Backup and restore

It’s crucial to regularly back up your tables to recover them in case of system crashes, hardware failure, or data corruption/loss. Backups are also necessary before upgrading to a new version of Manticore Search that changes the table format, and for transferring data to another system when migrating to a new server.

The manticore-backup tool, included in the official Manticore Search packages, automates the process of backing up tables for an instance running in RT mode.

Installation

If you followed the official installation instructions, you should already have everything installed and don’t need to worry. Otherwise, manticore-backup requires PHP 8.1.10 and specific modules or manticore-executor, which is a part of the manticore-extra package, and you need to ensure that one of these is available.

Note that manticore-backup is not available for Windows yet.

How to use

First, make sure you’re running manticore-backup on the same server where the Manticore instance you are about to back up is running.

Second, we recommend running the tool under the root user so the tool can transfer ownership of the files you are backing up. Otherwise, a backup will be also made but with no ownership transfer. In either case, you should make sure that manticore-backup has access to the data dir of the Manticore instance.

The only required argument for manticore-backup is --backup-dir, which specifies the destination for the backup. If you don’t provide any additional arguments, manticore-backup will: - locate a Manticore instance running with the default configuration - create a subdirectory in the --backup-dir directory with a timestamped name - backup all tables found in the instance

manticore-backup --config=path/to/manticore.conf --backup-dir=backupdir

Copyright (c) 2023, Manticore Software LTD (https://manticoresearch.com)

Manticore config file: /etc/manticoresearch/manticore.conf
Tables to backup: all tables
Target dir: /mnt/backup/

Manticore config
  endpoint =  127.0.0.1:9308

Manticore versions:
  manticore: 5.0.2
  columnar: 1.15.4
  secondary: 1.15.4
2022-10-04 17:18:39 [Info] Starting the backup...
2022-10-04 17:18:39 [Info] Backing up config files...
2022-10-04 17:18:39 [Info]   config files - OK
2022-10-04 17:18:39 [Info] Backing up tables...
2022-10-04 17:18:39 [Info]   pq (percolate) [425B]...
2022-10-04 17:18:39 [Info]    OK
2022-10-04 17:18:39 [Info]   products (rt) [512B]...
2022-10-04 17:18:39 [Info]    OK
2022-10-04 17:18:39 [Info] Running sync
2022-10-04 17:18:42 [Info]  OK
2022-10-04 17:18:42 [Info] You can find backup here: /mnt/backup/backup-20221004171839
2022-10-04 17:18:42 [Info] Elapsed time: 2.76s
2022-10-04 17:18:42 [Info] Done

To back up specific tables only, use the --tables flag followed by a comma-separated list of tables, for example --tables=tbl1,tbl2. This will only backup the specified tables and ignore the rest.

manticore-backup --backup-dir=/mnt/backup/ --tables=products

Copyright (c) 2023, Manticore Software LTD (https://manticoresearch.com)

Manticore config file: /etc/manticoresearch/manticore.conf
Tables to backup: products
Target dir: /mnt/backup/

Manticore config
  endpoint =  127.0.0.1:9308

Manticore versions:
  manticore: 5.0.3
  columnar: 1.16.1
  secondary: 0.0.0
2022-10-04 17:25:02 [Info] Starting the backup...
2022-10-04 17:25:02 [Info] Backing up config files...
2022-10-04 17:25:02 [Info]   config files - OK
2022-10-04 17:25:02 [Info] Backing up tables...
2022-10-04 17:25:02 [Info]   products (rt) [512B]...
2022-10-04 17:25:02 [Info]    OK
2022-10-04 17:25:02 [Info] Running sync
2022-10-04 17:25:06 [Info]  OK
2022-10-04 17:25:06 [Info] You can find backup here: /mnt/backup/backup-20221004172502
2022-10-04 17:25:06 [Info] Elapsed time: 4.82s
2022-10-04 17:25:06 [Info] Done

Arguments

Argument	Description
`--backup-dir=path`	This is the path to the backup directory where the backup will be stored. The directory must already exist. This argument is required and has no default value. On each backup run, manticore-backup will create a subdirectory in the provided directory with a timestamp in the name (`backup-[datetime]`), and will copy all required tables to it. So the `--backup-dir` is a container for all your backups, and it’s safe to run the script multiple times.
`--restore[=backup]`	Restore from `--backup-dir`. Just –restore lists available backups. `--restore=backup` will restore from `<--backup-dir>/backup`.
`--config=/path/to/manticore.conf`	Path to Manticore config. This is optional. If it’s not passed, a default one for your operating system will be used. It’s used to get the host and port to communicate with the Manticore daemon.
`--tables=tbl1,tbl2, ...`	Semicolon-separated list of tables that you want to back up. To back up all tables, omit this argument. All the provided tables must exist in the Manticore instance you are backing up from, or the backup will fail.
`--compress`	Whether the backed up files should be compressed. Not enabled by default.
`--unlock`	In rare cases when something goes wrong, tables can be left in a locked state. Use this argument to unlock them.
`--version`	Show the current version.
`--help`	Show this help.

