JVM Tuning Options :: SAS® 9.4 Web Applications: Tuning for Performance and Scalability, Third Edition

JVM Option Descriptions

The following table provides descriptions of the JVM options that you will tune in the SAS 9.4 middle-tier environment.

JVM Tuning Descriptions
JVM Option	Description
`-Xms`	Specifies the minimum heap size.
`-Xmx`	Specifies the maximum heap size.
`-XX:PermSize`	Specifies the initial permanent generation storage size. Applies only to the Java Virtual Machine on HP-UX, Linux, Solaris, and Windows platforms.
`-XX:MaxPermSize`	Specifies the maximum permanent generation size. Applies only to the Java Virtual Machine on HP-UX, Linux, Solaris, and Windows platforms.

JVM Tuning Options

Note: The following tuning options apply to the first maintenance release of SAS 9.4 and earlier. They also apply to servers that do not support the initial tunable parameters as documented in Initial Sizing and Tuning Configuration Options for Deployments.

The following table summarizes the general guidelines for tuning JVM options. These values are recommended initial settings for the tunable arguments. However, individual usage patterns vary and might benefit from additional tuning.

JVM Tuning Options
Deployment Topology	Server	Platform	JVM Option and Recommended Value
Single Server	All	HP-UX, Linux, Solaris, and Windows	`-Xms4096m` `-Xmx4096m` `-XX:PermSize:1280m` `-XX:MaxPermSize:1280m`
Single Server	All	AIX	`-Xms2048m` `-Xmx4096m`
Multiple Server	SASServer1 Instances	HP-UX, Linux, Solaris, and Windows	`-Xms4096m` `-Xmx4096m` `-XX:PermSize:768m` `-XX:MaxPermSize:768m`
Multiple Server	Other Server Instances	HP-UX, Linux, Solaris, and Windows	`-Xms2048m` `-Xmx2048m` `-XX:PermSize:512m` `-XX:MaxPermSize:512m`
Multiple Server	SASServer1 Instances	AIX	`-Xms2048m` `-Xmx4096m`
Multiple Server	Other Server Instances	AIX	`-Xms1024m` `-Xmx2048m`

Monitoring the server data can be combined with the recommended settings to further fine-tune the servers. For more information, see Monitoring and Troubleshooting.

JVM Tuning Options for SAS Web Applications

The following table provides JVM options that are used to configure the SAS web applications. A description is provided for each option to help you decide whether modifying a value is appropriate for your deployment.

JVM Tuning Parameters
JVM Option	Recommended Value	Description
`-Dhttp.proxyHost`	Proxy server host name. For example: `-Dhttp.proxyHost=hostname`	The HTTP proxy options are used by the SAS Information Delivery Portal to access document type definitions (DTDs) over the Internet. Use these options only when a proxy server for Internet connections exists. If you use a proxy server, make sure that the local domain, within the network boundary, is included in the exclude list.
`-Dhttp.proxyPort`	Proxy server port. For example: `-Dhttp.proxyPort=80`
`-Dhttp.nonProxyHosts`	Non-proxy host (exclude list). For example: `-Dhttp.nonProxyHosts= “*.example.com\|localhost”`
`-Djgroups.bind_addr`	Host name or IP address. For example: `-Djgroups.bind_addr=hostname`	Use this option on a system that has multiple network interfaces (physical or virtual). When this option is used and an IP address is specified for the bind_addr value, you can also specify: `-Dresolve.dns=false`
`-Dmulticast_udp_ip_ttl`	1 (default value is 64)	Use this option to restrict multicast traffic to a single subnet, based on your network topology.

JVM Tuning Options for SAS Web Application Server

In order to help ensure that you do not encounter problems with JVM memory for some advanced configuration procedures, you might need to change the JVM options for the server.

When SAS Web Application Server is deployed on UNIX, the JVM options are specified in the JVM_OPTS environment variable, which is specified in the SAS-configuration-directory/Levn/Web/WebAppServer/SASServer1_n/bin/setenv.sh file. If you have multiple instances of SAS Web Application Server, make the appropriate changes in each of the files.

For Windows deployments, the JVM options can be executed from a script or deployed as a service. When executed from a script, the JVM options are specified in the JAVA_OPTS environment variable, in the SAS-configuration-directory\Levn\Web\WebAppServer\SASServer1_n\bin\setenv.bat file. For Windows deployments that are deployed as a service, the JVM options are specified in the SAS-configuration-directory\Levn\Web\WebAppServer\SASServer1_n\conf\wrapper.conf file. Create a new entry for any new JVM options. The following example shows a few lines from the file:

# Java Additional Parameters
wrapper.java.additional.7=-Xmx4096m
wrapper.java.additional.8=-Xss256k
wrapper.java.additional.9=-Xms1024m
wrapper.java.additional.10=-XX:PermSize=768m
wrapper.java.additional.11=-XX:MaxPermSize=1280m

If you have multiple instances of SAS Web Application Server, make the same changes in each of the files.