Hi All,
A few other lab members and myself have just completed an Ohio State University Technical Report dealing with Qpid broker federation entitled "Scaling Advanced Message Queuing Protocol (AMQP) Architecture with Broker Federation and InfiniBand". The pdf is publicly available at http://nowlab.cse.ohio-state.edu/projects/amqp/ as well as ftp://ftp.cse.ohio-state.edu/pub/tech-report/TRList.html
Basically this report tests federation with k-nomial tree topology. We were unable to use Qpid rdma/InfiniBand (IB) due to problem documented on JIRA (QPID-1855). So we performed our experiments using IPoIB via Qpid TCP connector.
Based on what we saw in our experiments, each of us has written some questions for the list about how federation is designed & implemented internally. I've compiled the questions below. I make reference to figures and tables from the report where appropriate.
1. In detail how does the connection of a destination broker to a source broker with "qpid-route route add" differ from a consumer application declaring and binding a queue on a source broker? Are there functional differences in how messages are routed to a federated destination broker as opposed to a consumer? What anticipated affect would these differences have on host system performance?
2. Why does a chain of federated brokers to one consumer have a higher bytes/sec rate on their interfaces (using SYSSTAT/sar to collect traffic data on IPoIB interface) than a single broker to one consumer? This experiment is explained in Sections 3.1, 4.2, Figure 8a.
3. Why does the activity at the root broker and producer increase as we increase the federation tree? Our understanding was that the only work root broker/producer does is send messages to broker(s) they are directly connected to. (This is similar to question 2, but different experiment. In such situations the net interfaces on the producers and consumers (as well as brokers) of more complex trees showed elevatated bytes/sec rates compared to less complex trees. Experiment is explained in Sections 3.3, 4.4, Figure 14a.)
4. We observed that the tree P-B-4B-16C was performing better than the tree P-B-4B-4C. And I thought this was because more consumers being attached keeps the leaf brokers busy thus reducing the contention at the root broker. Can we confirm if this understanding is correct. (This is a comparison of the experiments performed in Sections 3.3/4.4 and 5. Compare numbers in Tables 5, 6, 7, 8, particularly the small message rate numbers in Tables 5 & 8 for 64B and 256B.)
5. What is the advised measurement for performance in federated broker-consumer design? (We used the benchmarks we created for our SC08 workshop paper last fall--also available at above sites. Delivered bandwidth in the current report is our benchmark bandwidth multiplied by number of consumers).
6. Which of the tests included with Qpid release might help us get more insights on our topology study?
Thanks in advance for an comments and insights. Greg Marsh Network Based Computing Lab Ohio State University --------------------------------------------------------------------- Apache Qpid - AMQP Messaging Implementation Project: http://qpid.apache.org Use/Interact: mailto:[email protected]
