Summary:
recent commit 671d15cbdd introduced some test failures:
```
===== Running stats_history_test
[==========] Running 9 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 9 tests from StatsHistoryTest
[ RUN ] StatsHistoryTest.RunStatsDumpPeriodSec
monitoring/stats_history_test.cc:63: Failure
dbfull()->SetDBOptions({{"stats_dump_period_sec", "0"}})
Not implemented: Not supported in ROCKSDB LITE
db/db_options_test.cc:28:11: error: unused variable 'kMicrosInSec' [-Werror,-Wunused-const-variable]
const int kMicrosInSec = 1000000;
```
This PR fixes these failures
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5477
Differential Revision: D15871814
Pulled By: miasantreble
fbshipit-source-id: 0a7023914d2c1784d9d2d3f5bfb47310d4855394
Summary:
This PR continues the work in https://github.com/facebook/rocksdb/pull/4748 and https://github.com/facebook/rocksdb/pull/4535 by adding a new DBOption `persist_stats_to_disk` which instructs RocksDB to persist stats history to RocksDB itself. When statistics is enabled, and both options `stats_persist_period_sec` and `persist_stats_to_disk` are set, RocksDB will periodically write stats to a built-in column family in the following form: key -> (timestamp in microseconds)#(stats name), value -> stats value. The existing API `GetStatsHistory` will detect the current value of `persist_stats_to_disk` and either read from in-memory data structure or from the hidden column family on disk.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5046
Differential Revision: D15863138
Pulled By: miasantreble
fbshipit-source-id: bb82abdb3f2ca581aa42531734ac799f113e931b
