We are providing a way to add a server parameter (setParameter) to change the destination shard insert concurrency. backporting to 4.4, 5.0 and 6.0.

syntax changes -
{setParameter: { migrationConcurrency: N }}

Description of Linked Ticket

Summary

This project is for backporting changes to parallelize portions of the existing chunk migration algorithm. We propose backporting this through mongoDB 4.4.

Motivation

During PM-2740 spike we implemented the following changes to realize up to 5 times higher chunk migration throughput:

• Increase the level of concurrency on the destination for the insert portion when moving a chunk.

As a result of that spike, we created PM-3014, which implements a new server parameter specifying the level of concurrency for the item above.