freezer 1.1.2

Install required packages

Ubuntu / Debian

Swift client and Keystone client:

$ sudo apt-get install -y python-swiftclient python-keystoneclient

MongoDB backup:

$ sudo apt-get install -y python-pymongo

MySQL backup:

$ sudo pip install pymysql

Freezer installation from Python package repo:

$ sudo pip install freezer

OR:

$ sudo easy_install freezer

The basic Swift account configuration is needed to use freezer. Make sure python-swiftclient is installed.

Also the following ENV var are needed you can put them in ~/.bashrc:

export OS_REGION_NAME=region-a.geo-1
export OS_TENANT_ID=<account tenant>
export OS_PASSWORD=<account password>
export OS_AUTH_URL=https://region-a.geo-1.identity.hpcloudsvc.com:35357/v2.0
export OS_USERNAME=automationbackup
export OS_TENANT_NAME=automationbackup

$ source ~/.bashrc

Let’s say you have a container called freezer_foobar-container, by executing “swift list” you should see something like:

$ swift list
freezer_foobar-container-2
$

These are just use case example using Swift in the HP Cloud.

Is strongly advised to use execute a backup using LVM snapshot, so freezer will execute a backup on point-in-time data. This avoid risks of data inconsistencies and corruption.

Backup

The most simple backup execution is a direct file system backup:

$ sudo freezerc --file-to-backup /data/dir/to/backup
--container freezer_new-data-backup --backup-name my-backup-name

By default –mode fs is set. The command would generate a compressed tar gzip file of the directory /data/dir/to/backup. The generated file will be segmented in stream and uploaded in the swift container called freezer_new-data-backup, with backup name my-backup-name

Now check if your backup is executing correctly looking at /var/log/freezer.log

Execute a MongoDB backup using lvm snapshot:

We need to check before on which volume group and logical volume our mongo data is. These information can be obtained as per following:

$ mount
[...]

Once we know the volume where our Mongo data is mounted on, we can get the volume group and logical volume info:

$ sudo vgdisplay
[...]
$ sudo lvdisplay
[...]

We assume our mongo volume is “/dev/mongo/mongolv” and the volume group is “mongo”:

$ sudo freezerc --lvm-srcvol /dev/mongo/mongolv --lvm-dirmount /var/lib/snapshot-backup
--lvm-volgroup mongo --file-to-backup /var/lib/snapshot-backup/mongod_ops2
--container freezer_mongodb-backup-prod --exclude "*.lock" --mode mongo --backup-name mongod-ops2

Now freezerc create a lvm snapshot of the volume /dev/mongo/mongolv. If no options are provided, default snapshot name is freezer_backup_snap. The snap vol will be mounted automatically on /var/lib/snapshot-backup and the backup meta and segments will be upload in the container mongodb-backup-prod with the name mongod-ops2.

Execute a file system backup using lvm snapshot:

$ sudo freezerc --lvm-srcvol /dev/jenkins/jenkins-home --lvm-dirmount
/var/snapshot-backup --lvm-volgroup jenkins
--file-to-backup /var/snapshot-backup --container freezer_jenkins-backup-prod
--exclude "\*.lock" --mode fs --backup-name jenkins-ops2

MySQL backup require a basic configuration file. The following is an example of the config:

$ sudo cat /root/.freezer/db.conf
host = your.mysql.host.ip
user = backup
password = userpassword

Every listed option is mandatory. There’s no need to stop the mysql service before the backup execution.

Execute a MySQL backup using lvm snapshot:

$ sudo freezerc --lvm-srcvol /dev/mysqlvg/mysqlvol
--lvm-dirmount /var/snapshot-backup
--lvm-volgroup mysqlvg --file-to-backup /var/snapshot-backup
--mysql-conf /root/.freezer/freezer-mysql.conf--container
freezer_mysql-backup-prod --mode mysql --backup-name mysql-ops002

All the freezerc activities are logged into /var/log/freezer.log.

Restore

As a general rule, when you execute a restore, the application that write or read data should be stopped.

