Damian Pacuszka
on
•
5 mins
There are a few different ways to achieve IP transparency, but one of the most effective is with the help of the great Proxy Protocol.
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.
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.
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.
HAProxy is awesome. So awesome in fact, that here at Loadbalancer.org HQ - I find it very difficult to generate enough load to break it...so let's try harder!
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.
How frustrating do you find it when hackers or robots fill in your website forms with "Buy Viagra Now!" type spam?
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.
Here at Loadbalancer.org we’re not known for being huge fans of GSLB solutions as some of our customers may already know.
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.
HAProxy 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 HAProxys IP - rather than the clients.
Once HAProxy 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.
Anomaly score based blocking is more flexible and effective than simple first error blocking.
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 HAproxy using TProxy.
Denial of Service (DOS) attacks can be used to degrade or cripple the functionality of a site.
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.
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.
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.
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.
Transparent mode with HAProxy allows you to see the IP Address of the clients computer while still having a high availability service using HAProxy.
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.
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.
I've previously blogged about how to get TPROXY and HAProxy working nicely together, but what if you want to terminate SSL traffic on the load balancer to use HAProxy to insert cookies in the standard HTTP stream to the backend servers?
If you use HAProxy as the load balancer then all of the backend servers see the traffic coming from the IP address of the load balancer.
Standard Kernel builds of LVS (Linux Virtual Server) don't have the ability to load balance traffic that is from the local node.