC] applied small fixes from early readers 2008-02-13 00:53:50 +01:00
Willy Tarreau
af85d944ea [DOC] fix erroneous "useallbackups" option in the doc 2008-02-13 00:53:45 +01:00
Willy Tarreau
41a340d7c8 [DOC] minor cleanup of the doc and notice to contributors 2008-01-22 12:25:31 +01:00
Krzysztof Piotr Oledzki
5259dfedd1 [MEDIUM]: rework checks handling
This patch adds two new variables: fastinter and downinter.
When server state is:
 - non-transitionally UP -> inter (no change)
 - transitionally UP (going down), unchecked or transitionally DOWN (going up) -> fastinter
 - down -> downinter

It allows to set something like:
        server sr6 127.0.51.61:80 cookie s6 check inter 10000 downinter 20000 fastinter 500 fall 3 weight 40
In the above example haproxy uses 10000ms between checks but as soon as
one check fails fastinter (500ms) is used. If server is down
downinter (20000) is used or fastinter (500ms) if one check pass.
Fastinter is also used when haproxy starts.

New "timeout.check" variable was added, if set haproxy uses it as an additional
read timeout, but only after a connection has been already established. I was
thinking about using "timeout.server" here but most people set this
with an addition reserve but still want checks to kick out laggy servers.
Please also note that in most cases check request is much simpler
and faster to handle than normal requests so this timeout should be smaller.

I also changed the timeout used for check connections establishing.

Changes from the previous version:
 - use tv_isset() to check if the timeout is set,
 - use min("timeout connect", "inter") but only if "timeout check" is set
   as this min alone may be to short for full (connect + read) check,
 - debug code (fprintf) commented/removed
 - documentation

Compile tested only (sorry!) as I'm currently traveling but changes
are rather small and trivial.
2008-01-22 11:29:06 +01:00
Willy Tarreau
ced27013b6 [DOC] added documentation about HTTP header manipulations
This section has been inserted before the logging section.
2008-01-17 20:35:34 +01:00
Willy Tarreau
303c035725 [DOC] document all req* and rsp* keywords. 2008-01-17 19:01:39 +01:00
Willy Tarreau
198a744e1d [DOC] all server parameters have been documented 2008-01-17 12:05:32 +01:00
Willy Tarreau
eabeafaa21 [DOC] added "server", "source" and "stats" keywords
The documentation now lists all keywords except the req* and rsp*. The
"server" keyword has been documented for mandatory parameters. Specific
settings are still waiting to be written in a dedicated section.
2008-01-16 16:17:06 +01:00
Willy Tarreau
b1e52e8c44 [MEDIUM] support fully transparent proxy on Linux (USE_LINUX_TPROXY)
Using some Linux kernel patches, it is possible to redirect non-local
traffic to local sockets when IP forwarding is enabled. In order to
enable this option, we introduce the "transparent" option keyword on
the "bind" command line. It will make the socket reachable by remote
sources even if the destination address does not belong to the machine.
2008-01-13 14:49:51 +01:00
Willy Tarreau
844e3c53da [DOC] added documentation for "option tcplog" to "use_backend"
- options tcplog, tcpsplice and transparent have been documented.
- keywords "srvtimeout", "timeout queue", "timeout server" and
  "timeout tarpit" have been documented
- keywords "transparent" and "use_backend" have been documented

Only "server", "source" and "stats *" remain undocumented
2008-01-11 16:28:18 +01:00
Willy Tarreau
a453bddac2 [DOC] document options nolinger to ssl-hello-chk
Options nolinger, persist, smtpchk and ssl-hello-chk have been
documented. All keywords and options up to and including option
tcpka are now documented.
2008-01-08 19:50:52 +01:00
Krzysztof Piotr Oledzki
25b501a6b1 [MEDIUM]: Count retries and redispatches also for servers, fix redistribute_pending, extend logs, %d->%u cleanup
This patch extends a little previously added functionality to also
count retries and redispatches for servers. Now it is possible to know
which server causes redispatches as it is not always the same that takes
most retries.

While working with the code I found that redistribute_pending() does not increment
srv->redispatches && be->redispatches. I don't know how to test it but
I think the fix is correct. If not I can withdraw it.

I also extended logs to show how many retries were done and if redispatching
was necessary ('+'). I'm using an additional session flag SN_REDISP to match
redispatched connections. I had to rearrange all defines in session.h to make
more room for it.

The documentation about logs was also fixed a little (sorry, english only),
as current version uses totally different format. BTW: examples are still
outdated, maybe next time...

