Administration guide > Tune and performance


ORB properties and file descriptor settings


ORB properties

The ORB is used by WebSphere eXtreme Scale to communicate over a TCP stack and is set in...

java/jre/lib/orb.properties

For a heavy load of large objects, enable ORB fragmentation by specifying the following setting:

com.ibm.CORBA.FragmentSize=<right size>

Prevent ThreadPool growth by specifying the following setting:

com.ibm.CORBA.ThreadPool.IsGrowable=false

Set proper timeouts to avoid excess threads in an abnormal situation by specifying the following settings:


File descriptor

UNIX and Linux systems there is a limit to the number of open files allowed per process. The operating system specifies the number of open files permitted. If this value is set too low, a memory allocation error will occur on AIX, and too many files opened are logged.

In the UNIX system terminal window, set this value higher than the default system value. For large SMP machines with clones, set to unlimited.

For AIX configurations set this value to -1 (unlimited) with the command ulimit -n -1.

For Solaris configurations set this value to 16384 with the command ulimit -n 16384.

To display the current value use the command ulimit -a.


Parent topic:

Configure Object Request Brokers


Parent topic:

Tune and performance


Related concepts

Operating systems and network tuning

Plan for network ports

JVM tuning for WXS

Use WebSphere Real Time


Related tasks

Enable NIO or ChannelFramework on the ORB

Use the Object Request Broker with stand-alone WebSphere eXtreme Scale processes

Configure a custom Object Request Broker

Configure failover detection

Tune the dynamic cache provider

Tune the cache sizing agent for accurate memory consumption estimates

Related reference

ORB properties file

Operational checklist