Repository: camel Updated Branches: refs/heads/master 2b4d13f75 -> c66552d99
Added camel-jgroups docs to Gitbook Project: http://git-wip-us.apache.org/repos/asf/camel/repo Commit: http://git-wip-us.apache.org/repos/asf/camel/commit/c66552d9 Tree: http://git-wip-us.apache.org/repos/asf/camel/tree/c66552d9 Diff: http://git-wip-us.apache.org/repos/asf/camel/diff/c66552d9 Branch: refs/heads/master Commit: c66552d9911e17d4e8dfd31ebd5a36f8b05562d8 Parents: 2b4d13f Author: Andrea Cosentino <anco...@gmail.com> Authored: Wed Apr 27 10:07:38 2016 +0200 Committer: Andrea Cosentino <anco...@gmail.com> Committed: Wed Apr 27 10:08:00 2016 +0200 ---------------------------------------------------------------------- .../camel-jgroups/src/main/docs/jgroups.adoc | 276 +++++++++++++++++++ docs/user-manual/en/SUMMARY.md | 1 + 2 files changed, 277 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/camel/blob/c66552d9/components/camel-jgroups/src/main/docs/jgroups.adoc ---------------------------------------------------------------------- diff --git a/components/camel-jgroups/src/main/docs/jgroups.adoc b/components/camel-jgroups/src/main/docs/jgroups.adoc new file mode 100644 index 0000000..1374936 --- /dev/null +++ b/components/camel-jgroups/src/main/docs/jgroups.adoc @@ -0,0 +1,276 @@ +[[JGroups-JGroupsComponent]] +JGroups Component +~~~~~~~~~~~~~~~~~ + +*Available since Camel 2.10.0* + +http://www.jgroups.org[JGroups] is a toolkit for reliable multicast +communication. The *jgroups:* component provides exchange of messages +between Camel infrastructure and http://jgroups.org[JGroups] clusters. + +Maven users will need to add the following dependency to their `pom.xml` +for this component. + +[source,xml] +------------------------------------------------------------ +<dependency> + <groupId>org.apache-extras.camel-extra</groupId> + <artifactId>camel-jgroups</artifactId> + <!-- use the same version as your Camel core version --> + <version>x.y.z</version> +</dependency> +------------------------------------------------------------ + +Starting from the Camel *2.13.0*, JGroups component has been moved from +Camel Extra under the umbrella of the Apache Camel. If you are using +Camel *2.13.0* or higher, please use the following POM entry instead. + +[source,xml] +------------------------------------------------------------ +<dependency> + <groupId>org.apache.camel</groupId> + <artifactId>camel-jgroups</artifactId> + <!-- use the same version as your Camel core version --> +  <version>x.y.z</version> +</dependency> +------------------------------------------------------------ + +[[JGroups-URIformat]] +URI format +^^^^^^^^^^ + +[source,java] +----------------------------- +jgroups:clusterName[?options] +----------------------------- + +Where *clusterName* represents the name of the JGroups cluster the +component should connect to. + +[[JGroups-Options]] +Options +^^^^^^^ + + +// component options: START +The JGroups component supports 3 options which are listed below. + + + +[width="100%",cols="2s,1m,8",options="header"] +|======================================================================= +| Name | Java Type | Description +| channel | Channel | Channel to use +| channelProperties | String | Specifies configuration properties of the JChannel used by the endpoint. +| enableViewMessages | boolean | If set to true the consumer endpoint will receive org.jgroups.View messages as well (not only org.jgroups.Message instances). By default only regular messages are consumed by the endpoint. +|======================================================================= +// component options: END + + + +// endpoint options: START +The JGroups component supports 7 endpoint options which are listed below: + +[width="100%",cols="2s,1,1m,1m,5",options="header"] +|======================================================================= +| Name | Group | Default | Java Type | Description +| clusterName | common | | String | *Required* The name of the JGroups cluster the component should connect to. +| channelProperties | common | | String | Specifies configuration properties of the JChannel used by the endpoint. +| bridgeErrorHandler | consumer | false | boolean | Allows for bridging the consumer to the Camel routing Error Handler which mean any exceptions occurred while the consumer is trying to pickup incoming messages or the likes will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions that will be logged at WARN/ERROR level and ignored. +| enableViewMessages | consumer | false | boolean | If set to true the consumer endpoint will receive org.jgroups.View messages as well (not only org.jgroups.Message instances). By default only regular messages are consumed by the endpoint. +| exceptionHandler | consumer (advanced) | | ExceptionHandler | To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this options is not in use. By default the consumer will deal with exceptions that will be logged at WARN/ERROR