http://git-wip-us.apache.org/repos/asf/activemq-6/blob/4245a6b4/docs/user-manual/en/management.xml ---------------------------------------------------------------------- diff --git a/docs/user-manual/en/management.xml b/docs/user-manual/en/management.xml deleted file mode 100644 index f1b868f..0000000 --- a/docs/user-manual/en/management.xml +++ /dev/null @@ -1,1117 +0,0 @@ -<?xml version="1.0" encoding="UTF-8"?> -<!-- ============================================================================= --> -<!-- Licensed to the Apache Software Foundation (ASF) under one or more --> -<!-- contributor license agreements. See the NOTICE file distributed with --> -<!-- this work for additional information regarding copyright ownership. --> -<!-- The ASF licenses this file to You under the Apache License, Version 2.0 --> -<!-- (the "License"); you may not use this file except in compliance with --> -<!-- the License. You may obtain a copy of the License at --> -<!-- --> -<!-- http://www.apache.org/licenses/LICENSE-2.0 --> -<!-- --> -<!-- Unless required by applicable law or agreed to in writing, software --> -<!-- distributed under the License is distributed on an "AS IS" BASIS, --> -<!-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. --> -<!-- See the License for the specific language governing permissions and --> -<!-- limitations under the License. --> -<!-- ============================================================================= --> - -<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"; [ -<!ENTITY % BOOK_ENTITIES SYSTEM "ActiveMQ_User_Manual.ent"> -%BOOK_ENTITIES; -]> -<chapter id="management"> - <title>Management</title> - <para>ActiveMQ has an extensive management API that allows a user to modify a server - configuration, create new resources (e.g. JMS queues and topics), inspect these resources - (e.g. how many messages are currently held in a queue) and interact with it (e.g. to remove - messages from a queue). All the operations allows a client to <emphasis>manage</emphasis> - ActiveMQ. It also allows clients to subscribe to management notifications.</para> - <para>There are 3 ways to manage ActiveMQ:</para> - <itemizedlist> - <listitem> - <para>Using JMX -- JMX is the standard way to manage Java applications</para> - </listitem> - <listitem> - <para>Using the core API -- management operations are sent to ActiveMQ server using - <emphasis>core messages</emphasis></para> - </listitem> - <listitem> - <para>Using the JMS API -- management operations are sent to ActiveMQ server using - <emphasis>JMS messages</emphasis></para> - </listitem> - </itemizedlist> - <para>Although there are 3 different ways to manage ActiveMQ each API supports the same - functionality. If it is possible to manage a resource using JMX it is also possible to achieve - the same result using Core messages or JMS messages.</para> - <para>This choice depends on your requirements, your application settings and your environment to - decide which way suits you best.</para> - <section> - <title>The Management API</title> - <para>Regardless of the way you <emphasis>invoke</emphasis> management operations, the - management API is the same.</para> - <para>For each <emphasis>managed resource</emphasis>, there exists a Java interface describing - what can be invoked for this type of resource.</para> - <para>ActiveMQ exposes its managed resources in 2 packages:</para> - <itemizedlist> - <listitem> - <para><emphasis>Core</emphasis> resources are located in the <literal - >org.apache.activemq.api.core.management</literal> package</para> - </listitem> - <listitem> - <para><emphasis>JMS</emphasis> resources are located in the <literal - >org.apache.activemq.api.jms.management</literal> package</para> - </listitem> - </itemizedlist> - <para>The way to invoke a <emphasis>management operations</emphasis> depends whether JMX, core - messages, or JMS messages are used.</para> - <note> - <para>A few management operations requires a <literal>filter</literal> parameter to chose - which messages are involved by the operation. Passing <literal>null</literal> or an - empty string means that the management operation will be performed on <emphasis>all - messages</emphasis>.</para> - </note> - <section> - <title>Core Management API</title> - <para>ActiveMQ defines a core management API to manage core resources. For full details of - the API please consult the javadoc. In summary:</para> - <section id="management.core.server"> - <title>Core Server Management</title> - <itemizedlist> - <listitem> - <para>Listing, creating, deploying and destroying queues</para> - <para>A list of deployed core queues can be retrieved using the <literal - >getQueueNames()</literal> method.</para> - <para>Core queues can be created or destroyed using the management operations - <literal>createQueue()</literal> or <literal>deployQueue()</literal> or - <literal>destroyQueue()</literal>)on the <literal - >ActiveMQServerControl</literal> (with the ObjectName <literal - >org.apache.activemq:module=Core,type=Server</literal> or the resource name <literal - >core.server</literal>)</para> - <para><literal>createQueue</literal> will fail if the queue already exists while - <literal>deployQueue</literal> will do nothing.</para> - </listitem> - <listitem> - <para>Pausing and resuming Queues</para> - <para>The <literal>QueueControl</literal> can pause and resume the underlying - queue. When a queue is paused, it will receive messages but will not deliver - them. When it's resumed, it'll begin delivering the queued messages, if any. - </para> - </listitem> - <listitem> - <para>Listing and closing remote connections</para> - <para>Client's remote addresses can be retrieved using <literal - >listRemoteAddresses()</literal>. It is also possible to close the - connections associated with a remote address using the <literal - >closeConnectionsForAddress()</literal> method.</para> - <para>Alternatively, connection IDs can be listed using <literal - >listConnectionIDs()</literal> and all the sessions for a given connection - ID can be listed using <literal>listSessions()</literal>.</para> - </listitem> - <listitem> - <para>Transaction heuristic operations</para> - <para>In case of a server crash, when the server restarts, it it possible that - some transaction requires manual intervention. The <literal - >listPreparedTransactions()</literal> method lists the transactions which - are in the prepared states (the transactions are represented as opaque Base64 - Strings.) To commit or rollback a given prepared transaction, the <literal - >commitPreparedTransaction()</literal> or <literal - >rollbackPreparedTransaction()</literal> method can be used to resolve - heuristic transactions. Heuristically completed transactions can be listed - using the <literal>listHeuristicCommittedTransactions()</literal> and <literal - >listHeuristicRolledBackTransactions</literal> methods.</para> - </listitem> - <listitem> - <para>Enabling and resetting Message counters</para> - <para>Message counters can be enabled or disabled using the <literal - >enableMessageCounters()</literal> or <literal - >disableMessageCounters()</literal> method. To reset message counters, it is - possible to invoke <literal>resetAllMessageCounters()</literal> and <literal - >resetAllMessageCounterHistories()</literal> methods.</para> - </listitem> - <listitem> - <para>Retrieving the server configuration and attributes</para> - <para>The <literal>ActiveMQServerControl</literal> exposes ActiveMQ server - configuration through all its attributes (e.g. <literal>getVersion()</literal> - method to retrieve the server's version, etc.)</para> - </listitem> - <listitem> - <para>Listing, creating and destroying Core bridges and diverts</para> - <para>A list of deployed core bridges (resp. diverts) can be retrieved using the <literal - >getBridgeNames()</literal> (resp. <literal>getDivertNames()</literal>) method.</para> - <para>Core bridges (resp. diverts) can be created or destroyed using the management operations - <literal>createBridge()</literal> and <literal>destroyBridge()</literal> - (resp. <literal>createDivert()</literal> and <literal>destroyDivert()</literal>) on the <literal - >ActiveMQServerControl</literal> (with the ObjectName <literal - >org.apache.activemq:module=Core,type=Server</literal> or the resource name <literal - >core.server</literal>).</para> - </listitem> - <listitem> - <para>It is possible to stop the server and force failover to occur with any currently attached clients.</para> - <para>to do this use the <literal>forceFailover()</literal> on the <literal - >ActiveMQServerControl</literal> (with the ObjectName <literal - >org.apache.activemq:module=Core,type=Server</literal> or the resource name <literal - >core.server</literal>) </para> - <note> - <para>Since this method actually stops the server you will probably receive some sort of error - depending on which management service you use to call it. - </para> - </note> - </listitem> - </itemizedlist> - </section> - <section> - <title>Core Address Management</title> - <para>Core addresses can be managed using the <literal>AddressControl</literal> class - (with the ObjectName <literal>org.apache.activemq:module=Core,type=Address,name="<the - address name>"</literal> or the resource name <literal>core.address.