Finally, I changed %d -> %u for retries/redispatches as those variables
are declared as unsigned.
2008-01-06 16:43:05 +01:00
Willy Tarreau
51c9bde060 [MINOR] tarpit timeout is also allowed in backends
Since the tarpit action may be set in backends too, its timeout
must be configurable there.
2008-01-06 13:40:03 +01:00
Willy Tarreau
036fae0ec9 [MEDIUM] introduce "timeout http-request" in frontends
In order to offer DoS protection, it may be required to lower the maximum
accepted time to receive a complete HTTP request without affecting the client
timeout. This helps protecting against established connections on which
nothing is sent. The client timeout cannot offer a good protection against
this abuse because it is an inactivity timeout, which means that if the
attacker sends one character every now and then, the timeout will not
trigger. With the HTTP request timeout, no matter what speed the client
types, the request will be aborted if it does not complete in time.
2008-01-06 13:24:40 +01:00
Willy Tarreau
a0250ba38d [OPTIM] introduce global parameter "tune.maxaccept"
This new parameter makes it possible to override the default
number of consecutive incoming connections which can be
accepted on a socket. By default it is not limited on single
process mode, and limited to 8 in multi-process mode.
2008-01-06 11:22:57 +01:00
Willy Tarreau
c73ce2b111 [MINOR] add support for the "backlog" parameter
Add the "backlog" parameter to frontends, to give hints to
the system about the approximate listen backlog desired size.

In order to protect against SYN flood attacks, one solution is
to increase the system's SYN backlog size. Depending on the
system, sometimes it is just tunable via a system parameter,
sometimes it is not adjustable at all, and sometimes the system
relies on hints given by the application at the time of the
listen() syscall. By default, HAProxy passes the frontend's
maxconn value to the listen() syscall. On systems which can
make use of this value, it can sometimes be useful to be able
to specify a different value, hence this backlog parameter.
2008-01-06 10:55:10 +01:00
Willy Tarreau
c27debfe56 [DOC] document options forwardfor to logasap
Options forwardfor, http_proxy, httpchk, httpclose, httplog and logasap
have been documented.
2008-01-06 08:57:02 +01:00
Willy Tarreau
a8efd362b2 [STATS] add support for "show info" on the unix socket
It is sometimes required to know some informations such as the
process uptime when consulting statistics. This patch adds the
"show info" command to query those informations on the UNIX
socket.
2008-01-03 10:19:15 +01:00
Willy Tarreau
bf1f816ecf [DOC] document more options
All options up to and including "forceclose" have been documented.
2007-12-28 17:42:56 +01:00
Willy Tarreau
2769aa050a [DOC] large update to the configuration manual
Keywords from "errorloc" to "monitor-uri" inclusive have been added.
Some fixes applied too.
2007-12-27 18:26:09 +01:00
Krzysztof Oledzki
336d475d13 [MEDIUM]: Inversion for options
This patch adds a possibility to invert most of available options by
introducing the "no" keyword, available as an additional prefix.
If it is found arguments are shifted left and an additional flag (inv)
is set.

It allows to use all options from a current defaults section, except
the selected ones, for example:

-- cut here --
defaults
        contimeout      4200
        clitimeout      50000
        srvtimeout      40000
        option contstats

listen stats 1.2.3.4:80
	no option contstats
-- cut here --

Currenly inversion works only with the "option" keyword.

The patch also moves last_checks calculation at the end of the readcfgfile()
function and changes "PR_O_FORCE_CLO | PR_O_HTTP_CLOSE" into "PR_O_FORCE_CLO"
in cfg_opts so it is possible to invert forceclose without breaking httpclose
(and vice versa) and to invert tcpsplice in one proxy but to keep a proper
last_checks value when tcpsplice is used in another proxy. Now, the code
checks for PR_O_FORCE_CLO everywhere it checks for PR_O_HTTP_CLOSE.

I also decided to depreciate "redisp" and "redispatch" keywords as it is IMHO
better to use "option redispatch" which can be inverted.

Some useful documentation were added and at the same time I sorted
(alfabetically) all valid options both in the code and the documentation.
2007-12-27 11:52:06 +01:00
Willy Tarreau
0ba2750591 [DOC] big update to the configuration manual
New in this version is a small intro to HTTP, then a detailed
explanation of the following keywords :

  acl, appsession, balance, bind, block, capture cookie,
  capture request header, capture response header, clitimeout,
  contimeout, cookie, default_backend, disabled, enabled, errorfile,
  http-check disable-on-404, monitor fail, option contstats,
  timeout client, timeout clitimeout, timeout connect,
  timeout contimeout.

