Hmm.. I don't think that memory problems can explain the difference between
2 sec and 45 minutes.. It's just too much. The data is the same?
If you are generating LOH objects in a loop, it might be useful to set the
vars =null immediately when they are not needed.
This can help GC to keep some order in LOH.
You can also try to use this (at least in debugging code) instead of just
GC.Collect():
GC.Collect(); // Put dead or dying in finalizer queue
GC.WaitForPendingFinalizers(); // Hopefully this clears things
GC.Collect(); // Collect also resources released by finalizers, if any
And then attach perf monitor to chec GC times%, heap sizes and other memory
values. They can give some more indications what's going on.
Comparing them with dev machine results might be interesting.
"Sjors" <sjors@nospam.nospam> ha scritto nel messaggio
news:0344F773-475A-4176-93BA-A4498B9089B9@microsoft.com...
[quoted text, click to view] > Hi,
>
> I'm debugging some code running on Windows 2003 R2, .Net 1.1 as windows
> service. The code parses medium sized (ca 1,5MB) csv files. Recently this
> code starts throwing OOM exceptions running a loop that, for as far as I
> can
> determine, uses short living large objects. The file is read into a
> DataTable
> and for every row of the table 1 or 2 DataTable.Select(..)'s are called.
> The
> result (array of DataRow) consists of a few rows that are examined and if
> some condition is met are deleted from the DataTable.
> This process takes about 2 sec. on my development machine (XP Pro, 512MB,
> 2,8GHz CPU) but on the server it takes 45 mins. and after that time the
> OOM
> exception is thrown.
>
> I'm thinking about LOH fragmentation resulting in excessive RAM use and
> thus
> excessive paging and for that very poor performance. I added some
> GC.Collect() instructions to the loop, but to no effect. I also set the
> resulting array to Nothing (no effect).
>
> A lengthy post. I hope someone sees a pattern.
>
> Thanks for any reaction.
>
> Sjors.
Thanks Laura T.,
I allready tried your suggestions before posting the question. To no no
effect obviously.
I was able to solve this thing by rewriting a loop that doesn't use the
DataTable.Select() method. Parsing the file on the production server after
the modification took a few secs (comparable to my dev. machine with the
Select()). My conslusion is that .Net Framework 1.1 for OS W2003 has a memory
leak in method DataTable.Select().
If you can come up with a different explanation I'd very much like to hear it.
Regards,
Sjors.
[quoted text, click to view] "Laura T." wrote:
> Hmm.. I don't think that memory problems can explain the difference between
> 2 sec and 45 minutes.. It's just too much. The data is the same?
> If you are generating LOH objects in a loop, it might be useful to set the
> vars =null immediately when they are not needed.
> This can help GC to keep some order in LOH.
> You can also try to use this (at least in debugging code) instead of just
> GC.Collect():
>
> GC.Collect(); // Put dead or dying in finalizer queue
> GC.WaitForPendingFinalizers(); // Hopefully this clears things
> GC.Collect(); // Collect also resources released by finalizers, if any
>
> And then attach perf monitor to chec GC times%, heap sizes and other memory
> values. They can give some more indications what's going on.
> Comparing them with dev machine results might be interesting.
>
>
>
> "Sjors" <sjors@nospam.nospam> ha scritto nel messaggio
> news:0344F773-475A-4176-93BA-A4498B9089B9@microsoft.com...
> > Hi,
> >
> > I'm debugging some code running on Windows 2003 R2, .Net 1.1 as windows
> > service. The code parses medium sized (ca 1,5MB) csv files. Recently this
> > code starts throwing OOM exceptions running a loop that, for as far as I
> > can
> > determine, uses short living large objects. The file is read into a
> > DataTable
> > and for every row of the table 1 or 2 DataTable.Select(..)'s are called.
> > The
> > result (array of DataRow) consists of a few rows that are examined and if
> > some condition is met are deleted from the DataTable.
> > This process takes about 2 sec. on my development machine (XP Pro, 512MB,
> > 2,8GHz CPU) but on the server it takes 45 mins. and after that time the
> > OOM
> > exception is thrown.
> >
> > I'm thinking about LOH fragmentation resulting in excessive RAM use and
> > thus
> > excessive paging and for that very poor performance. I added some
> > GC.Collect() instructions to the loop, but to no effect. I also set the
> > resulting array to Nothing (no effect).
> >
> > A lengthy post. I hope someone sees a pattern.
> >
> > Thanks for any reaction.
> >
> > Sjors.
>
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