Hi, I've checked the process of switching over between ACTIVE and NON-active processes and it  doesn't work.

After default installation of Heartbeat MS in my pod I see 4 processes:

python3 -u misshtbtd.py -v

For example their PIDs are: 7, 10, 14, 16.

The first one with PID 7 is active and hb_common table is populated about it:

process_id |   source_name   | last_accessed_time | current_state 
----------{}+{}-------------{}{}----------------{}{}-------------
          7     | dcae-heartbeat- |         1663608587   | RUNNING

If I kill this process I expect the main process to switch over to another one and table hb_common should be updated.

In logs I see the following:

2022-09-16 12:07:04,428 | {}main{} | misshtbtd | main | 359 |  INFO | ('MSHBT: hb_common values ', 7, 'RUNNING', 'dcae-heartbeat-', 1663329631)
2022-09-16 12:07:04,428 | {}main{} | misshtbtd | main | 363 |  INFO | ('MSHBD:pid,srcName,state,time,ctime,timeDiff is', 7, 'dcae-heartbeat-', 'RUNNING', 1663329631, 1663330024, 393)
2022-09-16 12:07:04,428 | {}main{} | misshtbtd | main | 406 |  INFO | MSHBD:Active instance is inactive for long time: Time to switchover
2022-09-16 12:07:04,428 | {}main{} | misshtbtd | main | 408 |  INFO | MSHBD:Initiating to become Active Instance
2022-09-16 12:07:04,428 | {}main{} | misshtbtd | main | 410 |  INFO | MSHBD:HB and DBM thread are waiting to become ACTIVE
2022-09-16 12:07:04,442 | {}main{} | misshtbtd | create_update_hb_common | 121 |  INFO | MSHBT:Updated  hb_common DB with new values
2022-09-16 12:07:09,596 | {}main{} | db_monitoring | db_monitoring | 228 |  INFO | DBM:Inactive instance or hb_common state is not RUNNING

So as I see the main process is going to update hb_common to switch to another PID. But it never happens.

Looking at code I see that this 'process_id' column is never updated in the table! - file misshtbtd.py has following procedure:

elif update_flg == 1:
            cur.execute(
                "UPDATE hb_common SET LAST_ACCESSED_TIME = %s, CURRENT_STATE = %s "
                "WHERE PROCESS_ID = %s AND SOURCE_NAME = %s",
                (current_time, state, process_id, source_name),
            )
            _logger.info("MSHBT:Updated  hb_common DB with new values")

So as you may see it updates only last_accessed_time and current_state columns.