%% date:: [[2023-08-25]] parent:: %% # [[Logstash]] %% Last Updated: - [[2021-02-10]] %% [site](https://www.elastic.co/logstash) Logstash is an [[Open source]] tool that takes raw data as input and transforms or aggregates it into a more usable format. Logstash is the "L" in the popular [[ELK stack]]. In [[Load Testing]], Logstash is often used to parse load testing results for ingestion by a [[Data Visualization]] tool. For large or long tests, it can also be used to aggregate results from multiple load generators to use, for example, data averaged out over 3 seconds rather than the full raw data. ## Using Logstash ### Installing Logstash Tap the [[Elastic]] [[Homebrew]] repo: `brew tap elastic/tap` Then install Logstash: `brew install elastic/tap/logstash\-full` ### Starting Logstash `logstash` to run in the foreground `brew services start elastic/tap/logstash\-full` to run it and have it automatically restarted on login