Usage

Once the twindb-backup package is installed you need to edit configuration file /etc/twindb/twindb-backup.cfg. The configuration defines what has to be backed up, where to and all other options.

Let’s review each configuration section.

Backup Source

[source] section defines what to backup.

TwinDB Backup supports backing up MySQL database and local directories .

In backup_dirs you specify which directories to backup. Each directory is separated by a white space. If the directory contains spaces it must be quoted..

backup_mysql tells whether the tool should backup MySQL or not.

[source]

backup_dirs = /etc /root /home "/path/to/important files"
backup_mysql = yes

Backup Destination

The [destination] section specifies where to store backup copies.

backup_destination can be either ssh (if you want to store backups on a remote SSH server), or s3 (if you want to store backups in Amazon S3), or gsc (if the backup should be stored in Google Cloud).

In the optional keep_local_path you can specify a local path where the tool will store a local copy of the backup. It’s useful if you want to stream a MySQL backup to S3 and would like to keep a local copy as well.

[destination]

backup_destination = ssh
keep_local_path = /var/backup/local

Compression

In the [compression] section you can specify compression method such as gzip, pigz, bzip2 and lbzip2. You can use parallel compression by using pigz or lbzip2, and specify number of threads to use in parallel. Number of threads defaults to number of cores minus one, if not specified. Level specifies the compression level from 1 to 9. By default the tool uses gzip for compression.

[compression]

program = pigz
threads = 4
level = 9

Amazon S3

In the [s3] section you specify Amazon credentials as well as an S3 bucket where to store backups.

[s3]

AWS_ACCESS_KEY_ID = XXXXX
AWS_SECRET_ACCESS_KEY = YYYYY
AWS_DEFAULT_REGION = us-east-1
BUCKET = twindb-backups

Google Cloud Storage

In the [gcs] section you specify Google credentials as well as cloud storage bucket where to store backups.

[gcs]

GC_CREDENTIALS_FILE = XXXXX
BUCKET = twindb-backups

SSH Settings

If your backup destination is an SSH server, you specify the ssh parameters in [ssh] section. It is assumed you configured SSH keys authentication. It will not work if you need to enter a password to login to backup_host.

[ssh]

backup_host = 127.0.0.1
backup_dir = /path/to/directory_with_backups
ssh_user = root
ssh_key = /root/.ssh/id_rsa
ssh_port = 22

MySQL

XtraBackup needs to connect to MySQL. In the [mysql] section you specify a defaults file with user and password.

It also tells the tool how often it should take full copies. By default it will take the full copy daily. if so, the hourly copies will be incremental. If full_backup is set to weekly then the tool will take full backups every week, and daily and hourly copies will be incremental.

The expire_log_days options specifies the retention period for MySQL binlogs. By default it’s seven days.

[mysql]

mysql_defaults_file = /etc/twindb/my.cnf
full_backup = daily
expire_log_days = 7

Backing up MySQL Binlog

Every time TwinDB Backup runs it also copies MySQL binary log. However you probably want to copy binlogs more often than the incremental backup runs. It’s not feasible to run incremental backup let’s say every five minutes.

To keep Recovery Point Objective minimal it is recommended take incremental copies every hour and additionally copy binlogs every five minutes. The cron configuration should look like this:

*/5      root twindb-backup backup --binlogs-only hourly
@hourly  root twindb-backup backup hourly
@daily   root twindb-backup backup daily
@weekly  root twindb-backup backup weekly
@monthly root twindb-backup backup monthly
@yearly  root twindb-backup backup yearly

Encryption

The tool uses GPG for encrypting/decrypting backup copies. To enable encryption add [gpg] section to the configuration file. It’s your responsibility to generate and manage the encryption key.

[gpg]

keyring = /root/.gnupg/pubring.gpg
secret_keyring = /root/.gnupg/secring.gpg
recipient = backupuser@youdomain.com

Retention Policy

In [retention] section you specify how many copies you want to keep on the remote storage (s3 or ssh).

[retention]

hourly_copies  = 24
daily_copies   = 7
weekly_copies  = 4
monthly_copies = 12
yearly_copies  = 3

Local Retention Policy

if keep_local_path is defined in Backup Destination the tool will apply [retention_local] on the local copies.

[retention_local]

hourly_copies  = 1
daily_copies   = 1
weekly_copies  = 0
monthly_copies = 0
yearly_copies  = 0

Running Intervals

By default twindb-backup will run hourly, daily, weekly, monthly and yearly. If you would like to skip some runs [intervals] section is the right place to do so.

[intervals]

run_hourly  = yes
run_daily   = yes
run_weekly  = yes
run_monthly = yes
run_yearly  = yes

Monitoring

TwinDB Backup currently supports two ways to monitor backups. For a simple case you can use emails notifications. The tool doesn’t produce any output if a run was successful and will log any errors to standard error output.

For comprehensive monitoring TwinDB Backup exports backup and restore metrics to Datadog.

Email notification

The twindb-backup package installs a cron job. If a backup job fails it will send standard error output to an email from the $MAILTO environment variable. It can be defined in the cron configuration file /etc/cron.d/twindb-backup.

MAILTO = alerts@yourdomain.com
@hourly  root twindb-backup backup hourly
@daily   root twindb-backup backup daily
@weekly  root twindb-backup backup weekly
@monthly root twindb-backup backup monthly
@yearly  root twindb-backup backup yearly

Datadog integration

To configure TwinDB Backup with Datadog you need to get api_key and app_key from Datadog. Check out https://app.datadoghq.com/account/settings#api for these.

When configured, TwinDB Backup will export two metrics to Datadog:

  • twindb.mysql.backup_time
  • twindb.mysql.restore_time
Backup time
Restore time

You can use those for building graphs and monitors. Check out the Monitoring MySQL Backups With Datadog and TwinDB Backup Tool for more details [1].

[export]

transport = datadog
api_key = 0269463bdd00317688ce40371b0774ab
app_key = d925774d7ae7ba22538eaf89e659f157f89e659f1
[1]The keys are fake.