level and ignored. +| exchangePattern | advanced | InOnly | ExchangePattern | Sets the default exchange pattern when creating an exchange +| synchronous | advanced | false | boolean | Sets whether synchronous processing should be strictly used or Camel is allowed to use asynchronous processing (if supported). +|======================================================================= +// endpoint options: END + + +[[JGroups-Headers]] +Headers +^^^^^^^ + +[width="100%",cols="10%,10%,10%,70%",options="header",] +|======================================================================= +|Header |Constant |Since version |Description + +|`JGROUPS_ORIGINAL_MESSAGE` |`JGroupsEndpoint.HEADER_JGROUPS_ORIGINAL_MESSAGE` |*2.13.0* |The original `org.jgroups.Message` instance from which the body of the +consumed message has been extracted. + +|`JGROUPS_SRC` |`JGroupsEndpoint.`HEADER_JGROUPS_SRC |*2.10.0* | *Consumer* : The `org.jgroups.Address` instance extracted by +`org.jgroups.Message`.getSrc() method of the consumed message. +*Producer*: The custom source `org.jgroups.Address` of the message to be sent. + +|`JGROUPS_DEST` |`JGroupsEndpoint.`HEADER_JGROUPS_DEST |*2.10.0* |*Consumer*: The `org.jgroups.Address` instance extracted by +`org.jgroups.Message`.getDest() method of the consumed message. +*Producer*: The custom destination `org.jgroups.Address` of the message to be sent. + +|`JGROUPS_CHANNEL_ADDRESS` |`JGroupsEndpoint.`HEADER_JGROUPS_CHANNEL_ADDRESS |*2.13.0* |Address (`org.jgroups.Address`) of the channel associated with the +endpoint. +|======================================================================= + +[[JGroups-Usage]] +Usage +^^^^^ + +Using `jgroups` component on the consumer side of the route will capture +messages received by the `JChannel` associated with the endpoint and +forward them to the Camel route. JGroups consumer processes incoming +messages +http://camel.apache.org/asynchronous-routing-engine.html[asynchronously]. + +[source,java] +---------------------------------------------- +// Capture messages from cluster named +// 'clusterName' and send them to Camel route. +from("jgroups:clusterName").to("seda:queue"); +---------------------------------------------- + +Using `jgroups` component on the producer side of the route will forward +body of the Camel exchanges to the `JChannel` instance managed by the +endpoint. + +[source,java] +-------------------------------------------------- +// Send message to the cluster named 'clusterName' +from("direct:start").to("jgroups:clusterName"); +-------------------------------------------------- + +[[JGroups-Predefinedfilters]] +Predefined filters +^^^^^^^^^^^^^^^^^^ + +Starting from version *2.13.0* of Camel, JGroups component comes with +predefined filters factory class named `JGroupsFilters.` + +If you would like to consume only view changes notifications sent to +coordinator of the cluster (and ignore these sent to the "slave" nodes), +use the `JGroupsFilters.dropNonCoordinatorViews()` filter. This filter +is particularly useful when you want a single Camel node to become the +master in the cluster, because messages passing this filter notifies you +when given node has become a coordinator of the cluster. The snippet +below demonstrates how to collect only messages received by the master +node. + +[source,java] +---------------------------------------------------------------------------------------- +import static org.apache.camel.component.jgroups.JGroupsFilters.dropNonCoordinatorViews; +... +from("jgroups:clusterName?enableViewMessages=true"). + filter(dropNonCoordinatorViews()). + to("seda:masterNodeEventsQueue"); +---------------------------------------------------------------------------------------- + +[[JGroups-Predefinedexpressions]] +Predefined expressions +^^^^^^^^^^^^^^^^^^^^^^ + +Starting from version *2.13.0* of Camel, JGroups component comes with +predefined expressions factory class named `JGroupsExpressions.` + +If you would like to create link:delayer.html[delayer] that would affect +the route only if the Camel context has not been started yet, use the +`JGroupsExpressions.delayIfContextNotStarted(long delay)` factory +method. The expression created by this factory method will return given +delay value only if the Camel context is in the state different than +`started`. This expression is particularly useful if you would like to +use JGroups component for keeping singleton (master) route within the +cluster. link:controlbus-component.html[Control Bus] `start` command +won't initialize the singleton route if the Camel Context hasn't been +yet started. So you need to delay a startup of the master route, to be +sure that it has been initialized after the Camel Context startup. +Because such scenario can happen only during the initialization of the +cluster, we don't want to delay startup of the slave node becoming the +new master - that's why we need a conditional delay expression. + +The snippet below