Re: Performance PSQL 10

If the engine is crashing, then there is something about the queries
being sent that must be addressed, either by identifying and changing
the queries, or by getting Pervasive to fix it. Obviously, you've
already submitted crash dumps, so this is hopefully moving along for
you. I would stay on top of Pervasive to get a fix for your problem.

It actually sounds like your problem may be different than the
"pauses", since the crashes are a different symptom. I'd get that
fixed, and THEN worry about any performance issues.
Goldstar Software Inc.
Pervasive-based Products, Training & Services
Bill Bach
BillBach@xxxxxxxxxxxxxxxxxxxx
http://www.goldstarsoftware.com
*** Chicago: Pervasive Service & Support Class - March 2008 ***


ackerliz@xxxxxxxxx wrote:

Hi Bill

We are a company that has been affected by this behaviour. Currently
at 9.5 on a Linux Redhat ES server installation.

The lag seems to have become tolerable to users. I will find that
occasionally my queries running from an Access ODBC connection will
time out and I have to rerun them or CTRL+ATL+DEL. This has also
happened occasionally from PCC on my desktop. With this, I have to
force quit PCC (from my Windows desktop), start it again. Otherwise it
just sits there forever doing nothing but displaying a busy state.

We crash the SQL engine (mked sp??) occasionally. We have narrowed
down one particular set of circumtances in which we can do this. To
date we haven't had a resolution. Attemps at resolution have been to
send core dumps (a few of them) to Pervasive's engineer team. We have
gone through our environment and tweaked and tested different
environment settings, pretty much we tried everything the Pervasive
team could come up with. I spent many hours on the phone with them.

The result is that we only occasionally crash the PSQL engine, I have
a terminal screen always running on the server, and we just issue a
service FORCE and service START command and we are back up running
within 30 seconds. Its a temporary pain in the ***, but as I say we
have learned to live with it. We are a small organization with only
about 15 concurrent users. The tolerance is mitigated by the fact
that our staff experience as many outages or blips if not more, from
the major insurance carrier's online application that we access all
day every day...and they have millions of dollars to spend on
technology development and resources!! We self-administer a benefit
plan but our adjudicator is one of North America's biggest insurance
carrier.

Liz



On Jan 9, 3:33 pm, "Bill Bach" <golds...@xxxxxxxxxxxxx> wrote:
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
        BillB...@xxxxxxxxxxxxxxxxxxxx
       http://www.goldstarsoftware.com
        *** Chicago: Pervasive Service & Support Class - March 2008
***





michael last wrote:
From: "michael last" <s...@xxxxxxxxxxxxxxxxxxxxx>
Subject: Performance PSQL 10
Date: Wed, 9 Jan 2008 17:55:02 +0100
Message-ID: <fm2u9d$3b...@xxxxxxxxxxxxxxxxxxxxx>
Lines: 39

Hi,

We have just upgraded a customer from Pervasive 2000 to Pervasive
10. This customer is now reporting, 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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