HAproxy 1.3.12

HA-Proxy is a TCP/HTTP reverse proxy which is particularly suited for high
availability environments. Indeed, it can :
- route HTTP requests depending on statically assigned cookies ;
- spread the load among several servers while assuring server persistence through the use of HTTP cookies ;
- switch to backup servers in the event a main one fails ;
- accept connections to special ports dedicated to service monitoring ;
- stop accepting connections without breaking existing ones ;
- add/modify/delete HTTP headers both ways ;
- block requests matching a particular pattern ;
It needs very little resource. HAproxy it is event-driven architecture allows it to easily
handle thousands of simultaneous connections on hundreds of instances without risking the systems stability.
Start parameters
There are only a few command line options :
-f < configuration file >
-n < high limit for the total number of simultaneous connections >
-N < high limit for the per-proxy number of simultaneous connections >
-d starts in foregreound with debugging mode enabled
-D starts in daemon mode
-q disable messages on output
-V displays messages on output even when -q or quiet are specified.
-c only checks config file and exits with code 0 if no error was found, or exits with code 1 if a syntax error was found.
-p < pidfile > asks the process to write down each of its childrens pids to this file in daemon mode.
-s shows statistics (only if compiled in)
-l shows even more statistics (implies -s)
The maximal number of connections per proxy is used as the default parameter for each instance for which the maxconn paramter is not set in the listen section.
The maximal number of total connections limits the number of connections used by the whole process if the maxconn parameter is not set in the global section.
The debugging mode has the same effect as the debug option in the global section. When the proxy runs in this mode, it dumps every connections, disconnections, timestamps, and HTTP headers to stdout. This should NEVER be used in an init script since it will prevent the system from starting up.
Statistics are only available if compiled in with the STATTIME option. Its only used during code optimization phases.
Enhancements:
- Content switching is now fully operational using ACLs.
- ACLs can look for matches in path and headers in addition to previously supported criteria.
- Integer comparison is now supported for header values. 15 pre-defined ACLs are provided.
- Error pages can be customized using external files.
- Several bugs have been fixed.
- This version will be maintained as a stable one during further development.