In 2.7 we refactored several areas of communication between master daemon and remote agents. The changes are "under the hood", tackling issues that take a toll in certain scenarios or high loaded setups using distributed indexes with remote nodes.
Resource sharing was done until now using RW locks. Under high load, usage of locks could run into issues when trying to make changes on the indexes. To overcome these issues, we had to rethink the relation between threads and indexes. […]