SWS File Cache Test

The file cache caches static content so that the server handles requests for static content quickly. The file cache contains information about files and static file content. The file cache also caches information that is used to speed up processing of server-parsed HTML.

By periodically monitoring the usage of the file cache, you will not only be introduced to ineffective cache usage patterns, but also irregularities in the cache size, both of which may contribute to a slowdown in server operations.

Using this test, you can monitor the usage of the file cache and detect sizing inadequacies.

Target of the test : An Oracle iPlanet Web Server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for the Oracle iPlanet web server instance being monitored.

Configurable parameters for the test
Parameter	Description
Test period	How often should the test be executed.
Host	The host for which the test is to be configured.
Port	The port number at which the specified Host listens to.
User	Specify the name of the administrator of the administration server to which the target web server is registered.
PasswdFile	The eG agent connects to the administration server to which the target web server is registered to extract the required metrics. To enable the eG agent to communicate with this administration server, you first need to create a password file containing the administrator password for accessing the server; this password file should be created in the install directory of the web server. Specify the name of this file in the PasswdFile text box; by default, this is admin.passwd.
AdminServer	Specify the IP address of the administration server to which the target web server is registered.
AdminPort	Indicate the port at which the administration server listens.
Config	In Web Server 7.0, all configurable elements of a server instance like web applications, configuration files, and search collection indexes are logically grouped and termed as a Configuration. To enable the test to locate the web server instance to be monitored, you need to mention the Configuration that applies to the instance. In the Config text box therefore, specify the name of the Configuration which the target web server instance uses.
Node	Node is a network resource, such as a server or a host. Instance refers to the environment of a web server daemon on a given node, including its configuration, log files and other runtime artifacts such as lock databases, caches and temporary files. To enable the test to identify the exact web server instance to be monitored, you need to specify the name of the Node on which the instance executes. The test will thus monitor only that web server instance that operates on the given Node and which uses the specified Config.
SSL	Set this flag to Yes if the administration server is SSL-enabled; if not, set it to No.
WebServerDir	Here, specify the Oracle iPlanet web server installation directory.

Measurements made by the test
Measurement	Description	Measurement Unit	Interpretation
No of cache hits	Indicates the number of times during the last measurement period the file cache was looked.	Number	Ideally, this value should be high.
No. of cache misses	Indicates the number of times during the last measurement period the file cache could not service requests for file information or static content.	Number	Ideally, this value should be low. A high value indicates an ineffective cache – in other words, the cache may not have adequate entries to service requests. This could be owing to the small cache heap size. You may want to consider resizing the cache heap, so that the file cache is able to accommodate more entries, and thus service more number of requests.
No. of cache content hits	Indicates the number of times during the last measurement period the cache was looked up for static content.	Number	Ideally, this value should be high.
Cache content misses	Indicates the number of times during the last measurement period the file cache could not service requests for static content.	Number	Ideally, this value should be low. A high value indicates an ineffective cache – in other words, enough content may not have been cached by the server, thus causing many requests to go unserviced. This could be owing to the small cache heap size. You may want to consider resizing the cache heap, so that the file cache is able to accommodate more content, and thus service more number of requests.
No. of file info lookups	Indicates the number of times during the last measurement period the file cache was looked up for file information.	Number	Ideally, this value should be high.
No of FI lookup failures	Indicates the number of times during the last measurement period the file cache could not service requests for file information.	Number	Ideally, this value should be low. A high value indicates an ineffective cache – in other words, enough file information may not have been cached by the server, thus causing many requests for file info to go unserviced. This could be owing to the small cache heap size. You may want to consider resizing the cache heap, so that the file cache is able to accommodate more file information, and thus service more number of requests.
No of entries	Indicates the current number of cache entries.	Number
Maximum cache size	Indicates the maximum number of entries that can be available in the file cache.	Number	The optimal file cache size is dependent on whether you are running a 32-bit or a 64-bit server. The available address space for a 32–bit server is limited to 4GB. The max-entries for file cache is based on the amount of Java heap, the number of threads (as specified by thread-pool/max-threads), and the connection queue size. It is recommended to cache small, frequently accessed static files in the file cache and use perfdump to ensure that the file cache hit ratio is close to 100%. To achieve this, you may increase file cache size and fine tune the max-entries for optimal performance. In a 64-bit server, due to the increased availability of address space, you can cache more static content in the file cache.
No of open file entries	Indicates the current number of open file entries.	Number	For performance reasons, the web server caches the open file descriptors of large files, to avoid opening and closing such files frequently. The value of this measure represents the number of open file descriptors that are currently in the cache.
Max open files allowed	Indicates the maximum number of open files allowed.	Number
Heap size	Indicates the current cache heap size.	MB
Maximum heap cache size	Indicates the maximum cache heap size.	MB	The optimal cache heap size depends upon how much system memory is free. A larger heap size means that the Web Server can cache more content and therefore obtain a better hit ratio. However, the heap size should not be so large that the operating system starts paging cached files.
Size of Mem mapped file	Indicates the current size of the memory mapped file content.	KB	For performance reasons, the web server caches the content of small files in memory. The value of this measure represents the number of small files that in cache.
Max mem mapped file size	Indicates the maximum size of the memory mapped file.	KB
Maximum age of entries	Indicates the maximum age of a valid cache entry.	Secs	This measure controls how long cached information is used after a file has been cached. An entry older than the maximum age is replaced by a new entry for the same file.
File cache enabled	Indicates whether the file cache has been enabled or not.	Boolean