Karate UI - Running scenarios in parallel throws an error 'HttpHostConnectException: connect to localhost:9222'

Question

I am trying to execute a feature with 3 scenarios in it using:

Results results = Runner.parallel(tagQuery, featurePaths, null, new ArrayList<>(), 3, karateOutputPath);

With @parallel=false works fine however when I removed, it fails with the following error:

com.intuit.karate.exception.KarateException: test_input.feature:50 - driver config / start failed: 
org.apache.http.conn.HttpHostConnectException: Connect to localhost:9222 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused: connect, options: {type=chrome, target=null}

This occurs at the * driver <url> phase. This is an intermittent failure which most of the time 2/3 scenarios pass and one fails with this error.

Version: 0.9.6.RC3

Answer 1

I recommend using Zalenium like Remote Browser Grid to achieve parallelism and make sure that your scenario are self-contained or atleast keep feature independent.