Hi Leon,
you're right - performance is decreasing with log enabled, not increasing.
Would be nice if it was so ;-)
Unfortunately I don't know how to measure specific values, at the moment I'm
listening to my users ("it was faster yesterday without log enabled") and
colleagues ("I had a case where everything went slow with log enabled").
How do you measure performance on your environments?
Regards,
Frank
Leon Rosenberg-3 wrote:
>
> do you have any resource problems?
> How do you know that the performance is falling, and what does falling
> exactly mean? 10%? 1%? 1 ms per request?
>
> regards
> Leon
>
> On 10/9/06, Frank Niedermann <[EMAIL PROTECTED]> wrote:
>>
>> David,
>>
>> CPU load is also very low, maximum is 80%. There are two CPUs (real, not
>> virtualized) in the server and according to the performance view on
>> Windows
>> there could be much more users on the system. But I'm not sure if that
>> performance view is true or not ...
>>
>> Frank
>>
>>
>> David Smith-2 wrote:
>> >
>> > But I'm not sure it would show as a disk bottleneck. If you have
>> > frequent small writes to a disk and each write is delayed while
>> > antivirus checks the datastream for virus signatures, the many tiny
>> > delays could aggegate in to a much bigger file i/o slow down. The
>> > system may experience a higher CPU load rather than a disk bottleneck.
>> >
>> > --David
>> >
>> > Frank Niedermann wrote:
>> >
>> >>David,
>> >>
>> >>that is a good idea from far, far away :-)
>> >>
>> >>Antivirus is enabled (I'm not suicidal, this is a Windows box ;) but
>> >>according to the Windows performance viewer there is no bottleneck on
>> the
>> >>harddisk, it's always way under 10% load.
>> >>
>> >>Frank
>> >>
>> >>
>> >>David Smith-2 wrote:
>> >>
>> >>
>> >>>I think a long time ago in a galaxy far, far away I remember something
>> >>>about antivirus impacting file I/O performance. Would your box happen
>> >>>to have antivirus enabled? If so, any chance you could exclude your
>> >>>logs from it and/or disable it for the purpose of a test?
>> >>>
>> >>>--David
>> >>>
>> >>>Frank Niedermann wrote:
>> >>>
>> >>>
>> >>>
>> >>>>Unfortunately I have to use Windows Server 2003 as the company behind
>> the
>> >>>>application we're using is not supporting UNIX/Linux.
>> >>>>
>> >>>>Windows also has performance utilities but they tell me that the
>> server
>> >>>>isn't heavily loaded at all.
>> >>>>
>> >>>>A good think would be to have a smaller access log just for
>> statistics,
>> >>>>
>> >>>>
>> >>like
>> >>
>> >>
>> >>>>only one line per user access and not every file which transferred to
>> the
>> >>>>user (html, images, js and so on) ...
>> >>>>
>> >>>>Frank
>> >>>>
>> >>>>
>> >>>>Tim Funk wrote:
>> >>>>
>> >>>>
>> >>>>
>> >>>>
>> >>>>>Something seems odd with your system. I have pounded some tomcat
>> >>>>>installations with old unix hardware with and without access logging
>> and
>> >>>>>could hardly tell the difference.
>> >>>>>
>> >>>>>In linux - i was able to tell more of a difference, but not enough
>> to
>> >>>>>turn off logging.
>> >>>>>
>> >>>>>I am at a loss of where the bottleneck is. If your using *nix - your
>> >>>>>system should have some OS benchmarking to see disk utilization or
>> other
>> >>>>>potential bottlenecks.
>> >>>>>
>> >>>>>Good luck.
>> >>>>>
>> >>>>>-Tim
>> >>>>>
>> >>>>>Frank Niedermann wrote:
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>>>I've installed LambdaProbe and it tells me that there are not much
>> >>>>>>Threads
>> >>>>>>(about 50) and most of them are in state of waiting or
>> timed_waiting.
>> So
>> >>>>>>that seems to be okay - but what if Tomcat sent the response to the
>> >>>>>>
>> >>>>>>
>> >>first
>> >>
>> >>
>> >>>>>>user request and then does the logging, while the next request or
>> other
>> >>>>>>users are waiting?
>> >>>>>>
>> >>>>>>And this:
>> >>>>>>The log files are under 20 MB, that should be fine, shoundn't it?
>> The
>> >>>>>>disk
>> >>>>>>is way far from beeing full and it's a RAID1 with SCSI disks so
>> they
>> >>>>>>should
>> >>>>>>have enough performance.
>> >>>>>>
>> >>>>>>I'm now totally unsure if I should enable access.log-files (to have
>> >>>>>>statistics with AWstats) or disable them (to have more performance)
>> ...
>> >>>>>>
>> >>>>>>Frank
>> >>>>>>
>> >>>>>>
>> >>>>>>Frank Niedermann wrote:
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>>Tim,
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>Tim Funk wrote:
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>>Unless you are max'd on working threads - access logging should
>> not
>> be
>> >>>>>>>>a
>> >>>>>>>>performance hit. Access logging takes pace after the response is
>> sent
>> >>>>>>>>to
>> >>>>>>>>the client.
>> >>>>>>>>
>> >>>>>>>>
>> >>>>>>>>
>> >>>>>>>>
>> >>>>>>>>
>> >>>>>>>>
>> >>>>>>>BUT if the access logs are big, AND you a re low on disk, AND/OR
>> your
>> >>>>>>>disk is SLOOOOW then that could be a problem. The overhead of
>> logging
>> >>>>>>>the access log is pretty low.
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>
>> >>>>>>>
>> >>>>>>The log files are under 20 MB, that should be fine, shoundn't it?
>> The
>> >>>>>>disk
>> >>>>>>is way far from beeing full and it's a RAID1 with SCSI disks so
>> they
>> >>>>>>should
>> >>>>>>have enough performance.
>> >>>>>>
>> >>>>>>I'm now totally unsure if I should enable access.log-files (to have
>> >>>>>>statistics with AWstats) or disable them (to have more performance)
>> ...
>> >>>>>>
>> >>>>>>Frank
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>---------------------------------------------------------------------
>> >>>>>To start a new topic, e-mail: users@tomcat.apache.org
>> >>>>>To unsubscribe, e-mail: [EMAIL PROTECTED]
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>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>
>> >>>>
>> >>>>
>> >>>>
>> >>>---------------------------------------------------------------------
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>> >>>To unsubscribe, e-mail: [EMAIL PROTECTED]
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>> >>>
>> >>>
>> >>>
>> >>>
>> >>>
>> >>
>> >>
>> >>
>> >
>> >
>> > ---------------------------------------------------------------------
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>> >
>> >
>> >
>>
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