demonstrates how to use conditional delaying with the +JGroups component to delay the initial startup of master node in the +cluster. + +[source,java] +----------------------------------------------------------------------------------------------------------------------------------------------------------------- +import static java.util.concurrent.TimeUnit.SECONDS; +import static org.apache.camel.component.jgroups.JGroupsExpressions.delayIfContextNotStarted; +import static org.apache.camel.component.jgroups.JGroupsFilters.dropNonCoordinatorViews; +... +from("jgroups:clusterName?enableViewMessages=true"). + filter(dropNonCoordinatorViews()). + threads().delay(delayIfContextNotStarted(SECONDS.toMillis(5))). // run in separated and delayed thread. Delay only if the context hasn't been started already. +  to("controlbus:route?routeId=masterRoute&action=start&async=true"); + +from("timer://master?repeatCount=1").routeId("masterRoute").autoStartup(false).to(masterMockUri); +----------------------------------------------------------------------------------------------------------------------------------------------------------------- + +[[JGroups-Examples]] +Examples +^^^^^^^^ + +[[JGroups-SendingreceivingmessagestofromtheJGroupscluster]] +Sending (receiving) messages to (from) the JGroups cluster +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + +In order to send message to the JGroups cluster use producer endpoint, +just as demonstrated on the snippet below. + +[source,java] +------------------------------------------------ +from("direct:start").to("jgroups:myCluster"); +... +producerTemplate.sendBody("direct:start", "msg") +------------------------------------------------ + +To receive the message from the snippet above (on the same or the other +physical machine) listen on the messages coming from the given cluster, +just as demonstrated on the code fragment below. + +[source,java] +------------------------------------------------------------ +mockEndpoint.setExpectedMessageCount(1); +mockEndpoint.message(0).body().isEqualTo("msg"); +... +from("jgroups:myCluster").to("mock:messagesFromTheCluster"); +... +mockEndpoint.assertIsSatisfied(); +------------------------------------------------------------ + +[[JGroups-Receiveclusterviewchangenotifications]] +Receive cluster view change notifications ++++++++++++++++++++++++++++++++++++++++++ + +The snippet below demonstrates how to create the consumer endpoint +listening to the notifications regarding cluster membership changes. By +default only regular messages are consumed by the endpoint. + +[source,java] +--------------------------------------------------------------------- +mockEndpoint.setExpectedMessageCount(1); +mockEndpoint.message(0).body().isInstanceOf(org.jgroups.View.class); +... +from("jgroups:clusterName?enableViewMessages=true").to(mockEndpoint); +... +mockEndpoint.assertIsSatisfied(); +--------------------------------------------------------------------- + +[[JGroups-Keepingsingletonroutewithinthecluster]] +Keeping singleton route within the cluster +++++++++++++++++++++++++++++++++++++++++++ + +The snippet below demonstrates how to keep the singleton consumer route +in the cluster of Camel Contexts. As soon as the master node dies, one +of the slaves will be elected as a new master and started. In this +particular example we want to keep singleton link:jetty.html[jetty] +instance listening for the requests on +address` http://localhost:8080/orders`. + +[source,java] +----------------------------------------------------------------------------------------------------------------------------------------------------------------- +import static java.util.concurrent.TimeUnit.SECONDS; +import static org.apache.camel.component.jgroups.JGroupsExpressions.delayIfContextNotStarted; +import static org.apache.camel.component.jgroups.JGroupsFilters.dropNonCoordinatorViews; +... +from("jgroups:clusterName?enableViewMessages=true"). + filter(dropNonCoordinatorViews()). + threads().delay(delayIfContextNotStarted(SECONDS.toMillis(5))). // run in separated and delayed thread. Delay only if the context hasn't been started already. +  to("controlbus:route?routeId=masterRoute&action=start&async=true"); + +from("jetty:http://localhost:8080/orders";).routeId("masterRoute").autoStartup(false).to("jms:orders"); +----------------------------------------------------------------------------------------------------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/camel/blob/c66552d9/docs/user-manual/en/SUMMARY.md ---------------------------------------------------------------------- diff --git a/docs/user-manual/en/SUMMARY.md b/docs/user-manual/en/SUMMARY.md index 6fae6d8..b0d9e0b 100644 --- a/docs/user-manual/en/SUMMARY.md +++ b/docs/user-manual/en/SUMMARY.md @@ -171,6 +171,7 @@ * [Jcr](jcr.adoc) * [JDBC](jdbc.adoc) * [Jetty](jetty.adoc) + * [Jgroups](jgroups.adoc) * [Kafka](kafka.adoc) * [Metrics](metrics.adoc) * [Mock](mock.adoc)
