Configure high availability and workload sharing of service integration
We can configure high availability and workload sharing of service integration without using messaging engine policy assistance.
Ensure to use the following procedure. Alternatively, we can configure high availability and workload sharing of service integration by using messaging engine policy assistance when we add a server cluster to a bus. We create messaging engines and their associated policies as part of the procedure, using the appropriate predefined messaging engine policy type. Alternatively, we can use a custom policy type and configure the messaging engine policy as required, and the relevant core group policies and match criteria are created automatically.
When you set up a service integration environment, we create bus members, either servers or clusters, that run messaging engines. For high availability, where the messaging engine can fail over, or workload sharing, where multiple messaging engines share the load on a destination, create a cluster bus member and configure high availability and workload sharing characteristics of the messaging engines.
If we do not require high availability or workload sharing, we can use a simple configuration and create a server bus member. You do not need the steps described in this topic.
The high availability and workload sharing characteristics of the messaging engines in the cluster are set by core group policies.
To see the policies configured in the system, we can use the console to open the Policies page. In the navigation pane, click Servers -> Core groups -> Core group settings -> core_group_name -> [Additional Properties] Policies.
One of the available policies is the default service integration policy, "Default SIBus Policy", which is the policy that a messaging engine uses unless you configure the system so that the engine uses another policy. The default policy is sufficient for many purposes and you might not need to alter the policy configuration. It is not advisable to alter the default service integration policy, because those changes will affect all messaging engines that the policy manages. Therefore, it is better to create and configure one or more new specific policies.
- Optional: Create a cluster, if it is not created already. See Create clusters.
- Add the cluster to the service integration bus. See Add a cluster to a bus without using messaging engine policy assistance.
A single messaging engine that uses the default service integration policy is created automatically.
For high availability without workload sharing, we can use this configuration and do not need to change it further. To configure the messaging engine behavior further, for example to specify preferred servers for the messaging engine, or enable the messaging engine to fail back, complete step 3.
- Optional: For high availability when to configure the messaging engine behavior, create and configure a policy for the messaging engine. Create a policy with the type "One of N" . See Create a policy for messaging engines and Configure a core group policy for messaging engines.
- Optional: For workload sharing without high availability, use the following steps:
- Add as many messaging engines as required to the cluster. Typically, a workload sharing configuration has one messaging engine for each server in the cluster. See Add a messaging engine to a cluster.
- Create and configure a policy for each messaging engine in the cluster. Create policies with the type Static. See Create a policy for messaging engines and Configure a core group policy for messaging engines.
- Optional: For workload sharing with high availability, use the following steps:
- Add as many messaging engines as required to the cluster. Typically, a workload sharing configuration has one messaging engine for each server in the cluster. See Add a messaging engine to a cluster.
- Create and configure a policy for each messaging engine in the cluster. Create policies with the type "One of N". See Create a policy for messaging engines and Configure a core group policy for messaging engines.
- Optional: To use an external high availability (HA) framework to manage high availability or workload sharing behavior, use the following steps:
- If we require workload sharing, add as many messaging engines as required to the cluster. Typically, a workload sharing configuration has one messaging engine for each server in the cluster. See Add a messaging engine to a cluster.
- Create and configure one policy for the messaging engines in the cluster. Create a policy with the type "No operation". See Create a policy for messaging engines and Configure a core group policy for messaging engines.
What to do next
If we created a high availability configuration for service integration, you might also want to configure high availability for the transaction service.If we created a workload sharing configuration, you might want to deploy a queue destination to the cluster, so that the queue is partitioned across the set of messaging engines.
Subtopics
- Create a policy for messaging engines
We create one or more core group policies for service integration to control the behavior of the messaging engine, or engines, in a server cluster. The policies support behavior such as high availability, workload sharing or scalability in a server cluster.
- Configure a core group policy for messaging engines
We can configure a core group policy for service integration to associate the policy with specific messaging engines and to specify messaging engine behavior, such as which server a messaging engine runs on, whether a messaging engine can fail over or fail back, and the frequency of messaging engine monitoring.
- Configure messaging engine failover for mixed version clusters
A messaging engine that is hosted on a WAS v7 or later server cannot fail over to a messaging engine that is hosted on a WAS v6 server. If we have a cluster bus member that consists of a mixture of Version 6 and Version 7.0 or later servers, you must make sure the high availability policy is configured to prevent this type of failover.
Related concepts
Service integration high availability and workload sharing configurations Bus member types and their effect on high availability and workload sharing Configuration for high availability Configuration for workload sharing with high availability Configuration for workload sharing or scalability Workload sharing Workload sharing with queue destinations High availability Messaging engine policy assistance Transactional high availability
Related tasks
Create a queue for point-to-point messaging Configure a core group policy for messaging engines Configure shared durable subscriptions for a connection factory Configure shared durable subscriptions for an activation specification Add a messaging engine to a cluster Add a cluster to a bus without using messaging engine policy assistance
Automate peer recovery for transactions and messages in WebSphere Application Server
Related information:
Messaging engine troubleshooting tips