Latest
How to connect and manage a Citrix NetScaler in the Loadbalancer ADC Portal
As a NetScaler specialist, they asked me to test the product and share my honest thoughts.
Insights from the load balancer experts
GSLB
The ultimate guide to Global Server Load Balancing (GSLB): Benefits, uses, and configurations
Global Server Load Balancing (GSLB) enables you to distribute internet or corporate network traffic across servers in multiple locations, anywhere in the world...
GSLB
Active/active for N+1 redundancy and > 1Tbps of ADC throughput
I've been repeatedly asked how our load balancers scale. So, I have decided to write down your options for endlessly scalable, high-performance load balancing...
High Availability
What is a load balancer? A comprehensive guide to load balancing
Hidden in data centers around the world, there are millions of load balancers that keep businesses and their applications fully functional 24/7 – making sure users enjoy a seamless and uninterrupted high-quality experience at every single click...
Microsoft
Enhanced Microsoft IIS health checks using VBscript
By default, the load balancer uses a TCP connect to the port defined in the Virtual Service to verify the health of each real (backend) server. For IIS, this would typically be port 80...
Microsoft
Windows NLB (WNLB) and its disadvantages
WNLB causes switch flooding and does not support multiple scheduling algorithms for distributing client load...
Open source
Stunnel X-Forward-For (XFF) with HAProxy and the PROXY Protocol
By default, the source IP address of the packet reaching the web servers is the IP address of the load balancer and not the IP address of the client...
Security
Heartbleed 2.0? Not exactly but more OpenSSL issues have been found
Whilst the Heartbleed bug was relatively easy to exploit, the latest batch of bugs are not...
Security
Loadbalancer.org 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 HAProxy 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...
HAProxy
3 Ways To Send HAProxy Health Check Email Alerts
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...
HAProxy
HAProxy 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.org 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.org 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)...
HAProxy
HAProxy email alerts guide
As of haproxy-1.6-dev1 it is now possible to send email alerts directly from HAProxy thanks to the excellent work done for us by Simon Horman...
HAProxy
Setting up HAProxy with Transparent Mode on Centos 6.x
Transparent mode with HAProxy allows you to see the IP Address of the clients computer while still having a high availability service using HAProxy...
Application Management
Load Balancing Exchange 2010 CAS Array with HAProxy (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...
WAF
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!..
HAProxy
Load Balancer performance: Benchmarking HAProxy 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...