Tolerance is a PHP library that provides fault tolerance and microservices related tools in order to be able to solve some of the problems introduced by microservices.
Software fails. Software communicates with other softwares. Software can be distributed or a set of services, which makes it even more subject to faults and monitoring/tracing problems.
The recommended way is to use Composer to install the tolerance/tolerance package.
$ composer require tolerance/tolerance
If you are using Symfony, then checkout the Symfony Bundle. Else, you should have a look to the different components.