IDS Forum

Re: New RFE entry needs votes

Posted By: Fernando Nunes
Date: Tuesday, 9 January 2018, at 8:23 a.m.

In Response To: Re: New RFE entry needs votes (BENJAMIN THOMPSON)

I suppose the problem is that we rarely use the logical log buffer fully.
On a busy system there's constantly some session doing a commit. And that
causes the flush of the logical log buffer.
This can frequently cause issues due to the saturation of the HDR buffers
(12, and not configurable) and eventually in worse scenarios, it may not
leave enough time to flush the buffer until it's needed again.
I must say I never faced this last situation, but it's common to see the
one caused by the HDR buffers.

3 years ago I created another RFE around the same issue:

http://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=45166

The idea here would be to delay the commit response to the application,
allowing the buffer to fill a bit more. The idea sounds good, and DB2 does
(or used to do) that. I think Oracle also implements something like this.
However I've heard informally (couldn't confirm) that this was removed from
DB2 because it caused more issues thant the ones it should solve.
The tricky part is to delay, "but not too much". The idea is that this
should work unnoticeable to the applications doing the commit, but at the
same time allow real buffer usage. The main point is that we can never tell
the application the data was committed (thus the flush) before it really
was.

In any case, Art's RFE will get my vote. I have serious doubts about the
current RFE process, considering it includes features already implemented
in the submitted state and many with many votes that seem to be ignored.
But it still should be a good way to express customer requirements to IBM.
I have hopes that HCL will improve the process.

For the more curious minds and the ones with free time, I digged into this
some time ago here:

http://informix-technology.blogspot.pt/2014/02/new-feature-nova-funcionalidade.html

Regards.

On Tue, Jan 9, 2018 at 1:04 PM, BENJAMIN THOMPSON <
benjamin.thompson@skybettingandgaming.com> wrote:

> Art,
>
> I have a question about this RFE. Is this a problem that cannot be solved
> by a
> larger logical log buffer or are you concerned about having too much data
> in
> the buffer not written to disk if you increase the buffer size?
>
> Ben.
>
>
> ************************************************************
> *******************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

--
Fernando Nunes
Portugal

http://informix-technology.blogspot.com
My email works... but I don't check it frequently...

Messages In This Thread

• New RFE entry needs votes
  Art Kagel -- Sunday, 7 January 2018, at 3:00 p.m.
  • Re: New RFE entry needs votes
    BENJAMIN THOMPSON -- Tuesday, 9 January 2018, at 7:04 a.m.
    • Re: New RFE entry needs votes
      Fernando Nunes -- Tuesday, 9 January 2018, at 8:23 a.m.
      • Re: New RFE entry needs votes
        david@smooth1.co.uk -- Wednesday, 10 January 2018, at 2:49 a.m.
      • Re: New RFE entry needs votes
        BENJAMIN THOMPSON -- Wednesday, 10 January 2018, at 11:00 a.m.
  • Re: New RFE entry needs votes
    Madison Pruet -- Thursday, 11 January 2018, at 1:09 a.m.
    • RE: New RFE entry needs votes
      John Miller -- Thursday, 11 January 2018, at 1:31 a.m.
      • Re: New RFE entry needs votes
        Fernando Nunes -- Thursday, 11 January 2018, at 3:37 a.m.
        • Re: New RFE entry needs votes
          Madison Pruet -- Thursday, 11 January 2018, at 6:31 p.m.

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