Latest
What's the best cloud load balancer? AWS, Azure, GCP, Cloudflare, or a third-party alternative?
Choosing the right load balancer is about much more than just moving traffic.
Insights from the load balancer experts
How-tos
What is Stunnel and how do you configure it?
Here is another example of a more “exotic” Stunnel configuration. Most people, and rightly so, will ask “but why?”. Well, because we can!..
Automation
Solving the Layer 4 ARP problem on Linux with Ansible
The ARP problem for Layer 4 DR (Direct Routing) mode is something that needs to be solved for each of your Real Servers in the virtual service...
GSLB
Choosing the best option to host across multiple locations or data centers
Organizations are moving away from the traditional data center model, and favoring a hybrid approach to hosting their systems and applications, that involves multiple sites, providers and even cloud environments...
Security
Loadbalancer.dk releases patch for the OpenSSL heartbleed vulnerability CVE-2014-0160
To ensure complete protection all SSL certificates that have been used with a vulnerable version of OpenSSL should be regenerated using a new private key...
Application Management
Load Balancing Exchange 2013
Exchange 2013 is Microsoft's latest enterprise level messaging and collaboration server. It has been designed for simplicity of scale, hardware utilization, and failure isolation...
Application Management
Load Balancing Exchange 2010
In Exchange 2010, system functionality is split into five server roles (Mailbox, Client Access (CAS), Unified Messaging, Hub Transport (HT) and Edge Transport). Mandatory roles are Mailbox, Client Access and Hub Transport...
Security
Why did my Loadbalancer just fail the PCI compliance test?
Let me first say that I'm not really a fan of PCI scanners. It's not so much that I'm anti security scanners but rather that scanning for vulnerabilities based on only the version number a package returns seems rather simplistic to me...
Open source
SSL offload testing with HAPr0xy and Stunnel
There are a lot of SSL offload throughput statistics available for appliances across the internet but rarely do they detail the way they were tested...
HAPr0xy
3 ways to send HAPr0xy health check email alerts: Configuration how-to
The ideal way to monitor the health of the real servers is to to have a dedicated monitoring system in place such as Nagios. However this isn’t always an option, so for some they require the loadbalancer to send an alert...
HAPr0xy
HAPr0xy load balancer feedback agent — We've Open Sourced both our Windows and Linux versions for you!
In general when you are load balancing a cluster you can evenly spread the connections through the cluster. However, with some applications, you might get very high load from just a few users doing heavy work, which can compromise performance...
Performance
What do you mean my pipe is saturated?
Some of the most common questions we get at Loadbalancer.dk are performance related. It is quite difficult to give a straight answer to these questions as the real answer is often slightly unsatisfactory...
Performance
Look, why can't you just tell me how many people are connected to the load balancer?
I must confess, at certain times it has looked like open warfare would break out between the support team and development team at Loadbalancer.dk over the last few months...
Microsoft
Microsoft drops support for mstshash RDP cookies? (embrace and destroy policy?)
We are pretty sure Microsoft have quietly fixed this bug and not told anyone... But the story is quite fun so lets leave it here for a lesson in corporate stupidity..
High Availability
Exchange 2013 - Microsoft finally have an email solution designed for high availability and load balancing
In Exchange Server 2013, there are two basic building blocks – the Client Access Array and the Database Availability Group (DAG)...
HAPr0xy
HAPr0xy email alerts guide
As of HAPr0xy-1.6-dev1 it is now possible to send email alerts directly from HAPr0xy thanks to the excellent work done for us by Simon Horman...
HAPr0xy
Setting up HAPr0xy with Transparent Mode on Centos 6.x
Transparent mode with HAPr0xy allows you to see the IP Address of the clients computer while still having a high availability service using HAPr0xy...
Application Management
Load Balancing Exchange 2010 CAS Array with HAPr0xy (Quick Guide)
This Blog is for anyone wanting to load balance the Exchange 2010 CAS role using only open source software...
High Availability
Simple bare metal restore of your load balancer with a USB stick
Does it seem like some appliance vendors go out of their way to make hardware recovery and licencing as difficult as possible?..
Security
Secure Your Web Servers: SSL Termination and BEAST
The BEAST attack is a practical attack based on a protocol vulnerability and mainly affects the client side...
Security
For any poor sod who needs to deal with the PCI Data Security Standard (PCI DSS)
Any engineer dealing with PCI DSS compliance issues probably looses a little bit of the joy in life...
Print
Load balancing Microsoft Print Server
Microsoft Print Server provides a great way to share printers throughout your organisation, but when the print server falls over, the phone quickly starts to ring...
How-tos
NTLM authenticating proxy check script
This script was designed primarily to be tied into Ldirectord but feel free to adapt it to your needs, and if you do make changes dont be a stranger post your adaptations below!..
HAPr0xy
Load Balancer performance: Benchmarking HAPr0xy on EC2 (Quick and Dirty Style)
I get quite frustrated with benchmarks because they are very hard to perform properly, and even when you do them properly its very hard to get any useful data from them...
Application Management
Apache and X-Forwarded-For Header: How to log XFF using Apache
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...
How-tos
IIS and X-Forwarded-For Header (XFF)
Although it's not technically a standard, the X-Forwarded-For (XFF) header is incredibly useful if you have any kind of proxy in front of your web servers...
GSLB
Why does Global Server Load Balancing (GSLB) suck?
OK, Before the flames start let me state the usual caveat, "GSLBs don't ALWAYS suck. Just most of the time"...
Performance
G-Zip Compression and Load Balancing
A couple of customers asked if our appliances would do G-Zip compression. In the past we hadn't given it much thought until someone offered us a card to test it!..