Fighting Fit Again

Here at Sencha, we’re constantly aware of how much you depend on our frameworks, tools, services and forums — to learn new skills, to develop amazing apps, and even just to hang out with our amazing community.

But we also know how frustrating it can be when things that you rely on on a daily basis suddenly aren’t, well, reliable. And how frustrating it can be when you don’t know why.

So, we’d like to apologize for some of the issues we’ve been having recently with our web server, and in particular, the performance of our forums, documentation, and main site. And explain how we got there and what we’re doing to ensure that it doesn’t happen again.

Firstly, like many other companies, we use Amazon Web Services to provide much of our web server infrastructure, and were affected by that service’s downtime several weeks ago. That certainly caused us to think carefully about how we wanted to provide more tolerance for our main site. Shortly afterwards, we launched Ext JS 4.0, a major upgrade to our flagship desktop framework, and accordingly we also doubled the number of our server instances to handle the demand.

Meanwhile, as part of the Ext JS SDK, we wanted to demonstrate exciting new features such as infinite scrolling and the buffered grid — and we needed to show their use against a real-world data source. Quite reasonably (we thought), we chose our own community forum’s database for many of our examples — a large and dynamic data source that we could easily create a server-side API for.

At this point, the unfortunate consequence probably writes itself. A highly popular SDK, containing a large number of highly data-driven demos, being used by tens of thousands of developers around the world all at once, via a larger pool of servers… all accessing a single database instance.

Sadly the database simply couldn’t take it in its stride. Although designed for the vBulletin forum software itself, it just didn’t have the appropriate optimizations for the sheer number of direct data queries that were being made.

So as a result, you’ll have noticed that forums have been running significantly slower than usual. And worse, on a small number of occasions recently, the impact has been significant enough to affect the other sites that rely on the same database server: namely the Sencha web site itself, our online documentation, and SenchaDevs.

But now that we have identified the cause of the issue, we’ve addressed it in a number of ways. We’ve optimized the database for the queries that the SDK grid examples are making, and for future versions of these examples, we’ll be using alternative data sources. We’ll also be distributing the database instances for different sites across different physical servers.

Finally, we’re installing European instances of our services so that developers to the east of GMT should have greatly improved responsiveness for all of these sites.

(As an aside, we’d also like to point out that our newly announced cloud services run on entirely different infrastructure. They are also proving extremely popular, but are designed to be completely scalable with demand, and have not been affected at all by this issue.)

So we’re on top of it, and are sure we’re able to put these disappointing events behind us. Our apologies again for any inconvenience caused.

And of course we hope to see you all on those blazingly-fast forums again!

Written by

James Pearce heads developer relations at Sencha. He is a technologist, writer, developer and practitioner, who has been working with the mobile web for over a decade. Previously he was the CTO at dotMobi and has a background in mobile startups, telecoms infrastructure and management consultancy. James is the creator of tinySrc, the WordPress Mobile Pack, WhitherApps, modernizr-server and confess.js, and has written books on mobile web development for both Wiley and Wrox.


  1. Michael Stahle says

    Yep, you weren’t the only ones hurt by Amazon. Still awesome frameworks, good, useful forums, and over all useful site! The only thing missing is the tutorial section.



  2. Jeremy Johnson says

    Glad to hear the issues are fixed and I get back to searching the forums and API docs as needed ;)

    Keep up the great work guys!

  3. says

    Bob – we haven’t compared Rackspace to Amazon. AWS uptime was pretty good for the last two years, so we thought we were pretty safe on it. In addition, it was cost-competitive, constantly rolling out new features and had a good bevy of tools and tools companies supporting it.

  4. Ryan Stuart says

    Would Amazon RDS or a NoSQL solution like Mongo solve your problems? Or is this already how you have solved them?

  5. snailgem says

    thank you, much better performance, tho still the occasional lag (you’re hitting, does this mean you’re not using the cloud any more?)

    maybe an upgrade to the prehistoric tutorials next? ;—–)

  6. camelCase says

    Did you fix the API Docs center at the same time? The old docs web app had performed perfectly for years, then the new investment money triggered a redesign of the docs center that was a perfect example everything a RIA web app should not do. When a new page arrived, is was rendered, then a second later it went through some belated CSS reformat convulsion. But worst of all the navigation tree then completely repainted, followed by a multi phase wriggle and pop tree expansion before the original doc item selection was highlighted once more.

    As to the look and feel of the new doc center, did you sub contract the design to the original creator of Bindows?

  7. Nick Poulden says

    @camelCase please see for the most recent version of the documentation which addresses all the issues you mentioned. Improvements over the old documentation app include the ability to function over the file:// protocol and History and Favorites dropdowns which persist across browser sessions by harnessing Local Storage.

    We will be publishing updates to the documentation as and when new features are added rather than waiting for a new release so please keep an eye on for updates.

  8. David Easley says

    > Improvements over the old documentation app include … History and Favorites

    Please, how do I create a Favorite?

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