Business critical websites such as customer care portals, e-commerce stores,
payment portals and so on, need to have real 24x7 uptime. Any downtime here
translates into business loss. Generally, this problem is solved using multiple
servers in a 'failover cluster' arrangement that use a single IP address for
the outside world wherein the cluster-manager automatically redirects a user to
a new target server as per the load and system condition. But this requires all
your servers to be at the same location, which may not be an option if the
outage was caused by power loss, malware or other malicious attack. Simple
Failover lets you have servers anywhere in the world. You need to provide it
access to the DNS server that manages records for this web domain. Simple
Failover polls a URL and on failure, updates relevant DNS records to point to a
working backup server.
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A 'Server Set' in Simple Failover represents two or more servers which
host the same Internet service (for example a website) for the same domain name.
It represents various properties of the service, such as domain name, service
type (HTTP, FTP, etc), DNS servers, and so on. At defined intervals, it monitors
the status (by polling) of each individual server in the Server Set. To update
the DNS, it uses Standard Dynamic DNS update, TSIG Signed Dynamic DNS Update, MS
DNS via WMI, HTTP based DynDNS service and Scripting.
Installing Simple Failover is simple and once installed you can see its icon
in the system tray. First we need to create a server set for our domain. From
the main window, click on File>New Server Set and provide the domain name to
be monitored as well as the IP addresses of the primary and backup servers where
the web site is hosted. You can also customize the polling interval, response
time and 'Failed Polls Accepted' settings.
Click on the Update DNS tab and check the Update DNS option to add the
addresses of DNS servers that manage this domain's records. Choose the update
method. If you are using a Windows DNS server, choose the 'Microsoft DNS via
WMI' option. You can also choose whether the first responding server (DNS)
should be updated or all responding severs or not.
The complete status of all the servers associated with a domain are available from a single console |
To receive an e-mail notification every time an error occurs, click on the
Notification tab. Here, provide the e-mail address where you want the alerts to
be sent and click on OK. Now in the main window you can see the Server Set you
just created and the status of individual servers. Whenever one of these Web
servers go down for any reason, Simple Failover will automatically update your
DNS servers to point them to one of the other servers that are up and running.
To view real time details of events, click on Activity Log tab. Clicking on
the Problems tab displays errors and problems detected by the software.
Swapnil Arora