Final answer:
Splunk log retention period can vary and is set by the organization using customizable data retention policies. These policies balance storage costs with the need for historical data analysis and can range from 30 days to multiple years, depending on organizational needs.
Step-by-step explanation:
The duration for which Splunk retains logs is not fixed by default and can be configured based on the requirements of the deployment. The retention period, known as the retention policy, is defined by Splunk's index settings and is generally determined by several factors including licensing, the storage capacity, the nature of the data, and organizational requirements. Some organizations may retain logs for a shorter period, like 30 or 90 days, while others with larger storage capabilities and regulatory requirements might retain logs for multiple years.
Splunk offers a feature called data retention policies, which allows administrators to specify how long the data should be kept within Splunk. These policies are customizable to fit varied compliance and business needs. It is common for retention policies to be set in a way that balances the need for historical data analysis with the cost of storage, sometimes leading to a tiered storage approach where the most critical data is retained for the longest period.