How to Resolve Lag and Unstoppable OGG Extract process

ERROR OGG-15163 There was a problem sending a message to EXTRACT (Timeout waiting for message)

The EXTRACT looks hung, but its status is still showing is “RUNNING”.

Restarting the process is my first thought to resolve issue , again I tried to restart manager as well but even after restart mgr also we can’t stop extract normally. At last, need force stop EXTRACT by killing the process. like below:

 GGSCI (oracleworlds.com) 5> info all
 Program Status Group Lag at Chkpt Time Since Chkpt
 MANAGER RUNNING 
 EXTRACT RUNNING EXTORC1 178:12:26 00:04:09
 EXTRACT RUNNING PMPORC1 00:00:00 00:00:05 

As you can see, the column “Lag at Chkpt” is far behind current time. Apparently, EXTRACT stops working. hear Something is wrong.

It is waiting for long time? Yes, it has been 178 hours long. If we don’t intervene immediately, it could be more issue. Therefore, we should try to restart EXTRACT and see the response.

Stop EXTRACT:

GGSCI (oracleworlds.com) 4> stop EXTORC1
 Sending STOP request to EXTRACT EXTORC1 ..
 2020-02-20 11:17:29 ERROR OGG-15163 There was a problem sending a message to EXTRACT EXTORC1 (Timeout waiting for message). 

It can’t be stopped. So we need to find another way around to resolve this issue.

KILL EXTRACT:

You can use KILL EXTRACT to kill an Extract process force fully running in regular or PASSIVE mode. Use this command only if a process cannot be stopped gracefully with the STOP EXTRACT command. By the way, the Manager process will not attempt to restart a killed Extract process.

 GGSCI (oracleworlds.com) 4> kill EXTRACT EXTORC1
 Sending KILL request to MANAGER ...
 Killed process (333805) for EXTRACT EXTORC1 

It should work. it’s the same process as killing the process on OS-level

After killing Extract
GGSCI (oracleworlds.com) 5> sh ps -ef | grep EXTORC1
ogguser 53627 35079 0 11:39 pts/1 00:00:00 sh -c ps -ef | grep EXTORC1
ogguser 53629 53627 0 11:39 pts/1 00:00:00 grep EXTORC1

 NOW Start EXTRACT:
 GGSCI (oracleworlds.com) 6> info all
 Program Status Group Lag at Chkpt Time Since Chkpt
 MANAGER RUNNING
 EXTRACT STOPPED EXTORC1 178:12:26 00:26:08
 EXTRACT RUNNING PMPORC1 00:00:00 00:00:03
 　
 GGSCI (oracleworlds.com) 6> start EXTORC1 
 Sending START request to MANAGER ...
 EXTRACT EXTORC1 starting
 　
 GGSCI (oracleworlds.com) 8> info all
 Program Status Group Lag at Chkpt Time Since Chkpt
 MANAGER RUNNING
 EXTRACT RUNNING EXTORC1 177:20:24 00:00:00
 EXTRACT RUNNING PMPORC1 178:20:11 00:00:03
 　
 GGSCI (oracleworlds.com) 8> info all
 MANAGER RUNNING
 EXTRACT RUNNING EXTORC1 91:42:26 00:00:05
 EXTRACT RUNNING PMPORC1 00:00:00 00:00:00

Now the extract is moving on and lag issue has been resolved.
 
 GGSCI (oracleworlds.com) 20> info all
 Program Status Group Lag at Chkpt Time Since Chkpt
 MANAGER RUNNING
 EXTRACT RUNNING EXTORC1 00:00:04 00:00:02
 EXTRACT RUNNING PMPORC1 00:00:00 00:00:08