Durable subscrption state is part of the MQTT specification which has
not been supported until now. This functionality is implemented via an
internal last-value queue. When an MQTT client creates, updates, or
adds a subscription a message using the client-ID as the last-value is
sent to the internal queue. When the broker restarts this data is read
from the queue and populates the in-memory MQTT data-structures.
Therefore subscribers can reconnect and resume their session's
subscriptions without have to manually resubscribe.
MQTT state is now managed centrally per-broker rather than in the
MQTTProtocolManager since there is one instance of MQTTProtocolManager
for each acceptor allowing MQTT connections. Managing state per acceptor
would allow odd behavior with clients connecting to different acceptors
with the same client ID.
The subscriptions are serialized as raw bytes with a "version" byte for
potential future use, but I intentionally avoided adding complex
scaffolding to support multiple versions. We can add that complexity
later if necessary.
Some tests needed to be changed since instantiating an MQTT protocol
manager now creates an internal queue. A handful of tests assume that no
queues will exist other than the ones they create themselves. I updated
the main test super-class so that an MQTT protocol manager is not
automatically instantiated when configuring a broker for in-vm support.
This commit introduces support for configuring a specific Duplicate ID cache size per address in the Artemis server. Previously, there was only a global setting for the ID cache size, but now each address can have its own cache size.
The changes include the addition of a new configuration property id-cache-size in the Artemis server configuration file. This property can now be specified under each address setting in the configuration file, and its value will determine the Duplicate ID cache size for that particular address. If the id-cache-size property is not specified for an address, it will use the global setting.
The test cases have been updated to cover this new functionality, and integration test have been added to verify that address-specific cache sizes work as expected.
Documentation has been added to address-settings.adoc, configuration-index.adoc and duplicate-detection.adoc
This commit contains the following changes:
- eliminate used, undeclared dependencies
- eliminate unused, declared dependencies
- fix scope for test dependencies
- eliminate org.hamcrest completely as its use involved deprecated code
as well as dependencies from multiple versions
In rare cases a store operation could silently fails or starves, blocking the
related server session and all delivering messages. Those server sessions can
be closed adding a management method that cleans their operation context
before closing them.
If the Security Manager is using Netty, and in particular the same Netty connection,
you could run into a deadlock / starvation.
This is particularly true in the Wildfly case where they reuse the same connection for everything via XNIO.
When resource audit logging is enabled STOMP is completely inoperable
due to an NPE during the protocol handshake. Unfortunately the failure
is completely silent. There are no logs to indicate a problem.
This commit fixes this problem via the following changes:
- Mitigate the original NPE via a check for null
- Move the logic necessary to set the "protocol connection" on the
"transport connection" to a class shared by all implementations.
- Add exception handling to log failures like this in the future.
- Add tests to ensure the audit logging is correct.
Currently JavaDoc is generated for many classes that don't need it.
JavaDoc should be reserved for user-facing classes (e.g. those used by
client application developers and developers embedding a broker into
their application). This commit narrows down the configuration to just
the classes that are needed. This will save time during release builds,
and save disk space wherever these files are stored (e.g. Apache
website).