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Benedict commented on CASSANDRA-5863: ------------------------------------- bq. Moving hot compressed chunks onto an SSD makes a lot of sense, but think that maybe these are two different tickets? One to bring the page/buffer cache in process, and store it uncompressed, the other to track hot file regions and store them on a cache drive. Just realised this is exactly what [~jbellis] already suggested. I would quite like to have a crack at this for 3.0 using CASSANDRA-6694 as a basis, so that we can move the cache off-heap and retain zero copy behaviour. > Create a Decompressed Chunk [block] Cache > ----------------------------------------- > > Key: CASSANDRA-5863 > URL: https://issues.apache.org/jira/browse/CASSANDRA-5863 > Project: Cassandra > Issue Type: New Feature > Components: Core > Reporter: T Jake Luciani > Assignee: Pavel Yaskevich > Labels: performance > Fix For: 2.1 beta2 > > > Currently, for every read, the CRAR reads each compressed chunk into a > byte[], sends it to ICompressor, gets back another byte[] and verifies a > checksum. > This process is where the majority of time is spent in a read request. > Before compression, we would have zero-copy of data and could respond > directly from the page-cache. > It would be useful to have some kind of Chunk cache that could speed up this > process for hot data. Initially this could be a off heap cache but it would > be great to put these decompressed chunks onto a SSD so the hot data lives on > a fast disk similar to https://github.com/facebook/flashcache. -- This message was sent by Atlassian JIRA (v6.2#6252)