After this commits in all LTS versions of mongo the following sharding statistics are now available through serverStatus:

• countDocsClonedOnCatchUpOnRecipient: the number of documents cloned during the catch up phase of the migration
• countBytesClonedOnCatchUpOnRecipient: the number of bytes cloned during the catch up phase of the migration
• countBytesClonedOnRecipient: the number of bytes cloned by the recipient of a migration
• countDonorMoveChunkCommitted: the total number of migrations committed by the node
• countDonorMoveChunkAborted: the number of migrations aborted in the node
• totalDonorMoveChunkTimeMillis: the total amount of time a migration took from beginning to end
• totalRecipientCriticalSectionTimeMillis: the amount of time in milliseconds the recipient of a migration spent holding the critical section

  Description of Linked Ticket

  Often, when investigating HELP tickets related to balancing, we need to access and combine data from FTDC, logs and configdump to figure some basic metrics such as:

• Migration throughput (how fast is this shard cloning data)
• Range deleter throughout (how fast is this shard executing its range deletions)
• Number of orphans documents (how many orphans documents are waiting to be deleted)

The following statistics should be available on serverStatus under the shardingStatistics group:

• countDocsClonedOnCatchUpOnRecipient: the number of documents cloned during the catch up phase of the migration
• countBytesClonedOnCatchUpOnRecipient: the number of bytes cloned during the catch up phase of the migration
• countBytesClonedOnRecipient: the number of bytes cloned by the recipient of a migration
• countDonorMoveChunkCommitted: the total number of migrations committed by the node
• countDonorMoveChunkAborted: the number of migrations aborted in the node
• totalDonorMoveChunkTimeMillis: the total amount of time a migration took from beginning to end
• totalRecipientCriticalSectionTimeMillis: the amount of time in milliseconds the recipient of a migration spent holding the critical section