Purpose

Purging may not have been set up at installation time. If the OMK database has grown large it's a good idea to purge it in 90 day increments until the desired retention period is realized.

Determine the Purge Older Than Value

In order to purge from the database in 90 day increments the date of the oldest record is required.

[root@opmantek ~]# mongo -u opUserRW -p op42flow42 nmis --eval 'db.rawlogs.findOne()'
MongoDB shell version v3.4.9
connecting to: mongodb://127.0.0.1:27017/nmis
MongoDB server version: 3.4.9
{
        "_id" : ObjectId("5543df5db5d690352f1eb2cb"),
        "entry" : "2015-05-01T16:17:19\t10.73.225.166\tUDP: [10.73.225.166]:14445->[10.72.0.31]\tSNMPv2-MIB::sysUpTime.0=23:5:15:52.26\tSNMPv2-MIB::snmpTrapOID.0=SNMPv2-SMI::enterprises.8072.4.0.3\tSNMPv2-MIB::snmpTrapEnterprise.0=SNMPv2-SMI::enterprises.8072.4",
        "time" : NumberLong(1430511439),
        "eventid" : ObjectId("5543df5db5d690352f1eb2ca"),
        "type" : "nmis_traplog"
}

Notice the 'time' property above; 1430511439. The date command may be used to reveal when this was.

[root@opmantek ~]# date --date @1430511439
Fri May  1 20:17:19 UTC 2015

The purge command can be passed a value in minutes with the option 'events_purge_older_than'. Some quick math will render an appropriate figure.

### Current unix epoch time
[root@opmantek ~]# date +%s
1513316674

### Let X be The difference of current time and oldest record time converted to minutes
>>> (1513316674-1430511439)/60
1380087.25

### There are 129600 minutes in 90 days.  Subtract 129600 minutes from X.
>>> 1380087 - 129600
1250487

### Based on this the events_purge_older_than should be 1250487

Run the opEvents Purge Command

First run the command in simulate mode to ensure the math is correct

[root@opmantek ~]# /usr/local/omk/bin/opevents-cli.exe act=purge events_purge_older_than=52560 debug=1 simulate=true
[Fri Dec 15 05:54:31 2017] [debug] cli[31377] Purging unwanted database indices
[Fri Dec 15 05:54:31 2017] [debug] cli[31377] Db purge of rawlogs: 0 entries (of 7161464) in rawLogs are older than 1y270d50m
Db purge of rawlogs: 0 entries (of 7161464) in rawLogs are older than 1y270d50m
[Fri Dec 15 05:54:31 2017] [debug] cli[31377] Simulated purging rawlogs: would remove 0 (of 7161464) entries from rawLogs
Simulated purging rawlogs: would remove 0 (of 7161464) entries from rawLogs
[Fri Dec 15 05:54:31 2017] [debug] cli[31377] Purging disabled for archivelogs
Purging disabled for archivelogs
[Fri Dec 15 05:54:33 2017] [debug] cli[31377] Db purge of events: 4692044 entries (of 5060913) in events are older than 36d12h
Db purge of events: 4692044 entries (of 5060913) in events are older than 36d12h
[Fri Dec 15 05:54:33 2017] [debug] cli[31377] Simulated purging events: would remove 4692044 (of 5060913) entries from events
Simulated purging events: would remove 4692044 (of 5060913) entries from events
[Fri Dec 15 05:54:37 2017] [debug] cli[31377] Db purge of events: 12831334 entries (of 13803156) in actionlog are older than 36d12h
Db purge of events: 12831334 entries (of 13803156) in actionlog are older than 36d12h
[Fri Dec 15 05:54:37 2017] [debug] cli[31377] Simulated purging events: would remove 12831334 (of 13803156) entries from actionlog
Simulated purging events: would remove 12831334 (of 13803156) entries from actionlog
[Fri Dec 15 05:54:37 2017] [debug] cli[31377] Purging disabled for reports
Purging disabled for reports

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

Continue this 90 day cycle until the desired retention period is attained.

Recover Disk Space - Compact MongoDB

The old records have been removed, but the data base is still taking the same amount of storage. In order to recover the disk space we will need to issue that MongoDB 'compact' command that will rewrite and defrag 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 admin
MongoDB shell version v3.4.9
connecting to: mongodb://127.0.0.1:27017/admin
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

DRAFT - How To - opEvents - Manually Purge Events From OMK Database