OpenJMS An Open Source Implementation of the JMS Specification Jim Alateras Intalio Inc.

OpenJMS

An Open Source Implementation of the JMS Specification

Jim AlaterasIntalio Inc.

2

Contents

JMS Specification

History of OpenJMS

Existing Architecture

Work In Progress

Deployment

Development Environment

Current Release

Future Direction

Q & A

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JMS Specifications

Two Messaging Models - Queues and Topics

Persistent and Non-Persistent Message Delivery

Five Message Types - Text, Byte, Object, Map and Stream

Synchronous and Asynchronous message consumption

Selectors, priority, QueueBrowser

Local and distributed transactions

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JMS Specifications - Queues

Sender publishers to the Queue and Receiver consumers

Supports multiple senders/receivers per queue

Message Ordering

Undefined Delivery semantics for > 1receiver

Persistent messages delivered exactly once

Non-persistent messages delivered at most once

m sg n

m sg 1m sg 2m sg 3m sg 4m sg 5m sg 6m sg 7

:::

Publisher1

Subscriber1consume

publishmsg1

msg4

msg3

msg2

msg1

msg6

msg5

msg4

msg3

msg2

msg6

msg5

SubscriberProducer

JM S Server

msg1

msg4

msg3

msg2

msg1

msg6

msg5

msg4

msg3

msg2

SubscriberProducer

JM S Server

msg5

msg6

msg6

msg5

msg3

Publisher3

Publisher2

m sg n

m sg 1m sg 2m sg 3m sg 4m sg 5m sg 6m sg 7

:::

Publisher1

Subscriber1Subscriber2

consumeconsume

publish

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JMS Specifications - Topics

Publisher publishes and Subscribers consumes

Multiple publishers/subscribers per topic

Subscriber each receives own copy of messages

Priority effects message delivery order

Persistent and non-persistent delivery semantics

m sg n

m sg 1m sg 2m sg 3m sg 4m sg 5m sg 6m sg 7

:::

Publisher1

Subscriber1consume

publish

Publisher3

Publisher2

m sg n

m sg 1m sg 2m sg 3m sg 4m sg 5m sg 6m sg 7

:::

Publisher1

Subscriber1Subscriber2

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JMS Providers

JMS Providers distribute JMS compliant components/products

21 vendors have a JMS offering

Four Open Source offerings including OpenJMS, ObjectCube, Joram and spyderMQ

A number of commercial products including MQSeries, FioranoMQ and SonicMQ

No compliance test suite available to compare the various offerings

No industry benchmarks to compare performance

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History of OpenJMS

Sponsored by the Exolab Group (OpenOrb, OpenEJB)

Started in Feb-2000

V0.1 released in May-2000 (pub-sub, p2p, non-persistent, rmi)

V0.2 released in Jun-2000 (jdbc-based persistence, gui, application, testharness)

V0.3 released in Aug-2000 (tcp, temporary destinations, database caching, selectors)

V0.4 released in Oct-2000 (bug fixes, initial queue browser, more client test coverage)

V0.5 released in Dec-2000 (wild card sub, queue browser and flow control)

3 core developers based in Melbourne

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OpenJMS Architecture

Service based adaptive architecture

Initial focus was on time-to-market and features (RMI and JDBM)

Failed to initially architect for availability and scalability

Second iteration is focusing on failover, clustering and load balancing

In the end the architecture was quite tolerable to change.

Subsequently released more widely used adaptors (TCP, JDBC)

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Server Internals

Destination Consumer

1

0..*

CacheIterator

1

1

Publisher

MessageManager

1

0..*

1

1

PriorityMessageCache

1

1

1

1

1

0..*

1

0..*

Message0..*0..*0..*

references

0..*

JMS Core

JMS Client

JMS Router

RMI

Server Skeleton Layer

Client Proxy Layer

TCP/IP IntraVM

JMS Cluster

PersistenceAdaptor

JDBCJDBM

LoggingAdaptor

JLogLog4j

ThreadPool

Database TransMgr

ServiceMgr Event

Scheduler

Lease

Logger

JMS Core

JM S Client

RMI

Server Skeleton Layer

Client Proxy Layer

TCP/IP IntraVM

PersistenceAdaptor

JDBCJDBM

LoggingAdaptor

JLogLog4j

ThreadPool

Database TransMgr

ServiceMgr Event

Scheduler

Lease

Logger

JM S Core

Service Layer

O RB Layer

JMS Client

JM S C lient L ibrary

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OpenJMS Configuration

XML based configuration file generated from Castor tool

Server configuration

Administered Destinations

Participants and Authentication

Persistent adaptors

<element name="ServerConfiguration"> <complexType content="empty" > <attribute name="serverClass" type="string" maxOccurs="1"/> <attribute name="clusterName" type="string" minOccurs="0" maxOccurs="1" /> <attribute name="jmsServerName" type="string" maxOccurs="1"/> <attribute name="jmsAdminServerName" type="string" maxOccurs="1"/> </complexType> </element

