[rrd-users] rrdcached and recreated files

Martin Sperl rrdtool at martin.sperl.org
Fri Aug 5 09:07:24 CEST 2011


While doing test-runs with rrdcache on a specific dataset, I have come 
across the following issue:

It seems as if rrdcached does not recognize if a file has been removed 
and then recreated again - it still retains the information about the 
last update time.

I did also try to connect to the socket and got stats output:
9 Statistics follow
QueueLength: 0
UpdatesReceived: 145268
FlushesReceived: 80
UpdatesWritten: 19
DataSetsWritten: 144719
TreeNodesNumber: 17
TreeDepth: 5
JournalBytes: 17962296
JournalRotate: 0

So 0 things in the queue

but I can not get a list of files that are in the cache but not queued, 
so I can not even clean those out via FORGET ...
And there is no FORGETALL or similar that could help...

The only way it seems to work is via restarting the cache after removal 
of the rrd files
And then the cache will complain about the old entries in Journal like this:

     handle_request_update: stat (/home/msperl/.../webcheck.rrd) failed.
- even though these have been updated before successfully and there was 
nothing left in the queue...
And the same lines come repeatedly - it does not cache that the file is 
not there (at least during cache replay)

Any Ideas how to get a flush going?
Also how to clean/truncate the journal when there is nothing in the queue?


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