The ArchMgr process drops daily at the time of Online Database Backup. This seems to only occur on one of the landscapes while the ArchMgr remains running on the rest.
Archive Manager does not restart after the olb on Sunday.
In prior versions of Spectrum, ddm_backup was used to make a backup of the DDMDB database. This process would stop
the ArchMgr, perform the backup, and then restart the ArchMgr when done. Current 10.4.x (NetOps 19.4, 20.2) versions of
Spectrum now use ddm_save.pl which in turn uses mysqlbackup to backup the database without needing to stop it.
The DDMDB backup is typically triggered from the post_olb_script (needs to be manually uncommented) and it would seem
the server was using an older version of that script still calling ddm_backup instead of the newer ddm_save.pl
Release : 10.4
Component : Spectrum Core / SpectroSERVER
Updated the $SPECROOT/custom/CsScript/post_olb_script to use ddm_save.pl
./ddm_save.pl -f $backup_dir/db_$time_string.DDMDb > $backup_dir/ddm_backup.log 2>&1
Note: Verify that the binary mysqlbackup exists in the $SPECROOT/SS/DDM/ folder before switching to ddm_save.pl