Veritas-bu

[Veritas-bu] Yet another bpstart/bpend script question

2007-01-19 11:48:59
Subject: [Veritas-bu] Yet another bpstart/bpend script question
From: Jason.Ellis at indymacbank.com (Ellis, Jason)
Date: Fri, 19 Jan 2007 08:48:59 -0800
Actually I plan to create .lock files for each stream as they call the
bpstart_notify script. For example:

Stream 1 starts and creates the stream_1.lock file.

Stream 2 starts and creates the stream_2.lock file.

Stream 3 starts and creates the stream_3.lock file.

Later:

Stream 2 completes and deletes its .lock file, but the bpend_notify
script still finds the .lock file for stream 1 and 3.

Stream 1 completes and deletes its .lock file, but the bpend_notify
script still finds the .lock file for stream 3.

Finally stream 3 completes and deletes its .lock file. The bpend_notify
script, not finding any more .lock files, runs the final tasks and
completes.

In theory this should work.

Jason Ellis
Technical Consultant, Data Protection Team
IndyMac Bank, La Mirada Datacenter
Phone: (714) 520-3414
Mobile: (714) 889-8734

-----Original Message-----
From: Ed Wilts [mailto:ewilts at ewilts.org] 
Sent: Thursday, January 18, 2007 7:42 PM
To: Ellis, Jason
Cc: veritas-bu at mailman.eng.auburn.edu
Subject: Re: [Veritas-bu] Yet another bpstart/bpend script question

On 1/18/2007 6:25 PM, Ellis, Jason wrote:
> I really need to capture the STREAM_NUMBER if possible to help
mitigate 
> a job with multiple data streams. My idea is to use lock files to 
> prevent the bpstart_notify from running once one stream has already 
> started, and the bpend_notify script from kicking off until the last 
> stream has completed.

This is a lost cause so save yourself some work.  There is no guarantee 
that the last stream won't complete before an earlier stream and unless 
you disallow retries completely, the task gets harder and harders.

What are you going to do if stream 1 starts, gets partially done, has a 
tape error, and retries?  What are you going to do if the last stream 
finishes early?  What are you going to do if the last stream dies 
completely and can't finish?

The problem is much harder than it looks...

        .../Ed

-- 
Ed Wilts, Mounds View, MN, USA
mailto:ewilts at ewilts.org