<the - address name></literal>). </para> - <itemizedlist> - <listitem> - <para>Modifying roles and permissions for an address</para> - <para>You can add or remove roles associated to a queue using the <literal - >addRole()</literal> or <literal>removeRole()</literal> methods. You can - list all the roles associated to the queue with the <literal - >getRoles()</literal> method</para> - </listitem> - </itemizedlist> - </section> - <section> - <title>Core Queue Management</title> - <para>The bulk of the core management API deals with core queues. The <literal - >QueueControl</literal> class defines the Core queue management operations (with - the ObjectName <literal>org.apache.activemq:module=Core,type=Queue,address="<the bound - address>",name="<the queue name>"</literal> or the resource name <literal - >core.queue.<the queue name></literal>).</para> - <para>Most of the management operations on queues take either a single message ID (e.g. - to remove a single message) or a filter (e.g. to expire all messages with a given - property.)</para> - <itemizedlist> - <listitem> - <para>Expiring, sending to a dead letter address and moving messages</para> - <para>Messages can be expired from a queue by using the <literal - >expireMessages()</literal> method. If an expiry address is defined, - messages will be sent to it, otherwise they are discarded. The queue's - expiry address can be set with the <literal>setExpiryAddress()</literal> - method.</para> - <para>Messages can also be sent to a dead letter address with the <literal - >sendMessagesToDeadLetterAddress()</literal> method. It returns the number - of messages which are sent to the dead letter address. If a dead letter address - is not defined, message are removed from the queue and discarded. The queue's - dead letter address can be set with the <literal - >setDeadLetterAddress()</literal> method.</para> - <para>Messages can also be moved from a queue to another queue by using the - <literal>moveMessages()</literal> method.</para> - </listitem> - <listitem> - <para>Listing and removing messages</para> - <para>Messages can be listed from a queue by using the <literal - >listMessages()</literal> method which returns an array of <literal - >Map</literal>, one <literal>Map</literal> for each message.</para> - <para>Messages can also be removed from the queue by using the <literal - >removeMessages()</literal> method which returns a <literal - >boolean</literal> for the single message ID variant or the number of - removed messages for the filter variant. The <literal - >removeMessages()</literal> method takes a <literal>filter</literal> - argument to remove only filtered messages. Setting the filter to an empty - string will in effect remove all messages.</para> - </listitem> - <listitem> - <para>Counting messages</para> - <para>The number of messages in a queue is returned by the <literal - >getMessageCount()</literal> method. Alternatively, the <literal - >countMessages()</literal> will return the number of messages in the queue - which <emphasis>match a given filter</emphasis></para> - </listitem> - <listitem> - <para>Changing message priority</para> - <para>The message priority can be changed by using the <literal - >changeMessagesPriority()</literal> method which returns a <literal - >boolean</literal> for the single message ID variant or the number of - updated messages for the filter variant.</para> - </listitem> - <listitem> - <para>Message counters</para> - <para>Message counters can be listed for a queue with the <literal - >listMessageCounter()</literal> and <literal - >listMessageCounterHistory()</literal> methods (see <xref - linkend="management.message-counters"/>). The message counters can also be - reset for a single queue using the <literal>resetMessageCounter()</literal> - method.</para> - </listitem> - <listitem> - <para>Retrieving the queue attributes</para> - <para>The <literal>QueueControl</literal> exposes Core queue settings through its - attributes (e.g. <literal>getFilter()</literal> to retrieve the queue's filter - if it was created with one, <literal>isDurable()</literal> to know whether the - queue is durable or not, etc.)</para> - </listitem> - <listitem> - <para>Pausing and resuming Queues</para> - <para>The <literal>QueueControl</literal> can pause and resume the underlying - queue. When a queue is paused, it will receive messages but will not deliver - them. When it's resume, it'll begin delivering the queued messages, if any. - </para> - </listitem> - </itemizedlist> - </section> - <section> - <title>Other Core Resources Management</title> - <para>ActiveMQ allows to start and stop its remote resources (acceptors, diverts, - bridges, etc.) so that a server can be taken off line for a given period of time - without stopping it completely (e.g. if other management operations must be performed - such as resolving heuristic transactions). These resources are:</para> - <itemizedlist> - <listitem> - <para>Acceptors</para> - <para>They can be started or stopped using the <literal>start()</literal> or. - <literal>stop()</literal> method on the <literal>AcceptorControl</literal> - class (with the ObjectName <literal - >org.apache.activemq:module=Core,type=Acceptor,name="<the acceptor - name>"</literal> or the resource name <literal>core.acceptor.<the - address name></literal>). The acceptors parameters can be retrieved using - the <literal>AcceptorControl</literal> attributes (see <xref - linkend="configuring-transports.acceptors"/>)</para> - </listitem> - <listitem> - <para>Diverts</para> - <para>They can be started or stopped using the <literal>start()</literal> or - <literal>stop()</literal> method on the <literal>DivertControl</literal> - class (with the ObjectName <literal - >org.apache.activemq:module=Core,type=Divert,name=<the divert name></literal> - or the resource name <literal>core.divert.<the divert name></literal>). - Diverts parameters can be retrieved using the <literal>DivertControl</literal> - attributes (see <xref linkend="diverts"/>)</para> - </listitem> - <listitem> - <para>Bridges</para> - <para>They can be started or stopped using the <literal>start()</literal> (resp. - <literal>stop()</literal>) method on the <literal>BridgeControl</literal> - class (with the ObjectName <literal - >org.apache.activemq:module=Core,type=Bridge,name="<the bridge - name>"</literal> or the resource name <literal>core.bridge.<the bridge - name></literal>). Bridges parameters can be retrieved using the <literal - >BridgeControl</literal> attributes (see <xref linkend="core-bridges" - />)</para> - </listitem> - <listitem> - <para>Broadcast groups</para> - <para>They can be started or stopped using the <literal>start()</literal> or - <literal>stop()</literal> method on the <literal - >BroadcastGroupControl</literal> class (with the ObjectName <literal - >org.apache.activemq:module=Core,type=BroadcastGroup,name="<the broadcast group - name>"</literal> or the resource name <literal - >core.broadcastgroup.<the broadcast group name></literal>). Broadcast - groups parameters can be retrieved using the <literal - >BroadcastGroupControl</literal> attributes (see <xref - linkend="clusters"/>)</para> - </listitem> - <listitem> - <para>Discovery groups</para> - <para>They can be started or stopped using the <literal>start()</literal> or - <literal>stop()</literal> method on the <literal - >DiscoveryGroupControl</literal> class (with the ObjectName <literal - >org.apache.activemq:module=Core,type=DiscoveryGroup,name="<the discovery group - name>"</literal> or the resource name <literal>core.discovery.<the - discovery group name></literal>). Discovery groups parameters can be - retrieved using the <literal>DiscoveryGroupControl</literal> attributes (see - <xref linkend="clusters"/>)</para> - </listitem> - <listitem> - <para>Cluster connections</para> - <para>They can be started or stopped using the <literal>start()</literal> or - <literal>stop()</literal> method on the <literal - >ClusterConnectionControl</literal> class (with the ObjectName <literal - >org.apache.activemq:module=Core,type=ClusterConnection,name="<the cluster - connection name>"</literal> or the resource name <literal - >core.clusterconnection.<the cluster connection name></literal>). - Cluster connections parameters can be retrieved using the <literal - >ClusterConnectionControl</literal> attributes (see <xref - linkend="clusters"/>)</para> - </listitem> - </itemizedlist> - </section> - </section> - <section> - <title>JMS Management API</title> - <para>ActiveMQ defines a JMS Management API to manage JMS <emphasis>administrated - objects</emphasis> (i.e. JMS queues, topics and connection factories).</para> - <section> - <title>JMS Server Management</title> - <para>JMS Resources (connection factories and destinations) can be created using the - <literal>JMSServerControl</literal> class (with the ObjectName <literal - >org.apache.activemq:module=JMS,type=Server</literal> or the resource name <literal - >jms.server</literal>).