Portal | Manuals | References | Downloads | Info | Programs | JCLs | Master the Mainframes
IBM Mainframe Computers Forums Index
 
Register
 
IBM Mainframe Computers Forums Index Mainframe: Search IBM Mainframe Forum: FAQ Memberlist Usergroups Profile Log in to check your private messages Log in
 

 

Accessing VSAM file in CICS and Batch

 
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> CICS
View previous topic :: :: View next topic  
Author Message
Pandora-Box

Moderator


Joined: 07 Sep 2006
Posts: 1529
Location: Andromeda Galaxy

PostPosted: Tue Jul 24, 2012 8:54 pm    Post subject: Accessing VSAM file in CICS and Batch
Reply with quote

Hi all,

Is there any other best way to access VSAM file from CICS ( Which just does a read ) and Batch process ( Updates the vsam file ) simultaneously apart from using RLS option which is not being an option in my shop??

Also this should be achieved without bothering CICS program execution.

Any suggestions or pointers will be really helpful indeed

Thanks
Back to top
View user's profile Send private message

Robert Sample

Global Moderator


Joined: 06 Jun 2008
Posts: 7913
Location: Bellevue, IA

PostPosted: Tue Jul 24, 2012 8:59 pm    Post subject:
Reply with quote

Are you expecting that the CICS region will be able to retrieve the updates made by the batch program?

There is a defined interface to allow batch programs access to CICS files (actually, there's even more than one such interface). You would do best by reading up on them.
Back to top
View user's profile Send private message
Pandora-Box

Moderator


Joined: 07 Sep 2006
Posts: 1529
Location: Andromeda Galaxy

PostPosted: Tue Jul 24, 2012 9:13 pm    Post subject:
Reply with quote

Quote:
Are you expecting that the CICS region will be able to retrieve the updates made by the batch program?


Doesnt RLS option in FCT support this??

I understand RLS is something like SHR (in JCL) which allows others to use the file so probably when it gets overwritten is it not possible to read updated data ?? Please correct my understanding icon_redface.gif

Since my shop doesnt support I coudnt try that out

Quote:
There is a defined interface to allow batch programs access to CICS files (actually, there's even more than one such interface). You would do best by reading up on them.


I am sorry I really dont know the name of the interface so only then I can read about them icon_sad.gif icon_sad.gif
Back to top
View user's profile Send private message
Peter cobolskolan

Active User


Joined: 06 Feb 2012
Posts: 104
Location: Sweden

PostPosted: Tue Jul 24, 2012 9:19 pm    Post subject: Reply to: Accessing VSAM file in CICS and Batch
Reply with quote

EXCI, EXternal Cics Interface, not to be mixed up with ECI, External Call Interface.
Back to top
View user's profile Send private message
Pandora-Box

Moderator


Joined: 07 Sep 2006
Posts: 1529
Location: Andromeda Galaxy

PostPosted: Tue Jul 24, 2012 9:43 pm    Post subject:
Reply with quote

Thanks Peter would try it and get back.
Back to top
View user's profile Send private message
Robert Sample

Global Moderator


Joined: 06 Jun 2008
Posts: 7913
Location: Bellevue, IA

PostPosted: Tue Jul 24, 2012 9:44 pm    Post subject:
Reply with quote

Make up your mind what you want. This
Quote:
apart from using RLS option which is not being an option in my shop??
directly contradicts
Quote:
Doesnt RLS option in FCT support this??
If your site doesn't allow RLS, why do you keep bringing it up? If you're not using RLS, you need to be familiar with how CICS handles data going to and from a file -- for example, there's been more than one post on this forum where someone expected data written by CICS to be immediately available to a batch program and unless the application takes steps to ensure that CICS is flushing the buffers, the data won't necessarily be seen by batch programs for possibly many hours.

The CICS External Interfaces Guide manual is a good place to start reading on the EXCI interface.
Back to top
View user's profile Send private message
dick scherrer

Site Director


Joined: 23 Nov 2006
Posts: 19270
Location: Inside the Matrix

PostPosted: Tue Jul 24, 2012 10:06 pm    Post subject: Reply to: Accessing VSAM file in CICS and Batch
Reply with quote

Hi Robert,

I believe in this case, the CICS access will be only reads. If i understand the question (and i well may not), will the batch updates be visable to online reads?

Hope i've not provided any confusion/mis-direction.

