Keyhole is an open-source project that provides a tool for quickly collecting statistics from a MongoDB cluster and producing performance analytics summaries in a few minutes. It can identify issues related to hardware resources, slow queries without proper indexes, and provide detailed information on cluster configurations, database schema, indexes, and index usages. Keyhole allows users to perform load tests, validate new MongoDB installations, and generate HTML reports with summaries of their cluster's stats and configurations. The tool also provides features such as identifying index redundancy and usage, generating HTML reports, and comparing the total index size under Storage to the system memory to ensure indexes fit entirely in RAM. Keyhole can be used to improve application performance tuning by analyzing mongo logs and Full-Time Diagnostic data Capture (FTDC).