Troubleshooting for Users

The following offers some solutions to common issues when setting up and using Fili. If you come across any issues that you think belong here, please feel free to contribute.

Table of Contents


The Fili logs are Jetty logs, so they can be found wherever your Jetty instance stores its logs.

The logs have a lot of information and should help indicate the error. More info on logging levels

App tests return a 500 error

It may be that the versions of dependencies in your application’s POM are out of sync with the dependency versions used by fili. If that is the case, then modifying your dependency versions to use the same version as fili should solve the problem.

Fili crashes and with IllegalStateException

There are two possible causes for Fili crashing with IllegalStateException: Couldn't create dir: path/to/mdbm/dimensionCache/page:

  1. The dimensionCache subdirectory in path/to/mdbm does not exist. Fili assumes path/to/mdbm/dimensionCache already exists, and does not attempt to create it.

  2. dimensionCache exists, but does not have the correct read/write/execute permissions. The user that Jetty is running under (typically nobody) needs to have read, write, and execute permissions on dimensionCache.

Server log claims the segment metadata loader is not healthy

Your dimensions have never been updated, and don’t have a lastUpdated field set. This can happen if you forgot to set up your dimension loader. You can get more details about the problem at the /healthcheck endpoint. If the dimensions are not being loaded, then see the Dimension Loading for more details on how to set up the dimension loader (or configure all of your dimensions to be non-loaded).

Debugging Queries

If you make a query to Fili that doesn’t work as expected it may be helpful to add the format=debug to the end of your query like below.

GET http://localhost:9998/v1/data/wikipedia/day?metrics=added&dateTime=2000-01-01/3000-01-01&format=debug

This lets you see the exact query which would have been sent to Druid. See the Druid Querying Docs