# Unexpected I/O exception on channel java.lang.IllegalStateException: Invalid Status Code 502 **URL:** \ **Category:** Gatling (Open-Source)\ **Created:** [October 16, 2017, 7:59am UTC](https://community.gatling.io/t/unexpected-i-o-exception-on-channel-java-lang-illegalstateexception-invalid-status-code-502/3992 "2017-10-16T07:59:37Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![thiru](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@thiru](https://community.gatling.io/u/thiru)\ **Post date:** [October 16, 2017, 7:59am UTC](https://community.gatling.io/t/unexpected-i-o-exception-on-channel-java-lang-illegalstateexception-invalid-status-code-502/3992/1 "2017-10-16T07:59:37Z")
Request DefaultFullHttpRequest(decodeResult: success, version: HTTP/1.1, content: EmptyByteBufBE) **My Scala file:** val httpProtocol = http .baseURL(“[http://IP](http://IP)”) .wsBaseURL(“ws://IP”) .header(“Pragma”,“no-cache”) .header(“Cache-Control”,“no-cache”) .header(“Upgrade”,“websocket”) .header(“Sec-WebSocket-Version”,“13”) .header(“User-Agent”,“Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36”) .header(“Accept-Encoding”,“gzip, deflate”) .header(“Accept-Language”,“en-US,en;q=0.8,hi;q=0.6”) .header(“Sec-WebSocket-Extensions”,“permessage-deflate; client\_max\_window\_bits”) .header(“Connection”,“Upgrade”) .header(“Upgrade”,“websocket”) val scn = scenario(“WebSocket”) .feed(feeder) .exec(ws(“Client Connection”).open(“URL”).check(wsAwait.within(300).until(1).regex("._reexp._"))) .pause(2) .exec(ws(“Client Connection Close”).close) setUp(scn.inject(atOnceUsers(1)).protocols(httpProtocol)) } ---
**Author:** ![slandelle](https://dub1.discourse-cdn.com/flex013/user_avatar/community.gatling.io/slandelle/32/4_2.png) [@slandelle](https://community.gatling.io/u/slandelle)\ **Post date:** [October 16, 2017, 8:01am UTC](https://community.gatling.io/t/unexpected-i-o-exception-on-channel-java-lang-illegalstateexception-invalid-status-code-502/3992/2 "2017-10-16T08:01:44Z")
Please provide an actionable reproducer so we can investigate. Nothing we can do without one. Thanks, ---
**Author:** ![thiru](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@thiru](https://community.gatling.io/u/thiru)\ **Post date:** [October 16, 2017, 8:17am UTC](https://community.gatling.io/t/unexpected-i-o-exception-on-channel-java-lang-illegalstateexception-invalid-status-code-502/3992/3 "2017-10-16T08:17:19Z")
This is a websocket based request using gatling. i am setting all the headers manually as mentioned in scenario/scala file. But NGINX which proxies my application is rejecting the gatling request with HTTP 502 error. I am surprised,if Gatling is adding any additional headers which are not accepted by NGINX ? Is there any other setting i have to do on gatling side so websocket request works ? The same request with the same headers is working with a local tool built on Browser + Jquery. the log says: 07:00:09.988 [WARN] o.a.n.h.WebSocketHandler - onError java.lang.IllegalStateException: Invalid Status Code 502 at org.asynchttpclient.ws.WebSocketUpgradeHandler.onCompleted(WebSocketUpgradeHandler.java:81) at org.asynchttpclient.netty.handler.WebSocketHandler$UpgradeCallback.call(WebSocketHandler.java:98) at org.asynchttpclient.netty.handler.AsyncHttpClientHandler.channelRead(AsyncHttpClientHandler.java:71) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438) at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:312) at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:286) at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at io.netty.handler.logging.LoggingHandler.channelRead(LoggingHandler.java:248) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1302) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131) at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:646) at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:581) at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:498) at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:460) at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:131) at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138) at java.lang.Thread.run(Thread.java:745) 07:00:09.989 [ERROR] o.a.n.h.WebSocketHandler - onError java.lang.IllegalStateException: Invalid Status Code 502 at org.asynchttpclient.ws.WebSocketUpgradeHandler.onCompleted(WebSocketUpgradeHandler.java:81) at org.asynchttpclient.netty.handler.WebSocketHandler.handleException(WebSocketHandler.java:206) at org.asynchttpclient.netty.handler.AsyncHttpClientHandler.exceptionCaught(AsyncHttpClientHandler.java:200) at io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:280) at io.netty.channel.AbstractChannelHandlerContext.notifyHandlerException(AbstractChannelHandlerContext.java:843) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:358) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438) at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:312) at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:286) at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at io.netty.handler.logging.LoggingHandler.channelRead(LoggingHandler.java:248) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1302) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131) at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:646) at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:581) at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:498) at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:460) at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:131) at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138) at java.lang.Thread.run(Thread.java:745) 07:00:09.989 [DEBUG] o.a.n.c.ChannelManager - Closing Channel [id: 0x776bdc95, L:/#####:42682 ! R:/######:80] 07:00:09.989 [DEBUG] o.a.n.h.WebSocketHandler - Channel Closed: [id: 0x776bdc95, L:/#######:42682 ! R:/########:80] with attribute INSTANCE 07:00:12.006 [DEBUG] i.g.c.a.Exit - End user #1 07:00:12.007 [DEBUG] i.g.c.c.Controller - End user #1 ---
**Author:** ![thiru](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@thiru](https://community.gatling.io/u/thiru)\ **Post date:** [November 22, 2017, 8:13am UTC](https://community.gatling.io/t/unexpected-i-o-exception-on-channel-java-lang-illegalstateexception-invalid-status-code-502/3992/4 "2017-11-22T08:13:34Z")
The issue with gatling is , it is sending the custome header value is CamelCase,If Server Side validation is CaseSensitive then gatling request fails. ---
**Author:** ![slandelle](https://dub1.discourse-cdn.com/flex013/user_avatar/community.gatling.io/slandelle/32/4_2.png) [@slandelle](https://community.gatling.io/u/slandelle)\ **Post date:** [November 22, 2017, 9:04am UTC](https://community.gatling.io/t/unexpected-i-o-exception-on-channel-java-lang-illegalstateexception-invalid-status-code-502/3992/5 "2017-11-22T09:04:50Z")
I don’t know which custom header you’re referring to, but quoting [RFC2616](https://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2): “Each header field consists of a name followed by a colon (”:") and the field value. Field names are case-insensitive." If your server deals with HTTP headers in a case sensitive manner, it’s buggy. ---
**Author:** ![thiru](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@thiru](https://community.gatling.io/u/thiru)\ **Post date:** [November 22, 2017, 9:42am UTC](https://community.gatling.io/t/unexpected-i-o-exception-on-channel-java-lang-illegalstateexception-invalid-status-code-502/3992/6 "2017-11-22T09:42:08Z")
It is said,By definition only header field names are case sensitive not values. ​ Upgrade: WebSocket Header name here: **Upgrade** can be in any case but the value **WebSocket** is case sensitive. if server is validating the value “websocket” and gatling sending it like “WebSocket” even my scenario file contains “websocket” ---
**Author:** ![slandelle](https://dub1.discourse-cdn.com/flex013/user_avatar/community.gatling.io/slandelle/32/4_2.png) [@slandelle](https://community.gatling.io/u/slandelle)\ **Post date:** [November 22, 2017, 10:25am UTC](https://community.gatling.io/t/unexpected-i-o-exception-on-channel-java-lang-illegalstateexception-invalid-status-code-502/3992/7 "2017-11-22T10:25:42Z")
I’m pretty sure we don’t rewrite header values (nor names). Please provide a reproducer. Then, why would you have Gatling send an Upgrade header in a request??? It’s a response header!