Oracle GoldenGate Performance: Checking Lag Time
In all types of replication, I common question is, "How far are we behind?" In GoldenGate, there are several simple ways to check lag. Both give the same information--just in different formats. In each case, first start the GoldenGate utility, ggsci.
Method 1: Lag Command
Using this method requires that you first log into the database.
> lag *
Sending GETLAG request to EXTRACT EXT1TEST ...
Last record lag 4 seconds.
Sending GETLAG request to REPLICAT REP1TESTP ...
Last record lag 245 seconds.
Sending GETLAG request to REPLICAT REP2TESTP ...
Last record lag 1,720 seconds.
Sending GETLAG request to REPLICAT REP3TESTP ...
Last record lag 1,303 seconds.
Sending GETLAG request to REPLICAT REP4TESTP ...
Last record lag 785 seconds.
Method 2: Info Command.
With this command, you don't actually need to be connected to the database.
> info all
Program Status Group Lag at ChkptTime Since Chkpt
EXTRACT RUNNING EXT1TEST 00:00:05 00:00:04
REPLICAT RUNNING REP1TESTP 00:06:24 00:00:00
REPLICAT RUNNING REP2TESTP 00:56:41 00:00:00
REPLICAT RUNNING REP3TESTP 00:43:24 00:00:00
REPLICAT RUNNING REP4TESTP 00:25:33 00:00:00
In both methods, you are given the lag time for each replicat. In the case shown here, we have 4 replicats. You can see that replicat REP2TESTP and REP3TESTP are each lagging nearly an hour.