Parameters for RHEL 4 operating system performance

[ran_sushmi]

I wanted to know the parameters which affect RHEL 4 OS performance. Our DB is oracle 10g. The parameters for DB performance could also be linked to the OS parameters. Our application is Java based and uses JBOSS as the AS and TOMCAT as the web server. I wanted to improve the performance of the system as we migrated our system to better hardware system and it is giving slow response.

I hope, my question is clear.

Please, help in solving the doubt.

regards

[coopstah13]

It is probably not the OS. What is going on in the system when you have a load on your server? Very little CPU utilization? High disk activity? What do you have the SGA and PGA values for the database set to? Do you have enough jdbc threads dedicated in the app server? There are a bunch of other things it could be, it is likely not the OS though, I use a default install of RHEL4 with that version of oracle and I don't do anything to the OS, only the DB.

[ran_sushmi]

thanks, for your answer. Sorry, for replying very late as I got very busy. I see more CPU utilization on the DB server. There are 2 servers, one for the application and one for the DB. Only, the DB server is showing high CPU utilization. The SGA values are as follows:-

--------------------------------------------------------------
sga_max_size big integer
2G
sga_target big integer
2G
--------------------------------------------------------------

The PGA values are as follows:-

--------------------------------------------------------------
bitmap_merge_area_size integer
1048576
create_bitmap_area_size integer
8388608
hash_area_size integer
131072
sort_area_size integer
65536
workarea_size_policy string

NAME TYPE
------------------------------------ --------------------------------
VALUE
------------------------------
AUTO
---------------------------------------------------------------------

Please help.

[coopstah13]

could be a lot of different things, try setting these parameters in /etc/sysctl.conf

fs.file-max = 65535
kernel.shmall = 2097152
kernel.shmmax = 2147483648
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
net.ipv4.ip_local_port_range = 1024 65535
net.core.rmem_default = 1048576
net.core.rmem_max = 1048576
net.core.wmem_default = 262144
net.core.wmem_max = 262144

reload after with sysctl -p

if you aren't CPU or disk bound, make sure you have enough JDBC threads in your thread pool, it could be that your application is starved for threads