Create the following script (and make it executable):
#!/bin/bash
exec 5<> /dev/tcp/127.0.0.1/11211
if [ $? -eq 0 ]; then
echo "stats" >&5
echo "quit" >&5
while read -u 5 -d $'\r' stat name value;
do
echo $value
done
exit 0
fi
exit 1
Mine is /usr/local/bin/memcached_stats.sh
It connects to the memcached daemon and spits out a sanitized version of the memcached stats command and output something like:
2754
2129139
1243545563
1.2.2
64
2299.898362
7336.774640
217721
7091925
1909177049
108
27653
633
234138327
7091925
220430936
13707391
352833
89610818966
1385141563315
2147483648
4
Add the following to your /etc/snmp/snmpd.conf and restart snmpd:
extend .1.3.6.1.4.1.1.900.100 memcached /usr/local/bin/memcached_stats.sh
This creates a table based on the output of the script where each line gets its own node.
If you want to confirm this run the following:
snmpwalk -v2c -c public 127.0.0.1 .1.3.6.1.4.1.1.900.100
You should get something like:
SNMPv2-SMI::enterprises.1.900.100.3.1.3.9.109.101.109.99.97.99.104.101.100 = INTEGER: 23
SNMPv2-SMI::enterprises.1.900.100.3.1.4.9.109.101.109.99.97.99.104.101.100 = INTEGER: 0
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.1 = STRING: "2754"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.2 = STRING: "2123005"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.3 = STRING: "1243539429"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.4 = STRING: "1.2.2"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.5 = STRING: "64"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.6 = STRING: "2290.369810"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.7 = STRING: "7308.630919"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.8 = STRING: "217652"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.9 = STRING: "7066934"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.10 = STRING: "1909286395"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.11 = STRING: "108"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.12 = STRING: "27628"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.13 = STRING: "633"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.14 = STRING: "233251848"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.15 = STRING: "7066934"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.16 = STRING: "219593496"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.17 = STRING: "13658352"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.18 = STRING: "348593"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.19 = STRING: "89233569948"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.20 = STRING: "1380956068373"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.21 = STRING: "2147483648"
SNMPv2-SMI::enterprises.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.22 = STRING: "4"
From that you can extrapolate which node is which stat, but lucky for you I've done all that already.
In datacollection-config.xml add the following to the top, but after all the rrd config:
<resourceType name="MemcachedStats" label="memcached stats" resourceLabel="memcached">
<persistenceSelectorStrategy class="org.opennms.netmgt.collectd.PersistAllSelectorStrategy"/>
<storageStrategy class="org.opennms.netmgt.dao.support.IndexStorageStrategy"/>
</resourceType>
Then in the groups section add the following:
<group name="memcached_stats" ifType="all">
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.1" instance="MemcachedStats" alias="pid" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.2" instance="MemcachedStats" alias="uptime" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.3" instance="MemcachedStats" alias="time" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.4" instance="MemcachedStats" alias="version" type="string" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.5" instance="MemcachedStats" alias="pointer_size" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.4" instance="MemcachedStats" alias="rusage_user" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.7" instance="MemcachedStats" alias="rusage_system" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.8" instance="MemcachedStats" alias="curr_items" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.9" instance="MemcachedStats" alias="total_items" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.10" instance="MemcachedStats" alias="bytes" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.11" instance="MemcachedStats" alias="curr_connections" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.12" instance="MemcachedStats" alias="total_connections" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.13" instance="MemcachedStats" alias="connection_structures" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.14" instance="MemcachedStats" alias="cmd_get" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.15" instance="MemcachedStats" alias="cmd_set" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.16" instance="MemcachedStats" alias="get_hits" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.17" instance="MemcachedStats" alias="get_misses" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.18" instance="MemcachedStats" alias="evictions" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.19" instance="MemcachedStats" alias="bytes_read" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.20" instance="MemcachedStats" alias="bytes_written" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.21" instance="MemcachedStats" alias="limit_maxbytes" type="integer" />
<mibObj oid=".1.3.6.1.4.1.1.900.100.4.1.2.9.109.101.109.99.97.99.104.101.100.22" instance="MemcachedStats" alias="threads" type="integer" />
</group>
And finally further down you want to find the systemDef tags for Net-SNMP & Net-SNMP (UCD) and add the following within the collect tags:
<includeGroup>memcached_stats</includeGroup>
Restart OpenNMS and and there you have it... when capsd rescans the hosts it'll start gathering these statistics
Below is a reference for the data that can be got from memcached:
- pid: process id of this serverprocess
- uptime: number of seconds this server has been running
- time: current UNIX time according to the server
- version: version string of this server
- pointer_size: default size of pointers on the host OS
- rusage_user: accumulated user time for this process
- rusage_system: accumulated system time for this process
- curr_items: current number of items stored by the server
- total_items: total number of items stored by this server ever since it started
- bytes: current number of bytes used by this server to store items
- curr_connections: number of open connections
- total_connections: total number of connections opened since the server started running
- connection_structures: number of connection structures allocated by the server
- cmd_get: cumulative number of retrieval requests
- cmd_set: cumulative number of storage requests
- get_hits: number of keys that have been requested and found present
- get_misses: number of items that have been requested and not found
- evictions: number of valid items removed from cache to free memory for new items
- bytes_read: total number of bytes read by this server from network
- bytes_written: total number of bytes sent by this server to network
- limit_maxbytes: number of bytes this server is allowed to use for storage
- threads: number of worker threads requested
All that is left is to build whatever graphing or reporting you'd like.
(Works on CentOS 5.2, OpenNMS 1.5.93-1, net-snmp 5.3.1, memcached 1.2.2)
Best Answer
To enable polling (and thus monitor the service state) you actually have to edit the poller-configuration.xml and add an entry for the service you want to poll. I was pretty amazed to find that Opennms does not supply a UI for this rather crucial use case.