Near cache statistic

[hazelcast]

Add possibility to retrieve statistic about near cache like
IMap.getLocalMapStats() does.
For example, EntryCount and EntryCost for objects in near cache.

Migrated from http://code.google.com/p/hazelcast/issues/detail?id=421

[cameronbraid]

I would like this feature too..

Is there a targeted version for which this feature will be implemented ?

[lukasblu]

Hej,

I'd like to have this feature too.

EntryCount should be straight forward to implement. EntryCost (memory consumption could be difficult for InMemoryFormat.OBJECT, but as with the map statistics, you could simply only support this for InMemoryFormat.BINARY).

Besides the two already mentioned stats, a measure of hit ratio would be awesome - e.g. number of hits and number of misses. For a cache this is really fundamental to decide if maintaining this cache is useful.

Thanks and best,
Lukas

[jerrinot]

there are already hits & getCount in the LocalMapStats.
Isn't getCount - hits == misses?

[eminn]

I already did some work for that but never created pull request for it. I will finish that, then create a pull request for it. Hopefully version 3.2 will contain near cache statistics

[lukasblu]

@jerrinot sure, however, this is on the map - and not on the near cache.

I'd like to know, for example, the ratio of get-requests which were served directly by the near cache versus the requests that had to go to the map, possible fetch the entry from a remote node, deserialize the entry and then return it.

This allows me to decide if a cache is useful. E.g. if most of the requests go to the map anyway, for example, because entries in the near cache are invalidate before I can benefit from having it in the near cache, then the cache can/should be removed.

Okay?

Best,
Lukas

[eminn]

see #1458