From 80c13a3f72d3721ce6de872231170b18c0dc6ff5 Mon Sep 17 00:00:00 2001
From: Benety Goh <benety@mongodb.com>
Date: Sun, 27 Oct 2019 17:42:41 +0000
Subject: SERVER-44186 index builds use same
 OperationContext::writesAreReplicated() setting across primaries and
 secondaries

---
 src/mongo/db/SConscript                          |  1 +
 src/mongo/db/index_builds_coordinator.cpp        |  7 +++++++
 src/mongo/db/index_builds_coordinator_mongod.cpp | 17 -----------------
 3 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index c0f40eebca9..8305d3dc094 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -765,6 +765,7 @@ env.Library(
         'db_raii',
         'index_build_entry_helpers',
         '$BUILD_DIR/mongo/db/catalog/collection_catalog',
+        '$BUILD_DIR/mongo/db/catalog/index_timestamp_helper',
     ],
 )
 
diff --git a/src/mongo/db/index_builds_coordinator.cpp b/src/mongo/db/index_builds_coordinator.cpp
index 4c20962831e..f570d9e3e13 100644
--- a/src/mongo/db/index_builds_coordinator.cpp
+++ b/src/mongo/db/index_builds_coordinator.cpp
@@ -37,6 +37,7 @@
 #include "mongo/db/catalog/commit_quorum_options.h"
 #include "mongo/db/catalog/database_holder.h"
 #include "mongo/db/catalog/index_build_entry_gen.h"
+#include "mongo/db/catalog/index_timestamp_helper.h"
 #include "mongo/db/catalog_raii.h"
 #include "mongo/db/concurrency/locker.h"
 #include "mongo/db/concurrency/write_conflict_exception.h"
@@ -147,6 +148,12 @@ void onCommitIndexBuild(OperationContext* opCtx,
         // index builds are not in effect because the index build would be aborted (most likely due
         // to a stepdown) before we reach here.
         if (replSetAndNotPrimaryAtStart) {
+            // Get a timestamp to complete the index build in the absence of a commitIndexBuild
+            // oplog entry.
+            repl::UnreplicatedWritesBlock uwb(opCtx);
+            if (!IndexTimestampHelper::setGhostCommitTimestampForCatalogWrite(opCtx, nss)) {
+                log() << "Did not timestamp index commit write.";
+            }
             return;
         }
         opObserver->onCommitIndexBuild(opCtx, nss, collUUID, buildUUID, indexSpecs, fromMigrate);
diff --git a/src/mongo/db/index_builds_coordinator_mongod.cpp b/src/mongo/db/index_builds_coordinator_mongod.cpp
index 628bb51c5ef..ab382899123 100644
--- a/src/mongo/db/index_builds_coordinator_mongod.cpp
+++ b/src/mongo/db/index_builds_coordinator_mongod.cpp
@@ -130,14 +130,6 @@ IndexBuildsCoordinatorMongod::startIndexBuild(OperationContext* opCtx,
     const auto deadline = opCtx->getDeadline();
     const auto timeoutError = opCtx->getTimeoutError();
 
-    // TODO: SERVER-39484 Because both 'writesAreReplicated' and
-    // 'shouldNotConflictWithSecondaryBatchApplication' depend on the current replication state,
-    // just passing the state here is not resilient to member state changes like stepup/stepdown.
-
-    // If the calling thread is replicating oplog writes (primary), this state should be passed to
-    // the builder.
-    const bool writesAreReplicated = opCtx->writesAreReplicated();
-
     // Task in thread pool should have similar CurOp representation to the caller so that it can be
     // identified as a createIndexes operation.
     LogicalOp logicalOp = LogicalOp::opInvalid;
@@ -155,7 +147,6 @@ IndexBuildsCoordinatorMongod::startIndexBuild(OperationContext* opCtx,
         indexBuildOptions,
         deadline,
         timeoutError,
-        writesAreReplicated,
         logicalOp,
         opDesc,
         replState
@@ -180,14 +171,6 @@ IndexBuildsCoordinatorMongod::startIndexBuild(OperationContext* opCtx,
 
         opCtx->setDeadlineByDate(deadline, timeoutError);
 
-        // Two phase index builds have to adapt to replication state transitions and decide if it
-        // is ok to write to the oplog. Therefore, the caller's replicated writes setting should
-        // have no effect on the index build thread.
-        boost::optional<repl::UnreplicatedWritesBlock> unreplicatedWrites;
-        if (IndexBuildProtocol::kTwoPhase != replState->protocol && !writesAreReplicated) {
-            unreplicatedWrites.emplace(opCtx.get());
-        }
-
         // Index builds should never take the PBWM lock, even on a primary. This allows the index
         // to continue running after the node steps down to a secondary.
         ShouldNotConflictWithSecondaryBatchApplicationBlock shouldNotConflictBlock(
-- 
cgit v1.2.1