Which load balancing mode is used in 3 App Nodes HA

Hi everyone,

Which load balancing mode is used in 3 App Nodes HA by default? Is it round-robin, least connection,…How to know which node is chosen to handle the write request from users? Thank you!

Load Balancer Requirements and example configurations can be found in the documentation under Load Balancer Configuration.

You can use either Rounder-Robin or Least Connection. If you’re looking to to identify your current server you will need to look into cookie based LBs that would give an identifier in your browser.

Hi @cbunge
It’s great to see you. That is for App Node’s load balancing mode from users to App Nodes and another question is when an application node sends a query to the database cluster (with 3 nodes multi-master replication as recommended by Morpheus), how do I know Morpheus’s load balancing mechanism determines which node will process that query. Thanks for answering!

The first part of your question is answered in my previous post.

As for the second question around the databases. It depends on how you’ve structured your morpheus.rb settings for the database. If your hosts are listed like ip => 3306, ip => 3306, etc you are configured basically in failover mode. Morpheus tries the first until it doesn’t work, then uses the second, etc.

Beyond that, determining the exact MySQL for each query would involve investigating your MySQL logs.

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Thank you for helpful information @cbunge

Hi @cbunge, I have Distributed App Nodes with Externalized DB ( 3 App nodes, 3 DB nodes, and a Load Balancer behind App nodes followed by installation guide). Please correct me if I’m wrong. Do App nodes always choose the first DB node that is declared in morpheus.rb file? And if the first DB node goes down the secondary node will handle the write, right?

Hope to see your reply, thank you so much!

Yes, that is accurate.

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thank you so much!