Mixed Sessions: HELP!! ( JAVA-DB2ConnectEE-DB2v6OS390-StoredProced ures)

Slot J.P.

Mixed Sessions: HELP!! ( JAVA-DB2ConnectEE-DB2v6OS390-StoredProced ures)
Dear Listers,

We have a situation using DB2 Connect 7.1 EE on NT for a JAVA application
using JDBC connecting to OS/390 DB2 v 6 using Cobol Stored Proceudes. In
this situation the end users get the results of anothers users transaction
on his/her screen. This is quite disturbing as you can imagine. Did anyone
encounter this problem somewhere with JAVA-DB2Connect-StoredProcedures?
Are there do's and don'ts in coding we might not be aware of?
Any help is much appreciated.

Kind regards,

Jaap Slot

Data Service Center
Rabobank ICT


Telephone 0031 (0)30 215 2220
Fax 0031 (0)30 215 3003
Mobile 0031 (0)6 5374 0167
mailto:[login to unmask email]










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Myron Miller

Re: Mixed Sessions: HELP!! ( JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)
(in response to Slot J.P.)
I saw this same problem with 7.1 and JAVA early. Are you on at least
fixpack 2a? And are you using pooling? Also, we had some problems with the
way the JAVA programs were connecting (source coding issues). We changed to
a more consistent connection interface (I don't remember the exact details).
Also we were using DB2 Connect pooling rather than JAVA Application Server
pooling. When we got rid of the DB2 Connect pooling the issue went away.

If you could provide some more details about your environment, such as
fixpack, pooling used, type of JAVA being used (beans or straight), it would
be helpful.

-----Original Message-----
From: Slot, JP (Jaap) [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 7:16 AM
To: [login to unmask email]
Subject: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredProced ures)
Importance: High


Dear Listers,

We have a situation using DB2 Connect 7.1 EE on NT for a JAVA application
using JDBC connecting to OS/390 DB2 v 6 using Cobol Stored Proceudes. In
this situation the end users get the results of anothers users transaction
on his/her screen. This is quite disturbing as you can imagine. Did anyone
encounter this problem somewhere with JAVA-DB2Connect-StoredProcedures?
Are there do's and don'ts in coding we might not be aware of?
Any help is much appreciated.

Kind regards,

Jaap Slot

Data Service Center
Rabobank ICT


Telephone 0031 (0)30 215 2220
Fax 0031 (0)30 215 3003
Mobile 0031 (0)6 5374 0167
mailto:[login to unmask email]










De informatie opgenomen in dit bericht kan vertrouwelijk zijn en
is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht
onterecht ontvangt, wordt u verzocht de inhoud niet te gebruiken en
de afzender direct te informeren door het bericht te retourneren.

The information contained in this message may be confidential
and is intended to be exclusively for the addressee. Should you
receive this message unintentionally, please do not use the contents
herein and notify the sender immediately by return e-mail.








Slot J.P.

Re: Mixed Sessions: HELP!! ( JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)
(in response to Myron Miller)
Myron,

I'm not sure what you mean with fixpack 2a, how can I find out?
We're not using pooling ; DB2CONNECT_IN_APP_PROCESS is not in effect.
We're not using beans, straight JAVA is used. We're also using MTS.EXE, does
that help you.
It would be so nice if you could remember some (juicy) details..
Thanks for your answer so far. It's good to know the problem has been
encountered before. Looking forward to your answer.

Kind Regards,

Jaap Slot

-----Original Message-----
From: Myron Miller [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 2:00 PM
To: [login to unmask email]
Subject: Re: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)


I saw this same problem with 7.1 and JAVA early. Are you on at least
fixpack 2a? And are you using pooling? Also, we had some problems with the
way the JAVA programs were connecting (source coding issues). We changed to
a more consistent connection interface (I don't remember the exact details).
Also we were using DB2 Connect pooling rather than JAVA Application Server
pooling. When we got rid of the DB2 Connect pooling the issue went away.

If you could provide some more details about your environment, such as
fixpack, pooling used, type of JAVA being used (beans or straight), it would
be helpful.

-----Original Message-----
From: Slot, JP (Jaap) [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 7:16 AM
To: [login to unmask email]
Subject: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredProced ures)
Importance: High


Dear Listers,

We have a situation using DB2 Connect 7.1 EE on NT for a JAVA application
using JDBC connecting to OS/390 DB2 v 6 using Cobol Stored Proceudes. In
this situation the end users get the results of anothers users transaction
on his/her screen. This is quite disturbing as you can imagine. Did anyone
encounter this problem somewhere with JAVA-DB2Connect-StoredProcedures?
Are there do's and don'ts in coding we might not be aware of?
Any help is much appreciated.

