As described in A case for Enterprise Widgets we had about 4 hours notice to get the project off the ground. Figuring out the server side was straightforward, we used a single ASP to query the database and retreive the scheduling information. To streamline things in the widget, we decided to put all the selection and time logic we could in the ASP. All the widget had to do was poll the sever every minute and display the results. The "Enterprise" Twist In a normal widget, you may poll once a day, on startup or maybe even once every few minutes. Each TechEd Schedule widget was going to poll once a minute. Based on some quick calculations, we where expecting about 10 to 20 hits on the server per second during peak periods. To keep the minimum load on all the components we decided to use JSON over HTTP instead of using XML, RSS or Web Services. JSON support is built in to most JavaScript engine. If you've never used it before, I encourage you to have a look, it may save you some time in future projects. In addition to being easy to cache in the ASP, using a simple string to represent the query results would keep the server load to an absolute minimum as well as make the parsing work in the widget a piece of cake.
Testing ? Stefan did his usual magic on the widget and we were all wrapped up by Monday night. The situation did not leave much time for testing. Before we turned the widget over to a few hundred users, we needed to make sure that it would work well, especially in an environment when users would be in intermittent network coverage. To simulate the conditions, we throttled a set of widgets to poll once every few seconds instead of once per minute and deployed them to as many machines as we could find. The last few tiny issues were resolved and at about 8pm on Monday night, we were ready to go.
Success ! In the end, it all came together. The TechEd IT team was instrumental in making this happen. What we learned here is that when widget projects are kept as simple and streamlined as possible, results can be achieved extremely quickly.
