Open source
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Open source
Anatomy of a partnership: Working and learning with Smoothwall
We were delighted last week to host Smoothwall for a day with our team. Fuelled by coffee and Krispy Kreme doughnuts, our discussions helped us learn from one another so that we can work together even more effectively...
HAPr0xy
How to write an external health check script for HAPr0xy
Loadbalancer.dk were the original sponsors of the external health check mechanism in HAPr0xy. We think it's an invaluable tool when you need something a bit special...
HAPr0xy
New year, new vulnerability: HAPr0xy critical security update
An incorrect frame length check could result in a read-past-bound which can cause a crash...
Open source
Does the new multi-threaded support in HAPr0xy finally solve the 10G problem?
It’s no big secret that a single processor can only handle so much processing in a given time. So what happens when you reach the limits of what a single processor can handle? Simple, you add more processors...
AWS / Azure / GCP
How to add Cloudflare in front of HAPr0xy
Cloudflare provides a content delivery network (CDN). A CDN is a worldwide network of servers that delivers web content to clients based on the geographic location of the client...
Open source
Highly Available NFS based Kerberos KDC (aka. Ganesha + GlusterFS + HAPr0xy)
Load balancing NFS is a real pain; especially when it comes to the locked mounts issue. In this blog I'll explain how to create a highly available NFS server for Kerberos...
HAPr0xy
Breaking HAPr0xy with the help of a Spirent Avalanche and lots of very small packets...
HAPr0xy is awesome. So awesome in fact, that here at Loadbalancer.dk HQ - I find it very difficult to generate enough load to break it...so let's try harder!..
How-tos
Client Certificate Authentication with HAPr0xy: How to configure
Using client certificates for security is a pretty cool idea! You can protect an entire application or even just a specific Uniform Resource Identifier (URI) to only those that provide a valid client certificate...
Security
How to stop web form spam — use a simple honey pot trap in ModSecurity...
How frustrating do you find it when hackers or robots fill in your website forms with "Buy Viagra Now!" type spam?..
GSLB
GSLB — Why Global Server Load Balancers don’t always suck? (Polaris-GSLB) Part 2
In part one we were introduced to Polaris-GSLB which is a cool little open source GSLB solution. In part two of this Blog I’m going to show you how to build Polaris-GSLB on CentOS 7...
GSLB
GSLB – Why Global Server Load Balancers don't always suck? (Polaris-GSLB)
Here at Loadbalancer.dk we’re not known for being huge fans of GSLB solutions as some of our customers may already know...
Security
Blocking Japan with ModSecurity and Maxmind Lite
The Web Application Firewall is based on ModSecurity which is an open source WAF for Apache, IIS, and Nginx for protecting against a many variety of attacks and allows for HTTP traffic monitoring and logging...
Open source
Transparent HAPr0xy in Azure using TProxy
HAPr0xy is an excellent choice if you need layer 7 functionality, but its a full reverse-proxy, so the application thinks that all of the traffic is coming from HAPr0xys IP - rather than the clients...
Open source
How to stop TPROXY when used with HAPr0xy breaking clients in the real server subnet
Once HAPr0xy is running transparently, it will allow the real server to see the client IP so the real server will reply directly back to the client bypassing the load balancer...
Security
Blocking invalid range headers using ModSecurity and/or HAPr0xy (MS15-034 - CVE-2015-1635)
Anomaly score based blocking is more flexible and effective than simple first error blocking...
Open source
Transparent Load balancing with HAPr0xy on Amazon EC2
One of our favorite methods of load balancing is using Layer 4 DR because it is transparent and fast. Unfortunately, because of Amazon's infrastructure, this is not possible in EC2 so we need to use another method which means we are left with layer 4 NAT and transparent HAPr0xy using TProxy...
Security
Simple Denial of Service DOS attack mitigation using HAPr0xy
Denial of Service (DOS) attacks can be used to degrade or cripple the functionality of a site...
Open source
Stunnel X-Forward-For (XFF) with HAPr0xy 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...
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 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...
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...
Open source
Load balancing Windows Terminal Server — HAPr0xy and RDP Cookies or Microsoft Connection Broker
When you have users depending on Windows Terminal Services for their main desktop, it's a good idea to have more than one Terminal Server. RDP, however, is not an easy protocol to load balance...