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Distributed nonce cache

In previous releases of WAS, the nonce was cached locally. WAS v6 and later use distributed nonce caching. The distributed nonce cache makes it possible to replicate nonce data among servers in a WebSphere Application Server cluster.

If nonce elements are in a SOAP header, all nonce values are cached by the server in the cluster. If the distributed nonce cache is enabled, the cached nonce values are copied to other servers in the same cluster. Then, if the message with the same nonce value is sent to (one of) other servers, the message is rejected. A received nonce cache value is cached and replicated in a push manner among other servers in the cluster with the same replication domain. The replication is an out-of-process call and, in some cases, is a remote call. Therefore, there is latency when the content of the cache in the cluster is updated.

For example, we might have application server A and application server B in cluster C.

Important: The distributed nonce caching feature uses the WAS data replication service (DRS). The data in the local cache is pushed to the cache in other servers in the same replication domain. The replication is an out-of-process call and, in some cases, is a remote call. Therefore, there is a possible delay in replication while the content of the cache in each application server within the cluster is updated. The delay might be due to network traffic, network workload, machine workload, and so on.


Related concepts

  • Nonce, a randomly generated token
  • Web Services Security enhancements


    Related tasks

  • Distributing nonce caching to servers in a cluster

  • Security considerations for web services