something specific for gcloud testing

Signed-off-by: olivier lamy <[email protected]>

jetty-load-generator-listeners/src/main/java/org/mortbay/jetty/load/generator/listeners/QpsListenerDisplay.java

@@ -25,6 +25,8 @@
 import org.eclipse.jetty.util.log.Logger;
 import org.mortbay.jetty.load.generator.LoadGenerator;
 
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.net.InetAddress;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
@@ -88,7 +90,16 @@ public void onCommit( Request request )
     @Override
     public void onFailure( Request request, Throwable failure )
     {
-        LOGGER.warn( "fail to send request", failure );
+        // gcloud log doesn't show stack trace to turn it to a String
+        LOGGER.warn( "fail to send request {}", toString( failure ) );
+    }
+
+    private String toString(Throwable t)
+    {
+        StringWriter sw = new StringWriter();
+        PrintWriter pw = new PrintWriter( sw);
+        t.printStackTrace(pw);
+        return sw.getBuffer().toString();
     }
 
     private static class ValueDisplayRunnable