DOCS-15518 serverStatus indexBulkBuilder (#2454) (#2478)

* DOCS-15518 Adds indexBulkBuilder to serverStatus

* Fixes per Shin Yee Tan

* Fixes build error

* Fixes build error

* Fixes build error

* Fixes per Ali

* Fixes per Ali

* Fixes per Shin

Author: kennethdyer

source/reference/command/serverStatus.txt

@@ -138,6 +138,48 @@ Output
    For the :dbcommand:`serverStatus` output specific to the version of
    your MongoDB, refer to the appropriate version of the MongoDB Manual.
 
+.. _server-status-indexBulkBuilder:
+
+indexBulkBuilder
+~~~~~~~~~~~~~~~~
+.. code-block:: json
+
+   "indexBulkBuilder": {
+      "count": <long>, 
+      "resumed": <long>, 
+      "filesOpenedForExternalSort": <long>, 
+      "filesClosedForExternalSort": <long>, 
+   }
+
+.. serverstatus:: indexBulkBuilder
+
+   Provides metrics for index bulk builder operations.  Use these metrics to
+   diagnose index build issues with :dbcommand:`createIndexes`, collection 
+   cloning during initial sync, index builds that resume after startup, and
+   statistics on disk usage by the external sorter.
+
+.. serverstatus:: indexBulkBuilder.count
+
+   The number of instances of the bulk builder created.
+
+.. serverstatus:: indexBulkBuilder.filesClosedForExternalSort
+
+   The number of times the external sorter closed a file handle to spill data
+   to disk.  Combine this value with 
+   :serverstatus:`~indexBulkBuilder.filesOpenedForExternalSort` to determine
+   the number of open file handles in use by the external sorter.
+
+.. serverstatus:: indexBulkBuilder.filesOpenedForExternalSort
+
+   The number of times the external sorter opened a file handle to spill data
+   to disk.  Combine this value with 
+   :serverstatus:`~indexBulkBuilder.filesClosedForExternalSort` to determine
+   the number of open file handles in use by the external sorter.
+
+.. serverstatus:: indexBulkBuilder.resumed
+
+   The number of times the bulk builder was created for a resumable index build.
+
 .. _server-status-instance-information:
 
 Instance Information