Sporadic Request Cancelled while in flight exception

We use core io in our CBAS integration tests and frequently, we get failures due to request cancelled while on flight. The stack trace doesn't show any useful hint as to the cause behind that:

java.lang.RuntimeException: java.lang.RuntimeException: com.couchbase.client.core.RequestCancelledException: Request cancelled in-flight.
at com.couchbase.analytics.test.dcp.CouchbaseConnectorStressTest.lambda$setUp$1(CouchbaseConnectorStressTest.java:97)
Caused by: com.couchbase.client.core.RequestCancelledException: Request cancelled in-flight.
at com.couchbase.client.core.endpoint.AbstractGenericHandler.handleOutstandingOperations(AbstractGenericHandler.java:487)
at com.couchbase.client.core.endpoint.AbstractGenericHandler.handlerRemoved(AbstractGenericHandler.java:468)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.callHandlerRemoved0(DefaultChannelPipeline.java:616)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.destroyDown(DefaultChannelPipeline.java:868)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.destroyUp(DefaultChannelPipeline.java:834)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.destroy(DefaultChannelPipeline.java:826)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.access$700(DefaultChannelPipeline.java:43)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline$HeadContext.channelUnregistered(DefaultChannelPipeline.java:1276)
at com.couchbase.client.deps.io.netty.channel.AbstractChannelHandlerContext.invokeChannelUnregistered(AbstractChannelHandlerContext.java:185)
at com.couchbase.client.deps.io.netty.channel.AbstractChannelHandlerContext.invokeChannelUnregistered(AbstractChannelHandlerContext.java:171)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.fireChannelUnregistered(DefaultChannelPipeline.java:811)
at com.couchbase.client.deps.io.netty.channel.AbstractChannel$AbstractUnsafe$7.run(AbstractChannel.java:699)
at com.couchbase.client.deps.io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:408)
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:402)
at com.couchbase.client.deps.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:140)
at com.couchbase.client.deps.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
at java.lang.Thread.run(Thread.java:745)