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.
This patch adds the "maxqueue" parameter to the server. This allows new
sessions to be immediately rebalanced when the server's queue is filled.
It's useful when session stickiness is just a performance boost (even a
huge one) but not a requirement.
This should only be used if session affinity isn't a hard functional
requirement but provides performance boost by keeping server-local
caches hot and compact).
Absence of 'maxqueue' option means unlimited queue. When queue gets filled
up to 'maxqueue' client session is moved from server-local queue to a global
one.
The following patch will give the ability to tweak socket linger mode.
You can use this option with "option nolinger" inside fronted or backend
configuration declaration.
This will help in environments where lots of FIN_WAIT sockets are
encountered.
It is now possible to read error messages from local files,
using the 'errorfile' keyword. Those files are read during
parsing, so there's no I/O involved. They make it possible
to return custom error messages with custom status and headers.
ACLs now support operators such as 'eq', 'le', 'lt', 'ge' and 'gt'
in order to give more flexibility to the language. Because of this
change, the 'dst_limit' keyword changed to 'dst_conn' and now requires
either a range or a test such as 'dst_conn lt 1000' which is more
understandable.
By default, epoll/kqueue used to return as many events as possible.
This could sometimes cause huge latencies (latencies of up to 400 ms
have been observed with many thousands of fds at once). Limiting the
number of events returned also reduces the latency by avoiding too
many blind processing. The value is set to 200 by default and can be
changed in the global section using the tune.maxpollevents parameter.
Peter van Dijk contributed this patch which implements the "smtpchk"
option, which is to SMTP what "httpchk" is to HTTP. By default, it sends
"HELO localhost" to the servers, and waits for the 250 message, but it
can also send a specific request.
The principle behind speculative I/O is to speculatively try to
perform I/O before registering the events in the system. This
considerably reduces the number of calls to epoll_ctl() and
sometimes even epoll_wait(), and manages to increase overall
performance by about 10%.
The new poller has been called "sepoll". It is used by default
on Linux when it works. A corresponding option "nosepoll" and
the command line argument "-ds" allow to disable it.
Patch from Fabrice Dulaunoy. Explanation below, and script
merged in examples/.
This patch allow to put a different address in the check part for each
server (and not only a specific port)
I need this feature because I've a complex settings where, when a specific
farm goes down, I need to switch a set of other farm either if these other
farm behave perfectly well.
For that purpose, I've made a small PERL daemon with some REGEX or PORT
test which allow me to test a bunch of thing.
Patch from Bryan Germann for 1.2.17.
In some circumstances, it is useful not to add the X-Forwarded-For
header, for instance when the client is another reverse-proxy or
stunnel running on the same machine and which already adds it. This
patch adds the "except" keyword to the "forwardfor" option, allowing
to specify an address or network which will not be added to this
header.
Patch from Marcus Rueckert for 1.2.17 :
"I added the attached patch to haproxy. I don't have a static uid/gid for
haproxy so i need to specify the username/groupname to run it as non
root user."
Released 1.3.1 with the following changes from 1.2.15 :
- now, haproxy warns about missing timeout during startup to try to
eliminate all those buggy configurations.
- added "Content-Type: text/html" in responses wherever appropriate, as
suggested by Cameron Simpson.
- implemented "option ssl-hello-chk" to use SSLv3 CLIENT HELLO messages to
test server's health
- implemented "monitor-uri" so that haproxy can reply to a specific URI with
an "HTTP/1.0 200 OK" response. This is useful to validate multiple proxies
at once.
This makes it possible to relay SSL connections in pure TCP instances while
ensuring the remote end really receives our data eventhough intermediate
agents (firewalls, proxies, ...) might acknowledge the connection.
Released 1.2.14 with the following changes :
- new HTML status report with the 'stats' keyword.
- added the 'abortonclose' option to better resist traffic surges
- implemented dynamic traffic regulation with the 'minconn' option
- show request time on denied requests
- definitely fixed hot reconf on OpenBSD by the use of SO_REUSEPORT
- now a proxy instance is allowed to run without servers, which is
useful to dedicate one instance to stats
- added lots of error counters
- a missing parenthesis preventd matching of cacheable cookies
- a missing parenthesis in poll_loop() might have caused missed events.
to 'close', but does not actually close any connection. The problem
is, there are some servers which don't close the connection even if
the proxy tells them 'Connection: close'. A workaround was added by
the way of a new option 'forceclose' (which implies 'httpclose'),
and which makes the proxy close the outgoing channel to the server
once it has sent all its headers. Just don't use this with the
'CONNECT' method of course !
were erroneously load-balanced while the doc said the opposite.