</para> - <itemizedlist> - <listitem> - <para>Listing, creating, destroying connection factories</para> - <para>Names of the deployed connection factories can be retrieved by the <literal - >getConnectionFactoryNames()</literal> method.</para> - <para>JMS connection factories can be created or destroyed using the <literal - >createConnectionFactory()</literal> methods or <literal - >destroyConnectionFactory()</literal> methods. These connection factories - are bound to JNDI so that JMS clients can look them up. If a graphical console - is used to create the connection factories, the transport parameters are - specified in the text field input as a comma-separated list of key=value (e.g. - <literal>key1=10, key2="value", key3=false</literal>). If there are multiple - transports defined, you need to enclose the key/value pairs between curly - braces. For example <literal>{key=10}, {key=20}</literal>. In that case, the - first <literal>key</literal> will be associated to the first transport - configuration and the second <literal>key</literal> will be associated to the - second transport configuration (see <xref linkend="configuring-transports"/> - for a list of the transport parameters)</para> - </listitem> - <listitem> - <para>Listing, creating, destroying queues</para> - <para>Names of the deployed JMS queues can be retrieved by the <literal - >getQueueNames()</literal> method.</para> - <para>JMS queues can be created or destroyed using the <literal - >createQueue()</literal> methods or <literal>destroyQueue()</literal> - methods. These queues are bound to JNDI so that JMS clients can look them - up</para> - </listitem> - <listitem> - <para>Listing, creating/destroying topics</para> - <para>Names of the deployed topics can be retrieved by the <literal - >getTopicNames()</literal> method.</para> - <para>JMS topics can be created or destroyed using the <literal - >createTopic()</literal> or <literal>destroyTopic()</literal> methods. These - topics are bound to JNDI so that JMS clients can look them up</para> - </listitem> - <listitem> - <para>Listing and closing remote connections</para> - <para>JMS Clients remote addresses can be retrieved using <literal - >listRemoteAddresses()</literal>. It is also possible to close the - connections associated with a remote address using the <literal - >closeConnectionsForAddress()</literal> method.</para> - <para>Alternatively, connection IDs can be listed using <literal - >listConnectionIDs()</literal> and all the sessions for a given connection - ID can be listed using <literal>listSessions()</literal>.</para> - </listitem> - </itemizedlist> - </section> - <section> - <title>JMS ConnectionFactory Management</title> - <para>JMS Connection Factories can be managed using the <literal - >ConnectionFactoryControl</literal> class (with the ObjectName <literal - >org.apache.activemq:module=JMS,type=ConnectionFactory,name="<the connection factory - name>"</literal> or the resource name <literal>jms.connectionfactory.<the - connection factory name></literal>).</para> - <itemizedlist> - <listitem> - <para>Retrieving connection factory attributes</para> - <para>The <literal>ConnectionFactoryControl</literal> exposes JMS - ConnectionFactory configuration through its attributes (e.g. <literal - >getConsumerWindowSize()</literal> to retrieve the consumer window size for - flow control, <literal>isBlockOnNonDurableSend()</literal> to know whether the - producers created from the connection factory will block or not when sending - non-durable messages, etc.)</para> - </listitem> - </itemizedlist> - </section> - <section> - <title>JMS Queue Management</title> - <para>JMS queues can be managed using the <literal>JMSQueueControl</literal> class (with - the ObjectName <literal>org.apache.activemq:module=JMS,type=Queue,name="<the queue - name>"</literal> or the resource name <literal>jms.queue.<the queue - name></literal>). </para> - <para><emphasis>The management operations on a JMS queue are very similar to the - operations on a core queue. </emphasis></para> - <itemizedlist> - <listitem> - <para>Expiring, sending to a dead letter address and moving messages</para> - <para>Messages can be expired from a queue by using the <literal - >expireMessages()</literal> method. If an expiry address is defined, - messages will be sent to it, otherwise they are discarded. The queue's - expiry address can be set with the <literal>setExpiryAddress()</literal> - method.</para> - <para>Messages can also be sent to a dead letter address with the <literal - >sendMessagesToDeadLetterAddress()</literal> method. It returns the number - of messages which are sent to the dead letter address. If a dead letter address - is not defined, message are removed from the queue and discarded. The queue's - dead letter address can be set with the <literal - >setDeadLetterAddress()</literal> method.</para> - <para>Messages can also be moved from a queue to another queue by using the - <literal>moveMessages()</literal> method.</para> - </listitem> - <listitem> - <para>Listing and removing messages</para> - <para>Messages can be listed from a queue by using the <literal - >listMessages()</literal> method which returns an array of <literal - >Map</literal>, one <literal>Map</literal> for each message.</para> - <para>Messages can also be removed from the queue by using the <literal - >removeMessages()</literal> method which returns a <literal - >boolean</literal> for the single message ID variant or the number of - removed messages for the filter variant. The <literal - >removeMessages()</literal> method takes a <literal>filter</literal> - argument to remove only filtered messages. Setting the filter to an empty - string will in effect remove all messages.</para> - </listitem> - <listitem> - <para>Counting messages</para> - <para>The number of messages in a queue is returned by the <literal - >getMessageCount()</literal> method. Alternatively, the <literal - >countMessages()</literal> will return the number of messages in the queue - which <emphasis>match a given filter</emphasis></para> - </listitem> - <listitem> - <para>Changing message priority</para> - <para>The message priority can be changed by using the <literal - >changeMessagesPriority()</literal> method which returns a <literal - >boolean</literal> for the single message ID variant or the number of - updated messages for the filter variant.</para> - </listitem> - <listitem> - <para>Message counters</para> - <para>Message counters can be listed for a queue with the <literal - >listMessageCounter()</literal> and <literal - >listMessageCounterHistory()</literal> methods (see <xref - linkend="management.message-counters"/>)</para> - </listitem> - <listitem> - <para>Retrieving the queue attributes</para> - <para>The <literal>JMSQueueControl</literal> exposes JMS queue settings through - its attributes (e.g. <literal>isTemporary()</literal> to know whether the queue - is temporary or not, <literal>isDurable()</literal> to know whether the queue is - durable or not, etc.)</para> - </listitem> - <listitem> - <para>Pausing and resuming queues</para> - <para>The <literal>JMSQueueControl</literal> can pause and resume the underlying - queue. When the queue is paused it will continue to receive messages but will - not deliver them. When resumed again it will deliver the enqueued messages, if - any. </para> - </listitem> - </itemizedlist> - </section> - <section> - <title>JMS Topic Management</title> - <para>JMS Topics can be managed using the <literal>TopicControl</literal> class (with - the ObjectName <literal>org.apache.activemq:module=JMS,type=Topic,name="<the topic - name>"</literal> or the resource name <literal>jms.topic.<the topic - name></literal>).</para> - <itemizedlist> - <listitem> - <para>Listing subscriptions and messages</para> - <para>JMS topics subscriptions can be listed using the <literal - >listAllSubscriptions()</literal>, <literal - >listDurableSubscriptions()</literal>, <literal - >listNonDurableSubscriptions()</literal> methods. These methods return - arrays of <literal>Object</literal> representing the subscriptions information - (subscription name, client ID, durability, message count, etc.). It is also - possible to list the JMS messages for a given subscription with the <literal - >listMessagesForSubscription()</literal> method.</para> - </listitem> - <listitem> - <para>Dropping subscriptions</para> - <para>Durable subscriptions can be dropped from the topic using the <literal - >dropDurableSubscription()</literal> method.</para> - </listitem> - <listitem> - <para>Counting subscriptions messages</para> - <para>The <literal>countMessagesForSubscription()</literal> method can be used to - know the number of messages held for a given subscription (with an optional - message selector to know the number of messages matching the selector)</para> - </listitem> - </itemizedlist> - </section> - </section> - </section> - <section id="management.jmx"> - <title>Using Management Via JMX</title> - <para>ActiveMQ can be managed using <ulink - url="http://www.oracle.com/technetwork/java/javase/tech/javamanagement-140525.html"; - >JMX</ulink>. </para> - <para>The management API is exposed by ActiveMQ using MBeans interfaces. ActiveMQ registers its - resources with the domain <literal>org.apache.activemq</literal>.