RFS Process not working

Problem:

The filesystem containing the archive destination in DR server was not accessible. As a result the log shipping got stopped. We defered the log shipping in the production server. After the filesystem was back, we enabled the log shipping but the RFS process in DR server was not running...The problem occured when the log 24717 was being shipped... When we queried

SQL> Select status, sequence# from v$managed_standby;

The status for MRP showed that it was waiting for gap...We then manually shipped the log file and then applied... When we enabled the shipping we found that the RFS process was still not started.....There were no error in the alert log of DR...We found a trace file in the production server with the following message..

tkcrrsarc: (WARN) Failed to find ARCH for message (message:0xa)
tkcrrpa: (WARN) Failed initial attempt to send ARCH message (message:0xa)

So we thought that the issue is with the archiver process....

Solution:

Check whether the archiver process is available for shipping log files. You can identify this by querying V$ARCHIVE_PROCESSES view.

SQL> Select * from v$archive_processes;

The output have the following columns:

Process: Indicates the process number.
Status: This should be ACTIVE
Log Sequence: Log sequence number of the log that is being shipped by the archiver. If it is not shipping any log then it should be 0.
State: This should be IDLE if the archiver is not shipping any log. If it is shipping any log then its state is BUSY.

In our case we had two archiver process running.

The status of both the arch process is ACTIVE.
The log sequence of First arch process is 0 and its state is IDLE. Hence it is healthy. However the log sequence of 2nd arch process is 24717 and its state is BUSY.

This was interesting because the problem occured when the arch process was transfering the log 24717. This log was then manually shipped and applied. But the process still shows that it was shipping the 24717 log...

So we thought of increasing the arch processes. We increased the arch process from two to four.

SQL> alter system set log_archive_max_processes=4 scope=both;

We queried the v$archive_processes, the 3rd and 4th arch process was ready to ship the log files 24718 and 24719 logs respectively with their corresponding state as IDLE...

We enabled the log shipping and the RFS process in DR was started and the log shipping went smoothly.

However the 2nd arch process still was showing the same log sequence (24717) and state (BUSY).... We then killed that archiver process....

Thanks