You can use a global cache to store state for integrations. With a global cache, each integration node can handle replies, even when the request was processed by another integration node.
When IBM® Integration Bus is used to integrate asynchronous systems, the integration node records information about the requester to correlate the replies correctly, as shown in the following diagram.
When this integration is deployed to multiple integration nodes for workload balancing, the reply will not necessarily return through the same integration node as the original request.
With a global cache, each integration node can handle replies, even when the request was processed by another integration node.