IDS Forum

Re: Long Blocking Checkpoint Duration And IDS 12.1

Posted By: Art Kagel
Date: Monday, 1 December 2014, at 8:24 a.m.

In Response To: Long Blocking Checkpoint Duration And IDS 12.1 Msg (NATYURAL HORACIO)

Tuning checkpoint duration and block time:

1. Reduce IO at checkpoint time by decreasing lru_min_dirty and

lru_max_dirty settings in your BUFFERPOOL parameters to flush more

aggressively between checkpoints.

2. Avoid AUTO_CKPTS and RTO_SERVER_RESTART.

3. Make all databases UNBUFFERED logging or use a small logical log

buffer if using BUFFERED logging.

4. Make sure that logical log, physical log, and data chunks are all on

separate sets of spindles from each other.

5. Make sure that there are as many CLEANERS configured as the larger of

actively updated #chunks and #lru queues (up to the max of 128).

6. NO RAID5!!!!!!!!!!!

7. No VMs running servers with high data volume requirements.

Art

Art S. Kagel, President and Principal Consultant
ASK Database Management
www.askdbmgt.com

Blog: http://informix-myview.blogspot.com/

Disclaimer: Please keep in mind that my own opinions are my own opinions
and do not reflect on the IIUG, nor any other organization with which I am
associated either explicitly, implicitly, or by inference. Neither do
those opinions reflect those of other individuals affiliated with any
entity with which I am affiliated nor those of the entities themselves.

On Mon, Dec 1, 2014 at 7:29 AM, NATYURAL HORACIO <horacio.natyural@gmail.com
> wrote:

> Hi,
>
> We are suddenly getting very long checkpoint durations.
>
> I would like to ask if any of you have encountered this error message ?
>
> We are already using the latest build of informix 12.1
>
> Thank you.
>
> 15:32:31 Physical Logging during partition extend: Number of bit map pages
> to
> be logged in critcal section: 62 Remaining Phyical Log: 370473
> 15:34:34 Checkpoint Completed: duration was 302 seconds.
> 15:34:34 Tue Nov 25 - loguniq 1312102, logpos 0xa73e018, timestamp:
> 0x60494ffc
> Interval: 689688
>
> 15:34:34 Maximum server connections 1663
> 15:34:34 Checkpoint Statistics - Avg. Txn Block Time 291.913, # Txns
> blocked
> 721, Plog used 9528, Llog used 37075
>
> Please take note that the average transaction blocktime is very high 291
> seconds and the checkpoint duration was very high as well.
>
> I just would like to know if the messages are related to each other. The
> physical logging during partition extend.
>
> I tried searching the net and the forums but no explanation yet.
>
> Please help as we are experiencing issues when the long checkpoints happen.
> Also, what parameter can be tuned for the long checkpoint we have or are
> the
> two messages related ?
>
> Thank you.
>
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

--089e0158b6b83080c305092786b5

Messages In This Thread

• Long Blocking Checkpoint Duration And IDS 12.1 Msg
  NATYURAL HORACIO -- Monday, 1 December 2014, at 7:29 a.m.
  • Re: Long Blocking Checkpoint Duration And IDS 12.1
    NATYURAL HORACIO -- Monday, 1 December 2014, at 7:34 a.m.
    • Re: Long Blocking Checkpoint Duration And IDS ....
      Art Kagel -- Monday, 1 December 2014, at 8:25 a.m.
      • Re: Long Blocking Checkpoint Duration And IDS ....
        NATYURAL HORACIO -- Monday, 1 December 2014, at 9:04 a.m.
  • Re: Long Blocking Checkpoint Duration And IDS 12.1
    Art Kagel -- Monday, 1 December 2014, at 8:24 a.m.
    • Re: Long Blocking Checkpoint Duration And IDS 12.1
      NATYURAL HORACIO -- Monday, 1 December 2014, at 8:39 a.m.
      • RE: Long Blocking Checkpoint Duration And IDS 12.1
        Mike Walker -- Monday, 1 December 2014, at 9:03 a.m.
      • Re: Long Blocking Checkpoint Duration And IDS 12.1
        Art Kagel -- Monday, 1 December 2014, at 11:08 a.m.

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