Tayra Documentation
You could possibly be in one of the below scenarios. Choose the best applicable to you.
Note: Alternatively, seeding can also be done by using
Caveat: While taking backup using rotating files, make sure older files are restored before being rolled over.
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Scenario 1
Taking backup from a fresh replica set (containing no data) and restoring to a fresh Mongo.Mechanics
Backup: Start backup utility on primary in tailable mode using the command:
backup -s localhost --port=27017 -f backup.log -tThe tool tails the primary oplog and backs up documents as operations are performed on primary. Should backup be aborted (using 'Ctrl + C'), the timestamp of last backed-up document is recorded and when backup resumes, it starts recording new documents. |
Restore: Start restore utility on the target to replay the backup using:
restore -d localhost --port=27020 -f backup.logThe tool will replay the documents from the backup file "backup.log" into the target mongo. |
Caveat: In case the backup is aborted, in order to prevent loss of data due to oplog falling off make sure that it is restarted in time. For sustained backups and restore, you may want to look at scenario 3.
Scenario 2
Taking backup from an existing replica set (having some data) and restoring to a fresh Mongo. For seeding purpose, take snapshot of the database using fsyncLock / fsyncUnlock.Mechanics
Taking Snapshot: Take a snapshot of primary into the file system using:
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Backup: Start backup utility on primary in tailable mode using:
backup -s localhost --port=27017 -f backup.log -tThe tool will catch up with the primary oplog and tail it to backup documents as operations are performed. |
Seeding: Start the target mongod with archived files in its dbpath using:
mongod --port 27021 --dbpath "location of archive/snapshot"The target mongo will be started in a consistent state. |
Restore: Start restore utility on the target to replay the backup using:
restore -d "localhost" --port=27021 -f backup.logThe tool will replay the documents from the backup file "backup.log" into the target mongo. |
mongodumpand
mongorestoreutility. For sustained backups and restore, you may want to look at scenario 3.
Scenario 3
Sustaining periodic backups and restore.Mechanics
Backup: Start backup utility on primary in tailable mode using the command:
backup -s localhost --port=27017 -f backup.log -t --fMax=4 --fSize=1MBThe tool will refer to "timestamp.out" and resume backup from the last backed up document in oplog. It will back up a total of 4MB data into 4 files in the above case. |
Archive: The files generated are-
'backup.log', 'backup.log.1', 'backup.log.2', 'backup.log.3' and 'backup.log.4'.As soon as backup.log.4 is created, move all 4 files (except backup.log - which is the running backup file) to a separate directory for consumption by restore utility. |
Restore: Start restore utility to replay from the backup across multiple files:
restore -d localhost --port=27017 -f backup.log -fAllThe tool will replay all the documents. |
Should you wish to perform selective backup and restore, or perform analysis prior to restoring, please find the details in the line items below.