This page captures frequently asked questions with a focus on errors that you may encounter when running Flux.

Table of contents

Common errors

How do I fix an error containing ‘java.net.BindException: Cannot assign requested address’?

You may encounter this error with any Flux command. The full error will contain the following:

java.net.BindException: Cannot assign requested address: Service 'sparkDriver' failed after 
16 retries (on a random free port)! Consider explicitly setting the appropriate binding address 
for the service 'sparkDriver' (for example spark.driver.bindAddress for SparkDriver) to the 
correct binding address.

The error is due to the underlying Spark runtime in Flux failing to startup. You can find a number of resolutions for this error, a few of which are summarized below:

  1. Include -Cspark.driver.bindAddress=127.0.0.1 to define a Spark bind address that does not use localhost.
  2. Run export SPARK_LOCAL_IP="127.0.0.1" to define a Spark bind address via an environment variable.
  3. If you are on a VPN, try disconnecting and reconnecting to the VPN.