Thursday 24 March 2016

SaaS and Cache

Skepticism to a design that supports hundreds of users through what appears to be a very restricted bandwidth connection is understandable but it is technically possible.

Once the traffic profile is understood, its simply a question of sizing the connection correctly to meet the demands of the site. In the UK and other countries with access to a well developed broadband service the minimum connection is likely to be in the order of 50-100Mbs which commonly exceeds the average connection speeds in countries where GSfE has been widely deployed.

In the future the cost of internet access will only ever come down and once greater speeds become affordable the bandwidth objection will be irrelevant for a school of any size.



An additional aid to bandwidth control could be provided by a proxy cache, a service that was common in just about every business that used the internet in the early days when bandwidth was limited and expensive.

Over time the requirement for a local cache was made redundant by cheaper contracts and the emergence of active content but it might be time to reassess this capability particular with respect to streaming media.

Unlike most businesses, schools have a unique profile with respect to media downloads. As part of a class project or group work multiple requests for the same resource can be made within a very short timescale. This makes a school an ideal candidate for some form of local media caching service.

If a teacher pre-loads a resource prior to the lesson subsequent requests will be made from the local cache which will increase the response times, improve the perceived reliability of the service and reduce the peak loading on the internet uplink.

The service would be tightly focused on certain sites delivering multimedia curriculum resources such as YouTube and Vimeo and wouldn't provide a general caching service for other SaaS services - in fact it would need go out of its way to avoid it.

The caching of video streaming services is a specialized operation, its not as simple as writing static HTML pages to disc.

A number of solutions exist, mostly based on the open-source Squid proxy engine but nothing specifically aimed at the education market which is surprising because the traffic profile in schools is so well suited to media caching.


Monday 14 March 2016

SaaS and Video Magic

One of the criticisms levelled at the SaaS approach is that it is poorly suited to activities that involve the manipulation of large data files.

The argument goes that SaaS can accommodate simple document editing but it fails when you try and incorporate media and other subjects such as design.

There’s little doubt that the best user experience for activities like video editing and 3D modelling is gained from running the software locally on a fairly highly specified machine with a decent graphics card. Trying to use cloud storage in this situation is going to run into some obvious problems.

Using a standard 100Mbs internet connection, thirty students each editing  a 3Gb file stored on cloud storage will take about two hours to open the file and suffer the same delay writing back.

Given this limitation most schools resort to the tried and tested method of hosting both the application and the data on-site.

This approach normally results in a dedicated ICT suite populated with iMacs or high-end PC workstations loaded with Adobe Creative Suite, Photoshop or something similar. If you have an engineering lab that requires a modelling tool the requirements are the same it’s just the software that's different.

In this arrangement files are accessed using a gigabit ethernet network that links back to a high capacity storage system that’s protected by backup software archiving data to secondary media store. The workstations are normally supported by additional servers for patching and virus protection as well as providing an imaging and recovery mechanism.

If the students require remote access this requires some additional software and hardware that’s scaled to cope with the graphics requirements and the number of concurrent user sessions.

Put this all together and you’re pretty much good to go with only licensing, software upgrades, storage growth, the hardware refresh cycle and the security aspects of a room full of twenty iMac’s to concern you in the future.

The final result is an expensive but well equipped ICT suite that students can book for two sessions a week, perhaps sharing a terminal with a colleague. Students can work from home on a PC or Mac workstation assuming the right client software is installed and you have made the investment in the additional on-premise hardware.


This is a fairly common setup in schools today because in 2006 it was only option - but could it be done differently in 2016 using SaaS.



Let's be practical. If the lesson plan absolutely requires that every student uses Adobe Photoshop to manipulate an graphic image then this is the world you live in and it’s likely to continue for quite some time. SaaS is not an option for you.

The streaming version of Creative Cloud might ride to your rescue but after two years it’s still only running as a closed beta program to schools in the US.  A general release would be a huge advance for schools and colleges but there’s no timescale for this. Call me a skeptic but while schools are happy to absorb the cost and not actively considering any other alternative, what's the hurry.

So where does that leave a SaaS based solution?


At a technical level the on-premise solution provides a good user experience because both the data and the editing software are linked by a high bandwidth connection so files open and close quickly which maintains the responsiveness of the system. Place either the data or the software on the wrong end of a internet connection and everything becomes slow and unusable.

So if you want to use SaaS the solution is simple, put both the data and the editing software in the cloud.

The strange thing is that when you do this - magic starts to happen.




First, the requirement for local storage disappears in a puff of pixie dust.

Students store media files on Google Drive taking advantage of unlimited storage and while other providers have similar schemes, they may not be so generous. Media can be recorded at any time or place using a tablet or smartphone and then transferred to cloud storage using built in ‘save to’ option, a far more convenient option than trying to restore back to windows file share.

This is one situation where personal devices could be used effectively in schools.  Modern smartphones have some astonishing capabilities to record and manipulate video including slow-motion, time lapse, HD and built-in editing tools. They are almost certainly more capable than a shared five year old digital camera. Regardless of the policy students are going to use smartphones anyway - it’s a lost battle.

Uploads from mobile devices will form the building blocks of a student project. These smaller files may well absorb some bandwidth from the school internet connection but they’re equally likely to be transferred across a home broadband connection or even personal data plan because the data is stored in the cloud not local storage.  The big one-off hit on the school internet connection goes away. Shazam!

Once in the cloud editing a 3Gb video file will be just as quick as a 3Mb clip and can be achieved on any device that supports a modern browser interface, including a Chromebook or legacy PC.

In all honesty the capability of video editing software currently available as SaaS can't match a local installation of Adobe Premiere Pro (yet) but do Year 10’s really need all the advanced features or do they just need something that’s simple to use, integrates closely with cloud storage and most important of all is accessible.

After all what’s the point of having a fully featured video editing suite if it’s behind a locked door most of the time?

A SaaS package like WeVideo provides students access to an editing tool that contains all of the the common features you require to create a professional looking video that works on a range of devices both in school and out and this offering is far from unique.

A quick search will reveal any number of offerings in the video editing, graphics editing and the 3D modelling space.

As a last thought, remember all those problems around software upgrades, remote access, storage growth and security, well they disappear as well.

It’s like magic!