Our app does a lot of writing. We were on Mongo 1.8 which has a global write lock. So concurrency was a big problem under load. We also have a lot of users with networks of 200k+ people – not even including followers. This meant that we had to have arrays in the User collection with 200k+ IDs to perform a lot of our queries. The RAM needed for indexes wasn't really worth the cost and performance started to become a big concern. In the end, our data makes more sense in SQL with a cache layer (Redis in our case) rather than NoSQL.
Our experience thus far in Mongo vs Postgres: go with what you know. We probably could have made Mongo work for us (especially Mongo 2.0+), but it was easier for us to work out the performance issues with Postgres. Plus, things made more sense in SQL.
If you're using Mongo and need a cloud provider, I can recommend the people at MongoLab. They really went above and beyond helping us get up and running and are really cool people.
I did something similar to watch hulu from Canada awhile back but I had split tunnelling disabled where all traffic goes through the vpn so no messing around with static routes and ips. Also setup a local DNS cache on the VPS and configured openvpn to use the VPS DNS cache when connected. CDN's generally use the ip of the DNS request to determine where to direct your browser to download the media, static host entries would avoid the DNS request though. I no longer have it setup, but I do have my config backed up somewhere. If someone's interested I'll look for it.
The fragmentation mentioned in the article to me highlights one of the main reasons why enterprises shy away from Android. On iOS, there is ONE email/calendar client with a known set of features/limitations. On android, almost every manufacturer has their own email client and their varying feature sets and bugs are not documented anywhere. For example: http://code.google.com/p/android/issues/detail?id=4760 How many posts in there are from google employees stating that it's not their problem because the email client the person is complaining about isn't written by google?
I had some discussions with Goodmail late last year about potentially using their service. We send a decent amount of mail via custom qmail servers. For us, it was a chicken and egg problem, Goodmail obviously required a maximum complaint rate but on the flip side higher complaint clients would be the ones most interested in the service. Our low complaint clients were already hitting the inbox and Goodmail didn't seem to justify the extra effort and cost to drive better engagement.
That was the original push, but lots of manufacturers botched the implementation. For example, some would apply 3:2 pulldown to 60hz and then double it instead of 5:5 pulldown. Nowadays 240hz are all the rage making movies look like a cheap karaoke video.
I've been using http://www.webpagetest.org which is pretty well known in WPO circles. It's not as "pretty" as your site, but offers more features like recording video, Dynatrace recordings, firstview vs 2ndview, etc.
+1 for http://www.webpagetest.org , it's probably one of the best if not THE best performance testing webapp on the web. I've been using it for a while and it's just amazing. I love your Academy section, as well as the simplicity of the site landingpage.
Does anyone actually use SNI? Looked into it but browser support would exclude ANY IE version on Windows XP which is pretty significant. Android and BB browsers also don't support it.
I don't know of mainstream hosts using it today, but I have to imagine that hosting companies want to offer it as an option to their customers.
Interesting point about Android and BB, I hadn't noticed that before. Kind of seems like a chicken and egg problem. Obviously server admins don't want to turn on the feature until the clients support it, but the client support will go slowly until there are servers requiring it.
IE/XP browser support is what held me back when I was looking at SNI. SNI would have definitely made a migration to Amazon AWS more compelling. Without SNI, every unique SSL certificate = unique external ip = unique EC2 instance.
