HBase Backup/Restore Based on HBase Snapshot

MFinally, we completed the implementation of our backup/restore solution, and would like to share with community through this jira.

We are leveraging existing hbase snapshot feature, and provide a general solution to common users. Our full backup is using snapshot to capture metadata locally and using exportsnapshot to move data to another cluster; the incremental backup is using offline-WALplayer to backup HLogs; we also leverage global distribution rolllog and flush to improve performance; other added-on values such as convert, merge, progress report, and CLI commands. So that a common user can backup hbase data without in-depth knowledge of hbase. Our solution also contains some usability features for enterprise users.

The detail design document and CLI command will be attached in this jira. We plan to use 10~12 subtasks to share each of the following features, and document the detail implement in the subtasks:

• Full Backup : provide local and remote back/restore for a list of tables
• offline-WALPlayer to convert HLog to HFiles offline (for incremental backup)
• distributed Logroll and distributed flush
• Backup Manifest and history
• Incremental backup: to build on top of full backup as daily/weekly backup
• Convert incremental backup WAL files into hfiles
• Merge several backup images into one(like merge weekly into monthly)
• add and remove table to and from Backup image
• Cancel a backup process
• backup progress status
• full backup based on existing snapshot

-------------------------------------------------------------------------------------------------------------
Below is the original description, to keep here as the history for the design and discussion back in 2013

There have been attempts in the past to come up with a viable HBase backup/restore solution (e.g., HBASE-4618). Recently, there are many advancements and new features in HBase, for example, FileLink, Snapshot, and Distributed Barrier Procedure. This is a proposal for a backup/restore solution that utilizes these new features to achieve better performance and consistency.

A common practice of backup and restore in database is to first take full baseline backup, and then periodically take incremental backup that capture the changes since the full baseline backup. HBase cluster can store massive amount data. Combination of full backups with incremental backups has tremendous benefit for HBase as well. The following is a typical scenario for full and incremental backup.

1. The user takes a full backup of a table or a set of tables in HBase.
2. The user schedules periodical incremental backups to capture the changes from the full backup, or from last incremental backup.
3. The user needs to restore table data to a past point of time.
4. The full backup is restored to the table(s) or to different table name(s). Then the incremental backups that are up to the desired point in time are applied on top of the full backup.

We would support the following key features and capabilities.

• Full backup uses HBase snapshot to capture HFiles.
• Use HBase WALs to capture incremental changes, but we use bulk load of HFiles for fast incremental restore.
• Support single table or a set of tables, and column family level backup and restore.
• Restore to different table names.
• Support adding additional tables or CF to backup set without interruption of incremental backup schedule.
• Support rollup/combining of incremental backups into longer period and bigger incremental backups.
• Unified command line interface for all the above.

The solution will support HBase backup to FileSystem, either on the same cluster or across clusters. It has the flexibility to support backup to other devices and servers in the future.