</para> - <para>For example, the <literal>ObjectName</literal> to manage a JMS Queue <literal - >exampleQueue</literal> is:</para> - <programlisting> -org.apache.activemq:module=JMS,type=Queue,name="exampleQueue"</programlisting> - <para>and the MBean is:</para> - <programlisting> -org.apache.activemq.api.jms.management.JMSQueueControl</programlisting> - <para>The MBean's <literal>ObjectName</literal> are built using the helper class <literal - >org.apache.activemq.api.core.management.ObjectNameBuilder</literal>. You can also use <literal - >jconsole</literal> to find the <literal>ObjectName</literal> of the MBeans you want to - manage. </para> - <para>Managing ActiveMQ using JMX is identical to management of any Java Applications using - JMX. It can be done by reflection or by creating proxies of the MBeans.</para> - <section id="management.jmx.configuration"> - <title>Configuring JMX</title> - <para>By default, JMX is enabled to manage ActiveMQ. It can be disabled by setting <literal - >jmx-management-enabled</literal> to <literal>false</literal> in <literal - >activemq-configuration.xml</literal>:</para> - <programlisting> -<!-- false to disable JMX management for ActiveMQ --> -<jmx-management-enabled>false</jmx-management-enabled></programlisting> - <para>If JMX is enabled, ActiveMQ can be managed locally using <literal>jconsole</literal>.</para> - <note> - <para>Remote connections to JMX are not enabled by default for security reasons. Please refer - to <ulink url="http://docs.oracle.com/javase/6/docs/technotes/guides/management/agent.html"; - >Java Management guide</ulink> to configure the server for remote management (system - properties must be set in <literal>run.sh</literal> or <literal>run.bat</literal> - scripts).</para> - </note> - <para>By default, ActiveMQ server uses the JMX domain "org.apache.activemq". To manage several - ActiveMQ servers from the <emphasis>same</emphasis> MBeanServer, the JMX domain can be - configured for each individual ActiveMQ server by setting <literal>jmx-domain</literal> - in <literal>activemq-configuration.xml</literal>: </para> - <programlisting> -<!-- use a specific JMX domain for ActiveMQ MBeans --> -<jmx-domain>my.org.apache.activemq</jmx-domain></programlisting> - <section> - <title>MBeanServer configuration</title> - <para>When ActiveMQ is run in standalone, it uses the Java Virtual Machine's <literal - >Platform MBeanServer</literal> to register its MBeans. This is configured in - JBoss Microcontainer Beans file (see <xref - linkend="server.microcontainer.configuration"/>):</para> - <programlisting> -<!-- MBeanServer --> -<bean name="MBeanServer" class="javax.management.MBeanServer"> - <constructor factoryClass="java.lang.management.ManagementFactory" - factoryMethod="getPlatformMBeanServer" /> -</bean></programlisting> - <para>When it is integrated in JBoss AS 5+, it uses the Application Server's own MBean - Server so that it can be managed using AS 5's jmx-console:</para> - <programlisting> -<!-- MBeanServer --> -<bean name="MBeanServer" class="javax.management.MBeanServer"> - <constructor factoryClass="org.jboss.mx.util.MBeanServerLocator" - factoryMethod="locateJBoss" /> -</bean></programlisting> - </section> - </section> - <section> - <title>Example</title> - <para>See <xref linkend="examples.jmx"/> for an example which shows how to use a remote - connection to JMX and MBean proxies to manage ActiveMQ.</para> - </section> - </section> - <section> - <title>Using Management Via Core API</title> - <para>The core management API in ActiveMQ is called by sending Core messages to a special - address, the <emphasis>management address</emphasis>.</para> - <para><emphasis>Management messages</emphasis> are regular Core messages with well-known - properties that the server needs to understand to interact with the management API:</para> - <itemizedlist> - <listitem> - <para>The name of the managed resource</para> - </listitem> - <listitem> - <para>The name of the management operation</para> - </listitem> - <listitem> - <para>The parameters of the management operation</para> - </listitem> - </itemizedlist> - <para>When such a management message is sent to the management address, ActiveMQ server will - handle it, extract the information, invoke the operation on the managed resources and send - a <emphasis>management reply</emphasis> to the management message's reply-to address - (specified by <literal>ClientMessageImpl.REPLYTO_HEADER_NAME</literal>). </para> - <para>A <literal>ClientConsumer</literal> can be used to consume the management reply and - retrieve the result of the operation (if any) stored in the reply's body. For portability, - results are returned as a <ulink url="http://json.org";>JSON</ulink> String rather than Java - Serialization (the <literal>org.apache.activemq.api.core.management.ManagementHelper</literal> can - be used to convert the JSON string to Java objects).</para> - <para>These steps can be simplified to make it easier to invoke management operations using - Core messages:</para> - <orderedlist> - <listitem> - <para>Create a <literal>ClientRequestor</literal> to send messages to the management - address and receive replies</para> - </listitem> - <listitem> - <para>Create a <literal>ClientMessage</literal></para> - </listitem> - <listitem> - <para>Use the helper class <literal - >org.apache.activemq.api.core.management.ManagementHelper</literal> to fill the message - with the management properties</para> - </listitem> - <listitem> - <para>Send the message using the <literal>ClientRequestor</literal></para> - </listitem> - <listitem> - <para>Use the helper class <literal - >org.apache.activemq.api.core.management.ManagementHelper</literal> to retrieve the - operation result from the management reply</para> - </listitem> - </orderedlist> - <para>For example, to find out the number of messages in the core queue <literal - >exampleQueue</literal>:</para> - <programlisting> -ClientSession session = ... -ClientRequestor requestor = new ClientRequestor(session, "jms.queue.activemq.management"); -ClientMessage message = session.createMessage(false); -ManagementHelper.putAttribute(message, "core.queue.exampleQueue", "messageCount"); -session.start(); -ClientMessage reply = requestor.request(m); -int count = (Integer) ManagementHelper.getResult(reply); -System.out.println("There are " + count + " messages in exampleQueue");</programlisting> - <para>Management operation name and parameters must conform to the Java interfaces defined in - the <literal>management</literal> packages.</para> - <para>Names of the resources are built using the helper class <literal - >org.apache.activemq.api.core.management.ResourceNames</literal> and are straightforward - (<literal>core.queue.exampleQueue</literal> for the Core Queue <literal - >exampleQueue</literal>, <literal>jms.topic.exampleTopic</literal> for the JMS Topic - <literal>exampleTopic</literal>, etc.).</para> - <section id="management.core.configuration"> - <title>Configuring Core Management</title> - <para>The management address to send management messages is configured in <literal - >activemq-configuration.xml</literal>:</para> - <programlisting> -<management-address>jms.queue.activemq.management</management-address></programlisting> - <para>By default, the address is <literal>jms.queue.activemq.management</literal> (it is - prepended by "jms.queue" so that JMS clients can also send management messages).</para> - <para>The management address requires a <emphasis>special</emphasis> user permission - <literal>manage</literal> to be able to receive and handle management messages. This - is also configured in activemq-configuration.xml:</para> - <programlisting> -<!-- users with the admin role will be allowed to manage --> -<!-- ActiveMQ using management messages --> -<security-setting match="jms.queue.activemq.management"> - <permission type="manage" roles="admin" /> -</security-setting></programlisting> - </section> - </section> - <section id="management.jms"> - <title>Using Management Via JMS</title> - <para>Using JMS messages to manage ActiveMQ is very similar to using core API.</para> - <para>An important difference is that JMS requires a JMS queue to send the messages to - (instead of an address for the core API).