Silence means yes, so I'll open a jira and bump that to 25%. J-D
On Mon, Dec 12, 2011 at 5:47 PM, Jean-Daniel Cryans <[email protected]> wrote: > Hey devs, > > A thought just stuck me while I was writing down a more detailed block > caching documentation: with HFileV2, the indexes now live in the block > cache which means that those who upgrade may all of a sudden get > terrible cache hit ratios because of all that memory taken by the > indexes. This is somewhat mitigated by the fact that people don't > usually need to keep _all_ the index blocks in memory so in the end > we're more efficient. > > Which brings me to a question: should we set hfile.block.cache.size > higher since indexes are now kept in the block cache? Currently it's > set to 20%. > > Looking over my own production machines I see that the > storefileIndexSize is around 600-700MB so that's potentially how much > more data I'd have to block cache (more likely it's half of that > that's really being used actively). > > What would be a good new default? 25%? 30%? How do we handle those > that will be pushed over the BC+memstore size limit because of that > change? > > Thx, > > J-D
