I am trying zabbix as monitoring system on our community network in Italy ( ninux.org )

I am experiencing a big problem with the agent, our devices are embedded system with openwrt and ~16MB of ram so we have noticed rapidly of a memory leak on latest version of zabbix_agentd

As you can see there [0] the free memory on the device is slowly decreasing after starting zabbix agentd end grow up instantly when /etc/init.d/zabbix_agentd restart is runned

To be able to run Zabbix on an embedded system like openwrt we had to apply some little patches [1] but they doesn't seems the cause of the memory leak

[0] http://eigenlab.org/~gioacchino/Immagini/zabbix_agentd_memory_leak.png
[1] http://eigenlab.org/~gioacchino/zabbix/patches/

More info here:

root@OpenWrt:~# zabbix_agentd -V
Zabbix Agent (daemon) v1.8.11 (revision 26205) (20 March 2012)
Compilation time: Apr 5 2012 15:56:04

root@OpenWrt:~# ps ax
PID USER VSZ STAT COMMAND
1 root 1384 S init
2 root 0 SW [kthreadd]
3 root 0 SW [ksoftirqd/0]
4 root 0 SW [events/0]
5 root 0 SW [khelper]
8 root 0 SW [async/mgr]
39 root 0 SW [sync_supers]
41 root 0 SW [bdi-default]
43 root 0 SW [kblockd/0]
71 root 0 SW [kswapd0]
72 root 0 SW [aio/0]
73 root 0 SW [crypto/0]
85 root 0 SW [mtdblockd]
91 root 0 SW [ar71xx-spi]
225 root 0 SW [ipolldevd]
278 root 0 SWN [jffs2_gcd_mtd4]
293 root 1376 S /bin/sh /etc/init.d/rcS S boot
294 root 1384 S init
296 root 1376 S logger -s -p 6 -t sysinit
308 root 1388 S syslogd -C16
310 root 1368 S klogd
324 root 780 S /sbin/hotplug2 --override --persistent --set-worker /
432 root 0 SW [events_nrt]
434 root 0 SW [cfg80211]
441 root 0 SW [khubd]
511 root 0 SW [phy0]
561 root 0 SW [bat_events]
670 root 1456 S hostapd -P /var/run/wifi-phy0.pid -B /var/run/hostapd
848 root 1132 S /usr/sbin/dropbear -P /var/run/dropbear.1.pid -s -p 2
858 root 800 S /usr/bin/mini_snmpd -c public -i br-clients,wlan0-1 -
900 root 1380 S watchdog -t 5 /dev/watchdog
1424 root 1380 S /usr/sbin/ntpd -n -p 0.openwrt.pool.ntp.org -p 1.open
5043 zabbix 1584 S /usr/sbin/zabbix_agentd
5044 zabbix 1584 S /usr/sbin/zabbix_agentd
5045 zabbix 1844 S /usr/sbin/zabbix_agentd <--- JUST AFTER SOME MINUTER FROM RESTART
5046 zabbix 1592 S /usr/sbin/zabbix_agentd
5084 root 1204 S /usr/sbin/dropbear -P /var/run/dropbear.1.pid -s -p 2
5085 root 1388 S -ash
5140 root 1376 R ps ax

root@OpenWrt:~# cat /etc/zabbix/zabbix_agentd.conf

1. This is config file for zabbix_agentd
2. To get more information about ZABBIX, go http://www.zabbix.com

1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. GENERAL PARAMETERS #################

1. List of comma delimited IP addresses (or hostnames) of ZABBIX servers.
2. No spaces allowed. First entry is used for sending active checks.
3. Note that hostnames must resolve hostname->IP address and
4. IP address->hostname.

Server=zabbix.eigenlab.org

1. Server port for sending active checks

#ServerPort=10051

1. Unique hostname. Required for active checks.

Hostname=localhost

1. Listen port. Default is 10050

#ListenPort=10050

1. IP address to bind agent
2. If missing, bind to all available IPs

#ListenIP=127.0.0.1

1. Number of pre-forked instances of zabbix_agentd.
2. Default value is 5
3. This parameter must be between 1 and 16

StartAgents=1

1. How often refresh list of active checks. 2 minutes by default.

#RefreshActiveChecks=120

1. Disable active checks. The agent will work in passive mode listening server.

#DisableActive=1

1. Enable remote commands for ZABBIX agent. By default remote commands disabled.

#EnableRemoteCommands=1

1. Specifies debug level
2. 0 - debug is not created
3. 1 - critical information
4. 2 - error information
5. 3 - warnings
6. 4 - information (default)
7. 5 - for debugging (produces lots of information)

DebugLevel=3

1. Name of PID file

PidFile=/var/run/zabbix/zabbix_agentd.pid

1. Name of log file.
2. If not set, syslog will be used

LogFile=/var/log/zabbix/zabbix_agentd.log

1. Spend no more than Timeout seconds on processing
2. Must be between 1 and 30

Timeout=3

1. 1. 1. 1. 1. 1. 1. USER-DEFINED MONITORED PARAMETERS #######
2. Format: UserParameter=<key>,<shell command>
3. Note that shell command must not return empty string or EOL only
   #UserParameter=system.test,who|wc -l
   1. 1. Set of parameter for monitoring MySQL server (v3.23.42 and later)
      2. Change -u<username> and add -p<password> if required
         #UserParameter=mysql.ping,mysqladmin -uroot ping|grep alive|wc -l
         #UserParameter=mysql.uptime,mysqladmin -uroot status|cut -f2 -d":"|cut -f1 -d"T"
         #UserParameter=mysql.threads,mysqladmin -uroot status|cut -f3 -d":"|cut -f1 -d"Q"
         #UserParameter=mysql.questions,mysqladmin -uroot status|cut -f4 -d":"|cut -f1 -d"S"
         #UserParameter=mysql.slowqueries,mysqladmin -uroot status|cut -f5 -d":"|cut -f1 -d"O"
         #UserParameter=mysql.qps,mysqladmin -uroot status|cut -f9 -d":"
         #UserParameter=mysql.version,mysql -V