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Programming Distributed Systems with YAMI4

7.3 Cache

The cache server can provide a simple, but effective temporary storage for arbitrary values which can be addressed by string keys. In principle, the cache server can play a role that is similar to the memcache server, which is frequently used as a component in many web services.

The cache server does not offer any persistency and is not supposed to be used as a long-term database.

The lifetime of values stored in the cache and their access methods can be summarized as:

• Data values can be created by client programs and stored in the cache with some key.
• Values can be looked up and retrieved based on keys - clients are supposed to know the keys of values they need to access.
• Whole entries can be deleted on request.
• Expired entries are automatically and regularly cleaned up by the cache itself with the configured frequency and expiration time.

There is no restriction on the format and content of values which are stored in the cache - in fact, they do not even need to represent valid parameters object and can be arbitrary blobs of binary data.

The following subsections describe the messaging ``API'' of the cache server and its configuration parameters.

7.3.1 Set

7.3.2 Get

7.3.3 Delete

7.3.4 Startup and Configuration