emqx4.3/changes/ce/fix-10500.en.md

Add several fixes, enhancements and features in Mria:

• protect mria:join/1,2 with a global lock to prevent conflicts between two nodes trying to join each other simultaneously Mria PR
• implement new function mria:sync_transaction/4,3,2, which blocks the caller until a transaction is imported to the local node (if the local node is a replicant, otherwise, it behaves exactly the same as mria:transaction/3,2) Mria PR
• optimize mria:running_nodes/0 Mria PR
• optimize mria:ro_transaction/2 when called on a replicant node Mria PR.