redis-snmp: redis performance monitoring through SNMP

2 minute read

The same way I created mysql-snmp a small Net-SNMP subagent that allows exporting performance data from MySQL through SNMP, I’m proud to announce the first release of redis-snmp to monitor Redis servers. It is also inspired by the Cacti MySQL Templates (which also covers Redis).

I originally created this Net-SNMP perl subagent to monitor some Redis performance metrics with OpenNMS.

The where

You’ll find the sources (which allows to produce a debian package) in the redis-snmp github repository

The what

Here are the kind of graphs and metrics you can export from a redis server:

Redis Connections

Redis Commands

Redis Memory

The how

Like mysql-snmp you need to run redis-snmp on a host that has a connectivity with the monitored redis server (the same host makes sense). You also need the following dependencies:

  • Net-SNMP >= (older versions contains a 64 bits varbind issue)
  • perl (tested under perl 5.10 from debian squeeze)

Once running, you should be able to ask your snmpd about redis values:

$ snmpbulkwalk -m'REDIS-SERVER-MIB' -v 2c  -c public .
REDIS-SERVER-MIB::redisConnectedClients.0 = Gauge32: 1
REDIS-SERVER-MIB::redisConnectedSlaves.0 = Gauge32: 0
REDIS-SERVER-MIB::redisUsedMemory.0 = Counter64: 154007648
REDIS-SERVER-MIB::redisChangesSinceLastSave.0 = Gauge32: 542
REDIS-SERVER-MIB::redisTotalConnections.0 = Counter64: 6794739
REDIS-SERVER-MIB::redisCommandsProcessed.0 = Counter64: 37574019

Of course you must adjust the hostname and community. SNMP v2c (or better) is mandatory since we’re reporting 64 bits values.

Note that you can get the OID translation to name only if the REDIS-SNMP-SERVER MIB is installed on the host where you run the above command.

OpeNMS integration

To integrate to OpenNMS, it’s as simple as adding the following group to your datacollection-config.xml file:

<group name="redis" ifType="ignore">
    <mibObj oid="." instance="0" alias="redisConnectedClnts" type="Gauge32" />
    <mibObj oid="." instance="0" alias="redisConnectedSlavs" type="Gauge32" />
    <mibObj oid="." instance="0" alias="redisUsedMemory" type="Gauge64" />
    <mibObj oid="." instance="0" alias="redisChangsSncLstSv" type="Gauge32" />
    <mibObj oid="." instance="0" alias="redisTotalConnectns" type="Counter64" />
    <mibObj oid="." instance="0" alias="redisCommandsPrcssd" type="Counter64" />

And the following graph definitions to your file: Connections
report.redis.redisconnections.command=--title "Redis Connections" \
 --width 565 \
 --height 200 \
 DEF:redisConnectedClnts={rrd1}:redisConnectedClnts:AVERAGE \
 DEF:redisConnectedSlavs={rrd2}:redisConnectedSlavs:AVERAGE \
 DEF:redisTotalConnectns={rrd3}:redisTotalConnectns:AVERAGE \
 LINE1:redisConnectedClnts#9B2B1B:"REDIS Connected Clients         " \
 GPRINT:redisConnectedClnts:AVERAGE:"Avg \\: %8.2lf %s" \
 GPRINT:redisConnectedClnts:MIN:"Min \\: %8.2lf %s" \
 GPRINT:redisConnectedClnts:MAX:"Max \\: %8.2lf %s\\n" \
 LINE1:redisConnectedSlavs#4A170F:"REDIS Connected Slaves          " \
 GPRINT:redisConnectedSlavs:AVERAGE:"Avg \\: %8.2lf %s" \
 GPRINT:redisConnectedSlavs:MIN:"Min \\: %8.2lf %s" \
 GPRINT:redisConnectedSlavs:MAX:"Max \\: %8.2lf %s\\n" \
 LINE1:redisTotalConnectns#38524B:"REDIS Total Connections Received" \
 GPRINT:redisTotalConnectns:AVERAGE:"Avg \\: %8.2lf %s" \
 GPRINT:redisTotalConnectns:MIN:"Min \\: %8.2lf %s" \
 GPRINT:redisTotalConnectns:MAX:"Max \\: %8.2lf %s\\n" Memory
report.redis.redismemory.command=--title "Redis Memory" \
  --width 565 \
  --height 200 \
  DEF:redisUsedMemory={rrd1}:redisUsedMemory:AVERAGE \
  AREA:redisUsedMemory#3B7AD9:"REDIS Used Memory" \
  GPRINT:redisUsedMemory:AVERAGE:"Avg \\: %8.2lf %s" \
  GPRINT:redisUsedMemory:MIN:"Min \\: %8.2lf %s" \
  GPRINT:redisUsedMemory:MAX:"Max \\: %8.2lf %s\\n" Commands
report.redis.rediscommands.command=--title "Redis Commands" \
 --width 565 \
 --height 200 \
 DEF:redisCommandsPrcssd={rrd1}:redisCommandsPrcssd:AVERAGE \
 AREA:redisCommandsPrcssd#FF7200:"REDIS Total Commands Processed" \
 GPRINT:redisCommandsPrcssd:AVERAGE:"Avg \\: %8.2lf %s" \
 GPRINT:redisCommandsPrcssd:MIN:"Min \\: %8.2lf %s" \
 GPRINT:redisCommandsPrcssd:MAX:"Max \\: %8.2lf %s\\n" Unsaved Changes
report.redis.redisunsavedchanges.command=--title "Redis Unsaved Changes" \
  --width 565 \
  --height 200 \
  DEF:redisChangsSncLstSv={rrd1}:redisChangsSncLstSv:AVERAGE \
  AREA:redisChangsSncLstSv#A88558:"REDIS Changes Since Last Save" \
  GPRINT:redisChangsSncLstSv:AVERAGE:"Avg \\: %8.2lf %s" \
  GPRINT:redisChangsSncLstSv:MIN:"Min \\: %8.2lf %s" \
  GPRINT:redisChangsSncLstSv:MAX:"Max \\: %8.2lf %s\\n"

Do not forget to register the new graphs in the report list at the top of file.

Restart OpenNMS, and it should start graphing your redis performance metrics. You’ll find those files in the opennms directory of the source distribution.

Enjoy :)