Go to file
Peter Dillinger b6e33dbc0e Fix HyperClockCache Rollback bug in #10801 (#10843)
Summary:
In https://github.com/facebook/rocksdb/issues/10801 in ClockHandleTable::Evict, we saved a reference to the hash value (`const UniqueId64x2& hashed_key`) instead of saving the hash value itself before marking the handle as empty and thus free for use by other threads. This could lead to Rollback seeing the wrong hash value for updating the `displacements` after an entry is removed.

The fix is (like other places) to copy the hash value before it's released. (We could Rollback while we own the entry, but that creates more dependences between atomic updates, because in that case, based on the code, the Rollback writes would have to happen before or after the entry is released by marking empty. By doing the relaxed Rollback after marking empty, there's more opportunity for re-ordering / ILP.)

Intended follow-up: refactoring for better code sharing in clock_cache.cc

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10843

Test Plan: watch for clean crash test, TSAN

Reviewed By: siying

Differential Revision: D40579680

Pulled By: pdillinger

fbshipit-source-id: 258e43b3b80bc980a161d5c675ccc6708ecb8025
2022-10-21 12:09:03 -07:00
.circleci
.github/workflows
buckifier
build_tools
cache
cmake
coverage
db
db_stress_tool
docs
env
examples
file
fuzz
include/rocksdb
java
logging
memory
memtable
microbench
monitoring
options
plugin
port
table
test_util
third-party
tools
trace_replay
util
utilities
.clang-format
.gitignore
.lgtm.yml
.watchmanconfig
AUTHORS
CMakeLists.txt
CODE_OF_CONDUCT.md
CONTRIBUTING.md
COPYING
DEFAULT_OPTIONS_HISTORY.md
DUMP_FORMAT.md
HISTORY.md
INSTALL.md
LANGUAGE-BINDINGS.md
LICENSE.Apache
LICENSE.leveldb
Makefile
PLUGINS.md
README.md
ROCKSDB_LITE.md
TARGETS
USERS.md
Vagrantfile
WINDOWS_PORT.md
common.mk
crash_test.mk
issue_template.md
rocksdb.pc.in
src.mk
thirdparty.inc

README.md

RocksDB: A Persistent Key-Value Store for Flash and RAM Storage

CircleCI Status Appveyor Build status PPC64le Build Status

RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)

This code is a library that forms the core building block for a fast key-value server, especially suited for storing data on flash drives. It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF) and Space-Amplification-Factor (SAF). It has multi-threaded compactions, making it especially suitable for storing multiple terabytes of data in a single database.

Start with example usage here: https://github.com/facebook/rocksdb/tree/main/examples

See the github wiki for more explanation.

The public interface is in include/. Callers should not include or rely on the details of any other header files in this package. Those internal APIs may be changed without warning.

Questions and discussions are welcome on the RocksDB Developers Public Facebook group and email list on Google Groups.

License

RocksDB is dual-licensed under both the GPLv2 (found in the COPYING file in the root directory) and Apache 2.0 License (found in the LICENSE.Apache file in the root directory). You may select, at your option, one of the above-listed licenses.