Understanding how FlexCache determines the validity of cached data will help you determine whether your data set is a good candidate for a FlexCache.
What a cached file contains When the client requests a data block of a specific file from a FlexCache volume, then the attributes of that file are cached, and that file is considered to be cached, even if all of its data blocks are not present in the FlexCache volume. If the requested data is cached and valid, a read request for that data is fulfilled without access to the origin volume.
How data changes affect FlexCache volumes
How data changes affect FlexCache volumes depends on where the change is made: on the FlexCache volume, the origin volume, or another FlexCache volume. If a file is directly updated on the origin volume, the cached copy of the file is invalidated. If the write request is relayed to the origin volume, only the changed blocks are invalidated in the FlexCache volume.
How cache consistency is achieved Cache consistency for FlexCache volumes is achieved by using three primary techniques: delegations, attribute cache timeouts, and write operation proxy.
What cache hits and misses are
Cache hits and misses indicate if the data requested by the client is served directly from the FlexCache volume or from the origin volume. The occurrence of a cache hit or miss depends on factors such as availability of the requested data in the cache, the attribute cache timeout values, and the difference between attributes of a file in the cache and the origin.