These files accompany a presentation on the AMQP protocol, and how to use Qpid Proton to carry out AMQP messaging operations.
Version 0.1, Kevin Boone, April 2023
To run these examples you will need:
- GCC with C++ support and template library
- Qpid Proton development files (e.g.,
dnf install qpid-proton-cpp-devel) - GNU make (optional -- these examples are easy to compile manually)
tcpdumpor WireShark, to trace the communication at the wire level- A message broker that supports AMQP (e.g., Apache Artemis). Some examples require two brokers in a failover group
- A tool for producing messages to, or consuming them from, a broker (although the sample programs here will do, at a pinch)
valgrind, if you want to run the memory leak example
All the examples are completely self-contained and can be built individually at the command line. For example:
$ g++ -o send_lots send_lots.cpp -lqpid-proton-cpp
None of the examples take any command-line arguments. To change basic
configuration like host and port, see the top of the main() method
in each file.
send_lots -- send a sequence of messages to the same address on a broker
receive_lots -- receive a sequence of messages from the same address on a
broker. Demonstrates also how to iterate properties and annotations.
receive_lots_multiple_consumers -- receive a sequence of messages from the
same address on a broker, using two different consumers (links) in the same
session. The example also shows how a Proton application might request
'topic-like' or 'queue-like' behaviour from the message broker.
receive_lots_multiple_connections -- receive a sequence of messages from the
two different addresses on a broker, using two different connections and sessions.
Unlike receive_lots_multiple_consumers, this version opens the possibility of
defining different handlers for each address (which is not demonstrated directly)
and using multiple threads per address (which is)
server -- a direct receiver. Listens for incoming connections, and accepts
messages on address foo. Shows some basic error handling
container_per_thread -- demonstrates how to consume messages from a broker on
multiple concurrent connections, where Proton itself is not thread-safe (as it
was not in builds before C++-11).
receive_client_ack -- demonstrates client acknowledgement. The program
consumes from a message broker, but some messages can be rejected. What
happens at that point depends on the message broker -- probably the
message will go to a dead-letter queue. This program also shows how to
trap errors arising from message payload format conversion
send_receive_failover -- sends and receives messages from a pair of
brokers, and illustrates failover between them
receive_selector -- consumes messages filtered by a selector. Demonstrates,
as a side-effect, how to use proton::codec to format custom data types
send_lots_tls -- sends messages over a TLS-encrypted connection. Demonstrates
how to enable TLS and specify a trusted certificate.
send_lots_leaky -- like send_lots.cpp, but with a deliberate memory
leak. Try to find it using valgrind.
send_across_threads -- demonstrates how to run a Proton container in a
background thread, and use it to send messages in a (hopefully) thread-safe
way.