Tuesday, 30 September 2008

Tuning Soasuite 10133 and 11gDB under VMWare

In earlier posts I wrote about how to install the Oracle DB11g and SoaSuite 10133 in an Oracle Enterprise Linux based VM. Earlier this year I also wrote how to rename your SoaSuite installation when having renamed your host.

I did in fact a more or less default installation of both 11gDB and a SoaSuite 10133. But since the VM was to run on a 2GB laptop for courses I gave the VM only 1.6GB of memory. The database was sized so that it claimed about 640MB and the default J2EE+Webserver+soasuite installtion of the midtier resulted in two OC4J instances that both had a minimum heapsize of 512MB and a max of 1024. So at starting both database and soasuite I ran out of memory what results in a guest-os that gets very befriended with the harddrive (swapping all over the place).

So I took some time in getting the system tuned.

The database
First step was getting the database downsized. Earlier I shrinked the sga_max_size to about 470MB. So that was allready an improvement of about 170MB.

But that was not enough for me. So what I did was to startup an XE database. There I looked at the basic memory settings. For convenience I created a plain init.ora.
For the non-dba's amongst you, you can do that by loging on as internal with:
sqlplus "/ as sysdba"
having set the ORACLE_HOME and ORACLE_SID:
When you logged on as internal you can create an init.ora (also called a pfile) with:
create pfile from spfile;
Then you'll find an init.ora in the $ORACLE_HOME/dbs folder.

For an Oracle XE database the most interesting settings I found were:
  • java_pool_size=4194304
  • large_pool_size=4194304
  • shared_pool_size=67108864
  • open_cursors=300
  • sessions=20
  • pga_aggregate_target=70M
  • sga_target=210M
The sga_max_size was not set.
So I changed the 11g database with these settings, created a spfile from the pfile again (create spfile from pfile) started it again.

My initorcl.ora:

Mark that I unset the db_cache_size and memory_target. I also replaced the processes parameter with the sessions parameter being 20. These two parameters relate to eachother, one computed from the other.

I found that I had a database of 145MB! I could start the middletier, but then I could nog logon myself because of the shared-poolsize being to small. This turned out to be about 64M, while the sga_max_size (that I did not set) was 145M.

I changed my sga_max_size to explicitly 250M and the large_pool_size to 100M:
SQL> alter system set sga_max_size=250M scope=spfile;
System altered.
SQL> alter system set shared_pool_size=100M scope=spfile;
System altered.
Then restarting the database resulted in a database of 250M:
Total System Global Area 263639040 bytes
Fixed Size 1299284 bytes
Variable Size 209718444 bytes
Database Buffers 50331648 bytes
Redo Buffers 2289664 bytes

That looks better to me.

Total System Global Area 263639040 bytes
Fixed Size 1299284 bytes
Variable Size 209718444 bytes
Database Buffers 50331648 bytes
Redo Buffers 2289664 bytes

That looks better to me.

The MidTier
The changes in the middle tier are a little less complicated. In fact you have to change two settings in opmn. So go to the $ORACLE_HOME/opmn/conf directory of the middle tier.
There you'll find a file called opmn.xml.

In that file look for:
process-type id="home" module-id="OC4J" status="enabled"
Below that you'll find a node with start-parameters, having a data sub-node with "java-options". In the value-attribute of that node change -ms512M -mx1024M into -ms128M -mx128M. These are the minimum and maximum heapsizes. The home oc4j only needs 128M. It's recommended to give the OC4J at startup the max heapsize right away. Then it need not to grow.

Look again for:
process-type id="oc4j_soa" module-id="OC4J" status="enabled"
Find the same start-parameters, and do the same change but then give it heapsizes of 384M: -ms384M -mx384M.

This gave me aVM with a soasuite and 11g database that runs quite fine in a 1.6GB VM.
These settings are just "wet-thumb"-values. I must strictly say that these are not valid values for a production environment and even
might not be valid for a regular development environment with a significant number of developers.

But in my case it all fits, having even 40MB of memory left. According to "top" my VM is not swapping!

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