Kind regards,

Jaap Slot

Data Service Center
Rabobank ICT


Telephone 0031 (0)30 215 2220
Fax 0031 (0)30 215 3003
Mobile 0031 (0)6 5374 0167
mailto:[login to unmask email]










De informatie opgenomen in dit bericht kan vertrouwelijk zijn en
is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht
onterecht ontvangt, wordt u verzocht de inhoud niet te gebruiken en
de afzender direct te informeren door het bericht te retourneren.

The information contained in this message may be confidential
and is intended to be exclusively for the addressee. Should you
receive this message unintentionally, please do not use the contents
herein and notify the sender immediately by return e-mail.














De informatie opgenomen in dit bericht kan vertrouwelijk zijn en
is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht
onterecht ontvangt, wordt u verzocht de inhoud niet te gebruiken en
de afzender direct te informeren door het bericht te retourneren.

The information contained in this message may be confidential
and is intended to be exclusively for the addressee. Should you
receive this message unintentionally, please do not use the contents
herein and notify the sender immediately by return e-mail.



Myron Miller

Re: Mixed Sessions: HELP!! ( JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)
(in response to Slot J.P.)
You can go to the DB2 UDB site and see the various fixes. IBM releases sets
of fixes in what's called a fixpack and numbers them sequentially from the
release of the product: 1,2,3,4 etc. Fixpack 2a is a special correction
fixpack for FIXPACK 2 that resolves some problems with UDB, especially on
AIX servers. The current fixpack is 4. Catch in using 4 is if you are
using DB2 stored procedure builder, you must be fairly current with your DB2
maintenance as there is a required PTF for DB2 OS/390 that must be on for
Fixpack 4 to work correctly. And that PTF requires fixpack 4 to work
correctly as well.

Personally, right now, I'd recommend either fixpack 3 or 2a as the ones to
install. Fixpack 3 is essentially DB2 Connect 7.2 (DB2 UDB 7.2 also) and is
the latest point release of DB2 Connect.

I'm not sure how MTS.EXE comes into play with JAVA. Never seen it used here
so I cannot comment on it. I not sure of all the JAVA things because the
application was in the process of making a number of significant changes at
the time and the resolution just kinda fell out.

I do know that if you don't follow the following steps you can have
problems:
1) OPEN JDBC connection;
2) open statement
3) get data
4) close statement
5) close connection

And its critical to close the statement and the connection everywhere. That
is, even if you get thrown a JAVA or JDBC exception, you must close the
statement and connection. Otherwise bad things happen.

-----Original Message-----
From: Slot, JP (Jaap) [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 12:27 PM
To: [login to unmask email]
Subject: Re: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)


Myron,

I'm not sure what you mean with fixpack 2a, how can I find out?
We're not using pooling ; DB2CONNECT_IN_APP_PROCESS is not in effect.
We're not using beans, straight JAVA is used. We're also using MTS.EXE, does
that help you.
It would be so nice if you could remember some (juicy) details..
Thanks for your answer so far. It's good to know the problem has been
encountered before. Looking forward to your answer.

Kind Regards,

Jaap Slot

-----Original Message-----
From: Myron Miller [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 2:00 PM
To: [login to unmask email]
Subject: Re: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)


I saw this same problem with 7.1 and JAVA early. Are you on at least
fixpack 2a? And are you using pooling? Also, we had some problems with the
way the JAVA programs were connecting (source coding issues). We changed to
a more consistent connection interface (I don't remember the exact details).
Also we were using DB2 Connect pooling rather than JAVA Application Server
pooling. When we got rid of the DB2 Connect pooling the issue went away.

If you could provide some more details about your environment, such as
fixpack, pooling used, type of JAVA being used (beans or straight), it would
be helpful.

-----Original Message-----
From: Slot, JP (Jaap) [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 7:16 AM
To: [login to unmask email]
Subject: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredProced ures)
Importance: High


Dear Listers,

We have a situation using DB2 Connect 7.1 EE on NT for a JAVA application
using JDBC connecting to OS/390 DB2 v 6 using Cobol Stored Proceudes. In
this situation the end users get the results of anothers users transaction
on his/her screen. This is quite disturbing as you can imagine. Did anyone
encounter this problem somewhere with JAVA-DB2Connect-StoredProcedures?
Are there do's and don'ts in coding we might not be aware of?
Any help is much appreciated.

