DB2 10.5 for Linux, UNIX, and Windows
DB2 10.5 for Linux, UNIX, and Windows
The autorestart configuration parameter determines if the database manager automatically initiates crash recovery when a user connects to a database that had previously terminated abnormally. If the autorestart configuration parameter is not set, the user must issue an explicit restart database command before they can connect to the database.
When the autorestart parameter is set to ON, the next database connection attempt performs crash recovery automatically if necessary.
In a DB2® pureScale® environment, the automatic restart behavior changes. If a database member fails, member crash recovery is automatically initiated for that member. In addition, if both cluster caching facilities fail at the same time, group crash recovery is automatically initiated. During member crash recovery, no connections are allowed against the database through that member. An SQL1015N error is returned if you try to connect to the database through a member that requires crash recovery. If crash recovery fails, another attempt at crash recovery is made. If the second attempt at crash recovery fails, an ALERT is set for the member on the host where recovery fails and restart light for that member is performed on a different host.
When the autorestart parameter is set to OFF, the automated member crash recovery and group crash recovery processes are inactive and must be performed manually, if required. The crash recovery processes can be initiated with the RESTART DATABASE command.
In a DB2 pureScale environment, if a member fails and cannot be restarted on its original host (also known as home host), DB2 cluster services restarts that member on one of the other available member hosts in the DB2 pureScale cluster. This is known as restart light processing. When a member is in restart light mode, you cannot directly connect to it, therefore no manual restart is possible. You must first set the autorestart parameter back to ON. The restart light member then automatically detects the change in the database configuration parameter and initiates crash recovery if needed.