Revert "SERVER-30324 Move cluster_remove_shard_cmd to mongod"

This reverts commit 580cd9ec9e9c5b52d73491655d970d75a7ec1a9c.

1 files changed, 21 insertions, 3 deletions

diff --git a/src/mongo/s/catalog/sharding_catalog_client.h b/src/mongo/s/catalog/sharding_catalog_client.h
index f9e7a4c3484..81eb5c0a238 100644
--- a/src/mongo/s/catalog/sharding_catalog_client.h
+++ b/src/mongo/s/catalog/sharding_catalog_client.h
@@ -71,6 +71,16 @@ struct ConnectionPoolStats;
 }
 
 /**
+ * Used to indicate to the caller of the removeShard method whether draining of chunks for
+ * a particular shard has started, is ongoing, or has been completed.
+ */
+enum ShardDrainingStatus {
+    STARTED,
+    ONGOING,
+    COMPLETED,
+};
+
+/**
  * Abstracts reads of the sharding catalog metadata.
  *
  * All implementations of this interface should go directly to the persistent backing store
@@ -91,9 +101,6 @@ public:
     // Constant to use for configuration data majority writes
     static const WriteConcernOptions kMajorityWriteConcern;
 
-    // Constant to use for configuration data local writes
-    static const WriteConcernOptions kLocalWriteConcern;
-
     virtual ~ShardingCatalogClient() = default;
 
     /**
@@ -109,6 +116,17 @@ public:
     virtual void shutDown(OperationContext* opCtx) = 0;
 
     /**
+     * Tries to remove a shard. To completely remove a shard from a sharded cluster,
+     * the data residing in that shard must be moved to the remaining shards in the
+     * cluster by "draining" chunks from that shard.
+     *
+     * Because of the asynchronous nature of the draining mechanism, this method returns
+     * the current draining status. See ShardDrainingStatus enum definition for more details.
+     */
+    virtual StatusWith<ShardDrainingStatus> removeShard(OperationContext* opCtx,
+                                                        const ShardId& name) = 0;
+
+    /**
      * Updates or creates the metadata for a given database.
      */
     virtual Status updateDatabase(OperationContext* opCtx,