SERVER-44984 reduce index build thread pool default and index build external sort memory limit default

This reverts commit b48cb5d8e2a8ccab0f4be401cc2533e5c2b650ae.

5 files changed, 20 insertions, 17 deletions

diff --git a/etc/evergreen.yml b/etc/evergreen.yml
index 6c80f3a961e..a00fc3cdbeb 100644
--- a/etc/evergreen.yml
+++ b/etc/evergreen.yml
@@ -5074,12 +5074,10 @@ tasks:
       num_tasks: 10
       jstestfuzz_vars: --jsTestsDir ../jstests
       suite: jstestfuzz_sharded_continuous_stepdown
-      # TODO(SERVER-44896): Remove enableTwoPhaseIndexBuild from server parameters when two phase
-      # index builds work with this flow control setting.
       resmoke_args: >-
           --flowControlTicketOverride=3
           --storageEngine=wiredTiger
-          --mongodSetParameters="{logComponentVerbosity: {command: 2}, enableTwoPhaseIndexBuild: false}"
+          --mongodSetParameters="{logComponentVerbosity: {command: 2}}"
       name: jstestfuzz_sharded_continuous_stepdown_flow_control
 
 ## jstestfuzz concurrent sharded cluster continuous stepdown with flow control engaged ##
@@ -5094,13 +5092,10 @@ tasks:
       num_tasks: 2
       jstestfuzz_vars: --jsTestsDir ../jstests
       suite: jstestfuzz_sharded_continuous_stepdown
-      # TODO(SERVER-44896): Remove enableTwoPhaseIndexBuild from server parameters when two phase
-      # index builds work with this flow control setting.
       resmoke_args: >-
           --flowControlTicketOverride=30
           --storageEngine=wiredTiger
           --numClientsPerFixture=10
-          --mongodSetParameters="{enableTwoPhaseIndexBuild: false}"
       name: jstestfuzz_concurrent_sharded_continuous_stepdown_flow_control
 
 # jstestfuzz replication continuous stepdown with flow control engaged #
@@ -5115,12 +5110,10 @@ tasks:
       num_tasks: 30
       jstestfuzz_vars: --jsTestsDir ../jstests
       suite: jstestfuzz_replication_continuous_stepdown
-      # TODO(SERVER-44896): Remove enableTwoPhaseIndexBuild from server parameters when two phase
-      # index builds work with this flow control setting.
       resmoke_args: >-
           --flowControlTicketOverride=1
           --storageEngine=wiredTiger
-          --mongodSetParameters="{logComponentVerbosity: {command: 2}, enableTwoPhaseIndexBuild: false}"
+          --mongodSetParameters="{logComponentVerbosity: {command: 2}}"
       name: jstestfuzz_replication_continuous_stepdown_flow_control
 
 ## jstestfuzz concurrent replication continuous stepdown with flow control engaged ##
@@ -5135,13 +5128,10 @@ tasks:
       num_tasks: 15
       jstestfuzz_vars: --jsTestsDir ../jstests
       suite: jstestfuzz_replication_continuous_stepdown
-      # TODO(SERVER-44896): Remove enableTwoPhaseIndexBuild from server parameters when two phase
-      # index builds work with this flow control setting.
       resmoke_args: >-
           --flowControlTicketOverride=10
           --storageEngine=wiredTiger
           --numClientsPerFixture=10
-          --mongodSetParameters="{enableTwoPhaseIndexBuild: false}"
       name: jstestfuzz_concurrent_replication_continuous_stepdown_flow_control
 
 ## jstestfuzz replica set ##
diff --git a/src/mongo/db/catalog/multi_index_block.idl b/src/mongo/db/catalog/multi_index_block.idl
index 08b183e3560..311a7f701f1 100644
--- a/src/mongo/db/catalog/multi_index_block.idl
+++ b/src/mongo/db/catalog/multi_index_block.idl
@@ -52,12 +52,12 @@ server_parameters:
     default: true
 
   maxIndexBuildMemoryUsageMegabytes:
-    description: "Limits the amount of memory that simultaneous foreground index builds on one collection may consume for the duration of the builds"
+    description: "Limits the amount of memory that simultaneous index builds on one collection may consume for the duration of the builds"
     set_at:
       - runtime
       - startup
     cpp_varname: maxIndexBuildMemoryUsageMegabytes
     cpp_vartype: AtomicWord<int>
-    default: 500
+    default: 200
     validator:
-      gte: 100
+      gte: 50
diff --git a/src/mongo/db/index_builds_coordinator_mongod.cpp b/src/mongo/db/index_builds_coordinator_mongod.cpp
index c67de58a3fc..c386ac34e26 100644
--- a/src/mongo/db/index_builds_coordinator_mongod.cpp
+++ b/src/mongo/db/index_builds_coordinator_mongod.cpp
@@ -70,7 +70,7 @@ ThreadPool::Options makeDefaultThreadPoolOptions() {
     // We depend on thread pool sizes being equal between primaries and secondaries. If a secondary
     // has fewer resources than a primary, index build oplog entries can replicate in an order that
     // the secondary is unable to fulfill, leading to deadlocks. See SERVER-44250.
-    options.maxThreads = 10;
+    options.maxThreads = 3;
 
     // Ensure all threads have a client.
     options.onCreateThread = [](const std::string& threadName) {
@@ -86,6 +86,10 @@ IndexBuildsCoordinatorMongod::IndexBuildsCoordinatorMongod()
     : _threadPool(makeDefaultThreadPoolOptions()) {
     _threadPool.startup();
 }
+IndexBuildsCoordinatorMongod::IndexBuildsCoordinatorMongod(ThreadPool::Options options)
+    : _threadPool(std::move(options)) {
+    _threadPool.startup();
+}
 
 void IndexBuildsCoordinatorMongod::shutdown() {
     // Stop new scheduling.
diff --git a/src/mongo/db/index_builds_coordinator_mongod.h b/src/mongo/db/index_builds_coordinator_mongod.h
index 005779a26a2..3e86e06397a 100644
--- a/src/mongo/db/index_builds_coordinator_mongod.h
+++ b/src/mongo/db/index_builds_coordinator_mongod.h
@@ -55,6 +55,7 @@ public:
      * Sets up the thread pool.
      */
     IndexBuildsCoordinatorMongod();
+    IndexBuildsCoordinatorMongod(ThreadPool::Options options);
 
     /**
      * Shuts down the thread pool, signals interrupt to all index builds, then waits for all of the
diff --git a/src/mongo/db/index_builds_coordinator_mongod_test.cpp b/src/mongo/db/index_builds_coordinator_mongod_test.cpp
index 8709041d43f..8490b157381 100644
--- a/src/mongo/db/index_builds_coordinator_mongod_test.cpp
+++ b/src/mongo/db/index_builds_coordinator_mongod_test.cpp
@@ -73,7 +73,15 @@ void IndexBuildsCoordinatorMongodTest::setUp() {
     createCollection(_testFooNss, _testFooUUID);
     createCollection(_testBarNss, _testBarUUID);
     createCollection(_othertestFooNss, _othertestFooUUID);
-    _indexBuildsCoord = std::make_unique<IndexBuildsCoordinatorMongod>();
+
+    ThreadPool::Options options;
+    options.poolName = "IndexBuildsCoordinatorMongod";
+    options.minThreads = 0;
+    options.maxThreads = 5;
+    options.onCreateThread = [](const std::string& threadName) {
+        Client::initThread(threadName.c_str());
+    };
+    _indexBuildsCoord = std::make_unique<IndexBuildsCoordinatorMongod>(options);
 }
 
 void IndexBuildsCoordinatorMongodTest::tearDown() {