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...

<?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"

<?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

<?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.

<?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.

<?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..

<?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