Dear Ian,
No, this is not a known problem. I assume, you have updated
naviserver AND the modules. Do you have a test case
where this behavior can be reproduced?
We were running OpenACS.org for a while with dbipg without this problem.
But, what we noticed was the following:
- ndbipg needed a larger cachesize for prepared statements.
Otherwise, one runs quickly into cache trashing, where for
a full cache each sql query requires cache eviction, which
can bring the system to a crawl, when SQL queries are high.
(cachesize 1024*1024).
- nsdbipg works nicely, when all constants are replaced by bind variables.
When the query contains constants (e.g. acs object ids in OpenACS),
then the same query is kept multiple times with different constants
in the prepared-statements cache requiring more and more cache.
- We all agree that it is the best not to have such SQL queries with
constants, but when a complex framework
is used, rewriting all queries can be substantial work (OpenACS with
DotLRN contains about 1000 tables and views). Furthermore,
when there are subquery expressions based on "in"
(like "... item_id in (1, 99, 703)") with expressions of different
lengths,
then current bind variables run into a limit (one would still
need with the current approach different sequences for every
potential length).
After having addressed most of problems in the packages used
on openacs.org, that last problem caused us for the time being
to switch back to nsdbpg on openacs.org.
Can it be that you ran into the problem with the cache trashing?
It might be worth the try to increase the cachesize....
-g
Am 25.03.15 um 15:04 schrieb Ian Harding:
Hello!
I just upgraded to the latest and greatest naviserver and am having
some issues.
All my db connections eventually get tied up with
deallocate dbipg_6832018
type of queries that appear to be stuck. I haven't done any research
into this yet, but was wondering if this is a known bug.
If not I will get the version information and whatever else I can find
about locks, etc. Any other things I should look at let me know.
Ian
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