There are 3 main options that need to be set for data restore

File System Restore:

Execute a file system restore of the backup name adminui.git:

$ sudo freezerc --action restore --container freezer_foobar-container-2
--backup-name adminui.git
--restore-from-host git-HP-DL380-host-001 --restore-abs-path
/home/git/repositories/adminui.git/
--restore-from-date "2014-05-23T23:23:23"

MySQL restore:

Execute a MySQL restore of the backup name holly-mysql. Let’s stop mysql service first:

$ sudo service mysql stop

Execute Restore:

$ sudo freezerc --action restore --container freezer_foobar-container-2
--backup-name mysq-prod --restore-from-host db-HP-DL380-host-001
--restore-abs-path /var/lib/mysql --restore-from-date "2014-05-23T23:23:23"

And finally restart mysql:

$ sudo service mysql start

Execute a MongoDB restore of the backup name mongobigdata:

$ sudo freezerc --action restore --container freezer_foobar-container-2
--backup-name mongobigdata --restore-from-host db-HP-DL380-host-001
--restore-abs-path /var/lib/mongo --restore-from-date "2014-05-23T23:23:23"

List remote containers:

$ sudo freezerc --action info  -L

List remote objects in container:

$ sudo freezerc --action info --container freezer_testcontainer -l

Remove backups older then 1 day:

$ freezerc --action admin --container freezer_dev-test --remove-older-then 1 --backup-name dev-test-01

Low resources requirement

Freezer is designed to reduce at the minimum I/O, CPU and Memory Usage. This is achieved by generating a data stream from tar (for archiving) and gzip (for compressing). Freezer segment the stream in a configurable chunk size (with the option –max-seg-size). The default segment size is 64MB, so it can be safely stored in memory, encrypted if the key is provided, and uploaded to Swift as segment.

Multiple segments are sequentially uploaded using the Swift Manifest. All the segments are uploaded first, and then the Manifest file is uploaded too, so the data segments cannot be accessed directly. This ensue data consistency.

By keeping small segments in memory, I/O usage is reduced. Also as there’s no need to store locally the final compressed archive (tar-gziped), no additional or dedicated storage is required for the backup execution. The only additional storage needed is the LVM snapshot size (set by default at 5GB). The lvm snapshot size can be set with the option –lvm-snapsize. It is important to not specify a too small snap size, because in case a quantity of data is being wrote to the source volume and consequently the lvm snapshot is filled up, then the data is corrupted.

If the more memory is available for the backup process, the maximum segment size can be increased, this will speed up the process. Please note, the segments must be smaller then 5GB, is that is the maximum object size in the Swift server.

Au contraire, if a server have small memory availability, the –max-seg-size option can be set to lower values. The unit of this option is in bytes.

How the incremental works

The incremental backups is one of the most crucial feature. The following basic logic happens when Freezer execute:

1. Freezer start the execution and check if the provided backup name for the current node already exist in Swift

2. If the backup exists, the Manifest file is retrieved. This is important as the Manifest file contains the information of the previous Freezer execution.

The following is what the Swift Manifest looks like:

{
    'X-Object-Meta-Encrypt-Data': 'Yes',
    'X-Object-Meta-Segments-Size-Bytes': '134217728',
    'X-Object-Meta-Backup-Created-Timestamp': '1395734461',
    'X-Object-Meta-Remove-Backup-Older-Than-Days': '',
    'X-Object-Meta-Src-File-To-Backup': '/var/lib/snapshot-backup/mongod_dev-mongo-s1',
    'X-Object-Meta-Maximum-Backup-level': '0',
    'X-Object-Meta-Always-Backup-Level': '',
    'X-Object-Manifest': u'socorro-backup-dev_segments/dev-mongo-s1-r1_mongod_dev-mongo-s1_1395734461_0',
    'X-Object-Meta-Providers-List': 'HP',
    'X-Object-Meta-Backup-Current-Level': '0',
    'X-Object-Meta-Abs-File-Path': '',
    'X-Object-Meta-Backup-Name': 'mongod_dev-mongo-s1',
    'X-Object-Meta-Tar-Meta-Obj-Name': 'tar_metadata_dev-mongo-s1-r1_mongod_dev-mongo-s1_1395734461_0',
    'X-Object-Meta-Hostname': 'dev-mongo-s1-r1',
    'X-Object-Meta-Container-Segments': 'socorro-backup-dev_segments'
}

3. The most relevant data taken in consideration for incremental are:

• ‘X-Object-Meta-Maximum-Backup-level’: ‘7’

Value set by the option: –max-level int

Assuming we are executing the backup daily, let’s say managed from the crontab, the first backup will start from Level 0, that is, a full backup. At every daily execution, the current backup level will be incremented by 1. Then current backup level is equal to the maximum backup level, then the backup restart to level 0. That is, every week a full backup will be executed.

