Purpose

Purging may not have been set up at installation time.  If the OMK database has grown large it's a good idea to select an event retention period and manually purge the OMK database.

Related Documents

Purging of old data in opEvents

Determine Retention Interval

Select a retention period that provides infrastructure engineers with necessary event information and also complies with your organizations security and compliance policies. 

Run the opEvents Purge Command

The purge action is run with the opevents-cli.exe command line utility.  When using this utility the retention period is relative to the current time and is referred to as 'purge_older_than'.  The value passed with the command may be expressed in minutes, hours, or days (combinations are also possible).  Using days as an example, if the retention period were 1 year the command line option for the retention period would like like this:

...

Once satisfied that the desired action will occur; remove the simulate option and run the command again.

Recover Disk Space - Compact MongoDB

The old records have been removed, but the database is still taking the same amount of storage.  In order to recover the disk space we will need to issue the MongoDB 'compact' command.  This will rewrite and defragment the database. The safe approach is to shut down all daemons that are writing the the database prior to issuing the 'compact' command.

Shutdown OMK Services

service opeventsd stop
service opflow stop
service opconfigd stop
service nmisd stop
service omkd stop

Enter the mongo Shell and Compact opEvents Collections

[root@opmantek ~]# mongo -u opUserRW -p op42flow42 nmis
MongoDB shell version v3.4.9
connecting to: mongodb://127.0.0.1:27017/nmis
MongoDB server version: 3.4.9

> db.runCommand({compact: 'events'})
{ "ok" : 1 }
> db.runCommand({compact: 'rawlogs'})
{ "ok" : 1 
> db.runCommand({compact: 'actionlog'})
{ "ok" : 1 }
> 

Start OMK Services

service omkd start
service nmisd start
service opeventsd start
service opconfigd start
service opflowd start

Set Purging Policy

Now that the database has been cleaned up, set the purging policy in opCommon.  That procedure is found here: Purging of old data in opEvents