Hot Backup installation software is installed to provide online data backup. This installation software is recommended to be installed and activated on the server different from the one where your operating Wialon Local is launched.

The hot backup server provides real-time full replication of Wialon Local database (storage directory). There is a possibility of simultaneous usage of several hot backup servers with no additional licensing needed.

Installation

Requirements

The backup server is installed on the 64-bit Debian operating system. The main requirement is the size of the hard drive which should be at least the size of the main server. If you plan to use this server as the primary one in the event of a critical accident, its parameters should be similar to the parameters of the original server.

Installation

Use one of the methods described below to install the backup server.

Method 1 (preferred):

• download the archive and unpack it;
• run ./install.sh in the directory that was unpacked;
• answer the script's configuration questions;
• execute the service wlbackup restart command.

Enter the same parameters (address, port and access key) of your backup server on the Wialon Local administrator site.

Additional scripts:

• cold_backup.sh stops the backup module, makes an archive of its database and starts the backup module again. It deletes the oldest archive with data base if there is less than 20% of disk space left or if there are more than 5 storage archive files.
• add7dayscron.sh adds cold_backup.sh script in cron. As a result, the latter is executed once per week automatically.

Method 2:

• download the archive;
• unpack the archive in the working directory;
• activate a hot backup system. To do this, set the variable in the configuration file (custom/config.txt) as follows:

ADF_STORAGE_SYNC_SERVER = server_ip:port:access_key

where server_ip is the backup server's address (if there are several interfaces, choose the one that will be used for backup); port is the port where the backup server will 'listen' for connections; access key is the parameter necessary for additional protection of the connection to the port;

• start the service. To do this, go to the directory where the server is installed and run the ./adf_script start command as root. To stop the service, use the ./adf_script stop command.

Enter the same parameters (address, port and access key) of your backup server on the Wialon Local administrator site.

Recovery from failure

See below two variants of actions in case of a failure of the main server.

Recovery of the main server's work

The steps that should be followed to use reserve server database copy in case of Wialon Local server failure:

• stop Wialon Local on the main server;
• stop hot backup server;
• recover main server's working capacity;
• reinstall Wialon Local on it;
• move 'storage' directory from backup server to the main one;
• start Wialon Local on the main server.

If AVD maps are used, it is not necessary to restore the contents of the folder maps from the backup. However, downloading and readjustment of maps may slow down the process of restoring the service for the end users.

Using backup server as the main one

This alternative allows reducing the time of the server's inaccessibility to the end users.

Since it is supposed that in case of a hardware failure the backup server will become the main one, it is strongly recommended that their characteristics coincide, including the supplementary equipment (backup power supply, modems, etc.).

The action sequence, in this case, is as follows:

• Install Wialon Local on the backup server. The installation steps must be performed up to step 5 inclusive. To avoid accidental or intentional executing of step 6, it is recommended to restrict the access to the administration system to the local IP. To do this, it is necessary to change the line server_name in the file /etc/nginx/conf.d/lcm.conf leaving only localhost (127.0.0.1) in it and restart nginx.
• Install backup module to the backup server, define the path for saving storage by means of a symlink.
• In case of a failure of the main server stop the backup module and transfer the main IP to the backup server (that is switching the cable or changing the network settings).
• Log on to the administration system of the backup server, enter user name and password, repeat the configuration of the administration system of the main server (sites, maps, skins, restrictions, modems, etc.).
• Start Wialon Local on the backup server.

In order to back up maps, administration system's configuration or other necessary archives you can add lsyncd — the utility will instantly synchronize the files' changes on local and remote servers.