Use this task to configure the transactional deployment descriptor
attributes associated with an EJB or Web module, to enable a J2EE application
to use transactions.
Before you begin
This task assumes that you have an Enterprise Archive (EAR) file for
an application component that can be deployed in WebSphere Application Server.
For more details about assembling applications, see
Assembling applications
.
About this task
You can configure the deployment attributes of an application
by using an assembly tool.
This
topic describes the use of the Application Server Toolkit (AST) to configure
the deployment attributes of an application.
To set transactional attributes
in the deployment descriptor for an application component (enterprise bean
or servlet), complete the following steps.
Procedure
- Start the assembly tool. For information about starting
the AST, refer to the Application Server Toolkit information in the navigation
pane of this infocenter.
- Create or edit the application EAR file. For example,
to change attributes of an existing application, use the import wizard to
import the EAR file into the assembly tool. To start the import wizard:
- Click File-> Import-> EAR file
- Click Next, then select the EAR file.
- Click Finish.
- In the J2EE Hierarchy view, right-click the component instance,
then click Open With > Deployment Descriptor Editor. For
example:
- For a session bean, expand EJB Modules-> ejb_module_instance->
Deployment Descriptor-> Session Beans then select the bean instance.
- For a servlet, expand Web Modules-> web_application->
Deployment Descriptor-> web component then select the
servlet instance.
A property dialog notebook for the component's deployment
descriptor is displayed in the property pane.
- [For session beans only] Set the Transaction type attribute,
which defines the transactional manner in which the container invokes a method.
You can set this attribute to Container or Bean, as follows:
- To use container-managed transactions, set Container
- To use bean-managed transactions, set Bean
- In the deployment descriptor notebook, select the Bean tab. Under WebSphere
Extensions, optionally configure Local Transaction. To
enable management of local transaction containments, configure the following
component extensions attributes. These attributes configure, for the component,
the behavior of the container's local transaction containment (LTC) environment
that the container establishes whenever a global transaction is not present.
- Boundary
This setting specifies the containment boundary at which all contained
resource manager local transactions (RMLTs) must be completed. Possible values
are
Bean method or
ActivitySession.
- Resolver
This setting specifies the component responsible for initiating and
ending RMLTs. Possible values are
Application or
ContainerAtBoundary.
- Application: This is the default value. The application is responsible
for starting RMLTs and for completing them within the local transaction containment
(LTC) boundary. Any RMLTs that are not completed by the end of the LTC boundary
are cleaned up by the container according to the value of the Unresolved action
attribute.
- ContainerAtBoundary: The container is responsible for starting RMLTs and
for completing them within the LTC boundary. The container begins an RMLT
when a connection is first used within the LTC scope, and completes it automatically
at the end of the LTC scope. If Boundary is set to ActivitySession, the RMLTs
are enlisted as ActivitySession resources and directed to complete by the
ActivitySession. If Boundary is set to BeanMethod, the RMLTs are committed
at the end of the method by the container.
- Unresolved action
Specifies the direction that the container requests RMLTs to take,
if they are unresolved at the end of the LTC boundary scope and the Resolver
is set to Application. Possible values are
Rollback or
Commit.
- Rollback: This is the default value. At end of the LTC boundary scope,
the container instructs all unresolved RMLTs to roll back.
- Commit: At the end of the LTC boundary scope, the container instructs
all unresolved RMLTs to commit. The container will instruct the RMLTs to commit
only in the absence of an un-handled exception. If the application method
executing under the local transaction context ends with an exception, any
unresolved RMLTs are rolled back by the container. (This is the same behavior
as for global transactions.)
- Continuing in WebSphere Extensions, configure Global Transaction.
These attributes configure, for the component, behavior in the presence of
a global transaction.
- Component Transaction Timeout
- [For enterprise beans using container-managed transactions only.] Specifies
the transaction timeout, in seconds, for any new global transaction that the
container starts on behalf of the enterprise bean. For transactions started
on behalf of the component, the Component Transaction Timeout overrides the
default total transaction lifetime timeout configured in the transaction service
settings for the application server.
The following attributes
enable WS-AtomicTransaction and WS-BusinessActivity support:
- Use Web Services Atomic Transaction
- [For enterprise beans only.] When this attribute is selected, if the application
component makes any Web service requests, any transaction context is propagated
with the Web service requests in accordance with the WebSphere WS-AtomicTransaction
support described in Web Services Atomic Transaction support in WebSphere Application Server
.
