[GSS](7.3.z) WFLY-13933 - access-log entries might become lost during the shutdown even if graceful timeout is specified

To reproduce this issue, you can use either of the following methods to emulate slow down before completing to write all access log entries. Then, trigger shutdown during the slowdown. Use debugger to set thread-level breakpoint in Undertow's DefaultAccessLogReceiver#writeMessage() (or inside run()) Use byteman script to invoke Thread.sleep() in Undertow's DefaultAccessLogReceiver#writeMessage() (or inside run()) RULE DefaultAccessLogReceiver_writeMessage CLASS io.undertow.server.handlers.accesslog.DefaultAccessLogReceiver METHOD writeMessage AT ENTRY IF TRUE DO   traceStack( "-------------- io.undertow.server.handlers.accesslog.DefaultAccessLogReceiver#writeMessage() is invoked \n" );   Thread .sleep(10000L); // emulate slow down ENDRULE Then, follow the steps: 1. Send several requests to JBoss ab -n 10 -c 5 http: //127.0.0.1:8080/ 2. Shutdown JBoss (the same result happens regardless of using graceful shutdown or not) ./bin/shutdown.sh -c ":shutdown()" or ./bin/shutdown.sh -c ":shutdown(timeout=30)" EAP 7.2 waits shutdown for the task thread to complete writing all access-log entries. However, EAP 7.3 does not wait. It only waits for 100 milliseconds because of the behavior change by WFCORE-1632 . So, some log entries will be lost.