Others will be alphabetically added.
2007-12-24 16:55:16 +01:00
Robert Tsai
81ae1953bf [MEDIUM] add support for logging via a UNIX socket
The code in haproxy-1.3.13.1 only supports syslogging to an internet
address. The attached patch:

 - Adds support for syslogging to a UNIX domain socket (e.g., /dev/log).
   If the address field begins with '/' (absolute file path), then
   AF_UNIX is used to construct the socket. Otherwise, AF_INET is used.

 - Achieves clean single-source build on both Mac OS X and Linux
   (sockaddr_in.sin_len and sockaddr_un.sun_len field aren't always present).

For handling sendto() failures in send_log(), it appears that the existing
code is fine (no need to close/recreate socket) for both UDP and UNIX-domain
syslog server. So I left things alone (did not close/recreate socket).
Closing/recreating socket after each failure would also work, but would lead
to increased amount of unnecessary socket creation/destruction if syslog is
temporarily unavailable for some reason (especially for verbose loggers).

Please consider this patch for inclusion into the upstream haproxy codebase.
2007-12-05 10:47:29 +01:00
Willy Tarreau
e219db7a46 [MEDIUM] introduce the "timeout" keyword
A new "timeout" keyword replaces old "{con|cli|srv}timeout", and
provides the ability to independantly set the following timeouts :

  - client
  - tarpit
  - queue
  - connect
  - server
  - appsession

Additionally, the "clitimeout", "contimeout" and "srvtimeout" values
are supported but deprecated. No warning is emitted yet when they are
used since the option is very new.

Other timeouts should follow soon now.
2007-12-03 01:30:13 +01:00
Willy Tarreau
befdff11aa [DOC] add a bit of documentation about timers 2007-12-02 22:27:38 +01:00
Willy Tarreau
c7246fcdf3 [DOC] document "nbsrv" and "monitor fail" 2007-12-02 17:31:20 +01:00
Willy Tarreau
5764b38c38 [DOC] document the server's slowstart parameter 2007-11-30 17:46:49 +01:00
Willy Tarreau
dbc36f6e44 [DOC] document the "http-check disable-on-404" option 2007-11-30 12:29:11 +01:00
Alexandre Cassen
5eb1a9033a [MEDIUM] New option http_proxy
Hello,

You will find attached an updated release of previously submitted patch.
It polish some part and extend ACL engine to match IP and PORT parsed in
HTTP request. (and take care of comments made by Willy ! ;))

Best regards,
Alexandre
2007-11-29 15:43:32 +01:00
Willy Tarreau
f56fd8a285 [BUILD] make ebtree headers multiple-include compatible
ebtree did not support being included multiple times.
2007-11-28 14:23:05 +01:00
Willy Tarreau
e6d2e4dbdf [MINOR] merge ebtree version 3.0
Version 3.0 of ebtree has been merged in but is not used yet.
2007-11-28 14:20:44 +01:00
Krzysztof Piotr Oledzki
583bc96606 [MEDIUM] continous statistics
By default, counters used for statistics calculation are incremented
only when a session finishes. It works quite well when serving small
objects, but with big ones (for example large images or archives) or
with A/V streaming, a graph generated from haproxy counters looks like
a hedgehog.

This patch implements a contstats (continous statistics) option.
When set counters get incremented continuously, during a whole session.
Recounting touches a hotpath directly so it is not enabled by default,
as it has small performance impact (~0.5%).
2007-11-26 20:21:47 +01:00
Willy Tarreau
0173280bfa [MEDIUM] introduce the "url_param" balance method
Some applications do not have a strict persistence requirement, yet
it is still desirable for performance considerations, due to local
caches on the servers. For some reasons, there are some applications
which cannot rely on cookies, and for which the last resort is to use
a parameter passed in the URL.

The new 'url_param' balance method is there to solve this issue. It
accepts a parameter name which is looked up from the URL and which
is then hashed to select a server. If the parameter is not found,
then the round robin algorithm is used in order to provide a normal
load balancing across the servers for the first requests. It would
have been possible to use a source IP hash instead, but since such
applications are generally buried behind multiple levels of
reverse-proxies, it would not provide a good balance.

The doc has been updated, and two regression testing configurations
have been added.
2007-11-01 23:05:09 +01:00