When this attribute is not selected, Web service requests do not carry transaction
context.
- Send Web Services Atomic Transaction on requests
- [For Web components only.] When this attribute is selected,
if the application component makes any Web service requests, any transaction
context is propagated with the Web service requests in accordance with the
WebSphere WS-AtomicTransaction support described in Web Services Atomic Transaction support in WebSphere Application Server
. When this attribute is not selected, Web service requests
do not carry transaction context.
- Execute using Web Services Atomic Transaction on incoming requests
- [For Web components only.] When this attribute is selected, Web application
components are prepared to run under a received WS-AtomicTransaction context.
A Web application component can run under a received WS-AtomicTransaction
context in a similar way to an enterprise bean deployed with a Container
transaction type of Supports. When this attribute is not selected,
the container of the Web application component suspends any received transaction
context, in a similar way to the behavior of an EJB container for an enterprise
bean deployed with a Container transaction type of NotSupported.
If a policy set that is
attached to a client includes the WS-Transaction policy type, any active global
transaction context is propagated with a Web service request; this is analogous
to the Use Web Services Atomic Transaction and Send Web Services Atomic Transaction
on requests deployment descriptors described above. The inclusion of the WS-Transaction
policy type also causes the service to run under any received WS-AtomicTransaction
context. This is analogous to the Execute using Web Services Atomic Transaction
on incoming requests deployment descriptor described above.
- [For EJB components only] For container-managed transactions, configure
how the container manages the transaction boundaries when delegating a method
invocation to an enterprise bean's business method:
- In the deployment descriptor notebook, select the Assembly tab.
The Container Transactions box displays a table of the methods
for enterprise beans.
- For each method of the enterprise bean, set the Container
transaction type to an appropriate value. The default value
for the Container transaction type is Required, meaning that the
method invocation occurs in the context of a transaction. This transaction
is either the (local or remote) client component's transaction or, if the
client component does not execute under a transaction, a new transaction started
by the component's container.
If the application uses ActivitySessions, how the container manages
transaction boundaries when delegating a method invocation depends on both
the Container transaction type set in this task, and the ActivitySession
kind attribute as described in Setting EJB module ActivitySession deployment attributes
. For more detail about the relationship
between these two properties, see ActivitySession and transaction container policies in combination
.
- [For Web service applications that use a SOAP/JMS binding and participates
in WS-AtomicTransactions] Set the Container transaction type of the
message-driven bean named JMS router MDB to a value of NotSupported,
as described in the previous step. Web service applications that
use a SOAP/JMS binding include a router message-driven bean named JMS
router MDB in the assembled EAR. If a Web service uses a SOAP/JMS binding
and participates in WS-AtomicTransactions, as described in Web Services Atomic Transaction support in WebSphere Application Server
, set the Container transaction type of the JMS
router MDB to a value of NotSupported.
For Web service applications
that use a SOAP/HTTP binding and participate in WS-AtomicTransactions, you
do not need to do this.
- [For client application components only] If required, enable support
for transaction demarcation by the client. In the deployment descriptor
notebook, select the option Allow JTA demarcation.
This directs the client container to bind the JTA UserTransaction interface
into JNDI at java:comp/UserTransaction for the client component. There are
constraints on transaction support in the client container, which are described
in Client support for transactions
.
- Save your changes to the deployment descriptor.
- Close the deployment descriptor editor.
- When prompted, click Yes to save changes
to the deployment descriptor.
- Verify the archive files. For more information about
verifying files using the AST, refer to the Application Server Toolkit information
in the navigation pane of this infocenter.
- From the popup menu of the project, click Deploy to
generate EJB deployment code.
- Optional: Test your completed module on a WebSphere
Application Server installation. Right-click a module, click Run on Server,
and follow the instructions in the displayed wizard.
Important: Use Run
On Server for unit testing only. The assembly tool controls the WebSphere
Application Server installation and, when an application is published remotely,
the assembly tool overwrites the server configuration file for that server.
Do not use Run On Server on production servers.
What to do next
After assembling your application, use a systems management tool
to deploy the EAR file onto the application server that is to run the application.
For example, use the administrative console, as described in
Deploying and administering J2EE applications
.