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Improve rate_limiter_test.cc (#8904)

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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
main
Hui Xiao 3 years ago committed by Facebook GitHub Bot
parent 272cc77751
commit 65411b8d4e
1 changed files with 44 additions and 25 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 69
      util/rate_limiter_test.cc

69
util/rate_limiter_test.cc
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@ -24,7 +24,13 @@
namespace ROCKSDB_NAMESPACE {
// TODO(yhchiang): the rate will not be accurate when we run test in parallel.
class RateLimiterTest : public testing::Test {};
class RateLimiterTest : public testing::Test {
protected:
~RateLimiterTest() override {
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->ClearAllCallBacks();
}
};
TEST_F(RateLimiterTest, OverflowRate) {
GenericRateLimiter limiter(port::kMaxInt64, 1000, 10,
@ -39,14 +45,14 @@ TEST_F(RateLimiterTest, StartStop) {
TEST_F(RateLimiterTest, GetTotalBytesThrough) {
std::unique_ptr<RateLimiter> limiter(NewGenericRateLimiter(
20 /* rate_bytes_per_sec */, 1000 * 1000 /* refill_period_us */,
200 /* rate_bytes_per_sec */, 1000 * 1000 /* refill_period_us */,
10 /* fairness */));
for (int i = Env::IO_LOW; i <= Env::IO_TOTAL; ++i) {
ASSERT_EQ(limiter->GetTotalBytesThrough(static_cast<Env::IOPriority>(i)),
0);
}
std::int64_t request_byte = 10;
std::int64_t request_byte = 200;
std::int64_t request_byte_sum = 0;
for (int i = Env::IO_LOW; i < Env::IO_TOTAL; ++i) {
limiter->Request(request_byte, static_cast<Env::IOPriority>(i),
@ -67,7 +73,7 @@ TEST_F(RateLimiterTest, GetTotalBytesThrough) {
TEST_F(RateLimiterTest, GetTotalRequests) {
std::unique_ptr<RateLimiter> limiter(NewGenericRateLimiter(
20 /* rate_bytes_per_sec */, 1000 * 1000 /* refill_period_us */,
200 /* rate_bytes_per_sec */, 1000 * 1000 /* refill_period_us */,
10 /* fairness */));
for (int i = Env::IO_LOW; i <= Env::IO_TOTAL; ++i) {
ASSERT_EQ(limiter->GetTotalRequests(static_cast<Env::IOPriority>(i)), 0);
@ -75,7 +81,7 @@ TEST_F(RateLimiterTest, GetTotalRequests) {
std::int64_t total_requests_sum = 0;
for (int i = Env::IO_LOW; i < Env::IO_TOTAL; ++i) {
limiter->Request(10, static_cast<Env::IOPriority>(i), nullptr /* stats */,
limiter->Request(200, static_cast<Env::IOPriority>(i), nullptr /* stats */,
RateLimiter::OpType::kWrite);
total_requests_sum += 1;
}
@ -91,15 +97,16 @@ TEST_F(RateLimiterTest, GetTotalRequests) {
}
TEST_F(RateLimiterTest, GetTotalPendingRequests) {
std::unique_ptr<RateLimiter> limiter(
NewGenericRateLimiter(20 /* rate_bytes_per_sec */));
std::unique_ptr<RateLimiter> limiter(NewGenericRateLimiter(
200 /* rate_bytes_per_sec */, 1000 * 1000 /* refill_period_us */,
10 /* fairness */));
for (int i = Env::IO_LOW; i <= Env::IO_TOTAL; ++i) {
ASSERT_EQ(limiter->GetTotalPendingRequests(static_cast<Env::IOPriority>(i)),
0);
}
// This is a variable for making sure the following callback is called
// and the assertions in it are indeed excuted
bool nonzero_pending_requests_verified_ = false;
bool nonzero_pending_requests_verified = false;
SyncPoint::GetInstance()->SetCallBack(
"GenericRateLimiter::Request:PostEnqueueRequest", [&](void* arg) {
port::Mutex* request_mutex = (port::Mutex*)arg;
@ -114,13 +121,13 @@ TEST_F(RateLimiterTest, GetTotalPendingRequests) {
// We lock the mutex again so that the request thread can resume running
// with the mutex locked
request_mutex->Lock();
nonzero_pending_requests_verified_ = true;
nonzero_pending_requests_verified = true;
});
SyncPoint::GetInstance()->EnableProcessing();
limiter->Request(20, Env::IO_USER, nullptr /* stats */,
limiter->Request(200, Env::IO_USER, nullptr /* stats */,
RateLimiter::OpType::kWrite);
ASSERT_EQ(nonzero_pending_requests_verified_, true);
ASSERT_EQ(nonzero_pending_requests_verified, true);
EXPECT_EQ(limiter->GetTotalPendingRequests(Env::IO_USER), 0);
EXPECT_EQ(limiter->GetTotalPendingRequests(Env::IO_HIGH), 0);
