SQL SERVER 2000: low page life expectancy, high cache hit ration
Hi, I have a 32 BIT sql 2000 server with a database of +-300 GB. (AWE not enabled) on a IBM blade server HS21
We often have performance drops. ( large query can take from 10 till 300 sec).
When i look at the statistics is see a low pagelife expectancy.
What are the counters i should look for to exactly find my bottleneck?
Will enabling the AWE option and using all the physical ram (8GB) be a solution?
in attachment an example of values.
example.xls
We often have performance drops. ( large query can take from 10 till 300 sec).
When i look at the statistics is see a low pagelife expectancy.
What are the counters i should look for to exactly find my bottleneck?
Will enabling the AWE option and using all the physical ram (8GB) be a solution?
in attachment an example of values.
example.xls
Look at your CPU consumption when the performance is terrible. (Open Task manager or use Process Explorer from SysInternals).
Look at the SQLServer.exe process. If it is high, then I bet you have some bad queries.
Open Enterprise manager (or SSMS) and run sp_who2. Look for any queries that with high I/O counts.
Also, following HuSlayer's steps to upgrade the memory would help also.
Normally, major drops in performance are often caused by high-CPU utlization. High CPU is often caused by High I/O queries or lots of blocking.
Look at the SQLServer.exe process. If it is high, then I bet you have some bad queries.
Open Enterprise manager (or SSMS) and run sp_who2. Look for any queries that with high I/O counts.
Also, following HuSlayer's steps to upgrade the memory would help also.
Normally, major drops in performance are often caused by high-CPU utlization. High CPU is often caused by High I/O queries or lots of blocking.
ASKER
HI, thanks a lot for the tips.
When the performance is dropping, i don't see any significant values in my monitoring tool (which is IDERA diagnostics manager), this is why it's so difficult for me to tackle this.
The CPU stays well below 20%, i only see spikes in my disk queue length up to 240 on my E drive (which are 2 mirrored disk, and my tempdb is on this.)
At busy times i have +- 11000 compilations on avg is this a lot?
The performance drop is mainly seen by a very complex query which does +-300000 reads in different local databases. but when this occures all other queries are slower too.
When the performance is dropping, i don't see any significant values in my monitoring tool (which is IDERA diagnostics manager), this is why it's so difficult for me to tackle this.
The CPU stays well below 20%, i only see spikes in my disk queue length up to 240 on my E drive (which are 2 mirrored disk, and my tempdb is on this.)
At busy times i have +- 11000 compilations on avg is this a lot?
The performance drop is mainly seen by a very complex query which does +-300000 reads in different local databases. but when this occures all other queries are slower too.
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I don't really see a problem with 10 to 300 seconds with complex queries against a +300 GB DB, but if you're saying there's a drop in performance, that means you're been looking at stats earlier.
anyway you're a large DB which less than 3% of it will fit in the cache, so I would say YES AWE will help, Especially you're using Enterprise edition so take full advantage of it.
about the counters, I would suggest to watch that video about Perfmon and counters, it's a good one
http://www.brentozar.com/s
so I would recommend:
Step 1: Enable PAE support on Windows Server to allow large segment of physical memory to be used.
Step 2: Assign to enable Lock Pages in Memory permission to SQL Server account.
Step 3: Enable AWE Option:
sp_configure 'show advanced options', 1
RECONFIGURE
GO
sp_configure 'awe enabled', 1
RECONFIGURE
GO
Restart SQL Server with the following commands:
net stop mssqlserver
net start mssqlserver
Then, configure memory:
sp_configure 'min server memory', 1024
RECONFIGURE
GO
sp_configure 'max server memory', 8192
RECONFIGURE
GO
hope that helps :)