37- Minimize IoT System Downtime: Complete Tutorial on MQTT Clustering with Live Demo on Real HW

[@Ind4.0]

It mskes more sense now! Thanks for your time to create this.

[@blociot]

Glad it was useful for you

[@zyghom]

what a great video! thx

[@blociot]

Thank you for watching

[@Darkhan9]

Why use an even number of nodes in the cluster? What about split brain? And also with 2 nodes, the cluster can't even survive 1 node failure, it will go into read-only. That's why clusters of any distributed system are always an odd number, and at least 3 nodes. I assume it's pretty similar to Kafka, so this doesn't make much sense to me.

[@blociot]

Hi Adrian, Great point. This tutorial was just a demo to learn how to implement a cluster in EMQX and configuring NGINX as a load balancer. For sure, a cluster in production environment needs more considerations such as using SSL certificates to secure the communications, defining the number of participating nodes, etc. Which can't be included in one video. Also, EMQX uses Mria for their clustering which reduces the risk of a split-brain situation. You may get more information on their website: www.emqx.io/docs/en/latest/design/clustering.html#:~:text=One%20of%20the%20major%20challenges,is%20the%20only%20active%20cluster.

[@codecinn7170]

can i ask about the solution for emqx clustering in windows and linux. both linux emqx broker and windows broker has the same version which is 5.1.6, and cookie of "emqxsecretcookie", both linux and windows are able to ping each the linux is able to join the cluster (sudo emqx ctl cluster join emqx@192.168.50.178) , but it said "failed to join cluster, node down" windows join the cluster (emqx ctl cluster join emqx@192.168.50.12), do you guys have any suggestion to solve this issue ?

[@blociot]

@@codecinn7170 if I didn't get it wrong, your broker on a Windows machine fails to join the cluster? If this is the case, the first thing I'd check is the windows firewall. I'd turn it off to test or add a firewall rule to allow traffic on the port that you have defined for your broker.