</para> - <para>The <emphasis>management queue</emphasis> is a special queue and needs to be - instantiated directly by the client:</para> - <programlisting> -Queue managementQueue = ActiveMQJMSClient.createQueue("activemq.management");</programlisting> - <para>All the other steps are the same than for the Core API but they use JMS API - instead:</para> - <orderedlist> - <listitem> - <para>create a <literal>QueueRequestor</literal> to send messages to the management - address and receive replies</para> - </listitem> - <listitem> - <para>create a <literal>Message</literal></para> - </listitem> - <listitem> - <para>use the helper class <literal - >org.apache.activemq.api.jms.management.JMSManagementHelper</literal> to fill the message - with the management properties</para> - </listitem> - <listitem> - <para>send the message using the <literal>QueueRequestor</literal></para> - </listitem> - <listitem> - <para>use the helper class <literal - >org.apache.activemq.api.jms.management.JMSManagementHelper</literal> to retrieve the - operation result from the management reply</para> - </listitem> - </orderedlist> - <para>For example, to know the number of messages in the JMS queue <literal - >exampleQueue</literal>:</para> - <programlisting> -Queue managementQueue = ActiveMQJMSClient.createQueue("activemq.management"); - -QueueSession session = ... -QueueRequestor requestor = new QueueRequestor(session, managementQueue); -connection.start(); -Message message = session.createMessage(); -JMSManagementHelper.putAttribute(message, "jms.queue.exampleQueue", "messageCount"); -Message reply = requestor.request(message); -int count = (Integer)JMSManagementHelper.getResult(reply); -System.out.println("There are " + count + " messages in exampleQueue");</programlisting> - <section> - <title>Configuring JMS Management</title> - <para>Whether JMS or the core API is used for management, the configuration steps are the - same (see <xref linkend="management.core.configuration"/>).</para> - </section> - <section> - <title>Example</title> - <para>See <xref linkend="examples.management"/> for an example which shows how to use JMS - messages to manage ActiveMQ server.</para> - </section> - </section> - - <section id="management.notifications"> - <title>Management Notifications</title> - <para>ActiveMQ emits <emphasis>notifications</emphasis> to inform listeners of potentially - interesting events (creation of new resources, security violation, etc.).</para> - <para>These notifications can be received by 3 different ways:</para> - <itemizedlist> - <listitem> - <para>JMX notifications</para> - </listitem> - <listitem> - <para>Core messages</para> - </listitem> - <listitem> - <para>JMS messages</para> - </listitem> - </itemizedlist> - <section> - <title>JMX Notifications</title> - <para>If JMX is enabled (see <xref linkend="management.jmx.configuration"/>), JMX - notifications can be received by subscribing to 2 MBeans:</para> - <itemizedlist> - <listitem> - <para><literal>org.apache.activemq:module=Core,type=Server</literal> for notifications on - <emphasis>Core</emphasis> resources</para> - </listitem> - <listitem> - <para><literal>org.apache.activemq:module=JMS,type=Server</literal> for notifications on - <emphasis>JMS</emphasis> resources</para> - </listitem> - </itemizedlist> - </section> - <section> - <title>Core Messages Notifications</title> - <para>ActiveMQ defines a special <emphasis>management notification address</emphasis>. Core - queues can be bound to this address so that clients will receive management - notifications as Core messages</para> - <para>A Core client which wants to receive management notifications must create a core - queue bound to the management notification address. It can then receive the - notifications from its queue.</para> - <para>Notifications messages are regular core messages with additional properties - corresponding to the notification (its type, when it occurred, the resources which were - concerned, etc.).</para> - <para>Since notifications are regular core messages, it is possible to use message - selectors to filter out notifications and receives only a subset of all the - notifications emitted by the server.</para> - <section id="management.notifications.core.configuration"> - <title>Configuring The Core Management Notification Address</title> - <para>The management notification address to receive management notifications is - configured in <literal>activemq-configuration.xml</literal>:</para> - <programlisting> -<management-notification-address>activemq.notifications</management-notification-address></programlisting> - <para>By default, the address is <literal>activemq.notifications</literal>.</para> - </section> - </section> - <section> - <title>JMS Messages Notifications</title> - <para>ActiveMQ's notifications can also be received using JMS messages.</para> - <para>It is similar to receiving notifications using Core API but an important difference - is that JMS requires a JMS Destination to receive the messages (preferably a - Topic).</para> - <para>To use a JMS Destination to receive management notifications, you must change the server's - management notification address to start with <literal>jms.queue</literal> if it is a JMS Queue - or <literal>jms.topic</literal> if it is a JMS Topic:</para> - <programlisting> -<!-- notifications will be consumed from "notificationsTopic" JMS Topic --> -<management-notification-address>jms.topic.notificationsTopic</management-notification-address></programlisting> - <para>Once the notification topic is created, you can receive messages from it or set a - <literal>MessageListener</literal>:</para> - <programlisting> -Topic notificationsTopic = ActiveMQJMSClient.createTopic("notificationsTopic"); - -Session session = ... -MessageConsumer notificationConsumer = session.createConsumer(notificationsTopic); -notificationConsumer.setMessageListener(new MessageListener() -{ - public void onMessage(Message notif) - { - System.out.println("------------------------"); - System.out.println("Received notification:"); - try - { - Enumeration propertyNames = notif.getPropertyNames(); - while (propertyNames.hasMoreElements()) - { - String propertyName = (String)propertyNames.nextElement(); - System.out.format(" %s: %s\n", propertyName, notif.getObjectProperty(propertyName)); - } - } - catch (JMSException e) - { - } - System.out.println("------------------------"); - } -});</programlisting> - </section> - <section> - <title>Example</title> - <para>See <xref linkend="examples.management-notifications"/> for an example which shows - how to use a JMS <literal>MessageListener</literal> to receive management notifications - from ActiveMQ server.</para> - </section> - <section id="notification.types.and.headers"> - <title>Notification Types and Headers</title> - <para>Below is a list of all the different kinds of notifications as well as which headers are - on the messages. Every notification has a <literal>_HQ_NotifType</literal> (value noted in parentheses) - and <literal>_HQ_NotifTimestamp</literal> header. The timestamp is the un-formatted result of a call - to <literal>java.lang.System.currentTimeMillis()</literal>.</para> - <itemizedlist> - <listitem> - <para><literal>BINDING_ADDED</literal> (0)</para> - <para><literal>_HQ_Binding_Type</literal>, <literal>_HQ_Address</literal>, - <literal>_HQ_ClusterName</literal>, <literal>_HQ_RoutingName</literal>, - <literal>_HQ_Binding_ID</literal>, <literal>_HQ_Distance</literal>, - <literal>_HQ_FilterString</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>BINDING_REMOVED</literal> (1)</para> - <para><literal>_HQ_Address</literal>, <literal>_HQ_ClusterName</literal>, - <literal>_HQ_RoutingName</literal>, <literal>_HQ_Binding_ID</literal>, - <literal>_HQ_Distance</literal>, <literal>_HQ_FilterString</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>CONSUMER_CREATED</literal> (2)</para> - <para><literal>_HQ_Address</literal>, <literal>_HQ_ClusterName</literal>, - <literal>_HQ_RoutingName</literal>, <literal>_HQ_Distance</literal>, - <literal>_HQ_ConsumerCount</literal>, <literal>_HQ_User</literal>, - <literal>_HQ_RemoteAddress</literal>, <literal>_HQ_SessionName</literal>, - <literal>_HQ_FilterString</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>CONSUMER_CLOSED</literal> (3)</para> - <para><literal>_HQ_Address</literal>, <literal>_HQ_ClusterName</literal>, - <literal>_HQ_RoutingName</literal>, <literal>_HQ_Distance</literal>, - <literal>_HQ_ConsumerCount</literal>, <literal>_HQ_User</literal>, - <literal>_HQ_RemoteAddress</literal>, <literal>_HQ_SessionName</literal>, - <literal>_HQ_FilterString</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>SECURITY_AUTHENTICATION_VIOLATION</literal> (6)</para> - <para><literal>_HQ_User</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>SECURITY_PERMISSION_VIOLATION</literal> (7)</para> - <para><literal>_HQ_Address</literal>, <literal>_HQ_CheckType</literal>, - <literal>_HQ_User</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>DISCOVERY_GROUP_STARTED</literal> (8)</para> - <para><literal>name</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>DISCOVERY_GROUP_STOPPED</literal> (9)</para> - <para><literal>name</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>BROADCAST_GROUP_STARTED</literal> (10)</para> - <para><literal>name</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>BROADCAST_GROUP_STOPPED</literal> (11)</para> - <para><literal>name</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>BRIDGE_STARTED</literal> (12)</para> - <para><literal>name</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>BRIDGE_STOPPED</literal> (13)</para> - <para><literal>name</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>CLUSTER_CONNECTION_STARTED</literal> (14)</para> - <para><literal>name</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>CLUSTER_CONNECTION_STOPPED</literal> (15)</para> - <para><literal>name</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>ACCEPTOR_STARTED</literal> (16)</para> - <para><literal>factory</literal>, <literal>id</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>ACCEPTOR_STOPPED</literal> (17)</para> - <para><literal>factory</literal>, <literal>id</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>PROPOSAL</literal> (18)</para> - <para><literal>_JBM_ProposalGroupId</literal>, <literal>_JBM_ProposalValue</literal>, - <literal>_HQ_Binding_Type</literal>, <literal>_HQ_Address</literal>, - <literal>_HQ_Distance</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>PROPOSAL_RESPONSE</literal> (19)</para> - <para><literal>_JBM_ProposalGroupId</literal>, <literal>_JBM_ProposalValue</literal>, - <literal>_JBM_ProposalAltValue</literal>, <literal>_HQ_Binding_Type</literal>, - <literal>_HQ_Address</literal>, <literal>_HQ_Distance</literal></para> - </listitem> - </itemizedlist> - <itemizedlist> - <listitem> - <para><literal>CONSUMER_SLOW</literal> (21)</para> - <para><literal>_HQ_Address</literal>, <literal>_HQ_ConsumerCount</literal>, - <literal>_HQ_RemoteAddress</literal>, <literal>_HQ_ConnectionName</literal>, - <literal>_HQ_ConsumerName</literal>, <literal>_HQ_SessionName</literal></para> - </listitem> - </itemizedlist> - </section> - </section> - <section