High availability and auto-scaled Rocket.Chat

Highlights

Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework.

Environment Topology

The JPS package will deploy Rocket.Chat instance that will initially contian

• 1 nginx balancer to handle SSL and traffic
• 2 node.js containers with application itself
• 1 MongoDB ReplicaSet instance (3 MongoDB servers)

Specifics

Layer	Server	Number of CTs by default	Cloudlets per CT (reserved/dynamic)	Options
LB	Nginx 1.12.2	1	1/6	-
AS	Node.js 8.12.0	2	1/16	-
DB	MongoDB 4.0.9	3	1/16	-

• LB - Load balancer
• AS - Application server
• DB - Database

Rocket.Chat version: 1.0.3

Automatic scaling

Application layer is set to scale up to 4 indivirual Rocket.Chat instances if CPU load is higher than 70% over last 1 minute.

It will automatically scale down if load gets to lower than 10% of CPU usage over last 15 minutes to the original 2 application node setup.

See more on autoscaling: https://docs.jelastic.com/automatic-vertical-scaling

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Differences from https://github.com/jelastic-jps/rocket-chat

• deployed to NodeJS templates (horizontally scaled) with Nginx load balancer in front vs. deployed to rocketchat docker image (single compute node)
• database backend is MongoDB ReplicaSet (3 MongoDB servers) vs. single MongoDB node

Deployment

LICENSE

Licensed under GNU LGPLv3