DOCS-15825 add migration concurrency to server status (BACKPORT) (#2493)

* DOCS-15825 add migration concurrency to server status (#2453)

* DOCS-15825-add-migrationConcurrency-to-serverStatus

* DOCS-15825-add-migrationConcurrency-to-serverStatus

* DOCS-15825-add-migrationConcurrency-to-serverStatus

* DOCS-15825-add-migrationConcurrency-to-serverStatus

* DOCS-15825-add-migrationConcurrency-to-serverStatus

* DOCS-15825-add-migrationConcurrency-to-serverStatus

* DOCS-15825-add-migrationConcurrency-to-serverStatus

* DOCS-15825-add-migrationConcurrency-to-serverStatus

* DOCS-15825-add-migrationConcurrency-to-serverStatus

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Co-authored-by: jason-price-mongodb <[email protected]>

* DOCS-15825 add migration concurrency to server status

---------

Co-authored-by: jason-price-mongodb <[email protected]>

Author: jason-price-mongodb

source/reference/command/serverStatus.txt

@@ -4027,6 +4027,7 @@ shardingStatistics
                "countDocsDeletedOnDonor" : NumberLong(<num>),
                "countDonorMoveChunkLockTimeout" : NumberLong(<num>),
                "unfinishedMigrationFromPreviousPrimary" : NumberLong(<num>),
+               "chunkMigrationConcurrency” : NumberLong(<num>),
                "catalogCache" : {
                   "numDatabaseEntries" : NumberLong(<num>),
                   "numCollectionEntries" : NumberLong(<num>),
@@ -4250,6 +4251,16 @@ shardingStatistics
 
    .. versionadded:: 4.4
 
+.. serverstatus:: shardingStatistics.chunkMigrationConcurrency
+
+   The number of threads on the source shard and the receiving shard for
+   performing :ref:`chunk migration <migrate-chunks-sharded-cluster>`
+   operations.
+
+   *Only present when run on a shard.*
+
+   *Available starting in MongoDB 5.0.16*
+
 .. serverstatus:: shardingStatistics.catalogCache
 
    A document with statistics about the cluster's routing information cache.