id="management.message-counters"> - <title>Message Counters</title> - <para>Message counters can be used to obtain information on queues <emphasis>over - time</emphasis> as ActiveMQ keeps a history on queue metrics.</para> - <para>They can be used to show <emphasis>trends</emphasis> on queues. For example, using the - management API, it would be possible to query the number of messages in a queue at regular - interval. However, this would not be enough to know if the queue is used: the number of - messages can remain constant because nobody is sending or receiving messages from the queue - or because there are as many messages sent to the queue than messages consumed from it. The - number of messages in the queue remains the same in both cases but its use is widely - different.</para> - <para>Message counters gives additional information about the queues:</para> - <itemizedlist> - <listitem> - <para><literal>count</literal></para> - <para>The <emphasis>total</emphasis> number of messages added to the queue since the - server was started</para> - </listitem> - <listitem> - <para><literal>countDelta</literal></para> - <para>the number of messages added to the queue <emphasis>since the last message counter - update</emphasis></para> - </listitem> - <listitem> - <para><literal>messageCount</literal></para> - <para>The <emphasis>current</emphasis> number of messages in the queue</para> - </listitem> - <listitem> - <para><literal>messageCountDelta</literal></para> - <para>The <emphasis>overall</emphasis> number of messages added/removed from the queue - <emphasis>since the last message counter update</emphasis>. For example, if - <literal>messageCountDelta</literal> is equal to <literal>-10</literal> this means that - overall 10 messages have been removed from the queue (e.g. 2 messages were added and - 12 were removed)</para> - </listitem> - <listitem> - <para><literal>lastAddTimestamp</literal></para> - <para>The timestamp of the last time a message was added to the queue</para> - </listitem> - <listitem> - <para><literal>udpateTimestamp</literal></para> - <para>The timestamp of the last message counter update</para> - </listitem> - </itemizedlist> - <para>These attributes can be used to determine other meaningful data as well. For example, to know - specifically how many messages were <emphasis>consumed</emphasis> from the queue since the last update - simply subtract the <literal>messageCountDelta</literal> from <literal>countDelta</literal>.</para> - <section id="configuring.message.counters"> - <title>Configuring Message Counters</title> - <para>By default, message counters are disabled as it might have a small negative effect on - memory.</para> - <para>To enable message counters, you can set it to <literal>true</literal> in <literal - >activemq-configuration.xml</literal>:</para> - <programlisting> -<message-counter-enabled>true</message-counter-enabled></programlisting> - <para>Message counters keeps a history of the queue metrics (10 days by default) and - samples all the queues at regular interval (10 seconds by default). If message counters - are enabled, these values should be configured to suit your messaging use case in - <literal>activemq-configuration.xml</literal>:</para> - <programlisting> -<!-- keep history for a week --> -<message-counter-max-day-history>7</message-counter-max-day-history> -<!-- sample the queues every minute (60000ms) --> -<message-counter-sample-period>60000</message-counter-sample-period></programlisting> - <para>Message counters can be retrieved using the Management API. For example, to retrieve - message counters on a JMS Queue using JMX:</para> - <programlisting> -// retrieve a connection to ActiveMQ's MBeanServer -MBeanServerConnection mbsc = ... -JMSQueueControlMBean queueControl = (JMSQueueControl)MBeanServerInvocationHandler.newProxyInstance(mbsc, - on, - JMSQueueControl.class, - false); -// message counters are retrieved as a JSON String -String counters = queueControl.listMessageCounter(); -// use the MessageCounterInfo helper class to manipulate message counters more easily -MessageCounterInfo messageCounter = MessageCounterInfo.fromJSON(counters); -System.out.format("%s message(s) in the queue (since last sample: %s)\n", -messageCounter.getMessageCount(), -messageCounter.getMessageCountDelta());</programlisting> - </section> - <section> - <title>Example</title> - <para>See <xref linkend="examples.message-counters"/> for an example which shows how to use - message counters to retrieve information on a JMS <literal>Queue</literal>.</para> - </section> - </section> - <section> - <title>Administering ActiveMQ Resources Using The JBoss AS Admin Console</title> - <para>Its possible to create and configure ActiveMQ resources via the admin console within the JBoss Application Server.</para> - <para>The Admin Console will allow you to create destinations (JMS Topics and Queues) and JMS Connection Factories.</para> - <para>Once logged in to the admin console you will see a JMS Manager item in the left hand tree. All ActiveMQ resources - will be configured via this. This will have a child items for JMS Queues, Topics and Connection Factories, clicking - on each node will reveal which resources are currently available. The following sections explain how to create - and configure each resource in turn.</para> - <section> - <title>JMS Queues</title> - <para>To create a new JMS Queue click on the JMS Queues item to reveal the available queues. On the right hand - panel you will see an add a new resource button, click on this and then choose the default(JMS Queue) template - and click continue. The important things to fill in here are the name of the queue and the JNDI name of the - queue. The JNDI name is what you will use to look up the queue in JNDI from your client. For most queues this - will be the only info you will need to provide as sensible defaults are provided for the others. You will also - see a security roles section near the bottom. If you do not provide any roles for this queue then the servers - default security configuration will be used, after you have created the queue these will be shown in the configuration. - All configuration values, except the name and JNDI name, can be changed via the configuration tab after clicking - on the queue in the admin console. The following section explains these in more detail</para> - <para>After highlighting the configuration you will see the following screen</para> - <para> - <graphic fileref="images/console1.png" scalefit="1" width="500" align="center"/> - </para> - <para>The name and JNDI name can't be changed, if you want to change these recreate the queue with the appropriate - settings. The rest of the configuration options, apart from security roles, relate to address settings for a particular - address. The default address settings are picked up from the servers configuration, if you change any of these - settings or create a queue via the console a new Address Settings entry will be added. For a full explanation on - Address Settings see <xref linkend="queue-attributes.address-settings"/></para> - <para>To delete a queue simply click on the delete button beside the queue name in the main JMS Queues screen. - This will also delete any address settings or security settings previously created for the queues address</para> - <para>The last part of the configuration options are security roles. If non are provided on creation then the - servers default security settings will be shown. If these are changed or updated then new security settings are - created for the address of this queue. For more information on security setting see <xref linkend="security"/> </para> - <para>It is also possible via the metrics tab to view statistics for this queue. This will show statistics such - as message count, consumer count etc.</para> - <para>Operations can be performed on a queue via the control tab. This will allow you to start and stop the queue, - list,move,expire and delete messages from the queue and other useful operations. To invoke an operation click on - the button for the operation you want, this will take you to a screen where you can parameters for the operation can be set. - Once set clicking the ok button will invoke the operation, results appear at the bottom of the screen.</para> - </section> - <section> - <title>JMS Topics</title> - <para>Creating and configuring JMS Topics is almost identical to creating queues. The only difference is that the - configuration will be applied to the queue representing a subscription.</para> - </section> - <section> - <title>JMS Connection Factories</title> - <para>The format for creating connection factories is the same as for JMS Queues and topics apart from the configuration - being different. For as list of all the connection factory settings see the configuration index </para> - </section> - </section> -</chapter>
