We have seen this at several sites running Pervasive PSQL v9.5. The
"pauses", as they have come to be known, are periodic in nature, and do
not seem to be based on a specific function call or activity. As you
have seen, ALL database functionality seizes up for the duration of the
pause, and new requests get queued up in the comm threads. When it
releases, everything catches up, and no requests are lost.
We have not been able to duplicate this in a test environment, although
when examining production environments, we have seen an abnormally high
number of disk writes to the Windows pagefile. You may wish to monitor
disk writes to the C: drive (and the pagefile in particular, if you can
run FileMon) when this occurs. (It is especially obvious when the C:
drive is NOT where the data is located.
For the few sites that have been majorly impacted, optimization of the
disk subsystem, including the swapfile, seems to help. Using a RAID10
array has provided huge gains for several users.
What we REALLY need is a long enough pause and a site willing to crash
out the engine and take a complete core dump of the engine while it is
in one of these "pause" states. Unfortunately, the sites seeing this
problem are usually running mission-critical applications for which
downtime is not an option.
If you have an option of doing this, please let me know. You may need
to open an incident directly with Pervasive to get the results
analyzed, but I think this will be a good idea.
Honestly, I was really hoping that the issue was NOT going to exist in
PSQLv10...
Goldstar Software Inc.
Pervasive-based Products, Training & Services
Bill Bach
BillBach@[EMAIL PROTECTED]
Chicago: Pervasive Service & Sup****t Class - March 2008 ***
michael last wrote:
> From: "michael last" <shop@[EMAIL PROTECTED]
>
> Subject: Performance PSQL 10
> Date: Wed, 9 Jan 2008 17:55:02 +0100
> Message-ID: <fm2u9d$3bk$1@[EMAIL PROTECTED]
>
> Lines: 39
>
> Hi,
>
> We have just upgraded a customer from Pervasive 2000 to Pervasive 10.
> This customer is now re****ting, that our application is lagging very
> often for 5-20 seconds. That means that it looks like the software is
> not reacting anymore and all of the sudden it starts working again.
> This happens about 10 times a day on moreless all of the 50
> workstations and it is has not behaved like that with PVSW 2000.
>
> The current performance settings are as follows:
> Cache Allocation: 409MB
> Max Microkernal Memory Usage: 0%
> System Cache: on
>
> We have also noted that NTDBSMGR takes about 50% CPU from time to
> time and also at the same time we notice about 40 communication
> threads and about 60 worker threads (These values are going back to 0
> after about 5 seconds)
>
> We have checked other installations with near the same setup and
> never noticed that high CPU utilization and also note seeing that
> amount of threads being used. What can be the reason for that?
>
> We have also tried with System Cache=off and Max Microkernal Memory
> Usage = 60 without any changes. Are there any other settings which
> have impact to the performance?
>
> Any suggenstions will be very appreciated.
>
> Environment:
> Windows Server 2003 Intel Xeon Dual 3,2 GHz
> Memory 4GB
> Databases: 50 with total amount 108 GB via Transactional Btrieve
> (largest single DB=60GB) Persavive 10 - 50 user
>
> Thanks and regards
>
> Michael
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