• ‘X-Object-Meta-Always-Backup-Level’: ‘’

Value set by the option: –always-level int

When current level is equal to ‘Always-Backup-Level’, every next backup will be executed to the specified level. Let’s say –always-level is set to 1, the first backup will be a level 0 (complete backup) and every next execution will backup the data exactly from the where the level 0 ended. The main difference between Always-Backup-Level and Maximum-Backup-level is that the counter level doesn’t restart from level 0

• ‘X-Object-Manifest’: u’socorro-backup-dev/dev-mongo-s1-r1_mongod_dev-mongo-s1_1395734461_0’

Through this meta data, we can identify the exact Manifest name of the provided backup name. The syntax is: container_name/hostname_backup_name_timestamp_initiallevel

• ‘X-Object-Meta-Providers-List’: ‘HP’

This option is NOT implemented yet The idea of Freezer is to support every Cloud provider that provide Object Storage service using OpenStack Swift. The meta data allows you to specify multiple provider and therefore store your data in different Geographic location.

• ‘X-Object-Meta-Backup-Current-Level’: ‘0’

Record the current backup level. This is important as the value is incremented by 1 in the next freezer execution.

• ‘X-Object-Meta-Backup-Name’: ‘mongod_dev-mongo-s1’

Value set by the option: -N BACKUP_NAME, –backup-name BACKUP_NAME The option is used to identify the backup. It is a mandatory option and fundamental to execute incremental backup. ‘Meta-Backup-Name’ and ‘Meta-Hostname’ are used to uniquely identify the current and next incremental backups

• ‘X-Object-Meta-Tar-Meta-Obj-Name’: ‘tar_metadata_dev-mongo-s1-r1_mongod_dev-mongo-s1_1395734461_0’

Freezer use tar to execute incremental backup. What tar do is to store in a meta data file the inode information of every file archived. Thus, on the next Freezer execution, the tar meta data file is retrieved and download from swift and it is used to generate the next backup level. After the next level backup execution is terminated, the file update tar meta data file will be uploaded and recorded in the Manifest file. The naming convention used for this file is: tar_metadata_backupname_hostname_timestamp_backuplevel

• ‘X-Object-Meta-Hostname’: ‘dev-mongo-s1-r1’

The hostname of the node where the Freezer perform the backup. This meta data is important to identify a backup with a specific node, thus avoid possible confusion and associate backup to the wrong node.

Miscellanea

Available options:

$ freezerc
usage: freezerc [-h] [--action {backup,restore,info,admin}] [-F SRC_FILE]
                [-N BACKUP_NAME] [-m MODE] [-C CONTAINER] [-L] [-l]
                [-o OBJECT] [-d DST_FILE] [--lvm-auto-snap LVM_AUTO_SNAP]
                [--lvm-srcvol LVM_SRCVOL] [--lvm-snapname LVM_SNAPNAME]
                [--lvm-snapsize LVM_SNAPSIZE] [--lvm-dirmount LVM_DIRMOUNT]
                [--lvm-volgroup LVM_VOLGROUP] [--max-level MAX_BACKUP_LEVEL]
                [--always-level ALWAYS_BACKUP_LEVEL]
                [--restart-always-level RESTART_ALWAYS_BACKUP]
                [-R REMOVE_OLDER_THAN] [--no-incremental]
                [--hostname HOSTNAME] [--mysql-conf MYSQL_CONF_FILE]
                [--log-file LOG_FILE] [--exclude EXCLUDE]
                [--dereference-symlink {none,soft,hard,all}] [-U]
                [--encrypt-pass-file ENCRYPT_PASS_FILE] [-M MAX_SEG_SIZE]
                [--restore-abs-path RESTORE_ABS_PATH]
                [--restore-from-host RESTORE_FROM_HOST]
                [--restore-from-date RESTORE_FROM_DATE] [--max-priority] [-V]

