Author: supun Date: Mon Jun 29 02:40:34 2009 New Revision: 40281 URL: http://wso2.org/svn/browse/wso2?view=rev&revision=40281
Log: Adding content to cache mediator Modified: branches/esb/java/2.1/product/docs/xdoc/mediators/cache.xml Modified: branches/esb/java/2.1/product/docs/xdoc/mediators/cache.xml URL: http://wso2.org/svn/browse/wso2/branches/esb/java/2.1/product/docs/xdoc/mediators/cache.xml?rev=40281&r1=40280&r2=40281&view=diff ============================================================================== --- branches/esb/java/2.1/product/docs/xdoc/mediators/cache.xml (original) +++ branches/esb/java/2.1/product/docs/xdoc/mediators/cache.xml Mon Jun 29 02:40:34 2009 @@ -1,87 +1,118 @@ -<?xml version="1.0" encoding="iso-8859-1"?> -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" - "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd";> -<html xmlns="http://www.w3.org/1999/xhtml";> -<head> - <meta http-equiv="content-type" content="text/html; charset=iso-8859-1" /> - <title>WSO2 ESB - Cache Mediator </title> - <link href="css/esb-docs.css" rel="stylesheet" /> - <link href="styles/dist-docs.css" rel="stylesheet" type="text/css" - media="all" /> -</head> - -<body> -<h2>Cache Mediator</h2> - -<p>Cache mediator checks weather a message is seen before. If the message is -seen before it will execute a specified sequence. </p> - -<h3>Syntax</h3> -<pre xml:space="preserve"> <cache [id="string"] [hashGenerator="class"] [timeout="seconds"] [scope=(per-host | per-mediator)] - collector=(true | false) [maxMessageSize="in-bytes"]> - <onCacheHit [sequence="key"]> - (mediator)+ - </onCacheHit>? - <implementation type=(memory | disk) maxSize="int"/> - </cache></pre> - -<p>The cache mediator will evaluate the hash value of an incoming message as -described in the optional hash generator implementation (which should be a -class implementing the org.wso2.caching.digest.DigestGenerator interface). The -default hash generator is 'org.wso2.caching.digest.DOMHashGenerator'. If the -generated hash value has been found in the cache then the cache mediator will -execute the onCacheHit sequence which can be specified inline or referenced. -The cache mediator must be specified with an 'id' and two instances with this -same 'id' that correlates the response message into the cache for the request -message hash. The optional 'timeout' specifies the valid duration for cached -elements, and the scope defines if mediator instances share a common cache per -every host instance, or per every cache mediator pair (i.e. 'id') instance. The -'collector' attribute 'true' specifies that the mediator instance is a response -collection instance, and 'false' specifies that its a cache serving instance. -The maximum size of a message to be cached could be specified with the optional -'maxMessageSize' attributes in bytes and defaults to unlimited. Finally the -'implementation' element may define if the cache is disk or memory based, and -the 'maxSize' attribute defines the maximum number of elements to be cached. -</p> - -<p></p> - -<h3>UI Configuration</h3> -<img src="../cache-mediator/docs/images/cache_mediator_screenshot.jpg" alt="" -/> -<ul> - <li>Cache Id: Id for the cache configuration. You should have same id for a - cache mediator instance in incoming path and the corresponding mediator - instance in outgoing message path. </li> - <li>Cache Scope: Scope of the cache. This is important if the service is - deployed in a cluster. - <ul> - <li>Per-Host: The cache is kept only for the current host in a cluster. - </li> - <li>Per-Mediator: The cache is kept once for the whole cluster. </li> - </ul> - </li> - <li>Cache Type: Whether the mediator is in the incoming path (check request) - or the outgoing path (cache the response). - <ul> - <li>Finder: Set if the message is incoming path. This indicate the - mediator find for the request hash of each incoming message. </li> - <li>Collector: Set if the message is in outgoing path. This indicate the - mediator collect the response message in the cache. </li> - </ul> - </li> - <li>Hash Generator: The logic for finding the hash which check against each - incoming message. Default to org.wso2.caching.digest.DOMHASHGenerator </li> - <li>Cache Timeout: The cache timeout(The time to keep the cache before - expiring) in seconds. </li> - <li>Maximum Message Size: The limit of the message to cache in bytes. </li> - <li>Implementation Type: Currently only "In-Memory" is available. </li> - <li>On Cache Hit: Specify the sequence to follow when the cache mediator is - hit. You can either specify it as anonymous where you can define child - mediators for the Cache mediator or you can refer a named sequence of - mediators from the registry. </li> -</ul> - -<h3>Example</h3> -</body> -</html> +<?xml version="1.0" encoding="iso-8859-1"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" + "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd";> +<html xmlns="http://www.w3.org/1999/xhtml";> +<head> + <meta http-equiv="content-type" content="text/html; charset=iso-8859-1" /> + <title>WSO2 ESB - Cache Mediator </title> + <link href="css/esb-docs.css" rel="stylesheet" /> + <link