Re^2: DBD::Sybase query execute hangs randomly for Sybase IQ 15.4

I've tried running the SQL separately and unfortunately it always runs to completion, giving me the expected result. In my original post I've only posted a small fragment of a much larger code which executes many similar SQL statements within a very short time (like within 1 minute). The code is in fact used in a Datastage parallel job which spawns at least 4 instances of my Perl code in parallel. The code always gets stuck for the same SQL rather than for random (similar) SQLs. I'm also consulting Sybase DBAs to see if there is a limitation on the number of active connections at any time (which may be a setting specific to my database, set by the DBA or may be a Sybase IQ 15.4 default behavior). Since DBD::Sybase works fine with Sybase IQ, I'm inclined to believe that the problem may be related to the database rather than the code itself. Since Sybase 15.4 is a pretty recent iteration of the IQ product, perhaps some default behavior may have changed, I'm really not sure at the moment.

Comment on Re^2: DBD::Sybase query execute hangs randomly for Sybase IQ 15.4

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Re^3: DBD::Sybase query execute hangs randomly for Sybase IQ 15.4 by jfroebe (Parson) on Jun 19, 2013 at 17:13 UTC
In case your dbas need information on the Config file. In particular, look at: -iqgovern Number of concurrent queries (default is 2num_cpu+10) -gm* Number of connections that can be active at one time You might be running into blocking locks if the parallel runs of your Perl code are hitting the same pages. As far as Perl goes, you may want to enable DBI Tracing to determine if there is something funky going on. Jason L. Froebe Blog, Tech Blog	[reply]
Re^4: DBD::Sybase query execute hangs randomly for Sybase IQ 15.4 by cmahajan (Initiate) on Jun 20, 2013 at 01:34 UTC
I'm going to enable DBI tracing and will check the trace file for any hints. Will update the results here.	[reply]
Re^4: DBD::Sybase query execute hangs randomly for Sybase IQ 15.4 by cmahajan (Initiate) on Jun 25, 2013 at 02:47 UTC
I enabled DBI Tracing in my script and here's the error message I got in the trace file. I was lucky enough that the issue occurred shortly after I added the tracing code in my code. From the error message I believe that this is related to the network configuration on my Unix machine (IBM AIX). Any ideas on how to go about fixing this? =================================== -> FETCH for DBD::Sybase::db (DBI::db=HASH(0x30844064)~INNER 'Driver') ERROR: 50 'OpenClient message: LAYER = (4) ORIGIN = (1) SEVERITY = (5) NUMBER = (28) Server bhedw_dev, database Message String: ct_results(): protocol specific layer: external error: There is a tds protocol error. An illegal token was received. OpenClient message: LAYER = (1) ORIGIN = (1) SEVERITY = (1) NUMBER = (50) Server bhedw_dev, database Message String: ct_cmd_drop(): user api layer: external error: The connection has been marked dead. ===================================	[reply]
Re^5: DBD::Sybase query execute hangs randomly for Sybase IQ 15.4 by jfroebe (Parson) on Sep 19, 2013 at 13:08 UTC
Try running the query from isql or dbisql. isql will handle t-sql and dbisql will handle Watcom-SQL. Jason L. Froebe Blog, Tech Blog	[reply]