Note from wlad: Alibaba has added TokuDB backup support into xtrabackup: https://github.com/alibaba/AliSQLBackup/commit/26573de135d115b100dbbfb9698274463ade5c8d . So we are not the first.

We'll only support full backup in the first iteration, to incrementals or partials .
what needs to be done

During mariabackup --backup

when mariabackup --backup starts
check if rocksdb plugin is installed

*in the "synch" phase, under "flush tables with readlock, lock binlog"

 if (rocksdb_present) {

   if (backup to directory) {

     execute SET GLOBAL rocksdb_create_checkpoint=<backup-dir>/#rocksdb

     // this will create rocksdb subdirectory in the backup dir, we're done

  }

  else  {// backup to  stdio with xbstream

     execute SET GLOBAL rocksdb_create_checkpoint=<temp-dir>/#rocksdb

     copy <temp-dir>/#rocksdb  recursively in xbstream format to stdout

     remove <temp-dir>/#rocksdb 

  }

}

Do we need a parameter for whether to backup rocksdb or not?
Do we need a parameter for rocksdb temp-dir, in case backup is streaming?. It is beneficial temp directory is on the same volume, checkpoint will create hardlinks rather than copy.

During mariabackup copy-back

• copy <backup-dir>/#rocksdb to the rocksdb-data-dir (in absense of this parameter to <target-dir>/#rocksdb)

That's it.