SERVER-65337 set minThreads to 0: TenantMigrationDonorService, TenantMigrationRecipientService, ShardSplitDonorService.

4 files changed, 47 insertions, 1 deletions

diff --git a/src/mongo/db/repl/repl_server_parameters.idl b/src/mongo/db/repl/repl_server_parameters.idl
index 54d50dd464e..00ae89e4c7b 100644
--- a/src/mongo/db/repl/repl_server_parameters.idl
+++ b/src/mongo/db/repl/repl_server_parameters.idl
@@ -483,6 +483,16 @@ server_parameters:
         validator:
             gte: 1
 
+    minTenantMigrationRecipientThreadPoolSize:
+        description: >-
+            The minimum number of threads in the tenant migration recipient's thread pool.
+        set_at: startup
+        cpp_vartype: int
+        cpp_varname: minTenantMigrationRecipientThreadPoolSize
+        default: 0
+        validator:
+            gte: 1
+
     maxTenantMigrationDonorServiceThreadPoolSize:
         description: >-
             The maximum number of threads in the tenant migration donor service's thread pool.
@@ -492,6 +502,37 @@ server_parameters:
         default: 8
         validator:
             gte: 1
+    
+    minTenantMigrationDonorServiceThreadPoolSize:
+        description: >-
+            The minimum number of threads in the tenant migration donor service's thread pool.
+        set_at: startup
+        cpp_vartype: int
+        cpp_varname: minTenantMigrationDonorServiceThreadPoolSize
+        default: 0
+        validator:
+            gte: 1
+
+    maxShardSplitDonorServiceThreadPoolSize:
+        description: >-
+            The maximum number of threads in the shard split donor service's thread pool.
+        set_at: startup
+        cpp_vartype: int
+        cpp_varname: maxShardSplitDonorServiceThreadPoolSize
+        default: 8
+        validator:
+            gte: 1
+    
+    minShardSplitDonorServiceThreadPoolSize:
+        description: >-
+            The minimum number of threads in the shard split donor service's thread pool.
+        set_at: startup
+        cpp_vartype: int
+        cpp_varname: minShardSplitDonorServiceThreadPoolSize
+        default: 0
+        validator:
+            gte: 1
+
 
     shardSplitTimeoutMS:
         description: >-
diff --git a/src/mongo/db/repl/tenant_migration_donor_service.h b/src/mongo/db/repl/tenant_migration_donor_service.h
index 6eb481b45c1..c9f28ddcc07 100644
--- a/src/mongo/db/repl/tenant_migration_donor_service.h
+++ b/src/mongo/db/repl/tenant_migration_donor_service.h
@@ -59,6 +59,7 @@ public:
     ThreadPool::Limits getThreadPoolLimits() const override {
         ThreadPool::Limits limits;
         limits.maxThreads = repl::maxTenantMigrationDonorServiceThreadPoolSize;
+        limits.minThreads = repl::minTenantMigrationDonorServiceThreadPoolSize;
         return limits;
     }
 
diff --git a/src/mongo/db/repl/tenant_migration_recipient_service.cpp b/src/mongo/db/repl/tenant_migration_recipient_service.cpp
index 539e7c486b9..75ebc74f64c 100644
--- a/src/mongo/db/repl/tenant_migration_recipient_service.cpp
+++ b/src/mongo/db/repl/tenant_migration_recipient_service.cpp
@@ -281,6 +281,7 @@ NamespaceString TenantMigrationRecipientService::getStateDocumentsNS() const {
 ThreadPool::Limits TenantMigrationRecipientService::getThreadPoolLimits() const {
     ThreadPool::Limits limits;
     limits.maxThreads = maxTenantMigrationRecipientThreadPoolSize;
+    limits.minThreads = minTenantMigrationRecipientThreadPoolSize;
     return limits;
 }
 
diff --git a/src/mongo/db/serverless/shard_split_donor_service.cpp b/src/mongo/db/serverless/shard_split_donor_service.cpp
index 26e17a3e2b5..4c3fdabb39f 100644
--- a/src/mongo/db/serverless/shard_split_donor_service.cpp
+++ b/src/mongo/db/serverless/shard_split_donor_service.cpp
@@ -164,7 +164,10 @@ SemiFuture<HostAndPort> makeRecipientAcceptSplitFuture(
 }  // namespace detail
 
 ThreadPool::Limits ShardSplitDonorService::getThreadPoolLimits() const {
-    return ThreadPool::Limits();
+    ThreadPool::Limits limits;
+    limits.maxThreads = repl::maxShardSplitDonorServiceThreadPoolSize;
+    limits.minThreads = repl::minShardSplitDonorServiceThreadPoolSize;
+    return limits;
 }
 
 void ShardSplitDonorService::checkIfConflictsWithOtherInstances(