Hi again (and again) guys...
I have just read an article in the SQL Server magasine which says that its
recommanded to have 1 file by processor for the tempdb database.
does this recommandation is good for a data warehousing solution?
I'm suffering some disk issue and I have a lot of CXPacket wait types.
So I'm looking for solution to improve this...
but I can't do anything at the disk level.
My config:
Windows 2003 Ent.
SQL Server 2000 Ent.
4 Xeon 3.6Ghz with HT
4 Gb of RAM (/3Gb option set)
200 Gb on a SAN
I have some communication issue with the client I.T. Team, and I just know
that I have 200 Gb of disk, I have no idea about the disk config, cache
config etc...
I have no choice to use it.
I can't spread my files among dedicated disks (like moving log files, tempdb
database...)
the performance degrade specially when there is reading & writing activity
on the disk, like filling a table with the indexes in place or like doiong
an update on a "big" table (1 million of rows)
but complex select queries are slow too due to CXPacket waits.
I have added 7 files in for the tempdb database and 7 files for the staging
database.
For the moment I monitor the loading step which is slower then expected.
after this change the number of CXPacket wait types has increased from 10-20
waits to 150 waits!!!! (I'm using the sp_who1 cusomt procedure to see all
the wait type)
I have another client with near the same volume of data, a SAN and a smaller
hardware (2 cpu only, 2Gb of ram) and doing the same loading takes half of
the time!
I process 70 000rows / sec on this small server while I process 45
000rows/sec on my biggest but slower server...
I have a third client where the bottleneck is the disk controller, I reach
the maximum throughput of 80MB/s on it.
So our loading procedures are optimal for all client and the overral
solution is good except this one wherethesame procedures are slow.
what are my options?
The only answer I receive from the I.T. Team is: "The system is optimal, for
us there is no performance issue"
for us we clearly have issues on this server.
queries which generally takes 5 seconds to execute takes 35 seconds on this
server!
and we defrag ALL the indexes after every load.
thanks for your ideas if you have one :-)
Jerome.Jeje,
If the Average Queue Length is high then there is a disk bottle neck. The
disk subsystem may be optimal but still not fast enough for what you need.
Moving to more than one file in a filegroup on a multiprocessor server is
generally helpful. You've effectively increased the number of parrallel
tasks. Have you tried lowering your mdop?
"Jj" <willgart@.BBBhotmailAAA.com> wrote in message
news:%23PsrShk6FHA.3888@.TK2MSFTNGP10.phx.gbl...
> Hi again (and again) guys...
> I have just read an article in the SQL Server magasine which says that its
> recommanded to have 1 file by processor for the tempdb database.
> does this recommandation is good for a data warehousing solution?
> I'm suffering some disk issue and I have a lot of CXPacket wait types.
> So I'm looking for solution to improve this...
> but I can't do anything at the disk level.
> My config:
> Windows 2003 Ent.
> SQL Server 2000 Ent.
> 4 Xeon 3.6Ghz with HT
> 4 Gb of RAM (/3Gb option set)
> 200 Gb on a SAN
> I have some communication issue with the client I.T. Team, and I just know
> that I have 200 Gb of disk, I have no idea about the disk config, cache
> config etc...
> I have no choice to use it.
> I can't spread my files among dedicated disks (like moving log files,
> tempdb database...)
> the performance degrade specially when there is reading & writing activity
> on the disk, like filling a table with the indexes in place or like doiong
> an update on a "big" table (1 million of rows)
> but complex select queries are slow too due to CXPacket waits.
> I have added 7 files in for the tempdb database and 7 files for the
> staging database.
> For the moment I monitor the loading step which is slower then expected.
> after this change the number of CXPacket wait types has increased from
> 10-20 waits to 150 waits!!!! (I'm using the sp_who1 cusomt procedure to
> see all the wait type)
> I have another client with near the same volume of data, a SAN and a
> smaller hardware (2 cpu only, 2Gb of ram) and doing the same loading takes
> half of the time!
> I process 70 000rows / sec on this small server while I process 45
> 000rows/sec on my biggest but slower server...
> I have a third client where the bottleneck is the disk controller, I reach
> the maximum throughput of 80MB/s on it.
> So our loading procedures are optimal for all client and the overral
> solution is good except this one wherethesame procedures are slow.
> what are my options?
> The only answer I receive from the I.T. Team is: "The system is optimal,
> for us there is no performance issue"
> for us we clearly have issues on this server.
