ADM1823E  The active log is full and is held by application handle
“371”.  Terminate this application by COMMIT, ROLLBACK or FORCE
APPLICATION.

Doing some research there were a couple of potential causes

1.Potentially long running query – not commiting i.e database configured to run 12 log files on a circular.
If the transaction has not been commited and you go through the 12 log files – then try to write to log file 1 again – which is still holding the open transaction, then you’ve got a problem. This is one possible reason , and requires further investigation
2.Known problem of DB2 Health Monitor coming on every 2 hrs – despite having it turned off – requires Environment variable changes,more details below. This has already been dealth with via the DB2_FMP_COMM_HEAPSZ=0

The actual resolution of the problem : The problem reappeared after 2 hrs : Did the following:

db2 get snapshot for applications on MONITOR

and look for application handle “371”.

This showed that the last handles was in Lock-wait state , and the application was DB2HMON
I then released the lock db2 ” force application ( 371 ) ”

On this basis I discovered a current major issue with DB2 – regarading DB2 Health Monitor and OLTP dbs . Even if you have the Health Monitor turned OFF ,
every 2 hrs the Health Monitor will start and check everything is OK – run some maintenance etc – at this point there is a lot locking etc

I issued the following commands – see Appendix 1 on every instance on the server – and did a full restart. Note : the following changes are environment variables

db2 update dbm cfg using HEALTH_MON OFF
db2set DB2_FMP_COMM_HEAPSZ=0

 Ref:Jack Vamvas