10. What is sc_pack?¶
sc_pack is a “pack” of programs that helps manage edge servers running ShimmerCat Accelerator.
It includes and configures the following programs:
ShimmerCat QS: the program actually serving files
sc_logsagent: a small program that sends ShimmerCat’s logs to the mothership (our cloud service)
redis: used by ShimmerCat, and usually included right with it
supervisord: A utility that helps manage stacks of programs
A Celery worker, that takes instructions from the cloud service.
An update daemon, that can upon instructions download a new version of
sc_packand install it.
An image optimization service (
usher) that, when enabled, submits image optimization jobs to our cloud service.
Several utilities for synchronizing the configuration of a site across multiple deployment sites.
10.1. How everything runs¶
You can understand more easily what’s going on if you compare the programs in this list to a
well-coordinated sports team whose captain is
sc-pack itself is its coach or manager.
In Unix, each process has a parent, and here is how it looks for
<system process manager> -- sc_pack's supervisord -- redis-server -- sc_logs_agent -- shimmercat -- celery worker -- sc_pack's update
To learn more about how to setup your
sc_pack configuration, see setup sc_pack