Remote client closed the connection before completing outbound response error at hard refresh

[TanyaM]

Description:
Hard refreshing browser several times throws following error in backend.

[2018-09-10 10:29:08,707] ERROR {org.wso2.transport.http.netty.common.Util} - Remote client closed the connection before completing outbound response java.io.IOException: Remote client closed the connection before completing outbound response
	at org.wso2.transport.http.netty.common.Util.lambda$checkForResponseWriteStatus$9(Util.java:599)
	at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:507)
	at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:481)
	at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:420)
	at io.netty.util.concurrent.DefaultPromise.addListener(DefaultPromise.java:163)
	at io.netty.channel.DefaultChannelPromise.addListener(DefaultChannelPromise.java:93)
	at io.netty.channel.DefaultChannelPromise.addListener(DefaultChannelPromise.java:28)
	at org.wso2.transport.http.netty.common.Util.checkForResponseWriteStatus(Util.java:595)
	at org.wso2.transport.http.netty.contractimpl.HttpOutboundRespListener.writeOutboundResponseBody(HttpOutboundRespListener.java:194)
	at org.wso2.transport.http.netty.contractimpl.HttpOutboundRespListener.writeOutboundResponse(HttpOutboundRespListener.java:142)
	at org.wso2.transport.http.netty.contractimpl.HttpOutboundRespListener.lambda$null$35(HttpOutboundRespListener.java:94)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:403)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:463)
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138)
	at java.lang.Thread.run(Thread.java:748)

Affected Product Version:
4.3.0-rc1

Steps to reproduce:

1. Start the SP pack and go to any app (portal, business-rules etc)
2. Hard refresh browser several times

[this]

This is fixed in transport-http v6.0.193. We need to upgrade to it.

Fixed commit: wso2/transport-http@d20c95b#diff-16e2e4841a96f5eecfa810acd7eb020c
Fixed PR: wso2/transport-http#183

[minudika]

This is related to #928