Summary:
The persistent cache is designed to hop over errors and return key not found. So far, it has shown resilience to write errors, encoding errors, data corruption etc. It is not resilient against disappearing files/directories. This was exposed during testing when multiple instances of persistence cache was started sharing the same directory simulating an unpredictable filesystem environment.
This patch
- makes the write code path more resilient to errors while creating files
- makes the read code path more resilient to handle situation where files are not found
- added a test that does negative write/read testing by removing the directory while writes are in progress
Closes https://github.com/facebook/rocksdb/pull/1472
Differential Revision: D4143413
Pulled By: kradhakrishnan
fbshipit-source-id: fd25e9b
Summary:
Travis times out with persistent_cache_test, there is no way to increase the
timeout, so lower the test case for Travis
Test Plan: Run on travis and sandcastle
Subscribers: leveldb, dhruba, andrewkr
Differential Revision: https://reviews.facebook.net/D61863
Summary:
The patch is a continuation of part 5. It glues the abstraction for
file layout and metadata, and flush out the implementation of the API. It
adds unit tests for the implementation.
Test Plan: Run unit tests
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57549
Summary: Enabled build in Windows and corresponding fixes
Test Plan:
Compile and run persistent_cache_test in Windows and make check in
Linux
Reviewers: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D59307
Summary:
This provides provides an implementation of PersistentCacheTier that is
specialized for RAM. This tier does not persist data though.
Why do we need this tier ?
This is ideal as tier 0. This tier can host data that is too hot.
Why can't we use Cache variants ?
Yes you can use them instead. This tier can potentially outperform BlockCache
in RAW mode by virtue of compression and compressed cache in block cache doesn't
seem very popular. Potentially this tier can be modified to under stand the
disadvantage of the tier below and retain data that the tier below is bad at
handling (for example index and bloom data that is huge in size)
Test Plan: Run unit tests added
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57069
Karthikeyan Radhakrishnan