Technical data

Recovering cache grid after unexpected system shutdown
Troubleshooting Oracle In-Memory Database Cache 4-3
Check status of the cache agent
Check the status of the cache agent by using the ttStatus utility as described in
"Using the ttStatus utility" on page 1-2 to check the status of the cache agent.
If the cache agent is not running, start it as described in "Starting the cache agent" in
the Oracle In-Memory Database Cache User's Guide. If attempts to start the cache agent
fail, then investigate the possible causes and reboot the machine before attempting to
start the cache agent.
Check ORACLE_HOME environment variable
On UNIX or Linux platforms, check that the ORACLE_HOME environment variable is
set correctly for the shell from which you are starting the cache agent and the
TimesTen daemon. Use the ttmodinstall utility if you need to change the setting
for ORACLE_HOME.
See "Environment variables" in Oracle TimesTen In-Memory Database Installation Guide.
Check NLS environment variables
NLS environment variables are set in the environment where the TimesTen
application is running, even though TimesTen is not using the NLS environment
variables. Unset the NLS environment variables and restart the TimesTen daemon, the
cache agent, and the replication agent.
Recovering cache grid after unexpected system shutdown
The server may experience a system failure or an unexpected reboot, such as with a
power outage. In this case, the cache grid exits unexpectedly without the normal
shutdown procedure.
The following sections describe how to recover when the system unexpectedly shuts
down for two scenarios:
■ A portion of the cache grid nodes are still running
■ All cache grid nodes exited unexpectedly
A portion of the cache grid nodes are still running
When the server shuts down, some of the cache grid notes exited unexpectedly, but
others are still active. In this case, you must detach the dead nodes first by executing
ttGridDetachList from an attached node, as follows:
1. Connect to a surviving grid node and execute ttGridDetachList to force a
detach of all dead nodes from the grid.
2. Connect to the datastores on the rebooted server. Start the replication agent by
executing ttRepStart.
3. Attach the cache grid nodes by executing ttGridAttach.
4. Resume normal database operations.
All cache grid nodes exited unexpectedly
If all cache grid nodes exited unexpectedly when the server shut down, perform the
following tasks to recover the cache grid: