SERVER-55677 Remove resharding's DonorStateEnum::kPreparingToBlockWrites state

8 files changed, 32 insertions, 30 deletions

diff --git a/src/mongo/db/s/resharding/resharding_donor_service.cpp b/src/mongo/db/s/resharding/resharding_donor_service.cpp
index e88e38c88c1..5b27a1132b4 100644
--- a/src/mongo/db/s/resharding/resharding_donor_service.cpp
+++ b/src/mongo/db/s/resharding/resharding_donor_service.cpp
@@ -59,7 +59,7 @@
 
 namespace mongo {
 
-MONGO_FAIL_POINT_DEFINE(reshardingDonorFailsBeforePreparingToMirror);
+MONGO_FAIL_POINT_DEFINE(reshardingDonorFailsAfterTransitionToDonatingOplogEntries);
 MONGO_FAIL_POINT_DEFINE(removeDonorDocFailpoint);
 
 using namespace fmt::literals;
@@ -247,8 +247,7 @@ ExecutorFuture<void> ReshardingDonorService::DonorStateMachine::_runUntilBlockin
                                executor, abortToken);
                        })
                        .then([this, executor, abortToken] {
-                           return _awaitAllRecipientsDoneApplyingThenTransitionToPreparingToBlockWrites(
-                               executor, abortToken);
+                           return _awaitAllRecipientsDoneApplying(executor, abortToken);
                        })
                        .then(
                            [this] { _writeTransactionOplogEntryThenTransitionToBlockingWrites(); });
@@ -265,8 +264,8 @@ ExecutorFuture<void> ReshardingDonorService::DonorStateMachine::_runUntilBlockin
                   "error"_attr = status);
 
             return withAutomaticRetry(**executor, abortToken, [this, status] {
-                // It is illegal to transition into kError if state has already surpassed
-                // kPreparingToBlockWrites.
+                // It is illegal to transition into kError if the state is in or has already
+                // surpassed kBlockingWrites.
                 invariant(_donorCtx.getState() < DonorStateEnum::kBlockingWrites);
                 _transitionToError(status);
 
@@ -528,28 +527,27 @@ ExecutorFuture<void> ReshardingDonorService::DonorStateMachine::
         .thenRunOn(**executor)
         .then([this]() { _transitionState(DonorStateEnum::kDonatingOplogEntries); })
         .onCompletion([=](Status s) {
-            if (MONGO_unlikely(reshardingDonorFailsBeforePreparingToMirror.shouldFail())) {
+            if (MONGO_unlikely(
+                    reshardingDonorFailsAfterTransitionToDonatingOplogEntries.shouldFail())) {
                 uasserted(ErrorCodes::InternalError, "Failing for test");
             }
         });
 }
 
-ExecutorFuture<void> ReshardingDonorService::DonorStateMachine::
-    _awaitAllRecipientsDoneApplyingThenTransitionToPreparingToBlockWrites(
-        const std::shared_ptr<executor::ScopedTaskExecutor>& executor,
-        const CancellationToken& abortToken) {
+ExecutorFuture<void> ReshardingDonorService::DonorStateMachine::_awaitAllRecipientsDoneApplying(
+    const std::shared_ptr<executor::ScopedTaskExecutor>& executor,
+    const CancellationToken& abortToken) {
     if (_donorCtx.getState() > DonorStateEnum::kDonatingOplogEntries) {
         return ExecutorFuture<void>(**executor, Status::OK());
     }
 
     return future_util::withCancellation(_allRecipientsDoneApplying.getFuture(), abortToken)
-        .thenRunOn(**executor)
-        .then([this]() { _transitionState(DonorStateEnum::kPreparingToBlockWrites); });
+        .thenRunOn(**executor);
 }
 
 void ReshardingDonorService::DonorStateMachine::
     _writeTransactionOplogEntryThenTransitionToBlockingWrites() {
-    if (_donorCtx.getState() > DonorStateEnum::kPreparingToBlockWrites) {
+    if (_donorCtx.getState() > DonorStateEnum::kDonatingOplogEntries) {
         return;
     }
 
diff --git a/src/mongo/db/s/resharding/resharding_donor_service.h b/src/mongo/db/s/resharding/resharding_donor_service.h
index 1c855160881..782b9ac287f 100644
--- a/src/mongo/db/s/resharding/resharding_donor_service.h
+++ b/src/mongo/db/s/resharding/resharding_donor_service.h
@@ -141,7 +141,7 @@ private:
         const std::shared_ptr<executor::ScopedTaskExecutor>& executor,
         const CancellationToken& abortToken);
 
-    ExecutorFuture<void> _awaitAllRecipientsDoneApplyingThenTransitionToPreparingToBlockWrites(
+    ExecutorFuture<void> _awaitAllRecipientsDoneApplying(
         const std::shared_ptr<executor::ScopedTaskExecutor>& executor,
         const CancellationToken& abortToken);
 
diff --git a/src/mongo/db/s/resharding/resharding_donor_service_test.cpp b/src/mongo/db/s/resharding/resharding_donor_service_test.cpp
index 79de3f0fecb..312024e0223 100644
--- a/src/mongo/db/s/resharding/resharding_donor_service_test.cpp
+++ b/src/mongo/db/s/resharding/resharding_donor_service_test.cpp
@@ -298,7 +298,6 @@ TEST_F(ReshardingDonorServiceTest, WritesFinalReshardOpOplogEntriesWhileWritesBl
 TEST_F(ReshardingDonorServiceTest, StepDownStepUpEachTransition) {
     const std::vector<DonorStateEnum> donorStates{DonorStateEnum::kDonatingInitialData,
                                                   DonorStateEnum::kDonatingOplogEntries,
-                                                  DonorStateEnum::kPreparingToBlockWrites,
                                                   DonorStateEnum::kBlockingWrites,
                                                   DonorStateEnum::kDone};
     PauseDuringStateTransitions stateTransitionsGuard{controller(), donorStates};
@@ -327,7 +326,6 @@ TEST_F(ReshardingDonorServiceTest, StepDownStepUpEachTransition) {
                     notifyRecipientsDoneCloning(opCtx.get(), *donor, doc);
                     break;
                 }
-                case DonorStateEnum::kPreparingToBlockWrites:
                 case DonorStateEnum::kBlockingWrites: {
                     notifyToStartBlockingWrites(opCtx.get(), *donor, doc);
                     break;
diff --git a/src/mongo/db/s/resharding/resharding_metrics.cpp b/src/mongo/db/s/resharding/resharding_metrics.cpp
index cdfbeb8b6a9..92b33687e9c 100644
--- a/src/mongo/db/s/resharding/resharding_metrics.cpp
+++ b/src/mongo/db/s/resharding/resharding_metrics.cpp
@@ -126,14 +126,6 @@ void ReshardingMetrics::setDonorState(DonorStateEnum state) noexcept {
 
     const auto oldState = std::exchange(_currentOp->donorState, state);
     invariant(oldState != state);
-
-    if (state == DonorStateEnum::kPreparingToBlockWrites) {
-        _currentOp->inCriticalSection.start();
-    }
-
-    if (oldState == DonorStateEnum::kBlockingWrites) {
-        _currentOp->inCriticalSection.end();
-    }
 }
 
 void ReshardingMetrics::setRecipientState(RecipientStateEnum state) noexcept {
@@ -213,6 +205,16 @@ void ReshardingMetrics::onDocumentsCopied(int64_t documents, int64_t bytes) noex
     _cumulativeOp.bytesCopied += bytes;
 }
 
+void ReshardingMetrics::startInCriticalSection() {
+    stdx::lock_guard<Latch> lk(_mutex);
+    _currentOp->inCriticalSection.start();
+}
+
+void ReshardingMetrics::endInCritcialSection() {
+    stdx::lock_guard<Latch> lk(_mutex);
+    _currentOp->inCriticalSection.end();
+}
+
 void ReshardingMetrics::onOplogEntriesFetched(int64_t entries) noexcept {
     stdx::lock_guard<Latch> lk(_mutex);
     if (!_currentOp)
@@ -249,7 +251,6 @@ void ReshardingMetrics::onWriteDuringCriticalSection(int64_t writes) noexcept {
 
     invariant(checkState(_currentOp->donorState,
                          {DonorStateEnum::kDonatingOplogEntries,
-                          DonorStateEnum::kPreparingToBlockWrites,
                           DonorStateEnum::kBlockingWrites,
                           DonorStateEnum::kError}));
 
diff --git a/src/mongo/db/s/resharding/resharding_metrics.h b/src/mongo/db/s/resharding/resharding_metrics.h
index eed36a39786..81a7a7af8fd 100644
--- a/src/mongo/db/s/resharding/resharding_metrics.h
+++ b/src/mongo/db/s/resharding/resharding_metrics.h
@@ -72,12 +72,16 @@ public:
     // Allows updating metrics on "documents to copy" so long as the recipient is in cloning state.
     void onDocumentsCopied(int64_t documents, int64_t bytes) noexcept;
 
