Management of TM1 Database Log Files

The TM1 database generates the following log files:

1 - TM1 Database Message Log 

•    Required and cannot be disabled
•    Contains information about TM1 database startup, shutdown, Ti processes, major errors and warnings 
•    The current TM1 database message log file is named tm1server.log

Documentation: https://www.ibm.com/support/knowledgecenter/SSD29G_2.0.0/com.ibm.swg.ba.cognos.tm1_op.2.0.0.doc/c_usingthetm1servermessagelog_n16050c.html

The message log is automatically managed by the TM1 database.  By default the maximum log file size is 100 MB.  Once the log file grows larger than 100 MB it will be rolled over automatically by the TM1 database.  The tm1server.log file is renamed tm1server.log.1, and a new (empty) tm1server.log file is created.  By default a maximum of 20 TM1 database message log files are maintained by the TM1 database (tm1server.log, tm1server.log.1,...tm1server.log.19).  Maximum log file size and maximum number of historical files based by the TM1 database based on configuration in the tm1s-log.properties file

•    Required and cannot be disabled at the database level.  Cube logging may be enabled and disabled for specific cubes.
•    Transaction log files track changes to cube data 
•    Transaction log files capture the old value, new value, time of update, user that performed the update, cube name, element names for the intersection that was updated
•    Transaction log files are used as both auditing and data recovery 
•    Transaction logging can be enabled and disabled for select cubes.  This is done with the LOGGING column in the }CubeProperties cube
•    Transaction logging can be enabled and disabled during Ti processes using the CubeSetLogChanges Ti function
•    It is often desirable to disabled transaction logging during a Ti process that loads a large volume of data to a cube
•    Current transaction log file is named tm1s.log.  The file named tm1s.log is locked by the TM1 database and cannot be viewed or edited with a text editor
•    The current transaction log file is renamed to tm1s<timestamp>.log during a SaveDataAll (SaveDataAll happens automatically on shutdown or restart).  A new (empty) tm1s.log file is generated when the TM1 database starts, and during a SaveDataAll without a TM1 database restart

Documentation: https://www.ibm.com/support/knowledgecenter/SSD29G_2.0.0/com.ibm.swg.ba.cognos.tm1_op.2.0.0.doc/c_loggingtransactions_n160234.html

The transaction log files a not managed by the TM1 database as these log files contain a record of changes to data which may be required for review.  It's also possible for the transaction log files to grow very large.   TM1 database modelers must carefully consider if transaction logging is required during Ti processes.  In general, if a Ti process can be rerun to reload the same data into a cube, transaction logging can be disabled during the Ti process.  Transaction logging is typically desirable on cube during period of manual user data entry.  The TM1 model administrator should carefully consider how long to keep the historical transaction log files (historical files are named tm1s<timestamp>.log).  This should be determine based on the requirement to store changes.  If the historical transaction logs files must be permanently stored then it is recommended to either compressing transaction log files older than a specific date, or to move the files to a storage solution (e.g FTP the file outside of the Planning Analytics on IBM Cloud environment).  The historical transaction logs files may be opened and examined in a text editor.  A text editor that can open large files is recommended.  

•    Cannot be disabled
•    Individual Ti process error log files are created when the execution of a Ti process has an error
•    Name of the Ti process error log file is in the format tm1processerror_<ti process name>_<timestamp>.log
•    These log files are not cleaned up (deleted or archived) by the TM1 database

Manual intervention is required to delete or archive these log files.   A new log file is generated each time a Ti process errors (one log file per Ti execution).  A large volume of Ti process error logs could be generated for Ti processes that run frequently, and generate an error on each execution.   A large number of log files generated in the TM1 database logging directory may impact performance of the TM1 database when creating or updating log files.  The Planning Analytics Administration capability to download log files may also be impacted by a large number of files in the TM1 database logging directory.  It's recommended to limit the number of files in the TM1 database logging directory to under 2000 files.

4 - TM1 Database Audit Log

•    Optional
•    Enabled and disabled with the AuditLogOn parameter in tm1s.cfg 
•    Tracks logins, Ti process execution, and changes to metadata in the TM1 database
•    Audit logging is only on or off.  It is not possible to enabled audit logging for only some activity types.
•    The file name for the active audit log is tm1rawstore.<timestamp>.  The active audit log file is locked and may not be opened in a text editor.
•    The log file is rolled over by the TM1 database on restart
•    Historical audit log files are named tm1auditstore<timestamp>.log

Documentation: https://www.ibm.com/support/knowledgecenter/SSD29G_2.0.0/com.ibm.swg.ba.cognos.tm1_op.2.0.0.doc/c_usingtheauditlog_n160a4f.html

Audit logging is not managed automatically by the TM1 database.  If audit logging is enabled the TM1 modeler should determine how long audit logs are kept in the logging directory.   The audit log files may be significant in size.

•    This log file described specific events about the TM1 database
•    Consumed by the Planning Analytics Administration Agent
•    Automatically managed by the TM1 database based on the configuration in the tm1s-log.properties file (same as the TM1 database message log).