> queries which generally takes 5 seconds to execute takes 35 seconds on
> this server!
> and we defrag ALL the indexes after every load.
> thanks for your ideas if you have one :-)
> Jerome.
>|||Hi,
yes, I have played with the mdop option.
sometimes this improve the performance, sometimes this decrease the
performance.
for queries where I have "simple" joins and group by clause, I have less
issues then queries with outer join and lookup queires (queries statement
under the select statement select (select min(...) from tableA... ) as
mindate from tableB...))
The overall result of the entire process is a slower result when maxdop = 1.
update statements are always slow, and if I update a column with an index on
it... its really bad!
I have tried to add some files in my filegroups, but the result is not so
good, my staging queries generate 8 times more CXPacket locks.
I'll try some options and test it again.
if you have some other ideas, I'll take it ;-)
"Danny" <someone@.nowhere.com> wrote in message
news:91Gef.7467$vS4.4914@.trnddc01...
> Jeje,
> If the Average Queue Length is high then there is a disk bottle neck. The
> disk subsystem may be optimal but still not fast enough for what you need.
> Moving to more than one file in a filegroup on a multiprocessor server is
> generally helpful. You've effectively increased the number of parrallel
> tasks. Have you tried lowering your mdop?
>
> "Jj" <willgart@.BBBhotmailAAA.com> wrote in message
> news:%23PsrShk6FHA.3888@.TK2MSFTNGP10.phx.gbl...
>
Showing posts with label magasine. Show all posts
Showing posts with label magasine. Show all posts
Sunday, March 11, 2012
back again with my server performance issue...
Hi again (and again) guys...
I have just read an article in the SQL Server magasine which says that its
recommanded to have 1 file by processor for the tempdb database.
does this recommandation is good for a data warehousing solution?
I'm suffering some disk issue and I have a lot of CXPacket wait types.
So I'm looking for solution to improve this...
but I can't do anything at the disk level.
My config:
Windows 2003 Ent.
SQL Server 2000 Ent.
4 Xeon 3.6Ghz with HT
4 Gb of RAM (/3Gb option set)
200 Gb on a SAN
I have some communication issue with the client I.T. Team, and I just know
that I have 200 Gb of disk, I have no idea about the disk config, cache
config etc...
I have no choice to use it.
I can't spread my files among dedicated disks (like moving log files, tempdb
database...)
the performance degrade specially when there is reading & writing activity
on the disk, like filling a table with the indexes in place or like doiong
an update on a "big" table (1 million of rows)
but complex select queries are slow too due to CXPacket waits.
I have added 7 files in for the tempdb database and 7 files for the staging
database.
For the moment I monitor the loading step which is slower then expected.
after this change the number of CXPacket wait types has increased from 10-20
waits to 150 waits!!!! (I'm using the sp_who1 cusomt procedure to see all
the wait type)
I have another client with near the same volume of data, a SAN and a smaller
hardware (2 cpu only, 2Gb of ram) and doing the same loading takes half of
the time!
I process 70 000rows / sec on this small server while I process 45
000rows/sec on my biggest but slower server...
I have a third client where the bottleneck is the disk controller, I reach
the maximum throughput of 80MB/s on it.
So our loading procedures are optimal for all client and the overral
solution is good except this one wherethesame procedures are slow.
what are my options?
The only answer I receive from the I.T. Team is: "The system is optimal, for
us there is no performance issue"
for us we clearly have issues on this server.
queries which generally takes 5 seconds to execute takes 35 seconds on this
server!
and we defrag ALL the indexes after every load.
thanks for your ideas if you have one :-)
Jerome.
Jeje,
If the Average Queue Length is high then there is a disk bottle neck. The
disk subsystem may be optimal but still not fast enough for what you need.
Moving to more than one file in a filegroup on a multiprocessor server is
generally helpful. You've effectively increased the number of parrallel
tasks. Have you tried lowering your mdop?
"Jj" <willgart@.BBBhotmailAAA.com> wrote in message
news:%23PsrShk6FHA.3888@.TK2MSFTNGP10.phx.gbl...
> Hi again (and again) guys...
> I have just read an article in the SQL Server magasine which says that its
> recommanded to have 1 file by processor for the tempdb database.
> does this recommandation is good for a data warehousing solution?
> I'm suffering some disk issue and I have a lot of CXPacket wait types.
> So I'm looking for solution to improve this...
> but I can't do anything at the disk level.
> My config:
> Windows 2003 Ent.