Kind regards,

Jaap Slot

Data Service Center
Rabobank ICT


Telephone 0031 (0)30 215 2220
Fax 0031 (0)30 215 3003
Mobile 0031 (0)6 5374 0167
mailto:[login to unmask email]










De informatie opgenomen in dit bericht kan vertrouwelijk zijn en
is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht
onterecht ontvangt, wordt u verzocht de inhoud niet te gebruiken en
de afzender direct te informeren door het bericht te retourneren.

The information contained in this message may be confidential
and is intended to be exclusively for the addressee. Should you
receive this message unintentionally, please do not use the contents
herein and notify the sender immediately by return e-mail.














De informatie opgenomen in dit bericht kan vertrouwelijk zijn en
is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht
onterecht ontvangt, wordt u verzocht de inhoud niet te gebruiken en
de afzender direct te informeren door het bericht te retourneren.

The information contained in this message may be confidential
and is intended to be exclusively for the addressee. Should you
receive this message unintentionally, please do not use the contents
herein and notify the sender immediately by return e-mail.








Horacio Villa

Re: Mixed Sessions: HELP!! ( JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)
(in response to Myron Miller)
This is a question on JAAP's problem:
Could this happen because JAAP is using Temporary Tables in his stored
procedures and all the users are connecting to DB2 with the same userid and
everyone goes to the same Temporary Table?
Kind regards,
Horacio Villa
TTI S.A.
Buenos Aires - Argentina


-----Mensaje original-----
De: DB2 Data Base Discussion List En nombre de Myron Miller
Enviado el: Miércoles 21 de Noviembre de 2001 10:43
Para: [login to unmask email]
Asunto: Re: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)


You can go to the DB2 UDB site and see the various fixes. IBM releases sets
of fixes in what's called a fixpack and numbers them sequentially from the
release of the product: 1,2,3,4 etc. Fixpack 2a is a special correction
fixpack for FIXPACK 2 that resolves some problems with UDB, especially on
AIX servers. The current fixpack is 4. Catch in using 4 is if you are
using DB2 stored procedure builder, you must be fairly current with your DB2
maintenance as there is a required PTF for DB2 OS/390 that must be on for
Fixpack 4 to work correctly. And that PTF requires fixpack 4 to work
correctly as well.

Personally, right now, I'd recommend either fixpack 3 or 2a as the ones to
install. Fixpack 3 is essentially DB2 Connect 7.2 (DB2 UDB 7.2 also) and is
the latest point release of DB2 Connect.

I'm not sure how MTS.EXE comes into play with JAVA. Never seen it used here
so I cannot comment on it. I not sure of all the JAVA things because the
application was in the process of making a number of significant changes at
the time and the resolution just kinda fell out.

I do know that if you don't follow the following steps you can have
problems:
1) OPEN JDBC connection;
2) open statement
3) get data
4) close statement
5) close connection

And its critical to close the statement and the connection everywhere. That
is, even if you get thrown a JAVA or JDBC exception, you must close the
statement and connection. Otherwise bad things happen.

-----Original Message-----
From: Slot, JP (Jaap) [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 12:27 PM
To: [login to unmask email]
Subject: Re: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)


Myron,

I'm not sure what you mean with fixpack 2a, how can I find out?
We're not using pooling ; DB2CONNECT_IN_APP_PROCESS is not in effect.
We're not using beans, straight JAVA is used. We're also using MTS.EXE, does
that help you.
It would be so nice if you could remember some (juicy) details..
Thanks for your answer so far. It's good to know the problem has been
encountered before. Looking forward to your answer.

Kind Regards,

Jaap Slot

-----Original Message-----
From: Myron Miller [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 2:00 PM
To: [login to unmask email]
Subject: Re: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)


I saw this same problem with 7.1 and JAVA early. Are you on at least
fixpack 2a? And are you using pooling? Also, we had some problems with the
way the JAVA programs were connecting (source coding issues). We changed to
a more consistent connection interface (I don't remember the exact details).
Also we were using DB2 Connect pooling rather than JAVA Application Server
pooling. When we got rid of the DB2 Connect pooling the issue went away.

If you could provide some more details about your environment, such as
fixpack, pooling used, type of JAVA being used (beans or straight), it would
be helpful.

-----Original Message-----
From: Slot, JP (Jaap) [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 7:16 AM
To: [login to unmask email]
Subject: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredProced ures)
Importance: High


Dear Listers,

We have a situation using DB2 Connect 7.1 EE on NT for a JAVA application
using JDBC connecting to OS/390 DB2 v 6 using Cobol Stored Proceudes. In
this situation the end users get the results of anothers users transaction
on his/her screen. This is quite disturbing as you can imagine. Did anyone
encounter this problem somewhere with JAVA-DB2Connect-StoredProcedures?
Are there do's and don'ts in coding we might not be aware of?
Any help is much appreciated.

