OpenEJB Configuration -- Containers

|  |  |  | OpenEJB OpenJMS OpenORB Castor Tyrex |

Main
Welcome!
Download
Mailing Lists
The Team

Users
Quickstart
Hello World!
CMP Example
CMP Guide
Deploy
Startup
Validation
Configuration
Support
Request Feature
FAQ

Servers
Local Server
Remote Server
Tomcat

Integrators
Why OpenEJB
Overview
Design
Specification
Presentation

Developers
Custom Services
Release Plan
Source Code
SourceForge

OpenEJB Configuration Containers

## Declaring your Container

CMP Entity containers are defined with the <Container> element, under the <openejb> element. This is actually the declaration used for all containers defined in the container system. The part that actually makes it a cmp container is the ctype attribute, specifially, a ctype attribute set to CMP_ENTITY as such...

example_01.conf

    <?xml version="1.0"?>
    <openejb>

    <Container id="Default CMP Container" ctype="CMP_ENTITY"/>

    </openejb>

The really fun part is that the above configuration file is completely legal! If you started the server and pointed to this file...

./openejb.sh start -conf example_01.conf

...you would end up with a running server that contained only one container, called "Default CMP Container". You could then deploy beans into it and everything. There would be no other containers running in the server at all. If you telnet'd into the server and typed the 'system' command, you could see for yourself that there is nothing else in the system.

    dblevins@Miles /dev/OpenEJB
    $ telnet localhost 4200
    Trying 127.0.0.1...
    Connected to Miles
    Escape character is '^]'.
    OpenEJB Remote Server Console
    type 'help' for a list of commands
    [openejb]$ system
    Containers:
     Default CMP Container

    Deployments:
    [openejb]$

You see that. No beans, no JDBC resources, nothing but one CMP container called "Default CMP Container".

## Naming your Container

You can call the container anything you want, just change the value of the id attribute. Here is a container called "My PostgreSQL Contianer"

example_02.conf

    <?xml version="1.0"?>
    <openejb>

    <Container id="My PostgreSQL Container" ctype="CMP_ENTITY"/>

    </openejb>

If you were to deploy a CMP bean into this configuration, you would see "My PostgreSQL Container" in the list of usable containers, in fact, it would be the only container in the list.

    dblevins@Miles /dev/OpenEJB/openejb
    $ ./openejb.sh deploy -conf example_02.conf myCMPBean.jar
    ...(skipping to step two)...

    ==--- Step 2 ---==

    Please specify which container the bean will run in.
    Available containers are:

    Num     Type            ID

    1       CMP_ENTITY      My PostgreSQL Container

    Type the number of the container
    -options to view the list again
    or -help for more information.

    Container:

After deployment, you would end up with a configuration like this one

example_02.conf

    <?xml version="1.0"?>
    <openejb>

    <Container id="My PostgreSQL Container" ctype="CMP_ENTITY"/>

    <Deployments jar="myCMPBean.jar" />

    </openejb>

Most important, that bean will now be mapped directly to the container id "My PostgreSQL Container". So if you change the name of the container and do not redeploy the myCMPBean.jar to point to the new container id, you will have big problems!

## Container types

You can declare as many containers as you want. The available container types are:

| CMP_ENTITY
| BMP_ENTITY
| STATELESS
| STATEFUL

The containers can all be of the same type, or a mix of the types.

example_03.conf

    <?xml version="1.0"?>
    <openejb>

    <Container id="My PostgreSQL Container" ctype="CMP_ENTITY"/>
    <Container id="My MySQL Container" ctype="CMP_ENTITY"/>
    <Container id="My InstantDB Container" ctype="CMP_ENTITY"/>
    <Container id="My Stateful Session Container" ctype="STATEFUL"/>
    <Container id="My Stateless Session Container" ctype="STATELESS"/>

    </openejb>

## Configuring your Container

Of course, if you did have a configuration like the one above, it would be a bit pointless as all three of your CMP containers would be using the default CMP container configuration. To acually configure a container differently, you simply need to specifiy new values for the properties that the container has. These will override the defaults for that particular container declaration. So it's possible to declare multiple containers of the same type, but configure each one differently. Let's use our CMP_ENTITY containers above as an example.

example_03.conf

    <?xml version="1.0"?>
    <openejb>

    <Container id="My PostgreSQL Container" ctype="CMP_ENTITY">
        Global_TX_Database    conf/postgresql.cmp.global-database.xml
        Local_TX_Database     conf/postgresql.cmp.local-database.xml
    </Container>

