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
Markdown, which is currently used for user-facing documentation, is good
for a lot of things. However, it's not great for the kind of complex
documentation we have and our need to produce both multi-page HTML and
single-page PDF output via Maven.
Markdown lacks features which would make the documentation easier to
read, easier to navigate, and just look better overall.
The current tool-chain uses honkit and a tool called Calibre. Honkit is
written in TypeScript and is installed via NPM. Calibre is a native tool
so it must be installed via an OS-specific package manager. All this
complexity makes building, releasing, uploading, etc. a pain.
AsciiDoc is relatively simple like Markdown, but it has more features
for presentation and navigation not to mention Java-based Maven tooling
to generate both HTML and PDF. Migrating will improve both the
appearance of the documentation as well as the processes to generate and
upload it.
This commit contains the following changes:
- Convert all the Markdown for the User Manual, Migration Guide, and
Hacking guide to AsciiDoc via kramdown [1].
- Update the `artemis-website` build to use AsciiDoctor Maven tooling.
- Update `RELEASING.md` with simplified instructions.
- Update Hacking Guide with simplified instructions.
- Use AsciiDoc link syntax in Artemis Maven doc plugin.
- Drop EPUB & MOBI docs for User Manual as well as PDF for the Hacking
Guide. All docs will be HTML only except for the User Manual which
will have PDF.
- Move all docs up out of their respective "en" directory. This was a
hold-over from when we had docs in different languages.
- Migration & Hacking Guides are now single-page HTML since they are
relatively short.
- Refactor README.md to simplify and remove redundant content.
Benefits of the change:
- Much simplified tooling. No more NPM packages or native tools.
- Auto-generated table of contents for every chapter.
- Auto-generated anchor links for every sub-section.
- Overall more appealing presentation.
- All docs will use the ActiveMQ favicon.
- No more manual line-wrapping! AsciiDoc recommends one sentence per
line and paragraphs are separated by a blank line.
- AsciiDoctor plugins for IDEA are quite good.
- Resulting HTML is less than *half* of the previous size.
All previous links/bookmarks should continue to work.
[1] https://github.com/asciidoctor/kramdown-asciidoc
ARTEMIS-4375 Implement artemis shell using JLine3 integrated with auto-completion from picocli
This commit involves two JIRAs. One is adding PicoCLI and the next is Using JLine3 and implement a shell.
I have tried to keep these commits separate but these changes became interdependent hence the two JIRAs are squashed in this commit.
The "Airline" library we're currently using is deprecated according the
GitHub project - https://github.com/airlift/airline. It recommends using
either Airline 2 or Picocli. The former offers the simplest migration
path as it's almost completely compatible with the current code. This
commit implements that migration.
Improve the CORE client failover connecting to other live servers when all
reconnect attempts fails, i.e. in a cluster composed of 2 live servers,
when the server to which the CORE client is connected goes down the CORE
client should reconnect its sessions to the other liver broker.
When skipping the authentication cache details for the original
exception are not logged.
This commit ensures these details are logged and adopts the
ExceptionUtils class from Apache Commons Lang in lieu of the previous
custom implementation.
This commit fixes the following things:
- Moves connection audit logging to the resource audit logger instead
of using a dedicated logger as that would adversely impact upgrading
users, and arguably didn't make sense in the first place.
- Mitigates an potential NPE w.r.t. connection ID.
- Updates the "dummy" management connection to return a valid
connection ID.
There are certain use-cases where addresses will be auto-created and
never have a direct binding created on them. Because of this they will
never be auto-deleted. If a large number of these addresses build up
they will consume a problematic amount of heap space.
One specific example of this use-case is an MQTT subscriber with a
wild-card subscription and a large number of MQTT producers sending one
or two messages a large number of different MQTT topics covered by the
wild-card. Since no bindings are ever created on any of these individual
addresses (e.g. from a subscription queue) they will never be
auto-deleted, but they will eventually consume a large amount of heap.
The only way to deal with these addresses is to manually delete them.
There are also situations where queues may be created and never have
any messages sent to them or never have a consumer connect. These
queues will never be auto-deleted so they must be deleted manually.
This commit adds the ability to configure the broker to skip the usage
check so that these kinds of addresses and queues can be deleted
automatically.