Subject Re: [IBO] Performance problem with IB_Datapump
Author Robert martin
Thanks Geoff

My machines are windows 2000 (Ok), Windows XP SP2 (AMD Fine, P4 very
slow), Windows 2003 server (Xenon, extremely slow).

I will try setting the Affinity on the P4 machine here and see if this
helps. I am using Firebird Super Server. Watching the
processing activity in task manager shows large periods of in activity
followed by small bursts of processing. If it is Firebird, as you say I
will repost to the firebird support email.


Geoff Worboys wrote:

> > The common theme appears to be p4 CPUs causing problems.
> > The P4 3000 does not have hyperthreading enabled (I will
> > check this further) so probably the issue is not related
> > to this. The Pump is using Ib-Cursors for source and Dest
> > and is contained in its own transaction for each table.
> > The performance lag occurs during the Ib_Datapump.execute
> > method.
> > Any suggestions would be greatly appreciated.
> I've seen this before - with XP and hyperthreading enabled.
> If this is the same problem I've seen then...
> Its not IBO - its Firebird and possibly XP. (What
> operating systems are you running?)
> (Its nothing to do with cursors etc, even BLR based
> transfers are effected - DBak uses BLR, so I've seen it)
> Appropriate CPU affinity can help (matching the two
> logical processors than exist on the same physical), but
> does not resolve the problem completely
> The problem only occurs on network based (even if they
> are localhost) connections, true local connections appear
> to work fine.
> If you watch the transfer in progress you will see that
> it seems occur in bursts with big pauses in between.
> Perhaps this symptom varies with the size of the row
> (eg with images or large blobs perhaps the pause may
> occur on every row).
> Other activity from additional connections sometimes
> seems to "wake up" the transfer when it is paused.
> I have a Win2K system here with dual CPUs that does not
> have any problem (with default affinity settings). My XP
> system is also dual (physical) CPU - so four logical) and
> the problem varies considerably from table to table.
> Marco Lauria and myself spent considerable time trying to
> isolate the problem but even after applying various XP
> hotfixes the problem continues. I've since upgraded to
> XP SP2 and the problem still exists - although most of the
> time it does not effect me very much.
> Marco did post a message (Sep 2003) to the FB support list
> but did not get much response.
> The network aspect of the problem makes me wonder whether
> it may be worth playing with some of FB config settings,
> but I have not had time to try.
> You did not mention what version of FB. My experience with
> the problem described above is that it has existed since
> at least FB 0.9.4 (probably earlier) and still exists in
> FB 1.5.2.
> If you want to compare notes further let me know.
> --
> Geoff Worboys
> Telesis Computing

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