Summary:
- Fixed a bug in `RateLimiterTest.GeneratePriorityIterationOrder` that the callbacks in this test were not called starting from `i = 1`. Fix by increasing `rate_bytes_per_sec` and requested bytes.
- The bug is due to the previous `rate_bytes_per_sec` was set too small, resulting in `refill_bytes_per_period` less than `kMinRefillBytesPerPeriod`. Hence the actual `refill_bytes_per_period` was equal to `kMinRefillBytesPerPeriod` due to the logic [here](https://github.com/facebook/rocksdb/blob/main/util/rate_limiter.cc#L302-L303) and it ended up being greater than the previously set requested bytes. Therefore starting from `i = 1`, `RefillBytesAndGrantRequests()` and `GeneratePriorityIterationOrder` won't be called and the test callbacks was not triggered to execute the assertion.
- Added internal flag to assert callbacks are called in `RateLimiterTest.GeneratePriorityIterationOrder` to prevent any future changes defeat the purpose of the test [as suggested](https://github.com/facebook/rocksdb/pull/8890#discussion_r704915134)
- Increased `rate_bytes_per_sec` and bytes of each request in `RateLimiterTest.GetTotalBytesThrough`, `RateLimiterTest.GetTotalRequests`, `RateLimiterTest.GetTotalPendingRequests` to trigger the "long path" of execution (i.e, the one trigger RefillBytesAndGrantRequests()) to increase test coverage
- This increased the running time of the three tests, see test plan for time difference running locally
- Cleared up sync point effects after each test by calling `SyncPoint::GetInstance()->DisableProcessing();` and `SyncPoint::GetInstance()->ClearAllCallBacks();` in `~RateLimiterTest()` [as suggested](https://github.com/facebook/rocksdb/pull/8595/files#r697534279)
- It's fine to call these two methods even when `EnableProcessing()` or `SetCallBack()` is not called in the test or is already cleaned up. In those cases, calling these two functions in destructor is effectively no-op.
- This will allow cleaning up sync point effects of previous test even when the previous test failed in assertion.
- Added missing `SyncPoint::GetInstance()->DisableProcessing();` and `SyncPoint::GetInstance()->ClearCallBacks(..);` in existing tests for completeness
- Called `SyncPoint::GetInstance()->DisableProcessing();` and `SyncPoint::GetInstance()->ClearCallBacks(..);` in loop in `RateLimiterTest.GeneratePriorityIterationOrder` for completeness
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8904
Test Plan:
- Passing existing tests
- To verify the 1st change, run `RateLimiterTest.GeneratePriorityIterationOrder` with assertions of callbacks are indeed called under original `rate_bytes_per_sec` and request byte and under updated `rate_bytes_per_sec` and request byte. The former will fail the assertion while the latter succeeds.
- Here is the increased test time due to the 3rd change mentioned above in the summary. The relevant 3 tests mentioned in total increase the test time by 6s (~6000/33848 = 17.7% of the original total test time), which IMO is acceptable for better test coverage through running the "long path".
- current (run on branch rate_limiter_ut_improve locally)
[ RUN ] RateLimiterTest.GetTotalBytesThrough
[ OK ] RateLimiterTest.GetTotalBytesThrough (3000 ms)
[ RUN ] RateLimiterTest.GetTotalRequests
[ OK ] RateLimiterTest.GetTotalRequests (3001 ms)
[ RUN ] RateLimiterTest.GetTotalPendingRequests
[ OK ] RateLimiterTest.GetTotalPendingRequests (0 ms)
...
[----------] 10 tests from RateLimiterTest (43349 ms total)
[----------] Global test environment tear-down
[==========] 10 tests from 1 test case ran. (43349 ms total)
[ PASSED ] 10 tests.
- previous (run on branch main locally)
[ RUN ] RateLimiterTest.GetTotalBytesThrough
[ OK ] RateLimiterTest.GetTotalBytesThrough (0 ms)
[ RUN ] RateLimiterTest.GetTotalRequests
[ OK ] RateLimiterTest.GetTotalRequests (0 ms)
[ RUN ] RateLimiterTest.GetTotalPendingRequests
[ OK ] RateLimiterTest.GetTotalPendingRequests (0 ms)
...
[----------] 10 tests from RateLimiterTest (33848 ms total)
[----------] Global test environment tear-down
[==========] 10 tests from 1 test case ran. (33848 ms total)
[ PASSED ] 10 tests.
Reviewed By: ajkr
Differential Revision: D30872544
Pulled By: hx235
fbshipit-source-id: ff894f5c1a4bef70e8e407d53b00be45f776b3e4
65411b8d4e