Download PDF (1.3 MB) - IBM Redbooks

For business processes, Integration Designer is also used to control event monitoring. Check
the Event Monitor tab for your components and business processes to ensure that event
monitoring is applied judiciously.
For BPMN business process definitions (BPDs), auto-tracking is enabled by default. If
business requirements do not require tracking events for a BPD, turn off auto-tracking. If event
tracking is required, consider creating a tracking group to define a small set of events for
tracking purposes.
4.7.2 Tuning for large objects
This section describes tuning for performance when you use large objects (LOBs).
Increasing the Java heap size to its maximum
One of the key factors affecting large object processing is the maximum size of the Java heap.
This section describes how to set the heap size as large as possible on two commonly used
platforms, WIndows and AIX.
►
►
Windows (32-bit)
Because of address space limitations in the Windows 32-bit operating system, the largest
heap that can be obtained is 1.4 GB to 1.6 GB for 32-bit JVMs.
AIX (32-bit)
On AIX 32-bit systems, the Java 5 and Java 6 JVM typically support heaps in the range of
2 GB to 2.4 GB. Because the 4 GB address space allowed by the 32-bit system is shared
with other resources, the actual limit of the heap size depends on the memory that is used
by these resources. These resources include thread stacks, JIT compiled code, loaded
classes, shared libraries, and buffers used by OS system services. A large heap squeezes
address space reserved for other resources and might cause runtime failures.
Setting maximum heap sizes applies only to 32-bit JVMs; when using 64-bit JVMs, the heap
size is constrained only by the amount of available physical memory. The suggested
configuration for Business Process Manager servers is 64-bit.
For comprehensive heap setting techniques, see 4.16, “Advanced Java heap tuning” on
page 91.
Reducing or eliminating other processing while processing a LOB
One way to allow for larger object sizes is to limit concurrent processing within the JVM. Do
not expect to process a steady stream of the largest objects possible concurrently with other
Business Process Manager server and WebSphere Adapters activities. The operational
assumption when considering large objects is that not all objects are large or very large and
that large objects do not arrive often, perhaps only once or twice per day. If more than one
very large object is being processed concurrently, the likelihood of failure increases
dramatically.
The size and number of the normally arriving smaller objects affect the amount of Java heap
memory consumption in the system. In general, the heavier the load on a system when a
large object is being processed, the more likely that memory problems are encountered.
For adapters, the amount of concurrent processing can be influenced by setting the pollPeriod
and pollQuantity parameters. To allow for larger object sizes, set a relatively high value for
pollPeriod (for example, 10 seconds) and low value for pollQuantity (for example, 1 second) to
minimize the amount of concurrent processing that occurs. These settings are not optimal for
Chapter 4. Performance tuning and configuration 63