[Zope-dev] another Zope hanging..

[Tino Wildenhain]

Hi,

most problems with hanging zope come from external RDBMS-access.
You wont see anything useful in the logs because there are
some objects published before the *sql-method is hanging.
If you have a monitor program for your database, you see many
blocks on tables or rows during this times.
I expect it with DB-adapters not fully thread aware and -
with to high timeout.

In fact it seems we need timeoutsockets and asynchronous
rdb-access.

If one thread is hanging, in the scope of 120 instructions,
zope has to wait before the global interpreter lock
frees. So if its stuck in the call of a C library
(database adaptors are most in C) it cannot continue
until the call returns.

Regards
Tino Wildenhain

--On Donnerstag, 3. Mai 2001 17:51 +0200 Christian Scholz 
<cs@comlounge.net> wrote:

> Hi!
>
>> Alright... so you're getting an OSError 11, and you're using Zope 2.3.1.
>>
>> errno 11 is "temporarily unavailable" which means about as much as
>> "foobar feeblefar" as far as I'm concerned ;-).
>
> great :)
>
>> Though you've said the -M log isn't helpful here, I think it is.  If
>> this is happening when a certain method is hit, or at a certain time of
>> day, or when a certain number of connections are reached, etc., the -M
>> log in combination with requestprofiler can help determine this.
>> Otherwise it's a guessing game.
>
> ok, just thought that maybe some exception can be caught.. I will try to
> use requestprofiler now, though I checked the -M log before and around
> that time there was no obvious problem.. (also it's not loaded at the
> moment and it's  happening here and then, don't see a pattern there..)
>
> I will check (and maybe change the mysql adapter, as I recently had
> problems with it on a sun machine, too).
>
> thanks anyway :)
>
> Christian
>
>
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