+    // Starts/ends the timer recording the time spent in the critical section.
+    void startInCriticalSection();
+    void endInCritcialSection();
+
     // Allows updating "oplog entries to apply" metrics when the recipient is in applying state.
     void onOplogEntriesFetched(int64_t entries) noexcept;
     void onOplogEntriesApplied(int64_t entries) noexcept;
 
     // Allows tracking writes during a critical section when the donor's state is either of
-    // "preparing-to-block-writes" or "blocking-writes".
+    // "donating-oplog-entries" or "blocking-writes".
     void onWriteDuringCriticalSection(int64_t writes) noexcept;
 
     // Marks the completion of the current (active) resharding operation. Aborts the process if no
diff --git a/src/mongo/db/s/resharding/resharding_metrics_test.cpp b/src/mongo/db/s/resharding/resharding_metrics_test.cpp
index 1e7322aef1b..1e2177ec201 100644
--- a/src/mongo/db/s/resharding/resharding_metrics_test.cpp
+++ b/src/mongo/db/s/resharding/resharding_metrics_test.cpp
@@ -173,7 +173,8 @@ TEST_F(ReshardingMetricsTest, TestDonorAndRecipientMetrics) {
 
     // Update metrics for donor
     const auto kWritesDuringCriticalSection = 7;
-    getMetrics()->setDonorState(DonorStateEnum::kPreparingToBlockWrites);
+    getMetrics()->setDonorState(DonorStateEnum::kDonatingOplogEntries);
+    getMetrics()->startInCriticalSection();
     getMetrics()->onWriteDuringCriticalSection(kWritesDuringCriticalSection);
     advanceTime(Seconds(elapsedTime));
 
@@ -326,10 +327,11 @@ TEST_F(ReshardingMetricsTest, EstimatedRemainingOperationTime) {
 }
 
 TEST_F(ReshardingMetricsTest, CurrentOpReportForDonor) {
-    const auto kDonorState = DonorStateEnum::kPreparingToBlockWrites;
+    const auto kDonorState = DonorStateEnum::kDonatingOplogEntries;
     getMetrics()->onStart();
     advanceTime(Seconds(2));
     getMetrics()->setDonorState(kDonorState);
+    getMetrics()->startInCriticalSection();
     advanceTime(Seconds(3));
 
     const ReshardingMetrics::ReporterOptions options(
diff --git a/src/mongo/db/s/resharding/resharding_util_test.cpp b/src/mongo/db/s/resharding/resharding_util_test.cpp
index 70e24932c2b..1fc70d03434 100644
--- a/src/mongo/db/s/resharding/resharding_util_test.cpp
+++ b/src/mongo/db/s/resharding/resharding_util_test.cpp
@@ -134,7 +134,7 @@ TEST(ReshardingUtilTest, HighestMinFetchTimestampThrowsWhenDonorMissingTimestamp
 
 TEST(ReshardingUtilTest, HighestMinFetchTimestampSucceedsWithDonorStateGTkDonatingOplogEntries) {
     std::vector<DonorShardEntry> donorShards{
-        makeDonorShard(ShardId("s0"), DonorStateEnum::kPreparingToBlockWrites, Timestamp(10, 2)),
+        makeDonorShard(ShardId("s0"), DonorStateEnum::kBlockingWrites, Timestamp(10, 2)),
         makeDonorShard(ShardId("s1"), DonorStateEnum::kDonatingOplogEntries, Timestamp(10, 3)),
         makeDonorShard(ShardId("s2"), DonorStateEnum::kDonatingOplogEntries, Timestamp(10, 1))};
     auto highestMinFetchTimestamp = getHighestMinFetchTimestamp(donorShards);
diff --git a/src/mongo/s/resharding/common_types.idl b/src/mongo/s/resharding/common_types.idl
index cc34746dd93..e868c2f8d44 100644
--- a/src/mongo/s/resharding/common_types.idl
+++ b/src/mongo/s/resharding/common_types.idl
@@ -59,7 +59,6 @@ enums:
             kPreparingToDonate: "preparing-to-donate"
             kDonatingInitialData: "donating-initial-data"
             kDonatingOplogEntries: "donating-oplog-entries"
-            kPreparingToBlockWrites: "preparing-to-block-writes"
             kError: "error"
             kBlockingWrites: "blocking-writes"
             kDone: "done"