performance: IIS - Sqlserver locks influence??

Hi there,

We have a web application handling thousands of requests per seconds reading
sql server data which is heavily updated.
We are generally experiencing no performance problems.
On some occasions we get an increase of the traffic of about 15% for short
periods. In this case we observe something really strange: our webserver
CPU goes from about 40% usage to 100%, with memory usage keeping low (about
50%). We see at the same time that the number of sqlserver locks increases.
Are these 2 behaviours correlated? ..or any other ideas?
We are using w2k and sql2K

Thanks for your help

Alex"Alex Callea" <alex.callea@.sellys.com> wrote in message
news:O2QUzVZxEHA.1564@.TK2MSFTNGP09.phx.gbl...
> Hi there,
> We have a web application handling thousands of requests per seconds
> reading sql server data which is heavily updated.
> We are generally experiencing no performance problems.
> On some occasions we get an increase of the traffic of about 15% for short
> periods. In this case we observe something really strange: our webserver
> CPU goes from about 40% usage to 100%, with memory usage keeping low
> (about 50%). We see at the same time that the number of sqlserver locks
> increases.
> Are these 2 behaviours correlated? ..or any other ideas?

The traffic increases by 15%. The traffic passes through IIS. The
application in IIS calls SQL Server.

If I'm right, then this suggests that the behaviors correlate.

John Saunders
I know it's correlated but my question was to know if the increase number of
locks had cpu usage consequences on IIS.

We already noticed that the number of web requests being processed has huge
impact on webservers CPUs.
I'd like to know if the same apply with SQL locks(e.g. ADO.NET objects need
to wait more resulting in an increase of page processing time, etc...) as
the SQL server CPUs are almost not impacted by the increased traffic.
Thanks

Alex

"John Saunders" <johnwsaundersiii at hotmail.com> wrote in message
news:eIvurHbxEHA.3024@.TK2MSFTNGP14.phx.gbl...
> "Alex Callea" <alex.callea@.sellys.com> wrote in message
> news:O2QUzVZxEHA.1564@.TK2MSFTNGP09.phx.gbl...
>> Hi there,
>>
>> We have a web application handling thousands of requests per seconds
>> reading sql server data which is heavily updated.
>> We are generally experiencing no performance problems.
>> On some occasions we get an increase of the traffic of about 15% for
>> short periods. In this case we observe something really strange: our
>> webserver CPU goes from about 40% usage to 100%, with memory usage
>> keeping low (about 50%). We see at the same time that the number of
>> sqlserver locks increases.
>> Are these 2 behaviours correlated? ..or any other ideas?
> The traffic increases by 15%. The traffic passes through IIS. The
> application in IIS calls SQL Server.
> If I'm right, then this suggests that the behaviors correlate.
> John Saunders
"Alex Callea" <alex.callea@.sellys.com> wrote in message
news:uQxGoecxEHA.4028@.TK2MSFTNGP15.phx.gbl...
>I know it's correlated but my question was to know if the increase number
>of locks had cpu usage consequences on IIS.
> We already noticed that the number of web requests being processed has
> huge impact on webservers CPUs.
> I'd like to know if the same apply with SQL locks(e.g. ADO.NET objects
> need to wait more resulting in an increase of page processing time,
> etc...) as the SQL server CPUs are almost not impacted by the increased
> traffic.

Alex, I am certainly not an expert on IIS performance, but I can't think why
it would in any way be affected by SQL Server locks.

John
"John Saunders" <johnwsaundersiii at hotmail.com> wrote in message
news:uEOK$PgxEHA.908@.TK2MSFTNGP11.phx.gbl...
> "Alex Callea" <alex.callea@.sellys.com> wrote in message
> news:uQxGoecxEHA.4028@.TK2MSFTNGP15.phx.gbl...
>>I know it's correlated but my question was to know if the increase number
>>of locks had cpu usage consequences on IIS.
>>
>> We already noticed that the number of web requests being processed has
>> huge impact on webservers CPUs.
>> I'd like to know if the same apply with SQL locks(e.g. ADO.NET objects
>> need to wait more resulting in an increase of page processing time,
>> etc...) as the SQL server CPUs are almost not impacted by the increased
>> traffic.
> Alex, I am certainly not an expert on IIS performance, but I can't think
> why it would in any way be affected by SQL Server locks.

The relationship is probably indirect. Sql Server locks are a directly
related to the volume of work being done by Sql Server. Locks don't
indicate that clients are waiting, just that they are doing stuff. Reading
tables generates shared locks, updating tables generates update or exclusive
locks, etc. So the more work, the more locks.

David