Taking Snapshots of the Cache to Disk

[kutchar]

What would be the best way to snapshot the cache state to disk (all the elements and their expirations) on some interval to be able to recover the cache when the process restarts?

[ben-manes]

Take a look at the Policy api. It provides snapshot iteration order and the ability to query the internal metadata.

[kutchar]

I'm assuming you're referring to the following, right?

Policy.Expiration.oldest
Policy.Expiration.youngest
Policy.Expiration.getExpiresAfter

So considering the oldest and youngest are not constant time, wouldn't it be better to use the asMap since I just need a snapshot of the cache and not necessarily in any order?

Also, I'm assuming in either case I have to iterate through the iterator and call Expiration.getExpiresAfter on each item to get the expiration, correct?

[ben-manes]

If you don't care about order then, as you said, using asMap and ageOf would be best.

[kutchar]

Thanks :)

[ben-manes]

If you run into any snags be sure to let me know.