The good news is that if i have, i can remove it icon_cool.gif

d
Back to top
View user's profile Send private message
Pandora-Box

Moderator


Joined: 07 Sep 2006
Posts: 1529
Location: Andromeda Galaxy

PostPosted: Tue Jul 24, 2012 10:08 pm    Post subject:
Reply with quote

Hi Dick,

You got it right!!
Back to top
View user's profile Send private message
dbzTHEdinosauer

Global Moderator


Joined: 20 Oct 2006
Posts: 6966
Location: porcelain throne

PostPosted: Tue Jul 24, 2012 10:32 pm    Post subject:
Reply with quote

what you are asking for is a batch update to cause cics to refresh its buffers
(in the case the updated record is in a ci currently in a buffer)

i don't feel like spending the time to research in order to justify or refute the above.
i can only guess, so i will not.
Back to top
View user's profile Send private message
Bill O'Boyle

CICS Moderator


Joined: 14 Jan 2008
Posts: 2502
Location: Atlanta, Georgia, USA

PostPosted: Tue Jul 24, 2012 10:33 pm    Post subject: Reply to: Accessing VSAM file in CICS and Batch
Reply with quote

SYSB II from H&W Computer Systems is a viable option -

http://www.hwcs.com/software/sysb-ii
Back to top
View user's profile Send private message
Robert Sample

Global Moderator


Joined: 06 Jun 2008
Posts: 7913
Location: Bellevue, IA

PostPosted: Tue Jul 24, 2012 10:39 pm    Post subject:
Reply with quote

That will depend upon whether or not the VSAM file is in an LSR pool. From the CICS Performance Guide in the VSAM Tuning section:
Quote:
Before issuing a read to disk when using LSR, VSAM first scans the buffers to check if the control interval it requires is already in storage. If so, it may not have to issue the read. This buffer "lookaside" can reduce I/O significantly.
So if you're using LSR, the batch update wouldn't necessarily be seen by CICS, although the manual is not clear about precisely what circumstances would cause a buffer read versus disk access. Either don't use LSR for the file (which may, in turn, cause other performance issues) or do some testing before implementing the situation you're talking about to see how it works in reality.
Back to top
View user's profile Send private message
Pandora-Box

Moderator


Joined: 07 Sep 2006
Posts: 1529
Location: Andromeda Galaxy

PostPosted: Wed Jul 25, 2012 12:09 am    Post subject:
Reply with quote

Looks like lot of reading need to be done ahead

Thanks all
Back to top
View user's profile Send private message
vasanthz

Global Moderator


Joined: 28 Aug 2007
Posts: 1445
Location: Azeroth

PostPosted: Wed Jul 25, 2012 11:21 am    Post subject:
Reply with quote

Hello,
Quote:
Is there any other best way to access VSAM file from CICS ( Which just does a read ) and Batch process ( Updates the vsam file ) simultaneously apart from using RLS

I think DFSMStvs - (transactional vsam services) allows VSAM sharing between CICS and Batch.
DFSMS Transactional VSAM Services (DFSMStvs) is an optional z/OS feature that enables batch jobs and CICS online transactions to update shared VSAM data sets concurrently. Multiple batch jobs and online transactions can be run against the same VSAM data sets, and DFSMStvs helps ensure data integrity for concurrent batch updates while CICS ensures it for online updates.

I have no personal experience in using it, just theoritical idea of how it works with coupling facility processors.
Back to top
View user's profile Send private message
Pandora-Box

Moderator


Joined: 07 Sep 2006
Posts: 1529
Location: Andromeda Galaxy

PostPosted: Wed Jul 25, 2012 7:36 pm    Post subject:
Reply with quote

Thanks all for your inputs & time very valuable indeed.

Also the design is changed to make sure the file is closed and opened again in FCT after VSAM file is updated
Back to top
View user's profile Send private message
Jose Mateo

Active User


Joined: 29 Oct 2010
Posts: 110
Location: Puerto Rico

PostPosted: Mon Jul 30, 2012 7:51 pm    Post subject: Reply to: Accessing VSAM file in CICS and Batch
Reply with quote

Good day to all!

Read up on VSAM share options. Specifing the correct share option you could do what you are asking for.
Back to top
View user's profile Send private message
View previous topic :: :: View next topic  
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> CICS All times are GMT + 6 Hours
Page 1 of 1

 

Search our Forum:

Similar Topics
Topic Author Forum Replies Posted
No new posts CICS START AND CANCEL blayek CICS 1 Wed Dec 07, 2016 3:27 am
No new posts Add PD field from 2nd file to PD in 1st Sushant Garje DFSORT/ICETOOL 6 Thu Dec 01, 2016 4:32 pm
No new posts How does a called pgm know if its cal... Graeme Westerman COBOL Programming 4 Tue Nov 29, 2016 9:25 pm
No new posts File Aid to File Manager conversion murali3955 IBM Tools 4 Thu Nov 24, 2016 3:41 pm
No new posts How to convert the VBM file to VB or... Sulabh Agrawal JCL & VSAM 4 Fri Nov 18, 2016 1:04 pm


Facebook
Back to Top
 
Mainframe Wiki | Forum Rules | Bookmarks | Subscriptions | FAQ | Tutorials | Contact Us