I forgot that when using the VM transport the message is supposed to be copied on dispatch inside ActiveMQConnection so this may not be the exact issue, I need to look at it a bit more.
On Thu, May 31, 2018 at 9:41 AM, Christopher Shannon < christopher.l.shan...@gmail.com> wrote: > The issue is when using the VM transport and the getText() method has to > unmarshall data back into text from the byte sequence. This happens > because you go from the NIO to VM transport. > > The main problem is you have multiple threads (3 consumers) at the same > time calling getText() on the text message and there is a race condition > where it will set the content to null during it. > > I created a very simple test case to show the issue and created a jira > https://issues.apache.org/jira/browse/AMQ-6981 > > On Wed, May 30, 2018 at 6:06 PM, Arthur Naseef <a...@amlinv.com> wrote: > >> Try turning the broker and client logging up to trace and see what the >> logging shows for the message content. >> >> Also, try the following: >> - Same test with a Java producer (using plain ActiveMQ libs) instead of >> the >> Scala producer >> - Same test with a Java consumer (using plain ActiveMQ libs) instead of a >> Scala consumer >> - Use the "tcp" transport instead of the "nio" transport >> >> Anyway, the goal I would say is to trace the problem to the point of >> hand-off between the broker and client. For example, the following >> questions come to mind (for the problematic messages): >> - Is the broker receiving the body over the wire (i.e. tcp connection)? >> - Is the broker sending the body over the wire? >> - Is the client library receiving the body from the application? >> - Is the client library sending the body to the application? >> >> Hope this helps. >> >> Art >> >> >> On Wed, May 30, 2018 at 2:41 PM, codingismy11to7 <ste...@codemettle.com> >> wrote: >> >> > We recently updated from (ancient) ActiveMQ 5.10.x to 5.15.4. I've >> noticed >> > that text messages are now sporadically returning null as their message >> > bodies when they were sent with bodies. >> > >> > After failing to make a unit test showing this error, I created a >> project >> > that reproduces part of what our software is doing, which reliably >> > replicates the race condition (my last run got null message bodies on >> > ~0.03% >> > of messages). I was able to vastly simplify what our software is doing >> and >> > still reproduce, but when I tried to simplify further the issue stopped >> > appearing. >> > >> > Reproduction and full explanation: >> > https://github.com/CodeMettle/amq_null_body_repro >> > >> > Since I don't have a self-contained unit test I was hesitant to open an >> > issue directly and decided to send a message here instead. >> > >> > I'm a Scala/Akka developer, so I used the tools I was comfortable with >> to >> > make this reproduction without writing a lot of code, but I'm sure >> somebody >> > more comfortable in Java and the ActiveMQ API could reproduce in a unit >> > test. I'm assuming it has something to do with multiple Sessions >> consuming >> > the same topic and calling TextMessage.getText at the same time. >> > >> > Any suggestions of what to do next? >> > >> > Thanks >> > >> > >> > >> > -- >> > Sent from: http://activemq.2283324.n4.nabble.com/ActiveMQ-Dev- >> > f2368404.html >> > >> > >
