Presto Router

Presto Router is a service that sits in front of Presto clusters. It routes requests to Presto clusters, collects statistics from Presto clusters, and shows aggregated results in a UI.

Running Presto Router in your IDE

After building Presto, load the project into your IDE and run the router. In IntelliJ IDEA, use the following options to create a run configuration:

Main Class: com.facebook.presto.router.PrestoRouter
VM Options: -Drouter.config-file=etc/router-config.json -Dnode.environment=devel
Working directory: $MODULE_WORKING_DIR$ or $MODULE_DIR$ (Depends on your version of IntelliJ)
Use classpath of module: presto-router

The working directory should be the presto-router subdirectory.

If necessary, edit the etc/router-config.json file and add the Presto clusters' endpoints in the groups.members field.

Building the Web UI

Similar to the Presto Web UI, the router Web UI is also composed of React components and is written in JSX and ES6. To update this folder after making changes, run:

yarn --cwd presto-router/src/main/resources/router_ui/src install

If no JavaScript dependencies have changed (that is, no changes to package.json), it is faster to run:

yarn --cwd presto-router/src/main/resources/router_ui/src run package

To simplify iteration, you can run in watch mode, which automatically re-compiles when changes to source files are detected:

yarn --cwd presto-router/src/main/resources/router_ui/src run watch

To iterate quickly, re-build the project in IntelliJ after packaging is complete. Project resources are then hot-reloaded and changes are reflected on browser refresh.