Configure the WS-ReliableMessaging policy
When working with policy sets in the administrative console, we can customize some policies.
This task assumes that we are working with a policy set to which the WS-ReliableMessaging policy has been added.
Do not edit the policies associated with the provided default policy sets. If we have to modify the reliable messaging policy settings, use a copy of a default policy set or create a new policy set.
At any stage - that is, before or after we have built your reliable web service application, or configured your policy sets - we can set a property that configures endpoints to only support clients that use reliable messaging. This setting is reflected by WS-Policy if engaged.
To configure the WS-ReliableMessaging policy for a given policy set, use the administrative console to complete the following steps:
Tasks
- In the navigation pane, click Services > Policy sets > Application policy sets > policy_set_name > WS-ReliableMessaging. The WS-ReliableMessaging settings form is displayed.
- Modify one or more of the following properties:
- Standard
Select the WS-ReliableMessaging specification to use for reliable transmission of our messages. WS-ReliableMessaging Version 1.1 is the default value. Select the WS-ReliableMessaging specification to use for reliable transmission of our messages. WS-ReliableMessaging Version 1.1 is the default value. Details of the supported WS-ReliableMessaging specifications are available at the following web addresses:
- The WS-ReliableMessaging specification Version 1.0, February 2005.
- The OASIS WS-ReliableMessaging specification Version 1.1, February 2007.
If we plan to invoke a .NET-based web service, select WS-ReliableMessaging Version 1.0.
- Deliver messages in the order that they were sent
- Select this option if the sender of a request has to receive a response before it sends the next request, or if we want to enable transaction support for inbound (provider) message exchanges as described in Providing transactional recoverable messaging through WS-ReliableMessaging, or to marginally increase reliability as described in A message is not recovered after a server becomes unavailable.
Tip: When we enable this option, WS-ReliableMessaging ensures that the messages are made available to the requester application in the order that they were sent. That is, if WS-ReliableMessaging cannot make a given message available, it will not make any subsequent messages available. However, the requester application must also poll for the messages in the order in which it is to receive them. For example:
- WS-ReliableMessaging makes message 1 available, then message 2, then message 3.
- The requester application uses asynchronous polling to deliberately poll for message 2, then message 3, then message 1. All three messages are available, so this polling out of order is successful.
Even though WS-ReliableMessaging is delivering the messages in the order that they were sent, the requester application is choosing to receive them out of order.
- Quality of service
- Select the radio button for our required quality of service. The three choices are:
The default is unmanaged non-persistent.
- Unmanaged non-persistent
- We can configure web service applications to use WS-ReliableMessaging with a default in-memory store. This quality of service requires minimal configuration. However it is non-transactional and, although it allows for the resending of messages that are lost in the network, if a server becomes unavailable we will lose messages. This quality of service is for single server only and does not work in a cluster. (ZOS) This quality of service is not supported on the z/OS platform.
- Managed non-persistent
- This in-memory quality of service option uses a messaging engine to manage the sequence state, and messages are written to disk if memory is low. This quality of service allows for the re-sending of messages that are lost in the network, and can also recover from server failure. However, state is discarded after a messaging engine restart so in this case we will lose messages. This option supports clusters as well as single servers.
- Managed persistent
- This quality of service for asynchronous web service invocations is recoverable. This option also uses a messaging engine and message store to manage the sequence state. Messages are persisted at the web service requester server and at the web service provider server, and are recoverable if the server becomes unavailable. Messages that have not been successfully transmitted when a server becomes unavailable can continue to be transmitted after the server restarts.
All three qualities of service are supported when applications are deployed to the application server. Thin client and client container applications use the first option only.
In WebSphere Application Server Version 6.1, we could also configure whether to use the WS-MakeConnection protocol. This configuration option has now been removed from the administrative console panel, because the product now automatically determines whether WS-MakeConnection is used, based on the following criteria:
- Whether we are using WS-ReliableMessaging Version 1.0 or Version 1.1.
- Whether the requester supports WS-MakeConnection.
- Whether the message exchange protocol is synchronous or asynchronous.
- Click OK.
- Save changes to the master configuration.
After we have customized the reliable messaging policy, the associated policy set uses this policy to help ensure reliable delivery of messages.
Subtopics
- WS-ReliableMessaging settings
For the WS-ReliableMessaging policy we can configure the version of the WS-ReliableMessaging standard to use, the order in which messages are delivered, and the required quality of service (the reliability level) for message delivery. The product can enforce these policies on inbound messages and applies them to outbound messages.- WS-ReliableMessaging policy binding
To configure a web service application to use WS-ReliableMessaging, you attach a policy set containing a WS-ReliableMessaging policy type. This policy type offers a range of qualities of service: managed persistent, managed non-persistent, or unmanaged non-persistent. The managed qualities of service, managed persistent and managed non-persistent, are supported by the service integration bus. Select the bus and messaging engine to use for the reliable messaging protocol state.
Related:
Qualities of service for WS-ReliableMessaging Add assured delivery to web services through WS-ReliableMessaging Configure endpoints to only support clients that use WS-ReliableMessaging Configure a WS-ReliableMessaging policy set by WS-ReliableMessaging Detect and fix problems with WS-ReliableMessaging Tune web services reliable messaging applications Add policies to policy sets Deleting policies from policy sets Enable policies for policy sets Disable policies from policy sets Web services policies Add and remove policies Create policy set attachments Remove policy set attachments Manage policy set attachments Application policy sets collection Application policy set settings