[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.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 4a7c080..79fe2fa 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -6490,27 +6490,35 @@
-------------------------
The following commands are supported on the UNIX stats socket ; all of them
-must be terminated by a line feed. It is important to understand that when
-multiple haproxy processes are started on the same sockets, any process may
-pick up the request and will output its own stats.
+must be terminated by a line feed. The socket supports pipelining, so that it
+is possible to chain multiple commands at once provided they are delimited by
+a semi-colon or a line feed, although the former is more reliable as it has no
+risk of being truncated over the network. The responses themselves will each be
+followed by an empty line, so it will be easy for an external script to match a
+given response with a given request. By default one command line is processed
+then the connection closes, but there is an interactive allowing multiple lines
+to be issued one at a time.
-show stat [<iid> <type> <sid>]
- Dump statistics in the CSV format. By passing <id>, <type> and <sid>, it is
- possible to dump only selected items :
- - <iid> is a proxy ID, -1 to dump everything
- - <type> selects the type of dumpable objects : 1 for frontends, 2 for
- backends, 4 for servers, -1 for everything. These values can be ORed,
- for example:
- 1 + 2 = 3 -> frontend + backend.
- 1 + 2 + 4 = 7 -> frontend + backend + server.
- - <sid> is a server ID, -1 to dump everything from the selected proxy.
+It is important to understand that when multiple haproxy processes are started
+on the same sockets, any process may pick up the request and will output its
+own stats.
-show info
- Dump info about haproxy status on current process.
+help
+ Print the list of known keywords and their basic usage. The same help screen
+ is also displayed for unknown commands.
-show sess
- Dump all known sessions. Avoid doing this on slow connections as this can
- be huge.
+prompt
+ Toggle the prompt at the beginning of the line and enter or leave interactive
+ mode. In interactive mode, the connection is not closed after a command
+ completes. Instead, the prompt will appear again, indicating the user that
+ the interpreter is waiting for a new command. The prompt consists in a right
+ angle bracket followed by a space "> ". This mode is particularly convenient
+ when one wants to periodically check information such as stats or errors.
+ It is also a good idea to enter interactive mode before issuing a "help"
+ command.
+
+quit
+ Close the connection when in interactive mode.
show errors [<iid>]
Dump last known request and response errors collected by frontends and
@@ -6563,6 +6571,47 @@
is the slash ('/') in header name "header/bizarre", which is not a valid
HTTP character for a header name.
+show info
+ Dump info about haproxy status on current process.
+
+show sess
+ Dump all known sessions. Avoid doing this on slow connections as this can
+ be huge.
+
+show stat [<iid> <type> <sid>]
+ Dump statistics in the CSV format. By passing <id>, <type> and <sid>, it is
+ possible to dump only selected items :
+ - <iid> is a proxy ID, -1 to dump everything
+ - <type> selects the type of dumpable objects : 1 for frontends, 2 for
+ backends, 4 for servers, -1 for everything. These values can be ORed,
+ for example:
+ 1 + 2 = 3 -> frontend + backend.
+ 1 + 2 + 4 = 7 -> frontend + backend + server.
+ - <sid> is a server ID, -1 to dump everything from the selected proxy.
+
+ Example :
+ >>> $ echo "show info;show stat" | socat stdio unix-connect:/tmp/sock1
+ Name: HAProxy
+ Version: 1.4-dev2-49
+ Release_date: 2009/09/23
+ Nbproc: 1
+ Process_num: 1
+ (...)
+
+ # pxname,svname,qcur,qmax,scur,smax,slim,stot,bin,bout,dreq, (...)
+ stats,FRONTEND,,,0,0,1000,0,0,0,0,0,0,,,,,OPEN,,,,,,,,,1,1,0, (...)
+ stats,BACKEND,0,0,0,0,1000,0,0,0,0,0,,0,0,0,0,UP,0,0,0,,0,250,(...)
+ (...)
+ www1,BACKEND,0,0,0,0,1000,0,0,0,0,0,,0,0,0,0,UP,1,1,0,,0,250, (...)
+
+ $
+
+ Here, two commands have been issued at once. That way it's easy to find
+ which process the stats apply to in multi-process mode. Notice the empty
+ line after the information output which marks the end of the first block.
+ A similar empty line appears at the end of the second block (stats) so that
+ the reader knows the output has not been trucated.
+
/*
* Local variables:
* fill-column: 79