# High Availability

High availability refers to a system which aims to ensure an agreed level of operational performance for a higher than normal period. Log360 helps administrators maintain high availability for a server in case of failure of the primary server.

Log360 achieves this by employing a high availability architecture which designates a backup server to act as a shield to the primary server.

- The same database is used for both servers. At any given time, the primary server caters to user requests and the other one is inactive until the primary server is down.
- Whenever the primary server encounters unplanned downtime, the standby server becomes operational.

## Prerequisites

Before enabling this setting, ensure that the following conditions are satisfied.

1. The TCP/IP connections from Log360 to the database is not blocked by the firewall in both primary and standby servers.

2. The version of the Microsoft SQL server is higher than 2005.
3. Both instances of the product:

- Are installed and running as a service.
- Have the same build architecture (32-bit or 64-bit), version and build number.
- Are connected to the same domain and network.

4. If your IP range is 172.21.9.x, then the primary server, standby server, and the virtual IP should also lie in the IP range 172.21.9.x.

High Availability can only be disabled from the standby server. Please shutdown the component in the primary server and start it from the standby server.

## Configuration

Follow the below steps to enable this setting.

- Navigate to Admin → Administration → High Availability.
- Click Configure Now for the Log360 component.

Enter the appropriate values for the subsequent fields to enable this setting.

- Primary Server: This text box will contain the URL of the primary server on which the selected component is installed.
- Standby Server: Enter the details of the secondary server which will take over during the downtime of the primary server.

- Name/IP: Enter the URL of the secondary server.
- Username/Password: Enter the super administrator credentials of the component in the standby server.

Note: Super administrators are users who have been provided with full control over the application.

- Virtual IP: Enter a single IP which can access both primary and standby servers. When the product is accessed using this IP, data is routed directly through the server which is active.

- Virtual IP Address: A virtual IP address is an unused static IP address. Open cmd and try pinging an IP. If it throws the error "Request timed out", the IP is unused and can be used as the virtual IP.
- Virtual Host Name: A virtual host name is the alias given to the virtual IP. This can be set from the DNS server.

- Click Save.