This short report brings to light some interesting commits to scylladb.git master from the last week. Commits in the d84da3dc11c..7646e1448a4 range are covered.
There were 81 non-merge commits from 16 authors in that period. Some notable commits:
Tablet merges happen when the load balancer wants to reduce the number of tablets in a table. To merge tablets, the load balancer performs a “colocation migration” to move one tablet of the pair to the same node and shard as the other. It will now prefer migrating within the same rack. This is important for materialized view consistency.
A Seastar bug triggered a gdb bug which caused core dumps not to be processed correctly. Seastar now avoids leaving zombie threads, preventing the problem.
There is a new procedure for recovering from Raft group 0 majority loss. The procedure is safe for use with tablets.
Repair of one tablet will no longer prevent another tablet from being migrated.
The S3 driver has been made more robust.
Audit syslog output was improved to make it machine parseable.
The system can now constrain the replication factor to be equal to the number of racks. This greatly simplifies load balancing and will become the defaults.
See you in the next issue of last week in scylladb.git master!