    <Container id="My MySQL Container" ctype="CMP_ENTITY">
        Global_TX_Database  conf/mysql.cmp.global-database.xml
        Local_TX_Database   conf/mysql.cmp.local-database.xml
    </Container>

    <Container id="My InstantDB Container" ctype="CMP_ENTITY">
        Global_TX_Database  conf/instantdb.cmp.global-database.xml
        Local_TX_Database   conf/instantdb.cmp.local-database.xml
    </Container>

    <Container id="My Stateful Session Container" ctype="STATEFUL"/>
    <Container id="My Stateless Session Container" ctype="STATELESS"/>

    </openejb>

The format of the configuration parameters is actually just regular old java.util.Properties file format. It keeps things simple and doesn't require you to type endless amounts of tags that are just name/value pairs anyway. The java.util.Properties file format allows for spaces, tabs, colons, or equals signs to separate the name value pairs, so this would also be acceptable..

example_03.conf

    <?xml version="1.0"?>
    <openejb>

    <Container id="My PostgreSQL Container" ctype="CMP_ENTITY">
    ! This is a comment
        Global_TX_Database = conf/postgresql.cmp.global-database.xml
        Local_TX_Database=conf/postgresql.cmp.local-database.xml
    </Container>

    <Container id="My MySQL Container" ctype="CMP_ENTITY">
    # This is also a comment
        Global_TX_Database:conf/mysql.cmp.global-database.xml
        Local_TX_Database : conf/mysql.cmp.local-database.xml
    </Container>

    <Container id="My InstantDB Container" ctype="CMP_ENTITY">
        Global_TX_Database  conf/instantdb.cmp.global-database.xml
        Local_TX_Database           conf/instantdb.cmp.local-database.xml
    </Container>

    </openejb>

## Configuration properties

The actual properties that each container type accepts are different for each type. Here is a reference for each container type.

#### CMP_ENTITY properties

##### PoolSize

The default size of the method ready bean pools. Every bean class gets its own pool of this size. The value should be any integer.

Default:

    PoolSize 100

##### Global_TX_Database

The name of the database.xml file that is used for global or container managed transactions. This will be used when the TransactionManager is managing the transaction, such as when the tx attribute is Supports(and there is a client tx), RequiresNew, Required or Manditory.

Specifies the configuration for obtaining database connections and the mapping.xml schema which describes how beans map to the database.

Default:

    Global_TX_Database  conf/default.cmp_global_tx_database.xml

##### Local_TX_Database

The name of the database.xml file that is used for local or unspecified transaction contexts. This will be used when the TransactionManager is not managing the transaction, such as when the tx attribute is Supports (and there is no client tx), NotSupported, or Never.

Specifies the configuration for obtaining database connections and the mapping.xml schema which describes how beans map to the database.

Default:

    Local_TX_Database   conf/default.cmp_local_tx_database.xml

#### BMP_ENTITY properties

The BMP Container has no customizable properties to override.

#### STATEFUL properties

##### Passivator

The passivator is responsible for writing beans to disk at passivation time. Different passivators can be used by setting this property to the fully qualified class name of the PassivationStrategy implementation. The passivator is not responsible for invoking any callbacks or other processing, its only responsibly is to write the bean state to disk.

Known implementations:
| org.openejb.core.stateful.RAFPassivater
| org.openejb.core.stateful.SimplePassivater

Default:

    Passivator   org.openejb.core.stateful.SimplePassivater

##### TimeOut

Specifies the time to wait between invocations. This value is measured in minutes. A value of 5 would result in a time-out of 5 minutes between invocations.

Default:

    TimeOut  20

##### PoolSize

Specifies the size of the bean pools for this stateful SessionBean container.

Default:

    PoolSize  100

##### BulkPassivate

Property name that specifies the number of instances to passivate at one time when doing bulk passivation. Must be less than the PoolSize.

Default:

    BulkPassivate  50

#### STATELESS properties

##### StrictPooling

Specifies the whether or not to this stateless SessionBean container should use a strict pooling algorithm. true or false

Default:

    StrictPooling  true

Java, EJB, JDBC, JNDI, JTA, Sun, Sun Microsystems are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and in other countries. XML, XML Schema, XSLT and related standards are trademarks or registered trademarks of MIT, INRIA, Keio or others, and a product of the World Wide Web Consortium. All other product names mentioned herein are trademarks of their respective owners.