Upgrade Splunk All-in-one - Loss of logs on Universal Forwarder

[Silek]

Hello everyone,

I am planning to upgrade my all-in-one Splunk which is on version 7.2.4 to 8.1.

According to the documentation about the upgrade, I am able to perform this upgrade.

However, I have a little question:

Actually I am using a deployment-server and I am collecting logs from universal forwarders only. According to the documentation, I do not have to stop my indexer during the upgrade. In this case, I will not lose any logs during the upgrade.
If we are following the documentation, upgrade sounds very easy but we never know what can happen during the upgrade.

My All-in-one Splunk is installed on a virtualized machine and I will perform a snapshot. I will rollback if any problem happens during the upgrade.
During the upgrade my UFs will keep sending logs to my indexer but if I rollback, every log that my UFs sent to my indexer will be lost.

What can I do to prevent this loss of logs?

Thank you for your replies.

[gcusello · Accepted solution]

Hi @Silek,

if you're receiving logs only from Universal Forwarders you haven't any risk to lose any log because Universal Forwarders cache logs when the Indexer isn't active and then send him logs when it will restart.

Anyway, you haven't to restart your Splunk Server but, obviously, you have to restart Splunk during upgrade.

About the idea to perform a snapshot, it's a good idea.

Splunk upgrade it's very easy and it doesn't require much time for Splunk itself, but it could require some time if you have to upgrade many apps; did you performed the Splunk Upgrade Readiness App (https://splunkbase.splunk.com/app/4698/)?

After this you can know how much time you need for upgrade.

Ciao.

Giuseppe

[Silek]

Thank you for your reply @gcusello ,

Indeed, stoping the indexer is a good idea.

Yes, I performed the Splunk Upgrade readiness app and according to the result, I do not have any blocking apps, only warnings. I will spend some time to upgrade all my apps but it is not blocking for the upgrade itself.

[gcusello]

Hi @Silek,

As I said, you don't need to restart the Indexer server but only to restart Splunk during upgrade, anyway you don't lose any data from Forwarders.

Good for you.

Ciao and happy splunking.

Giuseppe

P.S.: Karma Points are appreciated by all the contributors 😉