SQL Anywhere for Linux - An error occurred during the SharedMemory connection attempt

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An error occurred during the SharedMemory connection attempt

Hans Erik Büscher

2005-05-27, 8:23 pm

Hi..

Iam running 9.0.1 (1965) on Debian woody 2.4.24hl2. Multible databases on
one database server (29) shared memory connection in a pure web-envirenment
(Apache 1.3+php4+UnixODBC). Fairly complex application.

I have configured quite some shared memory :
sysctl -w kernel.shmmax=1073741824

But every three weeks or so I will get
Warning: SQL error: [Sybase][ODBC Driver][Adaptive Server
Anywhere]Connection error: An error occurred during the SharedMemory
connection attempt, SQL state 08001 in SQLConnect in /var/www/blablabla.php
on line 61
No database connection

No clues in the standard log-files.

Simple configuration-file for Sybase server: (no ti, no tl, no cl)
# Server:
-n Production1
#Translation OFF
-ct-
#Customer Databases
/home/DATA/Sybase/REXREX/REXREX.db -n REXREX
......... + 28 bases..

Should I look for unclosed cursors (stored procedures)? Memoryleaks ? Or
should I just realize I have to reboot the server once a week ??

Yours...
Hans Büscher...

Mark Culp

2005-05-30, 11:23 am

ASA does not use system shared memory, and therefore increasing the shmmax
value has not effect.

It is difficult to know the exact reason for the failed connection attempt,
but here are some things to look for:
- running out of SYSV semaphores (check ipcs outout)
- running out of disk space on your TMP drive (typically /tmp)
- exceeding licensed number of connections

You may need to turn on additional diagnostic messages by adding
"-z -os 10m" to the server start line (-z turns on diagnostics, -os 10m says
keep the console log size to 10m).
--
Mark Culp
SQLAnywhere Research and Development
-------------------------------------------------------------------------
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** iAnywhere Developer Community at http://www.ianywhere.com/developer **
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"Hans Erik Büscher" wrote:
>
> Hi..
>
> Iam running 9.0.1 (1965) on Debian woody 2.4.24hl2. Multible databases on
> one database server (29) shared memory connection in a pure web-envirenment
> (Apache 1.3+php4+UnixODBC). Fairly complex application.
>
> I have configured quite some shared memory :
> sysctl -w kernel.shmmax=1073741824
>
> But every three weeks or so I will get
> Warning: SQL error: [Sybase][ODBC Driver][Adaptive Server
> Anywhere]Connection error: An error occurred during the SharedMemory
> connection attempt, SQL state 08001 in SQLConnect in /var/www/blablabla.php
> on line 61
> No database connection
>
> No clues in the standard log-files.
>
> Simple configuration-file for Sybase server: (no ti, no tl, no cl)
> # Server:
> -n Production1
> #Translation OFF
> -ct-
> #Customer Databases
> /home/DATA/Sybase/REXREX/REXREX.db -n REXREX
> ........ + 28 bases..
>
> Should I look for unclosed cursors (stored procedures)? Memoryleaks ? Or
> should I just realize I have to reboot the server once a week ??
>
> Yours...
> Hans Büscher...

Hans Erik Büscher

2005-06-23, 1:23 pm

Oh.. Im pretty sure that the upgrade from 9.01 to 9.02 fixed the error.
Probably because of this correction:

================(Rel
ease Build - Engineering Case #359428)============
====

A memory leak can have occurred in the ODBC driver if the database server
closed the connection for any reason, for example an idle time-out.
A pointer to the driver's connection object was being set to null, but
the object was not freed. This has now been corrected.

It is also possible,thout that the inherent PHP-upgrade (woody->sarge) fixet
it.

§;>heb

"Mark Culp" < reply_to_newsgroups_
only_please_nospam_m
ark.culp@iAnywhere.com>
skrev i en meddelelse news:429B2B70.8AD9B7AD@iAnywhere.com...[color=darkred]
> ASA does not use system shared memory, and therefore increasing the shmmax
> value has not effect.
>
> It is difficult to know the exact reason for the failed connection
> attempt,
> but here are some things to look for:
> - running out of SYSV semaphores (check ipcs outout)
> - running out of disk space on your TMP drive (typically /tmp)
> - exceeding licensed number of connections
>
> You may need to turn on additional diagnostic messages by adding
> "-z -os 10m" to the server start line (-z turns on diagnostics, -os 10m
> says
> keep the console log size to 10m).
> --
> Mark Culp
> SQLAnywhere Research and Development
> -------------------------------------------------------------------------
> ** Whitepapers, TechDocs, bug fixes are all available through the **
> ** iAnywhere Developer Community at http://www.ianywhere.com/developer **
> -------------------------------------------------------------------------
>
> "Hans Erik Büscher" wrote:

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