B.4. Performance Tab

Use attributes on the Performance tab to tune the SGD server.

From the command line, use the Section D.16, “tarantella config list” command to list these settings, and the Section D.15, “tarantella config edit” command to edit these settings.

B.4.1. Maximum Simultaneous Requests

Usage: Type a number in the field.

Description

The maximum number of requests the server processes simultaneously.

As a rough guide, set this to the number of central processing units (CPUs) multiplied by 4.

Too high a setting might degrade performance.

Changes to this attribute take effect immediately.

Command Line

Command option: --tuning-maxrequests num

Usage: Replace num with the maximum number of simultaneous requests.

The following example sets the maximum number of simultaneous requests to 7.

--tuning-maxrequests 7

B.4.2. Maximum Simultaneous User Sessions

Usage: Type a number in the field.

Description

The maximum number of simultaneous user sessions. A user session is defined as a connection between an SGD Client and the SGD server.

Once the limit is reached, connections are refused.

Too high a setting might degrade performance.

Changes to this attribute take effect immediately.

Command Line

Command option: --tuning-maxconnections num

Usage: Replace num with the maximum number of simultaneous user sessions.

The following example sets the maximum number of simultaneous user sessions to 1000.

--tuning-maxconnections 1000

B.4.3. Maximum File Descriptors

Usage: Type a number in the field.

Description

The maximum number of open file descriptors allowed.

Increasing this value increases the number of simultaneous connections that can be handled.

This value affects all SGD server components.

Too high a setting might degrade performance.

Changes to this attribute take effect when the server restarts.

Command Line

Command option: --tuning-maxfiledescriptors num

Usage: Replace num with the maximum number of open file descriptors.

The following example sets the maximum number of open file descriptors to 4096.

--tuning-maxfiledescriptors 4096

B.4.4. JVM Size

Usage: Type numbers in the fields.

Description

These attributes control the size and expansion rate of the memory allocated to the SGD server's Java Runtime Environment (JRE). The following attributes are available:

  • The amount of memory, in megabytes, to allocate initially for the SGD server's Java Virtual Machine (JVM). Set this to no greater than the amount of random access memory (RAM) on the host.

  • A scaling factor, expressed as a percentage, used to increase the amount of JVM software memory dynamically when needed.

  • An absolute maximum size in megabytes, that is never exceeded.

Too high a setting might degrade performance.

Changes to this attribute take effect when the server or JVM software restarts.

Command Line

Command option: --tuning-jvm-initial MB

Usage: Replace MB with the initial memory allocation for the JVM software, in megabytes.

Command option: --tuning-jvm-scale percent

Usage: Replace percentage with a dynamic scaling factor, expressed as a percentage.

Command option: --tuning-jvm-max MB

Usage: Replace MB with the maximum memory allocation for the JVM software, in megabytes.

The following examples set the initial JVM software size to 58 megabytes. The amount of JVM software memory can be scaled up to 150% when needed. The maximum JVM software size is set to 512 megabytes.

--tuning-jvm-initial 58
--tuning-jvm-scale 150
--tuning-jvm-max 512

B.4.5. Daily Resource Synchronization Time

Usage: Type a number in the field.

Description

When to start resource synchronization each day, if enabled for the array.

Use the server's local time zone.

Express the time in 24-hour clock format. For example, use 16:00 for 4 p.m.

Changes to this attribute take effect immediately.

Command Line

Command option: --tuning-resourcesync-time hh:mm

Usage: Replace hh:mm with the time, in 24-hour clock format.

The following example sets the resource synchronization time to 4:00 (4 a.m.)

--tuning-resourcesync-time 4:00

B.4.6. Load Balancing Groups

Usage: Type the load balancing groups for this SGD server in the field.

Description

This attribute is a string identifying the load balancing group for an SGD server in an array. This information can be used for application load balancing.

This attribute is used to enable optimal bandwidth usage. SGD servers are chosen from the same load balancing groups as application servers, where possible.

Leave this attribute blank unless your array spans a wide area network (WAN), or includes slow links, and you are using load balancing.

More than one string is allowed, but this slows application launch.

If used, set this attribute on all SGD servers in the array, and all application server objects in the organizational hierarchy.

Command Line

Command option: --server-location location

Usage: Replace location with a string identifying the load balancing group for the SGD server in the array.

The following example specifies a location of boston.

--server-location boston