EXPECT_EQ(limiter->GetTotalPendingRequests(Env::IO_MID), 0);
@ -158,7 +165,7 @@ TEST_F(RateLimiterTest, Modes) {
TEST_F(RateLimiterTest, GeneratePriorityIterationOrder) {
std::unique_ptr<RateLimiter> limiter(NewGenericRateLimiter(
20 /* rate_bytes_per_sec */, 1000 * 1000 /* refill_period_us */,
200 /* rate_bytes_per_sec */, 1000 * 1000 /* refill_period_us */,
10 /* fairness */));
bool possible_random_one_in_fairness_results_for_high_mid_pri[4][2] = {
@ -170,6 +177,11 @@ TEST_F(RateLimiterTest, GeneratePriorityIterationOrder) {
{Env::IO_USER, Env::IO_LOW, Env::IO_MID, Env::IO_HIGH}};
for (int i = 0; i < 4; ++i) {
// These are variables for making sure the following callbacks are called
// and the assertion in the last callback is indeed excuted
bool high_pri_iterated_after_mid_low_pri_set = false;
bool mid_pri_itereated_after_low_pri_set = false;
bool pri_iteration_order_verified = false;
SyncPoint::GetInstance()->SetCallBack(
"GenericRateLimiter::GeneratePriorityIterationOrder::"
"PostRandomOneInFairnessForHighPri",
@ -177,6 +189,7 @@ TEST_F(RateLimiterTest, GeneratePriorityIterationOrder) {
bool* high_pri_iterated_after_mid_low_pri = (bool*)arg;
*high_pri_iterated_after_mid_low_pri =
possible_random_one_in_fairness_results_for_high_mid_pri[i][0];
high_pri_iterated_after_mid_low_pri_set = true;
});
SyncPoint::GetInstance()->SetCallBack(
@ -186,6 +199,7 @@ TEST_F(RateLimiterTest, GeneratePriorityIterationOrder) {
bool* mid_pri_itereated_after_low_pri = (bool*)arg;
*mid_pri_itereated_after_low_pri =
possible_random_one_in_fairness_results_for_high_mid_pri[i][1];
mid_pri_itereated_after_low_pri_set = true;
});
SyncPoint::GetInstance()->SetCallBack(
@ -201,28 +215,30 @@ TEST_F(RateLimiterTest, GeneratePriorityIterationOrder) {
<< ", mid_pri_itereated_after_low_pri = "
<< possible_random_one_in_fairness_results_for_high_mid_pri[i][1]
<< std::endl;
pri_iteration_order_verified = true;
});
SyncPoint::GetInstance()->EnableProcessing();
limiter->Request(20 /* request max bytes to drain so that refill and order
limiter->Request(200 /* request max bytes to drain so that refill and order
generation will be triggered every time
GenericRateLimiter::Request() is called */
,
Env::IO_USER, nullptr /* stats */,
RateLimiter::OpType::kWrite);
ASSERT_EQ(high_pri_iterated_after_mid_low_pri_set, true);
ASSERT_EQ(mid_pri_itereated_after_low_pri_set, true);
ASSERT_EQ(pri_iteration_order_verified, true);
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->ClearCallBack(
"GenericRateLimiter::GeneratePriorityIterationOrder::"
"PreReturnPriIterationOrder");
SyncPoint::GetInstance()->ClearCallBack(
"GenericRateLimiter::GeneratePriorityIterationOrder::"
"PostRandomOneInFairnessForMidPri");
SyncPoint::GetInstance()->ClearCallBack(
"GenericRateLimiter::GeneratePriorityIterationOrder::"
"PostRandomOneInFairnessForHighPri");
}
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->ClearCallBack(
"GenericRateLimiter::GeneratePriorityIterationOrder::"
"PreReturnPriIterationOrder");
SyncPoint::GetInstance()->ClearCallBack(
"GenericRateLimiter::GeneratePriorityIterationOrder::"
"PostRandomOneInFairnessForMidPri");
SyncPoint::GetInstance()->ClearCallBack(
"GenericRateLimiter::GeneratePriorityIterationOrder::"
"PostRandomOneInFairnessForHighPri");
}
TEST_F(RateLimiterTest, Rate) {
@ -374,6 +390,7 @@ TEST_F(RateLimiterTest, LimitChangeTest) {
target / 1024, new_limit / 1024, refill_period / 1000);
}
}
ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
}
TEST_F(RateLimiterTest, AutoTuneIncreaseWhenFull) {
@ -413,6 +430,8 @@ TEST_F(RateLimiterTest, AutoTuneIncreaseWhenFull) {
ASSERT_GT(new_bytes_per_sec, orig_bytes_per_sec);
ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->ClearCallBack(
"GenericRateLimiter::Request:PostTimedWait");
// decreases after a sequence of periods where rate limiter is not drained
orig_bytes_per_sec = new_bytes_per_sec;

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