http://git-wip-us.apache.org/repos/asf/activemq-6/blob/4245a6b4/docs/user-manual/en/message-expiry.md ---------------------------------------------------------------------- diff --git a/docs/user-manual/en/message-expiry.md b/docs/user-manual/en/message-expiry.md new file mode 100644 index 0000000..a42939c --- /dev/null +++ b/docs/user-manual/en/message-expiry.md @@ -0,0 +1,85 @@ +Message Expiry +============== + +Messages can be set with an optional *time to live* when sending them. + +ActiveMQ will not deliver a message to a consumer after it's time to +live has been exceeded. If the message hasn't been delivered by the time +that time to live is reached the server can discard it. + +ActiveMQ's addresses can be assigned a expiry address so that, when +messages are expired, they are removed from the queue and sent to the +expiry address. Many different queues can be bound to an expiry address. +These *expired* messages can later be consumed for further inspection. + +Message Expiry +============== + +Using ActiveMQ Core API, you can set an expiration time directly on the +message: + + // message will expire in 5000ms from now + message.setExpiration(System.currentTimeMillis() + 5000); + +JMS MessageProducer allows to set a TimeToLive for the messages it sent: + + // messages sent by this producer will be retained for 5s (5000ms) before expiration + producer.setTimeToLive(5000); + +Expired messages which are consumed from an expiry address have the +following properties: + +- `_HQ_ORIG_ADDRESS` + + a String property containing the *original address* of the expired + message + +- `_HQ_ORIG_QUEUE` + + a String property containing the *original queue* of the expired + message + +- `_HQ_ACTUAL_EXPIRY` + + a Long property containing the *actual expiration time* of the + expired message + +Configuring Expiry Addresses +============================ + +Expiry address are defined in the address-setting configuration: + + <!-- expired messages in exampleQueue will be sent to the expiry address expiryQueue --> + <address-setting match="jms.queue.exampleQueue"> + <expiry-address>jms.queue.expiryQueue</expiry-address> + </address-setting> + +If messages are expired and no expiry address is specified, messages are +simply removed from the queue and dropped. Address wildcards can be used +to configure expiry address for a set of addresses (see ?). + +Configuring The Expiry Reaper Thread +==================================== + +A reaper thread will periodically inspect the queues to check if +messages have expired. + +The reaper thread can be configured with the following properties in +`activemq-configuration.xml` + +- `message-expiry-scan-period` + + How often the queues will be scanned to detect expired messages (in + milliseconds, default is 30000ms, set to `-1` to disable the reaper + thread) + +- `message-expiry-thread-priority` + + The reaper thread priority (it must be between 0 and 9, 9 being the + highest priority, default is 3) + +Example +======= + +See ? for an example which shows how message expiry is configured and +used with JMS. http://git-wip-us.apache.org/repos/asf/activemq-6/blob/4245a6b4/docs/user-manual/en/message-expiry.xml ---------------------------------------------------------------------- diff --git a/docs/user-manual/en/message-expiry.xml b/docs/user-manual/en/message-expiry.xml deleted file mode 100644 index f8d9100..0000000 --- a/docs/user-manual/en/message-expiry.xml +++ /dev/null @@ -1,100 +0,0 @@ -<?xml version="1.0" encoding="UTF-8"?> -<!-- ============================================================================= --> -<!-- Licensed to the Apache Software Foundation (ASF) under one or more --> -<!-- contributor license agreements. See the NOTICE file distributed with --> -<!-- this work for additional information regarding copyright ownership. --> -<!-- The ASF licenses this file to You under the Apache License, Version 2.0 --> -<!-- (the "License"); you may not use this file except in compliance with --> -<!-- the License. You may obtain a copy of the License at --> -<!-- --> -<!-- http://www.apache.org/licenses/LICENSE-2.0 --> -<!-- --> -<!-- Unless required by applicable law or agreed to in writing, software --> -<!-- distributed under the License is distributed on an "AS IS" BASIS, --> -<!-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. --> -<!-- See the License for the specific language governing permissions and --> -<!-- limitations under the License. --> -<!-- ============================================================================= --> - -<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"; [ -<!ENTITY % BOOK_ENTITIES SYSTEM "ActiveMQ_User_Manual.ent"> -%BOOK_ENTITIES; -]> -<chapter id="message-expiry"> - <title>Message Expiry</title> - <para>Messages can be set with an optional <emphasis>time to live</emphasis> when sending - them.</para> - <para>ActiveMQ will not deliver a message to a consumer after it's time to live has been exceeded. - If the message hasn't been delivered by the time that time to live is reached the server can - discard it.</para> - <para>ActiveMQ's addresses can be assigned a expiry address so that, when messages are expired, - they are removed from the queue and sent to the expiry address. Many different queues can be - bound to an expiry address. These <emphasis>expired</emphasis> messages can later be consumed - for further inspection.</para> - <section> - <title>Message Expiry</title> - <para>Using ActiveMQ Core API, you can set an expiration time directly on the message:</para> - <programlisting> -// message will expire in 5000ms from now -message.setExpiration(System.currentTimeMillis() + 5000);</programlisting> - <para>JMS MessageProducer allows to set a TimeToLive for the messages it sent:</para> - <programlisting> -// messages sent by this producer will be retained for 5s (5000ms) before expiration -producer.setTimeToLive(5000);</programlisting> - <para>Expired messages which are consumed from an expiry address have the following - properties:</para> - <itemizedlist> - <listitem> - <para><literal>_HQ_ORIG_ADDRESS</literal></para> - <para>a String property containing the <emphasis>original address</emphasis> of the - expired message </para> - </listitem> - <listitem> - <para><literal>_HQ_ORIG_QUEUE</literal></para> - <para>a String property containing the <emphasis>original queue</emphasis> of the - expired message </para> - </listitem> - <listitem> - <para><literal>_HQ_ACTUAL_EXPIRY</literal></para> - <para>a Long property containing the <emphasis>actual expiration time</emphasis> of the - expired message</para> - </listitem> - </itemizedlist> - </section> - <section id="message-expiry.configuring"> - <title>Configuring Expiry Addresses</title> - <para>Expiry address are defined in the address-setting configuration:</para> - <programlisting> -<!-- expired messages in exampleQueue will be sent to the expiry address expiryQueue --> -<address-setting match="jms.queue.exampleQueue"> - <expiry-address>jms.queue.expiryQueue</expiry-address> -</address-setting></programlisting> - <para>If messages are expired and no expiry address is specified, messages are simply removed - from the queue and dropped. Address wildcards can be used to configure expiry address for a - set of addresses (see <xref linkend="wildcard-syntax"/>).</para> - </section> - <section id="configuring.expiry.reaper"> - <title>Configuring The Expiry Reaper Thread</title> - <para>A reaper thread will periodically inspect the queues to check if messages have - expired.</para> - <para>The reaper thread can be configured with the following properties in <literal - >activemq-configuration.xml</literal></para> - <itemizedlist> - <listitem> - <para><literal>message-expiry-scan-period</literal></para> - <para>How often the queues will be scanned to detect expired messages (in milliseconds, - default is 30000ms, set to <literal>-1</literal> to disable the reaper thread)</para> - </listitem> - <listitem> - <para><literal>message-expiry-thread-priority</literal></para> - <para>The reaper thread priority (it must be between 0 and 9, 9 being the highest - priority, default is 3)</para> - </listitem> - </itemizedlist> - </section> - <section> - <title>Example</title> - <para>See <xref linkend="examples.expiry"/> for an example which shows how message expiry is - configured and used with JMS.