Technology Blog

Travel Butlers provide tailored holiday packages in South Africa and the neighbouring countries.  Traditionally their website development had been done in-house but they needed some advanced Google Maps API programming to push their site forward and make the experience for their customers that little bit better.

Often when using the command prompt in Windows Vista and Windows 7 you'll need to run the command as an Administrator and whilst running a command prompt elevated is not tough, it's fiddly. If you've forgotten to do it before you've moved your way around the file system it can be very annoying.

Before embarking on a MySQL Cluster installation, it is important to remember that MySQL Cluster is 'just' a storage engine for your existing MySQL database servers.  It stores data at the table level, not the whole database, it is therefore on the same functional level as MyISAM or INNODB.  You still need a standard MySQL server to access the table data and store the database information.  This has the fringe benefit that you can target specific tables to be saved to the cluster, rather than the whole database, if you have some tables that are either more important, or more heavily used.

In this article we are going to cover MySQL Cluster, it's installation on Debian (Lenny), Master-Master replication and how to tie all this together with HAProxy for a very high availability solution.

NB: At present you cannot request or share additional internal IP addresses with Rackspace Cloud, so you are going to have to use the external addresses.  With large databases this will incur additional bandwidth charges, be sure to evaluate this additional cost against the benefits provided by high availability.  When Rackspace allow the allocation of additional internal IPs, this article will be updated to reflect that.

To go with our Load Balanced Web Cluster, which provides good availability for your web services, providing high availability for your database is also likely to be an important requirement.  In most modern web apps, there's not much use having your webservers available constantly if your database is down.

There are a number of solutions to this with MySQL and every situation will require a different response, there are a lot of good articles out there to help you decide which solution is best. In this article we will be covering MySQL Master-Master replication and installation on Debian (Lenny) using Rackspace Cloud Servers.

The standard model of MySQL replication is a single master with multiple slaves, which provides you with very good read reliability, but writes can only be made to the master node.  This means that if the master fails, you can't just switch to another node and carry on as before, your slaves will become out of sync.  Additionally you can't load balance between your nodes for reads and writes.  By using a multiple master configuration, you can drop a node at any point and either switch your connection string to using the remaining master, or use load balancing and failover with HAProxy.

Upon creation, most Rackspace Cloud Servers have a completely open firewall policy that will allow any computer into any port on your machine.  Linux uses IPTables to firewall connections into and out of your server but needs a fair amount of configuration to get it working and for it to stay working on a reboot.

In this article we will cover basic saving and loading of IPTables rules in Debian/Ubuntu on shutdown and boot up as well as common rules that go with our other guides.

The Dixcart Group has a number of serviced offices in different locations including Surrey, Isle of Man and Madeira with a new office being set up in Guernsey before the end of the year. They have performed well in each of the existing locations.  

The Isle of Man centres, have however, enjoyed a huge amount of interest since launch and as isleofman.com put it:

The Dixcart Group's managed office service, the only one of its kind on the Island, has been declared a success. 

Suites in the Dixcart Business Centre - the recently refurbished Britannia House, Athol Street, and also at 69 Athol Street - began the new year close to full occupancy.

Dixcart Technical Solutions set up the IT when Britannia House was converted into serviced offices, supplying and fitting all of the networking equipment including the SpliceCom phone system. This hooks into the Group's system. The Businesses Centres are kept separate but the phone system allows the Surrey, Isle of Man and Guernsey Dixcart office to provide cover for any the three offices, when needed.  

The communication network for all of the serviced offices is managed by Dixcart and provides each tenant with their own private network which is either connected to a shared building internet line, or to their own dedicated internet connection if they so wish.

Read the full article on isleofman.com

Although data costs when at home are practically zero these days, and there are plans to reduce the cost of roaming when in the EU, using data whilst roaming is presently very costly and with more reliance on fetching e-mail whilst away from the office, bills have already started to creep up.

Dixcart Technical Solutions are working for a client on the beta of Joboso.com which allows job seekers to automatically register themselves with multiple job boards, affiliates to offer this service to their user base and job boards to get more relevant people signed up.