Which action is recommended to improve overall search performance?

Disabling indexed real-time search can significantly enhance overall search performance by reducing the load on Splunk’s indexing and search systems. When real-time searches are enabled, they continuously access and process incoming data, which can lead to increased resource usage and slower performance. Indexed real-time searches can strain the system because they require immediate access to the data as it arrives.

By disabling this feature, you can allocate more resources to other types of searches, such as historical searches, which generally offer better performance because they can utilize optimized indexing processes. This approach helps streamline operations, allowing for faster search responses and reduced resource contention in the Splunk environment.

The other options do not offer the same level of positive impact on search performance. For instance, increasing the retention time of indexed data may lead to more data being stored, which could slow down searches over time if not managed properly. Limiting the number of concurrent searches helps in managing system resources but might not drastically improve performance depending on workload and data size. Enabling event sampling can make searches faster, but it sacrifices some completeness and accuracy for speed, which might not be suitable for all scenarios.