> SQL Server 2000 Ent.
> 4 Xeon 3.6Ghz with HT
> 4 Gb of RAM (/3Gb option set)
> 200 Gb on a SAN
> I have some communication issue with the client I.T. Team, and I just know
> that I have 200 Gb of disk, I have no idea about the disk config, cache
> config etc...
> I have no choice to use it.
> I can't spread my files among dedicated disks (like moving log files,
> tempdb database...)
> the performance degrade specially when there is reading & writing activity
> on the disk, like filling a table with the indexes in place or like doiong
> an update on a "big" table (1 million of rows)
> but complex select queries are slow too due to CXPacket waits.
> I have added 7 files in for the tempdb database and 7 files for the
> staging database.
> For the moment I monitor the loading step which is slower then expected.
> after this change the number of CXPacket wait types has increased from
> 10-20 waits to 150 waits!!!! (I'm using the sp_who1 cusomt procedure to
> see all the wait type)
> I have another client with near the same volume of data, a SAN and a
> smaller hardware (2 cpu only, 2Gb of ram) and doing the same loading takes
> half of the time!
> I process 70 000rows / sec on this small server while I process 45
> 000rows/sec on my biggest but slower server...
> I have a third client where the bottleneck is the disk controller, I reach
> the maximum throughput of 80MB/s on it.
> So our loading procedures are optimal for all client and the overral
> solution is good except this one wherethesame procedures are slow.
> what are my options?
> The only answer I receive from the I.T. Team is: "The system is optimal,
> for us there is no performance issue"
> for us we clearly have issues on this server.
> queries which generally takes 5 seconds to execute takes 35 seconds on
> this server!
> and we defrag ALL the indexes after every load.
> thanks for your ideas if you have one :-)
> Jerome.
>
|||Hi,
yes, I have played with the mdop option.
sometimes this improve the performance, sometimes this decrease the
performance.
for queries where I have "simple" joins and group by clause, I have less
issues then queries with outer join and lookup queires (queries statement
under the select statement select (select min(...) from tableA... ) as
mindate from tableB...))
The overall result of the entire process is a slower result when maxdop = 1.
update statements are always slow, and if I update a column with an index on
it... its really bad!
I have tried to add some files in my filegroups, but the result is not so
good, my staging queries generate 8 times more CXPacket locks.
I'll try some options and test it again.
if you have some other ideas, I'll take it ;-)
"Danny" <someone@.nowhere.com> wrote in message
news:91Gef.7467$vS4.4914@.trnddc01...
> Jeje,
> If the Average Queue Length is high then there is a disk bottle neck. The
> disk subsystem may be optimal but still not fast enough for what you need.
> Moving to more than one file in a filegroup on a multiprocessor server is
> generally helpful. You've effectively increased the number of parrallel
> tasks. Have you tried lowering your mdop?
>
> "Jj" <willgart@.BBBhotmailAAA.com> wrote in message
> news:%23PsrShk6FHA.3888@.TK2MSFTNGP10.phx.gbl...
>
I have just read an article in the SQL Server magasine which says that its
recommanded to have 1 file by processor for the tempdb database.
does this recommandation is good for a data warehousing solution?
I'm suffering some disk issue and I have a lot of CXPacket wait types.
So I'm looking for solution to improve this...
but I can't do anything at the disk level.
My config:
Windows 2003 Ent.
SQL Server 2000 Ent.
4 Xeon 3.6Ghz with HT
4 Gb of RAM (/3Gb option set)
200 Gb on a SAN
I have some communication issue with the client I.T. Team, and I just know
that I have 200 Gb of disk, I have no idea about the disk config, cache
config etc...
I have no choice to use it.
I can't spread my files among dedicated disks (like moving log files, tempdb
database...)
the performance degrade specially when there is reading & writing activity
on the disk, like filling a table with the indexes in place or like doiong
an update on a "big" table (1 million of rows)
but complex select queries are slow too due to CXPacket waits.
I have added 7 files in for the tempdb database and 7 files for the staging
database.
For the moment I monitor the loading step which is slower then expected.
after this change the number of CXPacket wait types has increased from 10-20
waits to 150 waits!!!! (I'm using the sp_who1 cusomt procedure to see all
the wait type)
I have another client with near the same volume of data, a SAN and a smaller
hardware (2 cpu only, 2Gb of ram) and doing the same loading takes half of
the time!
I process 70 000rows / sec on this small server while I process 45
000rows/sec on my biggest but slower server...
