Compaction run causing errors on application log

Hi ,

We are live On DC1 , when Compaction runs every this looks good. When ever application switches to DC2, we are having below error on application logs. and moreover CB has auto failover setup and both are active-active. On DC2 , the ops/sec on a bucket is double of DC1 where item count is exactly the same. Looking for any documentation on troubleshooting Compaction issues.

Would appreciate if any shed some light on the above issue as where to start with.

@rag I am sorry that you are having issues on compaction runs. Can you please post the error? Looks like the error got lost in your post.

@raju Below is the warning observed on application log.

SQL warning 12, CAS 1234566. Failed to save record with key CUST/AbCdE/joKTo1b9ujghsFixr0WgwTYCx/eL2A=. The key already exists in the server. If you have supplied a CAS then the key exists with a CAS value different than specified. Tried for 0.000 sec. This may be due to lock expiration/contention and/or server unavailability. Will read the new CAS value and retry updating.

No errors or warning on any of couchbase logs.
The actual issue is whenever compaction is running , the application log is filled with above Warning. when we stop the compaction , there were no errors or warning and app is smooth. Want to know what is root cause ?