Summary:
Persistent cache tier is the tier abstraction that can work for any block
device based device mounted on a file system. The design/implementation can
handle any generic block device.
Any generic block support is achieved by generalizing the access patten as
{io-size, q-depth, direct-io/buffered}.
We have specifically tested and adapted the IO path for NVM and SSD.
Persistent cache tier consists of there parts :
1) File layout
Provides the implementation for handling IO path for reading and writing data
(key/value pair).
2) Meta-data
Provides the implementation for handling the index for persistent read cache.
3) Implementation
It binds (1) and (2) and flushed out the PersistentCacheTier interface
This patch provides implementation for (1)(2). Follow up patch will provide (3)
and tests.
Test Plan: Compile and run check
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57117
Summary:
The tsan error was because the random implementation we have is not
thread safe, using Random::GetTLSInstance
Test Plan: Run tests in Linux
Reviewers: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D59559
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:
PersistentCacheOptions class in persistent_cache_tier.h is not used any where yet in the code base
but it break the unity build because it have the same name as PersistentCacheOptions in table/persistent_cache_helper.h
Remove it temporarily, and the @krad can add it again with a different name when we start using it
Test Plan:
make unity_test -j64
make check -j64
Reviewers: kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D59349
Summary: Disable the test under TSAN temporary to temporarily the build
Test Plan: run the test under TSAN
Reviewers: kradhakrishnan, andrewkr, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D59337
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
Summary:
Fix 2 issues that was breaking Windows build
1) double to size_t potential downcast warning
2) port_posix is not ready for windows, avoiding building hash_table_bench to
avoid build break
Test Plan: compile in Windoes and make check
Reviewers: sdong, andrewkr
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D59265
Summary:
This diff provides the basic interface definitions of persistent read
cache system
PersistentCacheOptions captures the persistent read cache options used to
configure and control the system
PersistentCacheTier provides the basic building block for constructing tiered
cache
PersistentTieredCache provides a logical abstraction of tiers of cache layered
over one another
Test Plan: Compile
Reviewers: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57051
Summary: Add hash table (under persistent cache) to CMake list
Test Plan: Run hash_test in windows and make check in Linux
Reviewers: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D59151
Summary:
Persistent read cache isn't very applicable for lite builds. Wrapping
the code with #ifndef ROCKSDB_LITE .. #endif
Test Plan: Run unit, lite, lite_test
Reviewers: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D58563
Summary:
We expect the persistent read cache to perform at speeds upto 8 GB/s. In order
to accomplish that, we need build a index mechanism which operate in the order
of multiple millions per sec rate.
This patch provide the basic data structure to accomplish that:
(1) Hash table implementation with lock contention spread
It is based on the StripedHashSet<T> implementation in
The Art of multiprocessor programming by Maurice Henry & Nir Shavit
(2) LRU implementation
Place holder algorithm for further optimizing
(3) Evictable Hash Table implementation
Building block for building index data structure that evicts data like files
etc
TODO:
(1) Figure if the sharded hash table and LRU can be used instead
(2) Figure if we need to support configurable eviction algorithm for
EvictableHashTable
Test Plan: Run unit tests
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D55785
krad