Sun Java System Web Proxy Server 4.0.2 2005Q4 Configuration File Reference

Cache Elements

Cache elements are as follows:

FILECACHE

Configures the in-memory cache.

Subelements

The following table describes subelements for the FILECACHE element.

Table 2–21 FILECACHE subelements


Element	Required	Description
DESCRIPTION	zero or one	Contains a text description of this element.

Attributes

The following table describes attributes for the FILEACHE element.

Table 2–22 FILECACHE attributes


Attribute	Default	Description
`enabled`	true	Select this option, if not already selected.
`transmitfile`	false	When you enable Transmit File, the server caches open file descriptors for files in the file cache, rather than the file contents, and PR_TransmitFile is used to send the file contents to a client. When Transmit File is enabled, the distinction normally made by the file cache between small, medium, and large files no longer applies, because only the open file descriptor is being cached.
`contentcache`	true	Enables caching file content.
`tempdir`		Specifies the directory to store temporary files.
`maxage`	30	The maximum age in seconds of a valid cache entry. This setting controls how long cached information will continue to be used once the file is cached. An entry older than MaxAge is replaced by a new entry for the same file, if the same file is referenced through the cache.
`mediumfilesizelimit`	537600	Size in bytes of the largest (non-small) file that is considered to be medium size. The contents of medium files are cached by mapping the file into virtual memory (currently only on Unix platforms). The contents of "large" files (larger than "medium") are not cached, although information about large files is cached.
`mediumfilespace`	10485760	Specifies how much virtual memory will be used to map all medium sized files.
`smallfilesizelimit`	2048	Size in bytes of the largest file that is considered to be "small". The contents of small files are cached by allocating heap space and reading the file into it.
`smallfilespace`	1048576	Specifies how much heap space will be used for the cache, including heap space used to cache small files.
`maxfiles`	1024	The maximum number of files that may be in the cache at once.
`hashinitsize`	0

CACHE

Configures the disk cache.

Subelements

The following table describes subelements for the CACHE element.

Table 2–23 CACHE subelements


Element	Required	Description
DESCRIPTION	zero or one	Contains a text description of this element.
PARTITION	one or more	Cache partition is a reserved part of disk or memory that is set aside for caching purposes.
GC	zero or one	Cache garbage collector is used to delete files from the cache. Garbage collection can be done in either the automatic mode or the explicit mode.

Attributes

The following table describes attributes for the CACHE element.

Table 2–24 CACHE attributes


Attribute	Default	Description
`enabled`	true	Select this option, if not already selected.
`cachedir`	<`Install_Root>/<Instance_Directory>/cache`	Specifies the directory for caching.
`cachecapacity`	2000MB	The cache capacity should be set equal to or greater than the cache size. Setting the capacity larger than the cache size can be helpful if you know that you plan to increase the cache size later, such as by adding an external disk.

PARTITION

Configures the storage area on a disk that you set aside for caching. If you wish to have your cache span several disks, you need to configure at least one cache partition for each disk. Each partition can be independently administered. In other words, you can enable, disable, and configure a partition independently of all other partitions.

Subelements

The following table describes subelements for the PARTITION element.

Table 2–25 CACHE subelements


Element	Required	Description
DESCRIPTION	zero or one	Contains a text description of this element.

Attributes

The following table describes attributes for the PARTITION element.

Table 2–26 CACHE attributes


Attribute	Default	Description
`enabled`	true	Select this option, if not already selected.
`partitiondir`	`<Install_Root>/<Instance_Directory>/cache`	Specify the directory where the partition is to be created.
`partitionname`	part1	Specify a name for the partition.
`maxsize`	1600MB	The optional number for the maximum size, in megabytes, to allow for the cache partition to grow.
`minspace`	5MB	The minimum amount of available space, in megabytes, on the physical partition. This is the actual disk on which the cache partition resides. If less space is available, the proxy stops caching to that cache partition, even if it has not reached the maximum size (max-size). It continues to write to other partitions that are not full.

GC

Configures the cache garbage collector that deletes files from the cache. Garbage collection can be done in either the automatic mode or the explicit mode.

Subelements

The following table describes subelements for the GC element.

Table 2–27 CACHE subelements


Element	Required	Description
DESCRIPTION	zero or one	Contains a text description of this element.

Attributes

The following table describes attributes for the GC element.

Table 2–28 CACHE attributes


Attribute	Default	Description
`enabled`	true	Select this option, if not already selected.
`gchimargin`	80	Controls the percentage of the maximum cache size that, when reached, triggers garbage collection.
`gclomargin`	70	Controls the percentage of the maximum cache size that the garbage collector targets.
`gcleavefsfull`	60	Determines the percentage of the cache partition size below which garbage collection will not go.
`gcextramargin`	30	Sets the percentage of the cache to be removed by the garbage collector.