Kbase P3907: Investigating why Flushing Buffer Pool: buffers remaining during database shutdown
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
2/25/2005 |
|
Status: Verified
SYMPTOM(s):
Flushing Buffer Pool: 6 buffers remaining
Process left hanging in memory when proshut command is issued
The database takes a long time to shut down while the processes are left hanging in memory
<time> Flushing Buffer Pool (9175)
CAUSE:
During the shutdown process, a complete flush of the dirty buffers takes place. On customer sites running with a really big -B value and no APW's, this issue has been known to occur, because it is just taking too long to flush the buffer pool to disc and resolve contention of backout processes. Only Enterprise Licenses support APW option.
The message is informational, not an error. Eventually the system should shut down the database. The investigations needed are to find out why is it taking so long to flush memory to disk.
FIX:
If the database needs to be more aggressively shut down, issue:
proshut [dbname] -F -by
Any active connections will be terminated and proshut will not have to wait for these to exit themselves. If needing to shut the database down in order to back it up, insert a command to truncate the .bi file before starting the backup. Please refer to P3222: Using proshut -by or proshut -F for more information on this command.
If this scenario is happening often, it is worth considering the following the next time this issue occurs:
1.) Before killing the process or the broker, execute the following:
a) Run a promon session before proshut to gather all information on user activity.
b) Check the system for any rogue processes that haven't shut down and produce a stacktrace against them. There could be a process locking the shutdown.
c) Produce a stacktrace against the _mprshut process with kill -16 <process-id> to generate a protrace file
d) Send Progress Technical Support the stacktraces that result from the above action and we will be able to find exactly which processes were locking the shutdown.
2. Once proshut has been killed, does a "truncate bi" perform a crash recovery without an