Splunk Indexer Clustering: Your Hero in the Fight Against Data Loss

Received the dreaded email from AWS that “your volume experienced a failure due to multiple component failures and we were unable to recover it,” and want to learn how to protect against it in the future??

In this tutorial, we explore how Splunk Indexer Clustering protects your data against hardware failures and how to respond to this type of issue when it happens. Need more information? Check out the unabridged tutorial here!

While Splunk can continue to run in a cluster with a failed indexer, the cluster manager node will immediately start replicating data in the cluster to account for the failure and restore the desired state. This can pose a problem if you don’t have enough disk space in your cluster. It’s particularly an issue in smaller clusters, where losing a single cluster member could result in 25%-33% of the total storage suddenly being unavailable.?

Recovery Steps

1. Unless you’re low on disk space, let Splunk continue to operate.?
2. Resolve the storage issue.
3. Get Splunk back up and running–the cluster manager will work to restore the lost data.?
4. Monitor the recovery process.?
5. Clean-up the replicated data by clicking on the “Bucket status” button on the indexes tab of the cluster manager UI, and then clicking on the indexes with excess buckets.?
6. Initiate a rebalance of the data from the cluster manager UI from the “edit” dropdown list.?

And you’re done! Here are a few key takeaways:?

• Ensure your Splunk cluster is configured properly.?
• Use separate volumes/partitions for the operating system and application data.?
• If your environment is deployed in AWS, deploy your indexers across multiple availability zones, and configure multi-site clustering at the availability zone.?
• Don’t push the limits of your storage.?
• Have an incident response plan–and test it.?

Hopefully, this tutorial will help you be better prepared for dealing with this type of issue or responding to one if it were to happen to you.?

Happy Splunking!