optional arguments:
  -h, --help            show this help message and exit
  --action {backup,restore,info,admin}
                        Set the action to be taken. backup and restore are
                        self explanatory, info is used to retrieve info from
                        the storage media, while maintenance is used to delete
                        old backups and other admin actions. Default backup.
  -F SRC_FILE, --path-to-backup SRC_FILE, --file-to-backup SRC_FILE
                        The file or directory you want to back up to Swift
  -N BACKUP_NAME, --backup-name BACKUP_NAME
                        The backup name you want to use to identify your
                        backup on Swift
  -m MODE, --mode MODE  Set the technology to back from. Options are, fs
                        (filesystem), mongo (MongoDB), mysql (MySQL). Default
                        set to fs
  -C CONTAINER, --container CONTAINER
                        The Swift container used to upload files to
  -L, --list-containers
                        List the Swift containers on remote Object Storage
                        Server
  -l, --list-objects    List the Swift objects stored in a container on remote
                        Object Storage Server.
  -o OBJECT, --get-object OBJECT
                        The Object name you want to download on the local file
                        system.
  -d DST_FILE, --dst-file DST_FILE
                        The file name used to save the object on your local
                        disk and upload file in swift
  --lvm-auto-snap LVM_AUTO_SNAP
                        Automatically guess the volume group and volume name
                        for given PATH.
  --lvm-srcvol LVM_SRCVOL
                        Set the lvm volume you want to take a snaphost from.
                        Default no volume
  --lvm-snapname LVM_SNAPNAME
                        Set the lvm snapshot name to use. If the snapshot name
                        already exists, the old one will be used a no new one
                        will be created. Default freezer_backup_snap.
  --lvm-snapsize LVM_SNAPSIZE
                        Set the lvm snapshot size when creating a new
                        snapshot. Please add G for Gigabytes or M for
                        Megabytes, i.e. 500M or 8G. Default 5G.
  --lvm-dirmount LVM_DIRMOUNT
                        Set the directory you want to mount the lvm snapshot
                        to. Default not set
  --lvm-volgroup LVM_VOLGROUP
                        Specify the volume group of your logical volume. This
                        is important to mount your snapshot volume. Default
                        not set
  --max-level MAX_BACKUP_LEVEL
                        Set the backup level used with tar to implement
                        incremental backup. If a level 1 is specified but no
                        level 0 is already available, a level 0 will be done
                        and subesequently backs to level 1. Default 0 (No
                        Incremental)
  --always-level ALWAYS_BACKUP_LEVEL
                        Set backup maximum level used with tar to implement
                        incremental backup. If a level 3 is specified, the
                        backup will be executed from level 0 to level 3 and to
                        that point always a backup level 3 will be executed.
                        It will not restart from level 0. This option has
                        precedence over --max-backup-level. Default False
                        (Disabled)
  --restart-always-level RESTART_ALWAYS_BACKUP
                        Restart the backup from level 0 after n days. Valid
                        only if --always-level option if set. If --always-
                        level is used together with --remove-older-then, there
                        might be the chance where the initial level 0 will be
                        removed Default False (Disabled)
  -R REMOVE_OLDER_THAN, --remove-older-then REMOVE_OLDER_THAN
                        Checks in the specified container for object older
                        then the specified days. If i.e. 30 is specified, it
                        will remove the remote object older than 30 days.
                        Default False (Disabled)
  --no-incremental      Disable incremantal feature. By default freezer build
                        the meta data even for level 0 backup. By setting this
                        option incremental meta data is not created at all.
                        Default disabled
  --hostname HOSTNAME   Set hostname to execute actions. If you are executing
                        freezer from one host but you want to delete objects
                        belonging to another host then you can set this option
                        that hostname and execute appropriate actions. Default
                        current node hostname.
  --mysql-conf MYSQL_CONF_FILE
                        Set the MySQL configuration file where freezer
                        retrieve important information as db_name, user,
                        password, host. Following is an example of config
                        file: # cat ~/.freezer/backup_mysql_conf host = <db-
                        host> user = <mysqluser> password = <mysqlpass>
  --log-file LOG_FILE   Set log file. By default logs to /var/log/freezer.log
  --exclude EXCLUDE     Exclude files, given as a PATTERN.Ex: --exclude
                        '*.log' will exclude any file with name ending with
                        .log. Default no exclude
  --dereference-symlink {none,soft,hard,all}
                        Follow hard and soft links and archive and dump the
                        files they refer to. Default False.
  -U, --upload          Upload to Swift the destination file passed to the -d
                        option. Default upload the data
  --encrypt-pass-file ENCRYPT_PASS_FILE
                        Passing a private key to this option, allow you to
                        encrypt the files before to be uploaded in Swift.
                        Default do not encrypt.
  -M MAX_SEG_SIZE, --max-segment-size MAX_SEG_SIZE
                        Set the maximum file chunk size in bytes to upload to
                        swift Default 67108864 bytes (64MB)
  --restore-abs-path RESTORE_ABS_PATH
                        Set the absolute path where you want your data
                        restored. Default False.
  --restore-from-host RESTORE_FROM_HOST
                        Set the hostname used to identify the data you want to
                        restore from. If you want to restore data in the same
                        host where the backup was executed just type from your
                        shell: "$ hostname" and the output is the value that
                        needs to be passed to this option. Mandatory with
                        Restore Default False.
  --restore-from-date RESTORE_FROM_DATE
                        Set the absolute path where you want your data
                        restored. Please provide datime in forma "YYYY-MM-
                        DDThh:mm:ss" i.e. "1979-10-03T23:23:23". Make sure the
                        "T" is between date and time Default False.
  --max-priority        Set the cpu process to the highest priority (i.e. -20
                        on Linux) and real-time for I/O. The process priority
                        will be set only if nice and ionice are installed
                        Default disabled. Use with caution.
  -V, --version         Print the release version and exit