Status Code 502 returned by RStudio Server when executing 'client_init'

Problem

You may see an error similar to the below when attempting to launch a new session:

Whilst the example above refers to 'client_init' as the rpc call, there are a number of other values that can occur, such as 'console_input'.

Solution

First, you need to set the following directives in your /etc/rstudio/rserver.conf file:

session-ssl-enabled=0
rsession-proxy-max-wait-secs=45

Note that these directives need to be set on all nodes if you have multiple Workbench nodes. From there, restart the Workbench and launcher services:

sudo rstudio-server restart

sudo rstudio-launcher restart