Take a streaming backup¶
Percona XtraBackup supports streaming mode. Streaming mode sends a backup to STDOUT in the xbstream format instead of copying the files to the backup directory.
This method allows you to use other programs to filter the output of the backup, providing greater flexibility for storage of the backup. For example, compression is achieved by piping the output to a compression utility. One of the benefits of streaming backups and using Unix pipes is that the backups can be automatically encrypted.
To use the streaming feature, you must use the --stream,
providing the format of the stream (xbstream) and where to store
the temporary files:
$ xtrabackup --stream=xbstream --target-dir=/tmp
xtrabackup uses xbstream to stream all of the data files to STDOUT, in a
special xbstream format. After it finishes streaming all of the data files
to STDOUT, it stops xtrabackup and streams the saved log file too.
When compression is enabled, xtrabackup compresses the output data, except for the meta and non-InnoDB files which are not compressed, using the specified compression algorithm. Percona XtraBackup supports the following compression algorithms:
Zstandard (ZSTD)¶
The Zstandard (ZSTD) is a fast lossless compression algorithm that targets real-time compression scenarios and better compression ratios. ZSTD is the default compression algorithm for the --compress option.
To compress files using the ZSTD compression algorithm, use the --compress option:
$ xtrabackup --backup --compress --target-dir=/data/backup
The resulting files have the \*.zst format.
You can specify ZSTD compression level with the --compress-zstd-level(=#) option. The default value is 1.
$ xtrabackup –backup –compress –compress-zstd-level=1 –target-dir=/data/backup
lz4¶
To compress files using the lz4 compression algorithm, set the --compress option to lz4:
$ xtrabackup --backup --compress=lz4 --target-dir=/data/backup
The resulting files have the \*.lz4 format.
To decompress files, use the --decompress option.
Using xbstream as a stream option, backups can be copied and compressed in parallel. This option can significantly improve the speed of the backup process. In case backups were both compressed and encrypted, they must be decrypted before they are uncompressed.
| Task | Command |
|---|---|
Stream the backup into an archived named backup.xbstream |
$ xtrabackup --backup --stream=xbstream --target-dir=./ > backup.xbstream |
Stream the backup into a compressed archive named backup.xbstream |
$ xtrabackup --backup --stream=xbstream --compress --target-dir=./ > backup.xbstream |
| Encrypt the backup | $ xtrabackup --backup --stream=xbstream > backup.xbstream gzip -`` | openssl des3 -salt -k “password” backup.xbstream.gz.des3 |
| Unpack the backup to the current directory | $ xbstream -x < backup.xbstream |
| Send the backup compressed directly to another host and unpack it | $ xtrabackup --backup --compress --stream=xbstream --target-dir=./ | ssh user@otherhost "xbstream -x" |
Send the backup to another server using netcat |
On the destination host:$ nc -l 9999 | cat - > /data/backups/backup.xbstreamOn the source host: $ xtrabackup --backup --stream=xbstream | nc desthost 9999 |
| Send the backup to another server using a one-liner | $ ssh user@desthost “( nc -l 9999 > /data/backups/backup.xbstream & )” && xtrabackup --backup --stream=xbstream | nc desthost 9999 |
| Throttle the throughput to 10MB/sec using the pipe viewer tool | $ xtrabackup --backup --stream=xbstream | pv -q -L10m ssh user@desthost “cat - > /data/backups/backup.xbstream” |
| Checksum the backup during the streaming | On the destination host:$ nc -l 9999 | tee >(sha1sum > destination_checksum) > /data/backups/backup.xbstreamOn the source host: $ xtrabackup --backup --stream=xbstream | tee >(sha1sum > source_checksum) | nc desthost 9999Compare the checksums on the source host: $ cat source_checksum 65e4f916a49c1f216e0887ce54cf59bf3934dbadCompare the checksums on the destination host: $ cat destination_checksum 65e4f916a49c1f216e0887ce54cf59bf3934dbad |
| Parallel compression with parallel copying backup | $ xtrabackup --backup --compress --compress-threads=8 --stream=xbstream --parallel=4 --target-dir=./ > backup.xbstream |
Important
The streamed backup must be prepared before restoration. Streaming mode does not prepare the backup.
Get expert help¶
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