BACKUP SQL command reference

You can also back up your data through SQL by running the simple command BACKUP TO /path/to/backup.

Note, this command is not supported in Windows yet.

General syntax of BACKUP

BACKUP
  [{TABLE | TABLES} a[, b]]
  [{OPTION | OPTIONS}
    async = {on | off | 1 | 0 | true | false | yes | no}
    [, compress = {on | off | 1 | 0 | true | false | yes | no}]
  ]
  TO path_to_backup

For instance, to back up tables a and b to the /backup directory, run the following command:

BACKUP TABLES a, b TO /backup

There are options available to control and adjust the backup process, such as:

async: makes the backup non-blocking, allowing you to receive a response with the query ID immediately and run other queries while the backup is ongoing. The default value is 0.
compress: enables file compression using zstd. The default value is 0. For example, to run a backup of all tables in async mode with compression enabled to the /tmp directory:

BACKUP OPTION async = yes, compress = yes TO /tmp

Important considerations

The path should not contain special symbols or spaces, as they are not supported.
Ensure that Manticore Buddy is launched (it is by default).

How backup maintains consistency of tables

To ensure consistency of tables during backup, Manticore Search’s backup tools use the innovative FREEZE and UNFREEZE commands. Unlike the traditional lock and unlock tables feature of e.g. MySQL, FREEZE stops flushing data to disk while still permitting writing (to some extent) and selecting updated data from the table.

However, if your RAM chunk size grows beyond the rt_mem_limit threshold during lengthy backup operations involving many inserts, data may be flushed to disk, and write operations will be blocked until flushing is complete. Despite this, the tool maintains a balance between table locking, data consistency, and database write availability while the table is frozen.

When you use manticore-backup or the SQL BACKUP command, the FREEZE command is executed once and freezes all tables you are backing up simultaneously. The backup process subsequently backs up each table one by one, releasing the freeze after successfully backing up each table.

If backup fails or gets interrupted, the tool tries to unfreeze all the tables.

Restore

To restore a Manticore instance from a backup, use the manticore-backup command with the --backup-dir and --restore arguments. For example: manticore-backup --backup-dir=/path/to/backups --restore. If you don’t provide any argument for --restore, it will simply list all the backups in the --backup-dir.

manticore-backup --backup-dir=/mnt/backup/ --restore

Copyright (c) 2023, Manticore Software LTD (https://manticoresearch.com)

Manticore config file:
Backup dir: /tmp/

Available backups: 3
  backup-20221006144635 (Oct 06 2022 14:46:35)
  backup-20221006145233 (Oct 06 2022 14:52:33)
  backup-20221007104044 (Oct 07 2022 10:40:44)

To start a restore job, run manticore-backup with the flag --restore=backup name, where backup name is the name of the backup directory within the --backup-dir. Note that: 1. There can’t be any Manticore instance running on the same host and port as the one being restored. 2. The old manticore.json file must not exist. 3. The old configuration file must not exist. 4. The old data directory must exist and be empty.

If all conditions are met, the restore will proceed. The tool will provide hints, so you don’t have to memorize them. It’s crucial to avoid overwriting existing files, so make sure to remove them prior to the restore if they still exist. Hence all the conditions.

manticore-backup --backup-dir=/mnt/backup/ --restore=backup-20221007104044

Copyright (c) 2023, Manticore Software LTD (https://manticoresearch.com)

Manticore config file:
Backup dir: /tmp/
2022-10-07 11:17:25 [Info] Starting to restore...

Manticore config
  endpoint =  127.0.0.1:9308
2022-10-07 11:17:25 [Info] Restoring config files...
2022-10-07 11:17:25 [Info]   config files - OK
2022-10-07 11:17:25 [Info] Restoring state files...
2022-10-07 11:17:25 [Info]   config files - OK
2022-10-07 11:17:25 [Info] Restoring data files...
2022-10-07 11:17:25 [Info]   config files - OK
2022-10-07 11:17:25 [Info] The backup '/tmp/backup-20221007104044' was successfully restored.
2022-10-07 11:17:25 [Info] Elapsed time: 0.02s
2022-10-07 11:17:25 [Info] Done