I noticed some weird behavior with NingWSClient 2.4.3. when used with Spark.
Try this 1. Spin up spark-shell with play-ws2.4.3 in driver class path 2. Run this code val myConfig = new AsyncHttpClientConfigBean() config.setAcceptAnyCertificate(true) config.setFollowRedirect(true) val oneMinute = 60000 config.setMaxConnectionLifeTime(oneMinute) config.setConnectionTimeOut(oneMinute) config.setIdleConnectionInPoolTimeout(oneMinute) config.setReadTimeout(oneMinute) config.setRequestTimeout(oneMinute) config.setSslSessionTimeout(oneMinute) val client = NingWSClient(config) 1. Quit spark-shell 2. Spark-shell won’t quit. It will just sit there 3. Open a new spark shell, repeat the above code. And then client.close 4. Quit spark-shell 5. Spark-shell quits normally In context of a spark-application, the spark application won’t quit even though the jobs are complete and your main method has exited. It will sit there with the executors holding on to the cores. Looking at the thread dump, it seems like NingWSCLient starts a few threads, and the threads don’t die even after the spark application’s main method quits. Calling client.close cleans up the background threads and the application can exit normally. Has anyone seen this before? ________________________________________________________ The information contained in this e-mail is confidential and/or proprietary to Capital One and/or its affiliates and may only be used solely in performance of work or services for Capital One. The information transmitted herewith is intended only for use by the individual or entity to which it is addressed. If the reader of this message is not the intended recipient, you are hereby notified that any review, retransmission, dissemination, distribution, copying or other use of, or taking of any action in reliance upon this information is strictly prohibited. If you have received this communication in error, please contact the sender and delete the material from your computer.