Kind regards,

Jaap Slot

Data Service Center
Rabobank ICT


Telephone 0031 (0)30 215 2220
Fax 0031 (0)30 215 3003
Mobile 0031 (0)6 5374 0167
mailto:[login to unmask email]










De informatie opgenomen in dit bericht kan vertrouwelijk zijn en
is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht
onterecht ontvangt, wordt u verzocht de inhoud niet te gebruiken en
de afzender direct te informeren door het bericht te retourneren.

The information contained in this message may be confidential
and is intended to be exclusively for the addressee. Should you
receive this message unintentionally, please do not use the contents
herein and notify the sender immediately by return e-mail.


visit the




visit the






De informatie opgenomen in dit bericht kan vertrouwelijk zijn en
is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht
onterecht ontvangt, wordt u verzocht de inhoud niet te gebruiken en
de afzender direct te informeren door het bericht te retourneren.

The information contained in this message may be confidential
and is intended to be exclusively for the addressee. Should you
receive this message unintentionally, please do not use the contents
herein and notify the sender immediately by return e-mail.


visit the




visit the





Fred Nijdam

Re: Mixed Sessions: HELP!! ( JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)
(in response to Horacio Villa)
Great, suggestion!. I'll check this tomorrow - with JAAP. It's not that
long ago that they asked me to implement the temporary table(space).

With regards.



Slot J.P.

Re: Mixed Sessions: HELP!! ( JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)
(in response to Fred Nijdam)
Myron,

Thanks for your help with this. It took some time to figure out what the
problem really was.
This week we found and fixed the real problem. It turned out to be a caching
problem within the JAVA code.
Caching was done of the object parameters, the instances occasionaly were
overwritten by one another. We turned this caching off and tested for a
possible degrading performance.
It turned out the performance got better (no errors anymore) and the
application stays stable.

Thanks again for your remarks!

Kind regards,

Jaap Slot.

-----Original Message-----
From: Myron Miller [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 2:00 PM
To: [login to unmask email]
Subject: Re: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredP roced ures)


I saw this same problem with 7.1 and JAVA early. Are you on at least
fixpack 2a? And are you using pooling? Also, we had some problems with the
way the JAVA programs were connecting (source coding issues). We changed to
a more consistent connection interface (I don't remember the exact details).
Also we were using DB2 Connect pooling rather than JAVA Application Server
pooling. When we got rid of the DB2 Connect pooling the issue went away.

If you could provide some more details about your environment, such as
fixpack, pooling used, type of JAVA being used (beans or straight), it would
be helpful.

-----Original Message-----
From: Slot, JP (Jaap) [mailto:[login to unmask email]
Sent: Tuesday, November 20, 2001 7:16 AM
To: [login to unmask email]
Subject: Mixed Sessions: HELP!! (
JAVA-DB2ConnectEE-DB2v6OS390-StoredProced ures)
Importance: High


Dear Listers,

We have a situation using DB2 Connect 7.1 EE on NT for a JAVA application
using JDBC connecting to OS/390 DB2 v 6 using Cobol Stored Proceudes. In
this situation the end users get the results of anothers users transaction
on his/her screen. This is quite disturbing as you can imagine. Did anyone
encounter this problem somewhere with JAVA-DB2Connect-StoredProcedures?
Are there do's and don'ts in coding we might not be aware of?
Any help is much appreciated.

Kind regards,

Jaap Slot

Data Service Center
Rabobank ICT


Telephone 0031 (0)30 215 2220
Fax 0031 (0)30 215 3003
Mobile 0031 (0)6 5374 0167
mailto:[login to unmask email]










De informatie opgenomen in dit bericht kan vertrouwelijk zijn en
is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht
onterecht ontvangt, wordt u verzocht de inhoud niet te gebruiken en
de afzender direct te informeren door het bericht te retourneren.

The information contained in this message may be confidential
and is intended to be exclusively for the addressee. Should you
receive this message unintentionally, please do not use the contents
herein and notify the sender immediately by return e-mail.














De informatie opgenomen in dit bericht kan vertrouwelijk zijn en
is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht
onterecht ontvangt, wordt u verzocht de inhoud niet te gebruiken en
de afzender direct te informeren door het bericht te retourneren.

The information contained in this message may be confidential
and is intended to be exclusively for the addressee. Should you
receive this message unintentionally, please do not use the contents
herein and notify the sender immediately by return e-mail.