Hi,
I'm very new to Dubbo but I'd like to share some ideas. I am playing around
trying to implement a simple monitor for Dubbo (this one
https://github.com/bitstorm/wicket-coreui). To start grasping what I have
to do I've looked at what dubbo-monitor-simple (
https://github.com/apache/incubator-dubbo-ops) already does. While the
overall mechanism is quite clear I find difficult working with the current
URL-based notification mechanism (I'm referring to interface
NotifyListener). Extracting informations from url is not trivial and I
think we might use a more complex and clear object for this task. In
particular is difficult to be notified if a consumer application has been
unregistered.
Hope this could be helpful for future improvements.
Thank you.
On Mon, Jul 9, 2018 at 9:32 AM, Liujie Qin <[email protected]> wrote:
Hi All, Dubbo has become a excellent RPC framework with the efforts of
various partners in the community. However, in the process of
development,
we found some shortcomings of Dubbo 2.x, which is listed as follows:
- The maintainability is relatively poor. The code uses a lot of
dynamically generated classes. It is difficult to understand and
difficult
to debug. The code hierarchy is not clear enough, and the calling
logic
is
confusing. As an experienced Dubbo developer, sometimes it is
difficult
for
me to sort out the calling process of Dubbo 2.x; the more developed,
the
more difficult it is to maintain, so it needs to be refactored in
order
to
develop better.
- Some extensions cannot meet current needs, such as service addresses
push monitoring, performing Filter early interception requests before
service addresses selection, printing the process of route selection,
etc.
- The underlying Dubbo 2.X is based on synchronous calls. The
asynchronous call is wrapped synchronously. This introduces
inaccuracies
such as RT during asynchronous calls.
- At present, the service metadata information and the address of the
Dubbo service are coupled together. Most of the metadata is the same,
and
the metadata is redundant. At the same time, as the size of the
machine
increases, the Registry is under great pressure, especially when
machine
restart.
- The service registry and the configuration center are coupled
together, and after splitting, the management and storage of service
governance rule data such as routing rules can be better handled.
- The core is written based on JDK 1.6 and cannot use the newer JDK
features. It is recommended to upgrade JDK to 1.8 and above.
For the above reasons, in order to better develop Dubbo and attract more
people to participate in the development of the Dubbo community, I
propose
to refactor the Dubbo 2.x code. The newly developed version number is
Dubbo
3.x. Refactoring Dubbo 3.x will have the following advantages:
- Refactoring core modules to make the code more concise and
understandable
- Refactoring the routing process, Making the route process to
Pipeline
style,Making the route process can be observed
- Add new extension points to make it easier for developers to extend
the framework
- Add the Service Domain Model to enable developers to handle its
lifecycle
- Supports asynchronous interface, unified call process returns
CompleteFuture, synchronous call process uses CompleteFuture wrapper;
Solve
the problem of inaccurate statistics such as RT during asynchronous
call
- Splitting out the Configuration Center and Registry for better
control
and support for larger clusters
- Prepare for new features such as Http2 stream、Reactive stream
- Performance improvement
- And so on
Of course, refactoring Dubbo 3.x also faces the following challenges:
- A wide range of refactorings that can cause extension points to be
incompatible
- The Dubbo team may need to maintain two branches at the same time
for
a longer period of time
For the following challenges, we can do this:
-
For major extension points, such as Fitler, etc., be sure to ensure
compatibility and enable developers to smoothly upgrade
-
For some extension points, the Dubbo team will listen to the community
and selectively fix compatibility issues with some extension points.
Comments welcome!
thank you ~
--
Andrea Del Bene.
Apache Wicket committer.
