SERVER-107486 Create IDL for balancer configuration options (#38554)

Co-authored-by: Silvia Surroca <silvia.surroca@mongodb.com>
GitOrigin-RevId: f683e9727cedab031bddf5d099443d802f4f82ae

src/mongo/s/BUILD.bazel

@@ -76,6 +76,14 @@ idl_generator(
     ],
 )
 
+idl_generator(
+    name = "balancer_configuration_gen",
+    src = "balancer_configuration.idl",
+    deps = [
+        "//src/mongo/db:basic_types_gen",
+    ],
+)
+
 mongo_cc_library(
     name = "sharding_helpers",
     srcs = [
@@ -468,6 +476,7 @@ mongo_cc_library(
         "transaction_participant_failed_unyield_exception.cpp",
         "type_collection_common_types_gen",
         "would_change_owning_shard_exception.cpp",
+        ":balancer_configuration_gen",
 
         # TODO(SERVER-9414): Clean this up.
         "//src/mongo/db/repl:primary_only_service.h",

src/mongo/s/balancer_configuration.idl

@@ -0,0 +1,139 @@
+# Copyright (C) 2025-present MongoDB, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the Server Side Public License, version 1,
+# as published by MongoDB, Inc.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# Server Side Public License for more details.
+#
+# You should have received a copy of the Server Side Public License
+# along with this program. If not, see
+# <http://www.mongodb.com/licensing/server-side-public-license>.
+#
+# As a special exception, the copyright holders give permission to link the
+# code of portions of this program with the OpenSSL library under certain
+# conditions as described in each individual source file and distribute
+# linked combinations including the program with the OpenSSL library. You
+# must comply with the Server Side Public License in all respects for
+# all of the code used other than as permitted herein. If you modify file(s)
+# with this exception, you may extend this exception to your version of the
+# file(s), but you are not obligated to do so. If you do not wish to do so,
+# delete this exception statement from your version. If you delete this
+# exception statement from all source files in the program, then also delete
+# it in the license file.
+
+global:
+    cpp_namespace: "mongo"
+    cpp_includes:
+        - "mongo/s/request_types/migration_secondary_throttle_options.h"
+
+imports:
+    - "mongo/db/basic_types.idl"
+
+enums:
+    BalancerMode:
+        description: "Balancer mode enum"
+        type: string
+        values:
+            kFull: "full"
+            kOff: "off"
+
+    DayOfWeek:
+        description: "Valid days of the week for balancer windows"
+        type: string
+        values:
+            Sunday: "Sunday"
+            Monday: "Monday"
+            Tuesday: "Tuesday"
+            Wednesday: "Wednesday"
+            Thursday: "Thursday"
+            Friday: "Friday"
+            Saturday: "Saturday"
+
+structs:
+    ActiveWindow:
+        description: "Active window configuration for balancer"
+        strict: false
+        fields:
+            start:
+                type: string
+                description: "Start time in HH:MM format"
+                optional: false
+            stop:
+                type: string
+                description: "Stop time in HH:MM format"
+                optional: false
+
+    DayOfWeekWindow:
+        description: "Day of week specific active window configuration"
+        strict: false
+        fields:
+            day:
+                type: DayOfWeek
+                description: "Day of the week (must be a valid, capitalized day name)"
+                optional: false
+            start:
+                type: string
+                description: "Start time in HH:MM format"
+                optional: false
+            stop:
+                type: string
+                description: "Stop time in HH:MM format"
+                optional: false
+
+    BalancerSettings:
+        description: "Balancer configuration settings"
+        strict: false
+        fields:
+            mode:
+                type: BalancerMode
+                description: "Balancer mode (full or off)"
+                default: kFull
+            stopped:
+                type: bool
+                description: "Whether the balancer is stopped"
+                default: false
+            activeWindow:
+                type: ActiveWindow
+                description: "Time window when balancer is active"
+                optional: true
+            activeWindowDOW:
+                type: array<DayOfWeekWindow>
+                description: "Day-of-week specific active windows"
+                optional: true
+            _secondaryThrottle:
+                type: object
+                description: "Secondary throttle configuration"
+                optional: true
+            _waitForDelete:
+                type: bool
+                description: "Whether to wait for deletes to complete"
+                default: false
+            attemptToBalanceJumboChunks:
+                type: bool
+                description: "Whether to attempt balancing jumbo chunks"
+                default: false
+
+    ChunkSizeSettings:
+        description: "Chunk size configuration settings"
+        strict: false
+        fields:
+            value:
+                type: safeInt64
+                description: "Maximum chunk size in MB"
+                validator:
+                    gte: 1
+                    lte: 1024
+                optional: false
+
+    AutoMergeSettings:
+        description: "Auto merge configuration settings"
+        strict: false
+        fields:
+            enabled:
+                type: bool
+                description: "Whether auto merge is enabled"
+                default: true