Home » Infrastructure » Linux » My linux server is slow (Oracle 126.96.36.199)
|My linux server is slow [message #351736]
||Thu, 02 October 2008 15:13
Registered: April 2008
I am using Redhat redhat 4 update 4 kernal 2.6. My server is some time suddenly running slow.
The averge cpu load goes up to 50 to 60. (There is only two CPU and usually, the averge load
is between 1 to 2.5) That time, i see, there are several sessions connected.
Normally, we have 150 to 160 session. But when the server is slow, the total number of sessions
goes up to 400. At that time, it is taking long time to connect into the database. Even,
connecting into linux box is taking long time.
Our application server is showing this error message in log file.
ERROR] [2008-10-02 13:09:31] [JDBCExceptionReporter] The data source returned null from
org.hibernate.exception.GenericJDBCException: Cannot open connection
Here is my investigation and direction i am following.
1. Checking alert log and nothing is unusual.
2. I am running the script for every 30 min to check the hit ratio. Hit ratio is normal. It is more then
99% for library cache, dictionary cache, buffer cache.
Here are the scripts i am running for every 30 min to check
the hit ratio.
SELECT (1 - (v3.VALUE / (v1.VALUE + v2.VALUE))) * 100
FROM v$sysstat v1,
WHERE v1.NAME = 'db block gets'
AND v2.NAME = 'consistent gets'
AND v3.NAME = 'physical reads';
SELECT SUM(PINS) / (SUM(PINS) + SUM(RELOADS)) * 100
SELECT (SUM(GETS)/(SUM(GETS)+SUM(GETMISSES))) * 100
SELECT ROUND((100 * b.VALUE) /DECODE ((a.VALUE + b.VALUE),
0,1,(a.VALUE + b.VALUE)),2)
FROM v$sysstat a,
WHERE a.name = 'sorts (disk)'
AND b.name = 'sorts (memory)';
3. I am running the script for every 30 min to capture the login session info.
Today i had a problem at 9AM. I compared the below query result between 8.00AM output,
8.30AM output, 9.00AM output, 9.30AM output. I do not see any big difference...
a.sql_hash_value = b.hash_value
and a.sql_address = b.address
and a.sid = c.sid
4. I see the the below error message in my application server.
ERROR] [2008-10-02 13:09:31] [JDBCExceptionReporter] The data source returned
null from getConnection(user,password).
Cannot open connection
This error message shows that, oracle is not letting to accept any new connection...
Total number of connection all the time is around 100.
Here is my oracle version.
Oracle9i Enterprise Edition Release 188.8.131.52.0 - Production
PL/SQL Release 184.108.40.206.0 - Production
CORE 220.127.116.11.0 Production
TNS for Linux: Version 18.104.22.168.0 - Production
NLSRTL Version 22.214.171.124.0 - Production
Here is the SGA size.
Fixed Size 452620
Variable Size 1073741824
Database Buffers 536870912
Redo Buffers 2240512
Any one is phasing this problem??? Any direction to pursue this issue?
I am sorry if this input is not enough to throw your thoughts/ideas. Please do let me
know if you need any other input. I am glad to provide more info.
[Updated on: Thu, 02 October 2008 15:14]
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