The Qandidate.com blog has a new post today looking at fault tolerant programming in PHP applications. Essentially, this means writing your code so that error conditions are handled gracefully and with as little impact as possible.
In your application, every time you call an "external" service you are vulnerable to the failure in that service. That either might be a third party API being down, your database being unresponsive or unexpected errors from the 3rd party library you are using. With many developers and companies being interested in composing applications out of microservices at the moment, guarding for failures because of broken dependencies gets even more important.
They describe a situation where data is coming from an external source (an inventory service) and a timeout or connection failure occurs. They propose a sort of "circuit breaker" to be put in place to protect the application, fail fast on error and maybe even retry until the request is successful. They also point out a library from oDesk, Phystrix, that allows for fault tolerant execution through a wrapper that traps errors and deals with them instead of just breaking. This is the first part of a series, so in part two they'll show the library in use along with the React HTTP client.