[ 
https://issues.apache.org/jira/browse/AMQ-4710?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17130520#comment-17130520
 ] 

Jan-Philipp Benecke commented on AMQ-4710:
------------------------------------------

Any news about that bug ?

> The first heart-beat after a connection becomes idle isn't sent as quickly as 
> it should be
> ------------------------------------------------------------------------------------------
>
>                 Key: AMQ-4710
>                 URL: https://issues.apache.org/jira/browse/AMQ-4710
>             Project: ActiveMQ
>          Issue Type: Bug
>          Components: STOMP
>    Affects Versions: 5.8.0
>            Reporter: Andy Wilkinson
>            Assignee: Timothy A. Bish
>            Priority: Major
>             Fix For: 5.x
>
>         Attachments: AMQ-4710-double-heartbeat-frequency.patch, amq-4710.diff
>
>
> After ActiveMQ sends a stomp frame, it may not send a heart-beat for up to 
> almost 2x the negotiated interval.
> The following test should illustrate the problem:
> {code}
> import org.junit.Test;
> import static org.junit.Assert.*;
> public class ActiveMqHeartbeatTests {
>       @Test
>       public void heartbeats() throws Exception {
>               BrokerService broker = createAndStartBroker();
>               Socket socket = null;
>               try {
>                       socket = new Socket("localhost", 61613);
>                       byte[] connectFrame = 
> "CONNECT\nheart-beat:0,10000\naccept-version:1.2\n\n\0".getBytes();
>                       socket.getOutputStream().write(connectFrame);
>                       byte[] buffer = new byte[4096];
>                       long lastReadTime = System.currentTimeMillis();
>                       while (true) {
>                               int read = socket.getInputStream().read(buffer);
>                               byte[] frame = Arrays.copyOf(buffer, read);
>                               long now = System.currentTimeMillis();
>                               long timeSinceLastRead = now - lastReadTime;
>                               lastReadTime = now;
>                               System.out.println(new String(frame));
>                               System.out.println("Time since last read: " + 
> timeSinceLastRead + "ms");
>                               if (timeSinceLastRead > 15000) {
>                                       fail("Data not received for " + 
> timeSinceLastRead + "ms");
>                               }
>                       }
>               } finally {
>                       if (socket != null) {
>                               socket.close();
>                       }
>                       broker.stop();
>               }
>       }
>       private BrokerService createAndStartBroker() throws Exception {
>               BrokerService broker = new BrokerService();
>               broker.addConnector("stomp://localhost:61613");
>               broker.setStartAsync(false);
>               broker.setDeleteAllMessagesOnStartup(true);
>               broker.start();
>               return broker;
>       }
> }
> {code}
> For the initial read of the CONNECTED frame I see:
> {noformat}
> Time since last read: 49ms
> {noformat}
> However, it's then almost 20 seconds before a heart-beat's sent:
> {noformat}
> Time since last read: 19994ms
> {noformat}
> If I comment out the fail(…) line in the test, after the first heartbeat 
> taking almost 20000ms to be sent, things settle down and a heartbeat's 
> received every 10000ms.
> It looks like the write checker wakes up every 10000ms. The first time it 
> wakes up, it notices that the CONNECTED frame was sent and does nothing. It 
> then sleeps for a further 10000ms before checking again. As the CONNECTED 
> frame was sent very early in the first 10000ms window, this leads to it 
> taking almost 20000ms for the first heart-beat to be sent. From this point, 
> as no further data frames are sent, the write checker wakes up and sends a 
> heart-beat every 10000ms.
> In short, I don't think ActiveMQ is adhering to the requirement that "the 
> sender MUST send new data over the network connection at least every <n> 
> milliseconds".



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to