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7th February 2017

in Database Clustering

MS SQL Health Check

Posted by Neil Hosking 7th February in Database Clustering

Recently we've noticed more customers are load balancing Microsoft SQL Server. We already have a built in MySQL health check in the appliance, but until now we've avoided having a Microsoft SQL check as it is not open source.

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5th December 2016

in High Availability

GSLB – Why Global Server Load Balancers Don’t Always Suck? (Polaris-GSLB) Part 2

Posted by Aaron West 5th December in High Availability

In part one we were introduced to Polaris-GSLB which is a cool little open source GSLB solution, we went through a simple use case scenario and discussed the features it supports. In part two of this Blog I’m going to show you how to build Polaris-GSLB on CentOS 7.

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15th November 2016

in High Availability

GSLB – Why Global Server Load Balancers Don’t Always Suck? (Polaris-GSLB)

Posted by Aaron West 15th November in High Availability

There is a lovely open source project on GitHub called Polaris-GSLB, you can find out more about it here : https://github.com/polaris-gslb/polaris-gslb/wiki/Overview It allows us to perform health checks to test availability, define topologies to serve up local results for local clients and perform load balancing of up to 32 endpoints!

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28th September 2016

in AWS and Azure

Transparent HAProxy in Azure using TProxy

Posted by Ben Cabot 28th September in AWS and Azure

We all know that the built-in Azure load balancer is perfectly functional, but sometimes you need a proper load balancer. 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. So what can you do if the load balanced application needs to know the real clients IP address in Azure?

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5th February 2016

in Linux

Supporting two default gateways on your Loadbalancer with PBR(Policy Based Routing)

Posted by Aaron West 5th February in Linux

Occasionally we get asked questions about supporting multiple default gateways. Customers may have our appliance in two networks, each with it’s own gateway to the internet. Alternatively it may just be a big complex network with multiple routing paths and stateful devices which are fussy about seeing the whole connection so things get dropped.

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1st November 2013

in HAProxy

3 Ways To Send HAProxy Health Check Email Alerts

Posted by Ben Cabot 1st November in HAProxy

To follow up to Aarons blog on HAProxy emails alerts using logwatch I was looking into different ways to achieve the same results. Now the ideal way to monitor the health of the real servers is to to have a dedicated monitoring system in place such as Nagios( It even has a HAProxy plugin). However this is not always an option for some so they require the loadbalancer to send an alert. So I investigated some different options.

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28th August 2013

in AWS and Azure

Load balancing UDP on EC2

Posted by Ben Cabot 28th August in AWS and Azure

I had been tasked with finding a way to load balance UDP on AWS. Normally we would use ipvsadm in at layer 4 DR but because of the limitations in EC2 this is not possible so another method was needed. So this is a short guide on how to get a simple UDP load balancer running. We will be using pen, it is described as a simple tcp load balancer and has been around for a while.

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