</para> - </section> -</chapter> http://git-wip-us.apache.org/repos/asf/activemq-6/blob/4245a6b4/docs/user-manual/en/message-grouping.md ---------------------------------------------------------------------- diff --git a/docs/user-manual/en/message-grouping.md b/docs/user-manual/en/message-grouping.md new file mode 100644 index 0000000..2a0da9e --- /dev/null +++ b/docs/user-manual/en/message-grouping.md @@ -0,0 +1,198 @@ +Message Grouping +================ + +Message groups are sets of messages that have the following +characteristics: + +- Messages in a message group share the same group id, i.e. they have + same group identifier property (`JMSXGroupID` for JMS, + `_HQ_GROUP_ID` for ActiveMQ Core API). + +- Messages in a message group are always consumed by the same + consumer, even if there are many consumers on a queue. They pin all + messages with the same group id to the same consumer. If that + consumer closes another consumer is chosen and will receive all + messages with the same group id. + +Message groups are useful when you want all messages for a certain value +of the property to be processed serially by the same consumer. + +An example might be orders for a certain stock. You may want orders for +any particular stock to be processed serially by the same consumer. To +do this you can create a pool of consumers (perhaps one for each stock, +but less will work too), then set the stock name as the value of the +\_HQ\_GROUP\_ID property. + +This will ensure that all messages for a particular stock will always be +processed by the same consumer. + +> **Note** +> +> Grouped messages can impact the concurrent processing of non-grouped +> messages due to the underlying FIFO semantics of a queue. For example, +> if there is a chunk of 100 grouped messages at the head of a queue +> followed by 1,000 non-grouped messages then all the grouped messages +> will need to be sent to the appropriate client (which is consuming +> those grouped messages serially) before any of the non-grouped +> messages can be consumed. The functional impact in this scenario is a +> temporary suspension of concurrent message processing while all the +> grouped messages are processed. This can be a performance bottleneck +> so keep it in mind when determining the size of your message groups, +> and consider whether or not you should isolate your grouped messages +> from your non-grouped messages. + +Using Core API +============== + +The property name used to identify the message group is `"_HQ_GROUP_ID"` +(or the constant `MessageImpl.HDR_GROUP_ID`). Alternatively, you can set +`autogroup` to true on the `SessionFactory` which will pick a random +unique id. + +Using JMS +========= + +The property name used to identify the message group is `JMSXGroupID`. + + // send 2 messages in the same group to ensure the same + // consumer will receive both + Message message = ... + message.setStringProperty("JMSXGroupID", "Group-0"); + producer.send(message); + + message = ... + message.setStringProperty("JMSXGroupID", "Group-0"); + producer.send(message); + +Alternatively, you can set `autogroup` to true on the +`ActiveMQConnectonFactory` which will pick a random unique id. This can +also be set in the JNDI context environment, e.g. `jndi.properties`. +Here's a simple example using the "ConnectionFactory" connection factory +which is available in the context by default + + java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory + java.naming.provider.url=tcp://localhost:5445 + connection.ConnectionFactory.autoGroup=true + +Alternatively you can set the group id via the connection factory. All +messages sent with producers created via this connection factory will +set the `JMSXGroupID` to the specified value on all messages sent. This +can also be set in the JNDI context environment, e.g. `jndi.properties`. +Here's a simple example using the "ConnectionFactory" connection factory +which is available in the context by default: + + java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory + java.naming.provider.url=tcp://localhost:5445 + connection.ConnectionFactory.groupID=Group-0 + +Example +======= + +See ? for an example which shows how message groups are configured and +used with JMS. + +Example +======= + +See ? for an example which shows how message groups are configured via a +connection factory. + +Clustered Grouping +================== + +Using message groups in a cluster is a bit more complex. This is because +messages with a particular group id can arrive on any node so each node +needs to know about which group id's are bound to which consumer on +which node. The consumer handling messages for a particular group id may +be on a different node of the cluster, so each node needs to know this +information so it can route the message correctly to the node which has +that consumer. + +To solve this there is the notion of a grouping handler. Each node will +have its own grouping handler and when a messages is sent with a group +id assigned, the handlers will decide between them which route the +message should take. + +There are 2 types of handlers; Local and Remote. Each cluster should +choose 1 node to have a local grouping handler and all the other nodes +should have remote handlers- it's the local handler that actually makes +the decision as to what route should be used, all the other remote +handlers converse with this. Here is a sample config for both types of +handler, this should be configured in the *activemq-configuration.xml* +file. + + <grouping-handler name="my-grouping-handler"> + <type>LOCAL</type> + <address>jms</address> + <timeout>5000</timeout> + </grouping-handler> + + <grouping-handler name="my-grouping-handler"> + <type>REMOTE</type> + <address>jms</address> + <timeout>5000</timeout> + </grouping-handler> + +The *address* attribute refers to a [cluster connection and the address +it uses](#clusters.address), refer to the clustering section on how to +configure clusters. The *timeout* attribute referees to how long to wait +for a decision to be made, an exception will be thrown during the send +if this timeout is reached, this ensures that strict ordering is kept. + +The decision as to where a message should be routed to is initially +proposed by the node that receives the message. The node will pick a +suitable route as per the normal clustered routing conditions, i.e. +round robin available queues, use a local queue first and choose a queue +that has a consumer. If the proposal is accepted by the grouping +handlers the node will route messages to this queue from that point on, +if rejected an alternative route will be offered and the node will again +route to that queue indefinitely. All other nodes will also route to the +queue chosen at proposal time. Once the message arrives at the queue +then normal single server message group semantics take over and the +message is pinned to a consumer on that queue. + +You may have noticed that there is a single point of failure with the +single local handler. If this node crashes then no decisions will be +able to be made. Any messages sent will be not be delivered and an +exception thrown. To avoid this happening Local Handlers can be +replicated on another backup node. Simple create your back up node and +configure it with the same Local handler. + +Clustered Grouping Best Practices +--------------------------------- + +Some best practices should be followed when using clustered grouping: + +1. Make sure your consumers are distributed evenly across the different + nodes if possible. This is only an issue if you are creating and + closing consumers regularly. Since messages are always routed to the + same queue once pinned, removing a consumer from this queue may + leave it with no consumers meaning the queue will just keep + receiving the messages. Avoid closing consumers or make sure that + you always have plenty of consumers, i.e., if you have 3 nodes have + 3 consumers. + +2. Use durable queues if possible. If queues are removed once a group + is bound to it, then it is possible that other nodes may still try + to route messages to it. This can be avoided by making sure that the + queue is deleted by the session that is sending the messages. This + means that when the next message is sent it is sent to the node + where the queue was deleted meaning a new proposal can successfully + take place. Alternatively you could just start using a different + group id. + +3. Always make sure that the node that has the Local Grouping Handler + is replicated. These means that on failover grouping will still + occur. + +4. In case you are using group-timeouts, the remote node should have a + smaller group-timeout with at least half of the value on the main + coordinator. This is because this will determine how often the + last-time-use value should be updated with a round trip for a + request to the group between the nodes. + +Clustered Grouping Example +-------------------------- + +See ? for an example of how to configure message groups with a ActiveMQ +cluster
