Dynamic Cache attributes

The attributes provide dynamic cache information.

The Dynamic Cache attribute group provides information about the dynamic cache.

WebSphere® Application Server consolidates several caching activities, including servlets, web services, and WebSphere commands, into one service called the dynamic cache. These caching activities work together to improve application performance and share many configuration parameters, which are set in an application server's dynamic cache service. The dynamic cache works within an application server Java™ virtual machine (JVM), intercepting calls to cacheable objects, for example, through a servlet's service method or a command's execute method. It either stores the object's output to, or serves the object's content from, the dynamic cache.

The attributes within this group are used to build the Cache Analysis workspace.

Notes:
  • The attributes within this attribute group contain zeros for performance data if your site set configuration value Resource Data Collection Method to On Demand (for on-demand sampling) and you have not yet run applications that generate performance data. To report performance data in these attributes after installing and configuring the Data Collector, use the WebSphere administrative console to set the appropriate PMI instrumentation level.
  • The monitoring agent is set by default to provide on-demand sampling; thus the attributes within this attribute group initially contain zeros until you select the workspace and then select it again later. Each time you select the workspace, these attributes are updated with the latest data.

Cache Instance Name Indicates the cache instance name.

Cache Instance Type Indicates Cache instance type.

Current In-Memory Cache Size The number of cache entries currently in memory. The valid format is a positive integer.

In-Memory and Disk Timeout Rate (per sec) The rate (per second) of total in-memory and disk timeouts for the sampling interval. The valid format is a decimal (formatted to 3 decimal places).

In-Memory and Disk Timeouts The total number of in-memory and disk timeouts during the sampling interval. The valid format is a positive integer.

Instrumentation Level The instrumentation level for the dynamic cache. For WebSphere 6 or higher, the valid values are None, Basic, Extended, All, Custom. Blank if no instrumentation level is set.

Interval (sec) The length (in seconds) of the sampling interval. The valid format is a positive integer.

Maximum In-Memory Cache Size The maximum number of cache entries in memory. The valid format is a positive integer.

Node Name The name of the system on which the server is running. The valid format is an alphanumeric string, with a maximum of 128 characters.

Origin Node The name of the server subnode. The valid format is an alphanumeric string, with a maximum of 128 characters.

Sample Date and Time The date and time the monitoring agent collected the data. The valid format is a 12-character timestamp. For the STR and SCAN functions, the format is MM/DD/YY HH:MM:SS; the following table shows the values contained in this character string:

Table 1. Format of the 12-character timestamp
Character String Meaning
MM Month
DD Day
YY Year
HH Hour
MM Minute
SS Second

Example: 09/13/06 18:32:03 indicates the data was collected on September 13, 2006, at 18:32:03.

This attribute was designed for logging and reporting data-collection times rather than for creating situations. To specify a time and date for comparison and testing, use attributes from the Universal Time or Local Time groups.

Server Name The name of the WebSphere Application Server. The valid format is an alphanumeric string, with a maximum of 256 characters.

Set Instrumentation Level Type Indicates the WebSphere resource category, which is used by the agent to modify the Instrumentation Level for transaction data collection.

Summary of Cache Indicates that this row is a summary row of statistical totals collected for all the cache object types.