IDS Forum

RE: RE: Long Checkpoints with HDR and 11.5.

Posted By: Knox, Ernest
Date: Tuesday, 16 March 2010, at 4:44 p.m.

In Response To: Re: RE: Long Checkpoints with HDR and 11.5. (JACQUES RENAUT)

Well, the Informix tech replied as follows:

Further research revealed that the defect fix in 11.50.xC5 is only a
partial fix to the problem. The 11.50.xC6 contains another fix which is
supposed to finish the job.

We'll let you know how it turns out with FC6.

Thanks for all suggestions,
*******************************************************************
Ernie Knox
IT Database Administrator Specialist
Sears Holdings
3333 Beverly Rd., B4-266A
Hoffman Estates, IL. 60179
Office: (847) 286-5735
Email: Ernest.Knox@searshc.com
Blackberry: 2244650553@messaging.sprintpcs.com
Page via Skytel: 2244650553@sprint.skytel.com
Informix or MySQL Primary: 9110210@skytel.com
Informix or MySQL Secondary: 7276872@skytel.com

" Yes we can make a Change! "
" It's always a great day to watch Sports - GO LIONS, TIGERS, and BEARS!
"
" Lets not forget - GO Pistons and Red Wings! "
GSU
*******************************************************************

-----Original Message-----
From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
JACQUES RENAUT
Sent: Monday, March 15, 2010 2:08 PM
To: ids@iiug.org
Subject: Re: RE: Long Checkpoints with HDR and 11.5. [19343]

Art Kagel wrote:

No, Jacques, IDS secondaries do not share buffer pool updates with the
primary. Only the logical log buffers are transferred, so only the
server's
transaction rate would affect the data transfer rate between the servers
and
that would be about the same regardless of the LRU_MIN/MAX_DIRTY
settings.
Now changing the size of the logical log buffer on the other hand, would

have some effect, but minor, and the discrepancy between the number of
CPU
VPs on the two servers will have a much bigger effect.

Art

Art S. Kagel
Advanced DataTools (www.advancedatatools.com)

Reply:

No the secondaries do not share buffer pools, however, as log records
are
applied on the secondary, they mark buffers as dirty, and as part of the

checkpoint processing (ie when the secondary gets the logical log record
of
the checkpoint from the primary) the secondary is required to flush the
buffer
pool. Sorry if I was unclear in my first post, but trust me, I know what
I'm
talking about as I entered the defect. The way this buffer pool flush is
done
on the secondary can indeed hold up the primary. What you would see if
user
threads waiting on the log buff condition and you would see the
dr_prsend
thread waiting on the drcb_bqe condition. Now you can see that for other

reasons as well, but one reason is cause due to large buffer pool
flushing on
the secondary. Please refer to APAR IC60754.

Jacques Renaut
IBM Informix Advanced Support
APD Team

************************************************************************
*******
Forum Note: Use "Reply" to post a response in the discussion forum.

Messages In This Thread

• RE: Long Checkpoints with HDR and 11.5.
  Knox, Ernest -- Monday, 15 March 2010, at 1:01 p.m.
  • RE: Long Checkpoints with HDR and 11.5.
    Madison Pruet -- Monday, 15 March 2010, at 1:07 p.m.
    • RE: Long Checkpoints with HDR and 11.5.
      Knox, Ernest -- Monday, 15 March 2010, at 1:41 p.m.
      • RE: Long Checkpoints with HDR and 11.5.
        Madison Pruet -- Monday, 15 March 2010, at 2:33 p.m.
  • Re: RE: Long Checkpoints with HDR and 11.5.
    JACQUES RENAUT -- Monday, 15 March 2010, at 2:03 p.m.
    • Re: RE: Long Checkpoints with HDR and 11.5.
      Art Kagel -- Monday, 15 March 2010, at 2:29 p.m.
      • Re: RE: Long Checkpoints with HDR and 11.5.
        JACQUES RENAUT -- Monday, 15 March 2010, at 3:07 p.m.
        • RE: RE: Long Checkpoints with HDR and 11.5.
          Knox, Ernest -- Tuesday, 16 March 2010, at 4:44 p.m.
          • Re: RE: RE: Long Checkpoints with HDR and 11.5.
            JACQUES RENAUT -- Tuesday, 16 March 2010, at 5:21 p.m.
            • Re: RE: RE: Long Checkpoints with HDR and 11.5.
              Madison Pruet -- Tuesday, 16 March 2010, at 7:23 p.m.
            • RE: RE: RE: Long Checkpoints with HDR and 11.5.
              Knox, Ernest -- Tuesday, 16 March 2010, at 11:44 p.m.
    • Re: RE: Long Checkpoints with HDR and 11.5.
      Madison Pruet -- Monday, 15 March 2010, at 2:34 p.m.

IDS Forum is maintained by Administrator with WebBBS 5.12.