Weekly update (September 12 ~ September 18, 2016)

Last week, we landed 18 PRs in the TiDB repositories and 26 PRs in the TiKV repositories.

Notable changes to TiDB

• Add the Prometheus metrics and support push.
• Support the streaming aggregation operator.
• Rename xapi to distsql to improve readability.
• Add git hash to the TiDB server status API.
• Improve test coverage in the abstract syntax tree (AST).
• Enable the division operator for the distributed SQL statements.
• Fix several bugs.

Notable changes to TiKV

• Remove the stale peers that are out of region to fix 804.
• Ignore the tombstone stores when resolving the store address.
• Discard the droppable messages when channel is full to fix 1028.
• Capture the signal TERM/INT to close server gracefully.
• Capture the signal USR1 to log metrics.
• Support destroying regions asynchronously.
• Support the pushing metrics to Prometheus Push Gateway.

Notable changes to Placement Driver

• Add the API document.
• Support the pushing metrics to Prometheus Push Gateway.