Service supervision and logging

Imply ships with a supervise command that manages service lifecycles and console logs. It is configured through a single configuration file per machine. Each machine can potentially start many services. For example, when you run the command:

bin/supervise -c conf/supervise/master-with-zk.conf

This tells supervise to use the file conf/supervise/master-with-zk.conf to select which services to run.

By default, the supervise program runs in the foreground. You can run supervision in the background, if you want, by adding the --daemon argument:

bin/supervise -c conf/supervise/master-with-zk.conf --daemon

You can restart an individual service using its name. For example, to restart the zk service, run bin/service --restart zk from the distribution.

To shut down all services on a machine, kill the supervise process (CTRL-C or kill SUPERVISE_PID both work) or run the command bin/service --down from the distribution.


By default, logs are written to var/sv/<service>/current in the distribution. You can write these files to any location you want by passing the -d <directory> argument to bin/supervise.

For added convenience, you can also tail log files by running bin/service --tail <service>.

On MacOS and Linux, logs are automatically rotated using the included logger program. On other platforms, to prevent log files from growing forever, you can periodically truncate the logs using truncate -s 0 <logfile>.

Customizing supervision

You can modify the provided supervision files or create new files of your own. There are two kinds of lines in supervision files:

Updating a cluster

When updating an Imply cluster, you should follow the typical procedure for a Druid Rolling Update. If you have deployed your cluster with the Master, Query, and Data server configuration, then take note of the following:

Druid operations

Please see the Druid operations documentation for tips on best practices, extension usage, monitoring suggestions, multitenancy information, performance optimization, and many more topics.




Manage Data

Query Data



Special UI Features

Imply Manager