1 new chat request from Free onine sex chating girls

Even without accounting for the sizeable overhead of spawning an OS process that, on average, twiddles its thumbs for a minute before reporting that no one has sent the user a message, the waiting time could be spent servicing 60-some requests for regular Facebook pages.

The result of running out of Apache processes over the entire Facebook web tier is not pretty, nor is the dynamic configuration of the Apache process limits enjoyable.

1 new chat request from-361 new chat request from-19

Cache misses and database failure can be detected by the non-database layers and either reported to the user or worked around using replication.

While this architecture works pretty well in general, it isn't as successful in a chat application due to the high volume of long-lived requests, the non-relational nature of the data involved, and the statefulness of each request.

We chose to simulate the impact of many real users hitting many machines by means of a "dark launch" period in which Facebook pages would make connections to the chat servers, query for presence information and simulate message sends without a single UI element drawn on the page.

With the "dark launch" bugs fixed, we hope that you enjoy Facebook Chat now that the UI lights have been turned on.

Having Thrift available freed us to split up the problem of building a chat system and use the best available tool to approach each sub-problem.

The secret for going from zero to seventy million users overnight is to avoid doing it all in one fell swoop.

One of the things I like most about working at Facebook is the ability to launch products that are (almost) immediately used by millions of people.

Unlike a three-guys-in-a-garage startup, we don't have the luxury of scaling out infrastructure to keep pace with user growth; when your feature's userbase will go from 0 to 70 million practically overnight, scalability has to be baked in from the start.

The project I'm currently working on, Facebook Chat, offered a nice set of software engineering challenges: The most resource-intensive operation performed in a chat system is not sending messages.

Tags: , ,