Which of the following inputs are optional when configuring inputs.conf?

When configuring the inputs.conf file in Splunk, certain fields can be considered optional depending on the use case and the specific needs for data ingestion. Sourcetype, Host, and Blacklist can all be omitted if the user chooses not to define them. This flexibility allows for a wide range of configurations based on the requirements of the data being indexed.

The Sourcetype is a fundamental aspect of data classification within Splunk, but not having a designated sourcetype does not prevent the data from being ingested. Splunk will still index it, and it can be assigned a sourcetype later in the search process if needed.

Similarly, the Host field is used to define the origin of the logs. While it is beneficial for ensuring that data is neatly organized by source, it can be left unspecified if the default behavior of using the incoming data source's host is acceptable for the organization’s needs.

Lastly, the Blacklist field allows administrators to specify patterns of files or data to exclude from being processed. However, if no specific exclusions are necessary, this field can also be safely omitted without impacting data ingestion.

Therefore, designating all these inputs as optional provides administrators with the flexibility to tailor their data intake process without being constrained by mandatory fields.