ObjectServer data files

Learn about backing up ObjectServer data files.

When an ObjectServer shuts down, it writes its entire contents and state to the master_store.tab and table_store.tab files in the following directory:

$OMNIHOME/db/ObjectServer_name/

On restart, the ObjectServer process will read the contents of these two files into memory and resume its previous state. In addition to this process during start-up and shutdown, an ObjectServer will also “checkpoint” every 60 seconds where all persistent data is copied to checkpoint files (.chk). Between checkpoints, new and changed data is written to replay log files (.log). If the ObjectServer unexpectedly shuts down and is restarted, the ObjectServer process uses the combination of these files to rebuild the ObjectServer’s state. On a clean shutdown of the ObjectServer, all changes and updates are incorporated into the master_store.tab and table_store.tab files prior to shutdown effectively capturing a complete and self-contained snapshot of the ObjectServer’s state. After a clean shutdown, only the master_store.tab and table_store.tab files should be present in the ObjectServer’s db directory.

Should the ObjectServer checkpoint files become corrupted, the corrupted checkpoint .chk and .log files can be deleted and the ObjectServer started based on the existing master_store.tab and table_store.tab files. This however may mean that the ObjectServer is restored to a very old state if the ObjectServer has not been restarted in a while.