#scaling

The metrics-based autoscaler scales an app’s Machines based on any metric, such as pending work items or queue depth. Scaling on metrics other than requests or connections is useful for apps, like background workers, that aren’t running web services. Apps with services that need to scale based on HTTP requests can use the built-in Fly Proxy autostop/autostart feature for Machines.

This type of scaling presents some interesting technical challenges. I'll dig into our development workflow and how we address concepts like scaling, deployment, code review, and testing.

"Green Unicorn (gunicorn) is an HTTP/WSGI Server for UNIX designed to serve fast clients or sleepy applications."

"One of the things that I did when I wrapping up at Yahoo! was to begin to take a look at the current state of web frameworks. I ended up picking Django, but I have to say, I was disappointed with the state of what’s out there. Friends will have heard me bemoaning this sad state of affairs - that while Rails and Django might make CRUD easier, that the ORMs weren’t suitable for scaling beyond “toy” sizes, and that more importantly, they didn’t seem to address almost any of the pain points of building and maintaining a modern website."

"Spock Proxy supports range-based horizontal paritioning of a large MySQL database. The proxy intercepts SQL queries from the client, sends queries to the correct databases based on how the database is partitioned, then aggregates the results from each database and returns them to the client as a regular MySQL result set. "

"Slides from LinuxWorld presentation by John Engates, CTO of Rackspace."

"It seems that using queuing systems in web apps is the new hottness . While the basic idea itself certainly isn’t new, its application to modern, large, scalable sites seems to be. At the very least, it’s something that deserves talking about — so here’s how Flickr does it, to the tune of 11 million tasks a day."

"Shut up about scalability, no one is using your app anyway."

"it really is true that if you haven't done it, that is: been intimately involved growing a social web app from prototype to large/giant-scale on a UNIX stack, then you really don't know shit."

"Nice to see consistent hashing go from obscure to blindingly obvious in a few short whitepapers. "

"In essence MapReduce works by repeatedly sorting and merging data that is streamed to and from disk at the transfer rate of the disk. Contrast this to accessing data from a relational database that operates at the seek rate of the disk"

"Consistent hashing is a powerful idea for anyone building services that have to scale across a group of computers."

"One of the most important architectural decisions that must be done early on in a scalable web site project is splitting the data flow into two streams: one that is user specific and one that is generic."