commanded / commanded-swarm-registry

Distributed process registry using Swarm for Commanded

Commanded Swarm registry

Distributed process registry using Swarm for Commanded.

Supports running Commanded on a cluster of nodes.

MIT License

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Overview

• Changelog
• Getting started
• Cluster deployment
• Contributing
• Need help?

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Contributing

Pull requests to contribute new or improved features, and extend documentation are most welcome.

Please follow the existing coding conventions, or refer to the Elixir style guide.

You should include unit tests to cover any changes. Run mix test to execute the test suite.

Need help?

Please open an issue if you encounter a problem, or need assistance. You can also seek help in the Gitter chat room for Commanded.

For commercial support, and consultancy, please contact Ben Smith.

commanded-swarm-registry's Issues

Not all projections are running correctly

I have a setup with libcluster and three cluster nodes, and I sometimes get errors like the following.

18:59:50.813 [warn]  [swarm on app@server] [tracker:handle_topology_change] handoff failed for {CommandedApplication, Commanded.Event.Handler, "Projectors.Object"}: {{%RuntimeError{message: "attempted to call GenServer #PID<0.3862.0> but no handle_call/3 clause was provided"}, [{Commanded.Event.Handler, :handle_call, 3, [file: 'lib/gen_server.ex', line: 773]}, {:gen_server, :try_handle_call, 4, [file: 'gen_server.erl', line: 661]}, {:gen_server, :handle_msg, 6, [file: 'gen_server.erl', line: 690]}, {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 249]}]}, {GenServer, :call, [#PID<0.3862.0>, {:swarm, :begin_handoff}, 5000]}}

18:59:50.813 [error] GenServer #PID<0.3487.0> terminating
** (RuntimeError) attempted to call GenServer #PID<0.3862.0> but no handle_call/3 clause was provided
    (commanded 1.2.0) lib/gen_server.ex:773: Commanded.Event.Handler.handle_call/3
     (stdlib 3.12.1) gen_server.erl:661: :gen_server.try_handle_call/4
    (stdlib 3.12.1) gen_server.erl:690: :gen_server.handle_msg/6
    (stdlib 3.12.1) proc_lib.erl:249: :proc_lib.init_p_do_apply/3
Last message: {:DOWN, #Reference<0.1551621646.1983119361.7440>, :process, #PID<0.3862.0>, {%RuntimeError{message: "attempted to call GenServer #PID<0.3862.0> but no handle_call/3 clause was provided"}, [{Commanded.Event.Handler, :handle_call, 3, [file: 'lib/gen_server.ex', line: 773]}, {:gen_server, :try_handle_call, 4, [file: 'gen_server.erl', line: 661]}, {:gen_server, :handle_msg, 6, [file: 'gen_server.erl', line: 690]}, {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 249]}]}}

I'm not sure how to debug this. This means that the projectors stop working. When I restart a node they start again but then I get the same kinds of errors and not all projectors are running.

I don't really care if there are errors in the log, but I want my projectors to eventually be running, even if it takes a few restarts when taking a node down or up.

My setup looks like this: in my application I start the projectors as children to my application supervisor. Is there a good way to make sure that my projections are not going away when restarting a node? Should I look for something in particular in the logs?

Broken with Commanded 0.19

Interim fix:

{:commanded, "~> 0.19", override: true},
{:commanded_swarm_registry, "~> 0.2",
github: "commanded/commanded-swarm-registry", ref: "b48e18b"}

Cheers! 🍻