Create an online physical backup tool (similar to xtrabackup)

[yoshinorim]

We need an online physical backup tool, similar to xtrabackup in InnoDB. It should meet at least following features/conditions.

• Streaming backup (copying directly to remote host, since local host may not have enough space for backups)
• Can take consistent binlog position or GTID (so that we can create slave instances easily)
• Backup can finish within reasonable time (close to disk read & transfer & write time of the target data volume, and applying logs)
• Not too much write performance drops while taking backups
• Not too much read performance drops while taking backups

Nice to have:

• Incremental backup
• Partial backups (per CF)