I have a third client where the bottleneck is the disk controller, I reach
the maximum throughput of 80MB/s on it.
So our loading procedures are optimal for all client and the overral
solution is good except this one wherethesame procedures are slow.
what are my options?
The only answer I receive from the I.T. Team is: "The system is optimal, for
us there is no performance issue"
for us we clearly have issues on this server.
queries which generally takes 5 seconds to execute takes 35 seconds on this
server!
and we defrag ALL the indexes after every load.
thanks for your ideas if you have one :-)
Jerome.
Jeje,
If the Average Queue Length is high then there is a disk bottle neck. The
disk subsystem may be optimal but still not fast enough for what you need.
Moving to more than one file in a filegroup on a multiprocessor server is
generally helpful. You've effectively increased the number of parrallel
tasks. Have you tried lowering your mdop?
"Jj" <willgart@.BBBhotmailAAA.com> wrote in message
news:%23PsrShk6FHA.3888@.TK2MSFTNGP10.phx.gbl...
> Hi again (and again) guys...
> I have just read an article in the SQL Server magasine which says that its
> recommanded to have 1 file by processor for the tempdb database.
> does this recommandation is good for a data warehousing solution?
> I'm suffering some disk issue and I have a lot of CXPacket wait types.
> So I'm looking for solution to improve this...
> but I can't do anything at the disk level.
> My config:
> Windows 2003 Ent.
> SQL Server 2000 Ent.
> 4 Xeon 3.6Ghz with HT
> 4 Gb of RAM (/3Gb option set)
> 200 Gb on a SAN
> I have some communication issue with the client I.T. Team, and I just know
> that I have 200 Gb of disk, I have no idea about the disk config, cache
> config etc...
> I have no choice to use it.
> I can't spread my files among dedicated disks (like moving log files,
> tempdb database...)
> the performance degrade specially when there is reading & writing activity
> on the disk, like filling a table with the indexes in place or like doiong
> an update on a "big" table (1 million of rows)
> but complex select queries are slow too due to CXPacket waits.
> I have added 7 files in for the tempdb database and 7 files for the
> staging database.
> For the moment I monitor the loading step which is slower then expected.
> after this change the number of CXPacket wait types has increased from
> 10-20 waits to 150 waits!!!! (I'm using the sp_who1 cusomt procedure to
> see all the wait type)
> I have another client with near the same volume of data, a SAN and a
> smaller hardware (2 cpu only, 2Gb of ram) and doing the same loading takes
> half of the time!
> I process 70 000rows / sec on this small server while I process 45
> 000rows/sec on my biggest but slower server...
> I have a third client where the bottleneck is the disk controller, I reach
> the maximum throughput of 80MB/s on it.
> So our loading procedures are optimal for all client and the overral
> solution is good except this one wherethesame procedures are slow.
> what are my options?
> The only answer I receive from the I.T. Team is: "The system is optimal,
> for us there is no performance issue"
> for us we clearly have issues on this server.
> queries which generally takes 5 seconds to execute takes 35 seconds on
> this server!
> and we defrag ALL the indexes after every load.
> thanks for your ideas if you have one :-)
> Jerome.
>
|||Hi,
yes, I have played with the mdop option.
sometimes this improve the performance, sometimes this decrease the
performance.
for queries where I have "simple" joins and group by clause, I have less
issues then queries with outer join and lookup queires (queries statement
under the select statement select (select min(...) from tableA... ) as
mindate from tableB...))
The overall result of the entire process is a slower result when maxdop = 1.
update statements are always slow, and if I update a column with an index on
it... its really bad!
I have tried to add some files in my filegroups, but the result is not so
good, my staging queries generate 8 times more CXPacket locks.
I'll try some options and test it again.
if you have some other ideas, I'll take it ;-)
"Danny" <someone@.nowhere.com> wrote in message
news:91Gef.7467$vS4.4914@.trnddc01...
> Jeje,
> If the Average Queue Length is high then there is a disk bottle neck. The
> disk subsystem may be optimal but still not fast enough for what you need.
> Moving to more than one file in a filegroup on a multiprocessor server is
> generally helpful. You've effectively increased the number of parrallel
> tasks. Have you tried lowering your mdop?
>
> "Jj" <willgart@.BBBhotmailAAA.com> wrote in message
> news:%23PsrShk6FHA.3888@.TK2MSFTNGP10.phx.gbl...
>
Subscribe to:
Posts (Atom)