11.10. Troubleshooting
If an operation seems to hang, see the output of status ().
Check for the presence of the following conditions:
- The cluster line shows 0% CPU, no message traffic and an unchanging number of buffers
wired, this is probably a bug. To reset, restart the cluster or the offending process if found.
Restart is done by executing raw_exit (); over an SQL connection to the process in question.
- The cluster line shows many threads waiting compared to total threads. If CPU is 0 and
this does not change there could be a transaction that holds locks indefinitely. To clear, execute
txn_killall (1); . Do this at a node that has local threads waiting. This is seen in the Lock Status
paragraph of status ('') when connected to the node in question.
- The cluster line shows a changing number in the pfs field. The system is swapping
and slowed down.
- If the status () itself hangs, try another process of the cluster. See that there is
no temporary atomic activity like a long checkpoint. If the situation persists there is a bug.
The checkpoint can be seen by the presence of the checkpinmt_in_progress file in each server's
working directory.
- To check the integrity of database files, do cl_exec ('backup ''/dev/null'''); If
this returns, the databases are OK. If one is found to be corrupt the corresponding server exits.
