After upgrading from 7.x to 8.x, Elasticsearch cannot start

Elastic Stack Elasticsearch
1

These are the errors in the logs:

Aug 29 13:45:34 ELK-Stack.uhtasi.local systemd-entrypoint[13266]: Error occurred during initialization of boot layer

Aug 29 13:45:34 ELK-Stack.uhtasi.local systemd-entrypoint[13266]: java.lang.module.ResolutionException: Modules tools and jdk.jdi export package com.sun.jdi to module HdrHistogram

Aug 29 13:45:35 ELK-Stack.uhtasi.local systemd-entrypoint[13266]: ERROR: Elasticsearch died while starting up, with exit code 1

Help is appreciated!

2

You have not provided a lot of information, so there is not a lot to go on.

Did you follow the official upgrade guide available in the documentation?

Also please share any errors and context around these from the Elasticsearch logs.

3

I just reverted back to pre-upgrade.

This is my current Upgrade Assistant:

upgrade
upgrade941×828 38.1 KB

I am bypassing the "Back up your data" since I am snapshotting the virtual machine on the VMware side anyway, if that's fine.

My question: Is the rolling upgrade required? Or can I just do the RPM method without doing the rolling upgrade?

4

That is not a supported backup method, so there is no guarantee that will work. Please see the official documentation for further details.

How many nodes do you have in the cluster?

5

How many nodes do you have in the cluster?

"number_of_nodes" : 1

What are the next steps?

6

If you only have one node you can ignore the instructions around rolling upgrade. You will need to upgrade in place with downtime.