[GSS](7.3.z) UNDERTOW-1856 - Undertow read-timeout can cause closing a connection for long running request even if the request processing is not reading any request data

Use ajp-listener instead of http-listener. Because AjpReadListener executes the call to channel.suspendReads() (= ReadTimeoutStreamSourceConduit.suspendReads()) that can cancel the read-timeout expiration at here .

1. Configure read-timeout on http-lister in undertow subsystem. For example: <subsystem xmlns= "urn:jboss:domain:undertow:10.0" ...> ...(snip)... <server name= " default -server" > <http-listener name= " default " read-timeout= "10000" socket-binding= "http" redirect-socket= "https" enable-http2= " true " record-request-start-time= " true " /> <https-listener name= "https" socket-binding= "https" security-realm= "ApplicationRealm" enable-http2= " true " /> <host name= " default -host" alias= "localhost" > <location name= "/" handler= "welcome-content" /> <http-invoker security-realm= "ApplicationRealm" /> <access-log pattern= "%h %l %u %t &quot;%r&quot; %s %b %I %S &quot;%{i,User-Agent}&quot; %T" /> <filter-ref name= "dump-request-filter" /> </host> </server> ...(snip)... <handlers> <file name= "welcome-content" path= "${jboss.home.dir}/welcome-content" /> </handlers> <filters> <expression-filter name= "dump-request-filter" expression= "dump-request" /> </filters> </subsystem> 2. Deploy a war that contains the following sleep.jsp which invokes a longer Thread.sleep() than read-timeout: <% System .out.println( "start" ); Thread .sleep(11000L); System .out.println( "end" ); out.println( "sleep.jsp" ); %> 3. Use the following curl command to send a single request to sleep.jsp $ curl -v http: //127.0.0.1:8080/example/sleep.jsp This request can be processed successfully and access-log entry will be like the following: localhost - - [18/Jan/2021:13:58:36 +0900] "GET /example/sleep.jsp HTTP/1.1" 200 11 default task-2 lzwPlREuRnQZt_-jQMY_RbIIlvsx_D04j3HhpfRV "curl/7.29.0" 11.008 4. Use the following curl command to send two requests (1st one for the welcome content and 2nd one for sleep.jsp), so the 2nd request for sleep.jsp will be sent through the same KeepAlived connection. (Please make sure that execute the following command in one line.) $ curl -v http: //127.0.0.1:8080 http://127.0.0.1:8080/example/sleep.jsp Then, you will see that the curl command shows "Connection died, retrying a fresh connect" on the 2nd request for sleep.jsp. The retried request can be successful, but the initial attempt of sleep.jsp fails. (Note: the retrying request itself is up to the client's behavior. So, the retry may not happen with a different client (e.g. wget) or a different version.) And you will see the following access-log entries. Notice that the 2nd request for sleep.jsp is logged as returned as "200 OK" from I/O thread. localhost - - [18/Jan/2021:14:02:54 +0900] "GET / HTTP/1.1" 200 1531 default task-2 - "curl/7.29.0" 0.005 localhost - - [18/Jan/2021:14:03:04 +0900] "GET /example/sleep.jsp HTTP/1.1" 200 - default I/O-4 5jFVDw8qdTLfxAeJ9yZPiM-mP-tTXU9PaNt5B4aS "curl/7.29.0" 10.010 localhost - - [18/Jan/2021:14:03:15 +0900] "GET /example/sleep.jsp HTTP/1.1" 200 11 default task-1 Md0RG_zyRk5Qq7PKk08L0lH1sgTngglo6xXO9mVn "curl/7.29.0" 11.006