Horizontal Server Scaling inside the Cloud: Multi Nodes

Note: This document is based on Jelastic version 4.9

With Jelastic PaaS & CaaS, hosting of your applications becomes truly flexible. In addition to automatic vertical scaling, Jelastic also lets you increase/decrease the number of servers in your environment manually, if it is required for your application.

The process of scaling is fairly simple - just open the environment topology wizard and use the appropriate “+” and “-” buttons in its central pane to state the required amount of nodes for the selected server:

multi nodes

Tip: You are also able to automate horizontal scaling based on incoming load with the help of tunable triggers.

The maximum number of the same-type servers within a single environment layer depends on a particular hosting provider settings (usually this limit stands for 16 nodes). You can check the exact value within the Quotas & Pricing > Account Limits information frame.

All newly added servers are created at different hardware nodes, providing advanced reliability and high-availability.

high availability

Each environment node group (layer) is presented as a string with server full name. In case it includes several instances, layer name will be complemented with the xN label (where N - actual nodes amount).

Using the triangle icon before a particular layer, you can expand the full list of its nodes. Each of these containers has a unique Node ID identifier and can be accessed, configured or restarted separately:

node id

In order to facilitate interaction with numerous servers of the same type, Jelastic allows to mark a particular node with the appropriate label, e.g. to define master and slave instances in a DB cluster.

Just double-click at the default Node ID: xxx value (or hover over it reveal a special pencil icon) and specify the desired alternative name.

environment aliases

More information on this feature can be found in the Environment Aliases document.

You can scale horizontally all of the stacks in your environment:

The only exception is a Maven build-node (as there is no point to scale it).