Patching Issues
Microsoft AppFabric 1.1 for Windows Server cache clusters consist of several servers, cache hosts, that work together to provide a distributed cache. When one or more of the cache host servers require operating system of software updates, there are two main choices.
Use a maintenance window when the cache cluster is down to update the cache hosts servers.
Update one or more cache hosts at a time while the cache cluster is running.
Tip
For more information about these options and the considerations for each, see Updating Cache Servers.
If updates are performed during a maintenance window, any applications that attempt to access the cache cluster will get a Retry exception with an error substatus of CacheServerUnavailable. For more information, see Server Unavailability.
If cache hosts are updated on a running cache cluster, applications might see several potential errors. The following table lists the error and error substatus of several possible DataCacheException exceptions.
| Error | Error SubStatus |
|---|---|
RetryLater |
None |
RetryLater |
NotPrimary |
RetryLater |
NoWriteQuorum |
ConnectionTerminated |
None |
Timeout |
None |
In general, applications should anticipate and recover from common exceptions. For more information about how to write robust AppFabric cache client applications, see Handling Errors.
See Also
Concepts
2012-10-26