href="styles/dist-docs.css" rel="stylesheet" type="text/css" + media="all" /> +</head> + +<body> +<h2>Cache Mediator</h2> + +<p>When a message comes Cache mediator checks weather a equivalent message is +seen before. If the message is seen before it will execute a specified +sequence. It uses message hashes for checking the equivalence of messages. The +moment cache meditor finds that the message is a cached message, it will fetch +the cached response and prepare ESB for sending the response. In the case of a +sequence is specified for cache hit, user can send back the response message +within this sequence using a send mediator. If a sequence is not specified +cached response is sent back to the requestor. </p> + +<h3>Syntax</h3> +<pre xml:space="preserve"> <cache [id="string"] [hashGenerator="class"] [timeout="seconds"] [scope=(per-host | per-mediator)] + collector=(true | false) [maxMessageSize="in-bytes"]> + <onCacheHit [sequence="key"]> + (mediator)+ + </onCacheHit>? + <implementation type=(memory | disk) maxSize="int"/> + </cache></pre> + +<p>The cache mediator will evaluate the hash value of an incoming message as +described in the optional hash generator implementation (which should be a +class implementing the org.wso2.caching.digest.DigestGenerator interface). The +default hash generator is 'org.wso2.caching.digest.DOMHashGenerator'. If the +generated hash value has been found in the cache then the cache mediator will +execute the onCacheHit sequence which can be specified inline or referenced. +The cache mediator must be specified with an 'id' and two instances with this +same 'id' that correlates the response message into the cache for the request +message hash. The optional 'timeout' specifies the valid duration for cached +elements, and the scope defines if mediator instances share a common cache per +every host instance, or per every cache mediator pair (i.e. 'id') instance. The +'collector' attribute 'true' specifies that the mediator instance is a response +collection instance, and 'false' specifies that its a cache serving instance. +The maximum size of a message to be cached could be specified with the optional +'maxMessageSize' attributes in bytes and defaults to unlimited. Finally the +'implementation' element may define if the cache is disk or memory based, and +the 'maxSize' attribute defines the maximum number of elements to be cached. +</p> + +<p></p> + +<h3>UI Configuration</h3> +<img src="../cache-mediator/docs/images/cache_mediator_screenshot.jpg" alt="" +/> +<ul> + <li>Cache Id: Id for the cache configuration. You should have same id for a + cache mediator instance in incoming path and the corresponding mediator + instance in outgoing message path. </li> + <li>Cache Scope: Scope of the cache. This is important if the service is + deployed in a cluster. + <ul> + <li>Per-Host: The cache is kept only for the current host in a cluster. + </li> + <li>Per-Mediator: The cache is kept once for the whole cluster. </li> + </ul> + </li> + <li>Cache Type: Whether the mediator is in the incoming path (check request) + or the outgoing path (cache the response). + <ul> + <li>Finder: Set if the message is incoming path. This indicate the + mediator find for the request hash of each incoming message. </li> + <li>Collector: Set if the message is in outgoing path. This indicate the + mediator collect the response message in the cache. </li> + </ul> + </li> + <li>Hash Generator: The logic for finding the hash which check against each + incoming message. Default to org.wso2.caching.digest.DOMHASHGenerator </li> + <li>Cache Timeout: The cache timeout(The time to keep the cache before + expiring) in seconds. </li> + <li>Maximum Message Size: The limit of the message to cache in bytes. </li> + <li>Implementation Type: Currently only "In-Memory" is available. </li> + <li>On Cache Hit: Specify the sequence to follow when the cache mediator is + hit. You can either specify it as anonymous where you can define child + mediators for the Cache mediator or you can refer a named sequence of + mediators from the registry. </li> +</ul> + +<h3>Example</h3> +<pre xml:space="preserve"><definitions xmlns="http://ws.apache.org/ns/synapse"> + <in> + <cache timeout="20" scope="per-host" collector="false" + hashGenerator="org.wso2.caching.digest.DOMHASHGenerator"> + <implementation type="memory" maxSize="100"/> + </cache> + + <send> + <endpoint> + <address uri="http://localhost:9000/services/SimpleStockQuoteService"/> + </endpoint> + </send> + </in> + + <out> + <cache collector="true"/> + <send/> + </out> +</definitions></pre> + +<p>In this example, first message will be sent to the endpoint specified as +cache is not hit. The responce will come to the cache mediator inside the out +meduator and this will cache the response. The second equal message will match +the cache and response will be directly fetch from the cache and sent to the +requestor. This happens because no onCacheHit sequence is defined. </p> +</body> +</html> _______________________________________________ Esb-java-dev mailing list [email protected] https://wso2.org/cgi-bin/mailman/listinfo/esb-java-dev
