Weekly update (July 30 ~ August 05, 2016)

Last week, we landed 28 PRs in the TiDB repositories and 32 PRs in the TiKV repositories.

Notable changes to TiDB

• Add support for constant folding in the SQL optimizer.
• Optimize the query speed of the secondary index. In certain scenarios, only the data in the index needs to be read.
• Use dynamic programing to decide the join path for multiple tables.
• Adjust the command line to support setting the listening address.
• Prometheus metrics and golang pprof share the same port.
• Update the Documents repository.
• Fix several bugs.

Notable changes to TiKV

• Split the operations on RocksDB from scheduler thread to a worker pool.
• Support leader lease mechanism when the quorum check is enabled.
• Use pending snapshot regions check to avoid receiving multiple overlapping snapshots at the same time.
• Check down peers and report to Placement Driver(PD).
• Support time monitor to check whether time jumps back or not.

Notable changes to Placement Driver

• Reduce the “1234” and “9090” ports in PD. Now PD has only “2379” and “2380” ports for external use.
• Support the join flag to let PD join an existing cluster dynamically.
• Support the remove PD member API to remove a PD from a cluster dynamically.
• Support the list PD members API.