Hi Hemant, Yes, this looks like an issue with different library versions. You probably have 3 solutions: * use the netty version of Flink * shade your netty into your jar with relocations * ditch jasync and just use jdbc with a custom thread pool (little overhead)
On Wed, Mar 10, 2021 at 2:40 PM bat man <tintin0...@gmail.com> wrote: > Hi, > > I am using this library -* jasync-postgresql* [1] for async calls to > postgres in asyncio operator. I am using running Flink 1.9 on EMR. > I am facing this error - > > Caused by: java.lang.ClassCastException: > io.netty.channel.epoll.EpollEventLoopGroup cannot be cast to > io.netty.channel.MultithreadEventLoopGroup > at > com.github.jasync.sql.db.util.NettyUtils$DefaultEventLoopGroup$2.invoke(NettyUtils.kt:32) > at > com.github.jasync.sql.db.util.NettyUtils$DefaultEventLoopGroup$2.invoke(NettyUtils.kt:19) > at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74) > at > com.github.jasync.sql.db.util.NettyUtils.getDefaultEventLoopGroup(NettyUtils.kt) > at com.github.jasync.sql.db.Configuration.<init>(Configuration.kt:55) > at com.github.jasync.sql.db.Configuration.<init>(Configuration.kt) > at > com.flink.poc.inventory.AsyncJdbcRequest$AsyncDatabaseRequest.open(AsyncJdbcRequest.java:50) > at > org.apache.flink.api.common.functions.util.FunctionUtils.openFunction(FunctionUtils.java:36) > at > org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator.open(AbstractUdfStreamOperator.java:102) > at > org.apache.flink.streaming.api.operators.async.AsyncWaitOperator.open(AsyncWaitOperator.java:167) > at > org.apache.flink.streaming.runtime.tasks.StreamTask.openAllOperators(StreamTask.java:529) > at > org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:393) > at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:705) > at org.apache.flink.runtime.taskmanager.Task.run(Task.java:530) > at java.lang.Thread.run(Thread.java:748) > > I tried setting taskmanager.network.netty.transport: epoll still no > difference. Is this because of the netty version used by flink and the > library, this library uses - > NETTY_VERSION=4.1.49.Final > > [1] - https://github.com/jasync-sql/jasync-sql > > > Thanks, > Hemant >
