[CASSANDRA-5863] In process (uncompressed) page cache

• Type: Sub-task
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 3.6
• Labels: performance
• Assignee: Branimir Lambov
• Reporter: T Jake Luciani

Authors

Branimir Lambov

Reviewers

Pavel Yaskevich

• Created: 08/Aug/13 16:58
• Updated: 16/Apr/19 09:32
• Resolved: 03/May/16 14:52

Description

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, possibly off heap.

Issue Links

• breaks: CASSANDRA-11960 Hints are not seekable
• incorporates: CASSANDRA-11452 Cache implementation using LIRS eviction for in-process page cache
• is depended upon by: CASSANDRA-11681 Pick a better file_cache_size_in_mb default
• relates to: CASSANDRA-8271 Remove SSTableDeletingTask
• supercedes: CASSANDRA-6726 Recycle CompressedRandomAccessReader/RandomAccessReader buffers independently of their owners, and move them off-heap when possible