Summary:
Introduces and uses a SystemClock class to RocksDB. This class contains the time-related functions of an Env and these functions can be redirected from the Env to the SystemClock.
Many of the places that used an Env (Timer, PerfStepTimer, RepeatableThread, RateLimiter, WriteController) for time-related functions have been changed to use SystemClock instead. There are likely more places that can be changed, but this is a start to show what can/should be done. Over time it would be nice to migrate most (if not all) of the uses of the time functions from the Env to the SystemClock.
There are several Env classes that implement these functions. Most of these have not been converted yet to SystemClock implementations; that will come in a subsequent PR. It would be good to unify many of the Mock Timer implementations, so that they behave similarly and be tested similarly (some override Sleep, some use a MockSleep, etc).
Additionally, this change will allow new methods to be introduced to the SystemClock (like https://github.com/facebook/rocksdb/issues/7101 WaitFor) in a consistent manner across a smaller number of classes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7858
Reviewed By: pdillinger
Differential Revision: D26006406
Pulled By: mrambacher
fbshipit-source-id: ed10a8abbdab7ff2e23d69d85bd25b3e7e899e90
Summary:
This provides a workaround for two race conditions that will be fixed in
a more sophisticated way later. This PR:
(1) Makes the client serialize calls to `Timer::Start()` and `Timer::Shutdown()` (see https://github.com/facebook/rocksdb/issues/7711). The long-term fix will be to make those functions thread-safe.
(2) Makes `PeriodicWorkScheduler` atomically add/cancel work together with starting/shutting down its `Timer`. The long-term fix will be for `Timer` API to offer more specialized APIs so the client will not need to synchronize.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7888
Test Plan: ran the repro provided in https://github.com/facebook/rocksdb/issues/7881
Reviewed By: jay-zhuang
Differential Revision: D25990891
Pulled By: ajkr
fbshipit-source-id: a97fdaebbda6d7db7ddb1b146738b68c16c5be38
Summary:
This PR schedules a background thread (shared across all DB instances)
to flush info log every ten seconds. This improves debuggability in case
of RocksDB hanging since it ensures the log messages leading up to the hang
will eventually become visible in the log.
The bulk of this PR is moving monitoring/stats_dump_scheduler* to db/periodic_work_scheduler*
and making the corresponding name changes since now the scheduler handles info
log flushing, not just stats dumping.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7488
Reviewed By: riversand963
Differential Revision: D24065165
Pulled By: ajkr
fbshipit-source-id: 339c47a0ff43b79fdbd055fbd9fefbb6f9d8d3b5