Since load-balanced backup servers is one of the features some
people have been asking for, the problem was fixed to reflect the
documented behaviour and a new option 'allbackups' was introduced
to provide the feature to those who need it.
* second batch of socklen_t changes.
* clean-ups from Cameron Simpson.
* because tv_remain() does not know about eternity, using no timeout can
make select() spin around a null time-out. Bug reported by Cameron Simpson.
* client read timeout was not properly set to eternity initialized after an
accept() if it was not set in the config. It remained undetected so long
because eternity is 0 and newly allocated pages are zeroed by the system.
* do not call get_original_dst() when not in transparent mode.
* implemented a workaround for a bug in certain epoll() implementations on
linux-2.4 kernels (epoll-lt <= 0.21).
* implemented TCP keepalive with new options : tcpka, clitcpka, srvtcpka.
* changed the runtime argument to disable epoll() to '-de'
* changed the runtime argument to disable poll() to '-dp'
* added global options 'nopoll' and 'noepoll' to do the same at the
configuration level.
* added a 'linux24e' target to the Makefile for Linux 2.4 systems patched to
support epoll().
* changed default FD_SETSIZE to 65536 on Solaris (default=1024)
* conditionned signals redirection to #ifdef DEBUG_MEMORY
* implemented the HTTP 303 code for error redirection. This forces the
browser to fetch the given URI with a GET request. The new keyword for
this is 'errorloc303', and a new 'errorloc302' keyword has been created
to make them easily distinguishable.
* added more controls in the parser for valid use of '\x' sequence.
* few fixes from Alex & Klaus
* fixed a few errors in the documentation
* do not pre-initialize unused file-descriptors before select() anymore.
* add an architecture guide to the documentation
* released without any changes
* increased default BUFSIZE to 16 kB to accept max headers of 8 kB which is
compatible with Apache. This limit can be configured in the makefile now.
Thanks to Eric Fehr for the checks.
* added a per-server "source" option which now makes it possible to bind to
a different source for each (potentially identical) server.
* changed cookie-based server selection slightly to allow several servers to
share a same cookie, thus making it possible to associate backup servers to
live servers and ease soft-stop for maintenance periods. (Alexander Lazic)
* added the cookie 'prefix' mode which makes it possible to use persistence
with thin clients which support only one cookie. The server name is prefixed
before the application cookie, and restore back.
* fixed the order of servers within an instance to match documentation. Now
the servers are *really* used in the order of their declaration. This is
particularly important when multiple backup servers are in use.
* fixed a bug where a TCP connection would be logged twice if the 'logasap'
option was enabled without the 'tcplog' option.
* encode_string() would use hdr_encode_map instead of the map argument.
* the logged request is now encoded with '#XX' for unprintable characters
* new keywords 'capture request header' and 'capture response header' enable
logging of arbitrary HTTP headers in requests and responses
* removed "-DSOLARIS" after replacing the last inet_aton() with inet_pton()
* added the '-V' command line option to verbosely report errors even though
the -q or 'quiet' options are specified. This is useful with '-c'.
* added a Red Hat init script and a .spec from Simon Matter <simon.matter@invoca.ch>
* added 'rspdeny' and 'rspideny' to block certain responses to avoid sensible
information leak from servers.
* more examples added into the configuration
* the configurable HTTP health check introduced in 1.1.23 revealed a shameful
bug : the code still assumed that HTTP requests were the same size as the
original ones (22 bytes), and failed if they were not.
* added support for pidfiles.
* added the 'tcplog' option, which provides enhanced, HTTP-like logs for
generic TCP proxies, or lighter logs for HTTP proxies.
* fixed a time-out condition wrongly reported as client time-out in data
phase if the client timeout was lower than the connect timeout times the
number of retries.
* doc: added some precisions about the log timers
* if a client sent a full request then shut its write connection down, then
the request was aborted. This case was detected only when using haproxy
both as health-check client and as a server.
* if 'option httpchk' is used in a 'health' mode server, then responses will
change from 'OK' to 'HTTP/1.0 200 OK'.
* fixed a Linux-only bug in case of HTTP server health-checks, where a single
server response followed by a close could be ignored, and the server seen
as failed.
* renamed 'haproxy.txt' to 'haproxy-fr.txt'
* large documentation and examples cleanups