<PersistenceAdapterConfiguration minConsumerListSize="10000" minMessageListSize="40000" persistentType="RDBMS" driver="oracle.jdbc.driver.OracleDriver" url="jdbc:oracle:oci8:@test" userName="jim" password="ab1234" retries="5" timeout ="2000" />

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JNDI Integration

Client uses JNDI to lookup factories and destinations

Run an embedded JNDI provider

Connect to an external JNDI provider

Automatic object registration at start-up

Serverconnfactory1

topic1

queue1

connfactory 3

connfactory 2

JNDI Provider

Server

C lient

O penJM S Server

C lient

connfactory1

topic1queue1

connfactory 3connfactory 2

JNDI Provider

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Administration GUI

Initial Administration GUI deployed with v0.2

New Administration GUI available in v0.6

Create administered destinations

Start and stop the server

Purge persistent messages for a destination

Register durable subscribers

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Stateless Connections (WIP)

Original server maintained stateful client information

Compicates failover and dynamic load balancing

New architecture moves to stateless

Facilitates failover since client is not tied to a particular server

Facilitates dynamic load balancing

Client information is now part of the request context

OpenJMSClient

Context

ContextOpenJMS

Client

request

request

OpenJMSClient

Context

Context

OpenJMSClient

request

request

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OpenJMS Clustering (WIP)

OpenJMS will support clustering

Servers in the cluster share the same resources

Multicast channel for inter server comms

Client failover confined to the cluster

You can configure multiple independent clusters

Client uses multicast channel for connection

Server 1

Server 4Server 3

Server 2

cluster2P

P

P

P

P

C

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Cluster of OpenJMSServers

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Server 1

Server 3

cluster2

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Server 1

Server 3

cluster2

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ticas

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Config

Database

Server 1

Server 3

msg

mul

ticas

t cha

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Server1

Server2

multicastchannel

JNDIServer

1

4

43

2

5

6

Clients load balanced within the cluster

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Security (WIP)

Security is not specified by the JMS Specifications

OpenJMS uses JAAS for Authorization and Authentication

Authentication is based on participants

Participants are associated with an authentication data source

Supported actions are publish, consumer, browse and administer.

Security can be turned off

Authorization is fine grained and based on destinations, participants and actions

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Deployment

Standalone Server Configuration

Symmetric Federated Configuration

Cluster Configuration

Asymmetric Federated Configuration

ServerS1

ServerS2t1, t2

ServerS3

t1

t1, t2

t1

t1

t1

Destinationst1 ,t2, t3

Destinationst1 ,t2, t3

Destinationst1 ,t2, t3

ServerS1

ServerS2t1

t1

Destinationst1, t2

Destinationst1, t2

JMSServer

P

C

P P

P

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CCServer 1

Server 4Server 3

Server 2

cluster2P

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Cluster of OpenJMSServers

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Development Environment

Jakarta ANT as the project build tool

JTF (but will move to Junit for unit testing)

Bugzilla for bug management

Castor’s SourceGen for configuration

ANTLR for selectors

A host of open source libraries including log4j and Tyrex

OpenExec for load and performance tests

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Current Release

Publish-Subscribe and Point-to-Point

Persistent and Non-Persistent Message Delivery

Synchronous and asynchronous message consumption

Administration GUI

Message Selectors, Priority and QueueBrowser

Local transactions

Test cases and extensive examples

Stand alone or embeddable server

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Future Direction

Refactored messaging core

New administration GUI

Clustering and federation support

Explicit support for XML messaging

Improved performance of the messaging core

Complete ASF support which includes session pools and XA.

IIOP and SSL support

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Resources

OpenJMS

JMS Specifications

ANTLR

JUnit

Open Source Initiative

Castor, Tyrex

Jakarta ANT and Log4j

http://openjms.exolab.org

http://java.sun.com/products/jms

http://www.exolab.org

http://www.antlr.org

http://jakarta.apache.org

http://www.junit.org

http://www.opensource.org

Q & A

Thank you