How many indexers is too many?

[colinj]

As I've been building out our Splunk installation I've been treating the indexers as appliances. By that I mean all of the indexers are identical down to every indexer having every index. This allows me to have all forwarders writing to all of the indexers.

My thinking goes something like this:

1. If an indexer dies it's easy replace.
2. If I can spread the load across multiple indexer the indexers can use simpler hardware and need less storage.
3. As I need to grow my installation I can simply add more indexers.
4. Loss of any one indexer means a loss of only a portion of all indexed data.

So, this raises some questions:

• Is there a real or logical limit to the number of indexers I might have?
• When does adding more indexers start to make things worse instead of better?
• Is it better to have 4 8 CPU indexers or 8 4 CPU indexers?

Thanks!

[araitz · Accepted solution]

The answer is: "it depends". There is a spectrum of deployments out there from one laptop to scores of indexers. Beyond data volume, you should also analyze your search use cases.

Scaling horizontally and treating indexers as disposable commidities is generally the right approach. More, cheaper indexers is generally better than fewer, more expensive indexers. The main cost is management/deployment complexity.

For more best practices, see:

http://docs.splunk.com/Documentation/Splunk/4.3.1/Installation/CapacityplanningforalargerSplunkdeplo...