JDBC Type 4 Driver Performance Tuning Guide for Version 1.0

HP NonStop JDBC Type 4 Driver
Performance Tuning Guide for Version 1.0
Page 2 Hewlett-Packard Company — 529619-001 November 29, 2004
3 NonStop JDBC Type 4 Driver Tuning Tips
3.1 Configuration Tips
• Connection pooling. Use connection pooling either explicitly with your own
implementation, the Type 4 driver connection pooling mechanism (the default
is no connection pooling) or implicitly through a product that supports
connection pooling, such as BEA Weblogic Server, or IBM WebSphere, etc.
• Maximum pool size. Use the maxPoolSize and minPoolSize properties to
tune the connection pool.
o The default maxPoolSize is 0—“unlimited” pool size.
o The default minPoolSize is 0—connections are never physically closed
but are added to the connection pool.
o Set minPoolSize to the anticipated number of connections to be used.
For example, set minPoolSize to the number of application threads.
• Statement pooling. Set the maxStatements property to enable statement
pooling (the default is no statement pooling). For example,
SQLMXDataSource.setMaxStatements(100).
• Logging. Turn off logging. Set the t4LogLevel property to OFF (the default is
OFF). Set the DriverManager.setLogWriter() and/or
DataSource.setLogWriter() methods to null (the default is null).
• Heap manager. Increase or decrease the Java virtual machine (JVM) heap
size to balance performance versus memory usage. The Type 4 driver creates
objects that must be garbage collected by the JVM. For additional information
on JVM heap optimization, see the Tuning Garbage Collection with the 1.4.2
Java™ Virtual Machine at http://java.sun.com/docs/hotspot/gc1.4.2/ and
Turbo-charging Java HotSpot Virtual Machine, v1.4.x to Improve the
Performance and Scalability of Application Servers at
http://java.sun.com/developer/technicalArticles/Programming/turbo/.
3.2 Design and Programming Tips
• Do not use the same connection simultaneously in different threads. The
connection’s operations will be serialized. Use different connections with
different threads to get parallel execution.
• Use the same connection to execute multiple statements. Closing and
reopening a connection can be very costly.
• When using connection pooling, avoid setting the connection’s catalog,
schema, transaction isolation, and autocommit attributes programmatically at