High Availability — Protecting against downtime and ensuring business continuity with highly available clustered pairs

SNI is an extension to the TLS protocol which enables the client to broadcast its hostname when it tries to connect to your server. This allows you to use multiple SSL certificates on a single IP.

So, you've configured two Loadbalancer.org appliances as a clustered pair for high availability, the pair has been working fine but then one day you receive an email alert that one of the pair has failed for some reason.

Updates include an enhanced process for high availability appliance pairing, improved LBCLI, and advancement of the web user interface.

In Exchange Server 2013, there are two basic building blocks – the Client Access Array and the Database Availability Group (DAG).

Transparent mode with HAProxy allows you to see the IP Address of the clients computer while still having a high availability service using HAProxy.

This Blog is for anyone wanting to load balance the Exchange 2010 CAS role using only open source software.

Editor note: This blog has been updated many times since its original publication. Does it seem like some appliance vendors go out of their way to make hardware recovery and licencing as difficult as possible? Many engineers including myself have plenty of horror stories such as waiting hours for licence

There’s been a lot of debate here in the office about how best to capture both your Loadbalancer’s IP and the Source IP of the user in your access_log in Apache 2.4. This is the tried and tested method we've come up with.

OK, Before the flames start let me state the usual caveat, "GSLBs don't ALWAYS suck, just most of the time".

For a company touting the use of load balancers for high availability, it is important that our own website should be up!

Some vendors make a fair bit of hype about their products enabling 99.999% availability out of the box.