Database Reference
In-Depth Information
# cp -f /var/backup/cassandra/commitlogs/
1361544837468 /raid0/cassandra/commitlogs
restore_directories
The
restore_directories
parameter is the path to the directory in which
the archived CommitLogs are stored (see
Listing 7.18
)
.
Listing 7.18
Example
restore_directories
Path
/var/backup/cassandra/commitlogs/1361544837468
restore_point_in_time
The format of this parameter is a date and time grouping in the following format:
YYYY-MM-DD HH:mm:SS. Note that the hour part of the timestamp should be
in 24-hour format (see
Listing 7.19
)
.
Listing 7.19
24-Hour Time Format Example
2013-01-27 13:45:00
CommitLog Archiving Notes
There is one “gotcha” with CommitLog archiving. When restoring a CommitLog,
the restore stops as soon as the client-supplied timestamp is reached. Since the or-
der in which Cassandra receives mutations and appends them to the CommitLog
is not strictly by timestamp, that means that it is possible for some mutations to
remain unrecovered.
Since only one command is allowed under the CommitLog archive and restore
command sections, the easiest way to get around this is to have the setting point
to a script and take parameters. In other words, using a Bash script as the archive
command and another Bash script as the restore command, you can programmat-
ically script point-in-time archives and restores of CommitLogs.
