netty | Netty 4 | Websocket library

I'm trying to initiate a Springboot project using Open Jdk 15, Springboot 2.6.0, Springfox 3. We are working on a project that replaced Netty as the webserver and used Jetty instead because we do not need a non-blocking environment.

In the code we depend primarily on Reactor API (Flux, Mono), so we can not remove org.springframework.boot:spring-boot-starter-webflux dependencies.

I replicated the problem that we have in a new project.: https://github.com/jvacaq/spring-fox.

I figured out that these lines in our build.gradle file are the origin of the problem.

Facing below error while starting spark-shell with yarn master. Shell is working with spark local master.

Currently, google dataproc does not have spark 3.2.0 as an image. The latest available is 3.1.2. I want to use the pandas on pyspark functionality that spark has released with 3.2.0.

I am doing the following steps to use spark 3.2.0

1. Created an environment 'pyspark' locally with pyspark 3.2.0 in it
2. Exported the environment yaml with conda env export > environment.yaml
3. Created a dataproc cluster with this environment.yaml. The cluster gets created correctly and the environment is available on master and all the workers
4. I then change environment variables. export SPARK_HOME=/opt/conda/miniconda3/envs/pyspark/lib/python3.9/site-packages/pyspark (to point to pyspark 3.2.0), export SPARK_CONF_DIR=/usr/lib/spark/conf (to use dataproc's config file) and, export PYSPARK_PYTHON=/opt/conda/miniconda3/envs/pyspark/bin/python (to make the environment packages available)

Now if I try to run the pyspark shell I get:

Problem: for one of my unit-tests, I want to simulate throwing an exception (io.netty.handler.timeout.TimeoutException) in combination with Mockito. However, Java won't allow this because the exception is package-protected.

Right now I have the following bit of code:

I am running a Spring Boot app that uses WebClient for both non-blocking and blocking HTTP requests. After the app has run for some time, all outgoing HTTP requests seem to get stuck.

WebClient is used to send requests to multiple hosts, but as an example, here is how it is initialized and used to send requests to Telegram:

WebClientConfig:

It was a project that used to work well in the past, but after updating, the following errors appear.

I have a ktor app. I works fine when I run it in development mode. I package it in a docker image by copying over what the gradle application plugin provided. That also works fine on my local machine 8 cores. But now the strange part. When I do exactly the same thing on a rented V-Server also running Ubuntu-20.04 like my local system, ktor is incredible slow.

After upgrading from spring-boot-parent version 2.5.5 to 2.6.0, I started seeing these error messages spamming the logs:

[INFO] [stdout] 2022-01-11 13:40:01.157 WARN 76859 --- [ udp-epoll-2] i.m.s.reactor.netty.channel.FluxReceive : [6d1243de, L:/127.0.0.1:58160 - R:localhost/127.0.0.1:8125] An exception has been observed post termination, use DEBUG level to see the full stack: java.net.PortUnreachableException: readAddress(..) failed: Connection refused

Using DEBUG level:

I'd like connect to Delta using JDBC and would like to run the Spark Thrift Server (STS) in local mode to kick the tyres.

I start STS using the following command: