Hi Stefan
I just talked to our admins and they told me that zone reclaim already set
to 0 and the query is not the first or so. we run thousands of queries per
hour and just one or two take more than 0.2 seconds (up to 70 seconds by
test from today).
We have a database of around 10gb and about 40 tables. The servers have
32gb ram, 180 gb ssd hard drives and 24 cpus. So this should be ok.
We are running a single query per client. Client is a php script over
apache server making the requests.
Changing from normal connection to pconnection didn't make any difference.
During the hick up we had no other process running except apache and
monetdb and both didn't use to much cpu and the system also didn't use to
much cpu.
Any other suggestion would be appreciated.
Thanks
sebastian
Am 10.12.13 23:06 schrieb "Stefan Manegold" unter
Hi Sebastian,
given your brief description of the problem, I don't expect that MonetDB itself triggers/causes the problem, but rather suspect that it is related to the system you're running on.
If I understand you correctly, your machine has ample CPU and RAM resources to execute your queries, right?
Are you running a single query / client at a time, or are multiple queries / clients active concurrently?
Can / did you monitor the system behavior/activity during the "hick-ups"? E.g., are there other ("heavy") processes running? Is there (unexpected) I/O activity? Is there unexpectedly high CPU system (rather than user) load?
Please also see the experiences shared at in this blog post: http://engineering.linkedin.com/performance/optimizing-linux-memory-manage ment-low-latency-high-throughput-databases and this monetdb user mailing list thread: https://www.monetdb.org/pipermail/users-list/2013-December/thread.html#702 4
Best, Stefan
----- Original Message -----
HI,
We are using monetdb for some statistical analysis.
The queries are very fast (0.2 sec), but some times (not regularly) the queries get peeks of up to 32 sec for the same query.
CPU and RAM don't change and are way higher than actually needed.
Does any one have this same situation? Any idea what could be doing this?
Best regards and thanks to any help.
sebastian
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