Multi-broker not connecting to federates

[trevorhardy]

I'm pretty sure I've found a bug but I wanted to start the discussion here just in case this was user error. (We can easily move this over to the Issues forum once we confirm its a legit bug.)

Short version:
I tell the federates to connect to the broker on port n and they try port n+1.

I've tried manually adjusting the port numbers in the federates so they are using the ones specified for the multi-broker but the federates still aren't able to connect.

Long version:

I'm working on an example demonstrating the user of a multi-broker (that is, multi-protocol broker). I've posted the federation to HELICS-examples if you want to see everything. But here are the details I think that matter:

multi_broker_config.json:

{
  "comms": [
    {
      "type": "zmq",
      "interfaceport": 23410
    },
    {
      "type": "zmq",
      "interfaceport": 23700
    }
  ]
}

Charger federate config (excerpt):

{
  "name": "Charger",
  "coreType": "zmq",
  "brokerPort": 23410,
  ...
}

Controller federate config (excerpt):

{
  "name": "Controller",
  "coreType": "zmq",
  "brokerPort": 23410,
  ...
}

Battery federate config (excerpt):

{
  "name": "Battery",
  "coreType": "zmq",
  "brokerPort": 23700,
  ...
}

And the helics_cli config:

{
  "federates": [    
    {
      "directory": ".",
      "exec": "helics_broker -f 4 --loglevel=7",
      "host": "localhost",
      "name": "broker"
    },
    {
      "directory": ".",
      "exec": "python -u Charger.py 1",
      "host": "localhost",
      "name": "Charger",
      "loglevel": 1
    },
    {
      "directory": ".",
      "exec": "python -u Controller.py 1",
      "host": "localhost",
      "name": "Controller",
      "loglevel": 1
    },
    {
      "directory": ".",
      "exec": "python -u Battery.py 1",
      "host": "localhost",
      "name": "Battery",
      "loglevel": 1
    },
    {
      "directory": ".",
      "exec": "python -u Filter.py ",
      "host": "localhost",
      "name": "Filter",
      "loglevel": 1
    }
  ],
  "name": "EV_toy"
}

When I run this, none of the federates are able to connect to the broker and the get the following messages:

Controller:

[2020-09-28 10:32:42.481] [console] [warning] commWarning||72598-5ljrv-5i2Zt-l1kUn-QV6YO (0)::zmq broker connection timed out, trying again (2)
[2020-09-28 10:32:42.481] [console] [warning] commWarning||72598-5ljrv-5i2Zt-l1kUn-QV6YO (0)::sending message to tcp://127.0.0.1:23411

Charger:

[2020-09-28 10:32:42.191] [console] [warning] commWarning||72597-bYGb7-MTQu8-DK86X-s5qek (0)::zmq broker connection timed out, trying again (2)
[2020-09-28 10:32:42.191] [console] [warning] commWarning||72597-bYGb7-MTQu8-DK86X-s5qek (0)::sending message to tcp://127.0.0.1:23411
[2020-09-28 10:33:02.205] [console] [error] commERROR||72597-bYGb7-MTQu8-DK86X-s5qek (0)::zmq broker connection timed out after trying 5 times (2)
[2020-09-28 10:33:02.205] [console] [error] commERROR||72597-bYGb7-MTQu8-DK86X-s5qek (0)::receiver connection failure
Traceback (most recent call last):
  File "Charger.py", line 127, in <module>
    fed = h.helicsCreateCombinationFederateFromConfig("ChargerConfig.json")
  File "/Users/hard312/opt/anaconda3/envs/HELICS_UG_examples/lib/python3.8/site-packages/helics/capi.py", line 1596, in helicsCreateCombinationFederateFromConfig
    raise HelicsException("[" + str(err.error_code) + "] " + ffi.string(err.message).decode())
helics.capi.HelicsException: [-1] Unable to connect to broker->unable to register federate

And Battery:

[2020-09-28 10:32:42.191] [console] [warning] commWarning||72599-bZS6F-xGrtf-tjiyp-EwxFO (0)::zmq broker connection timed out, trying again (2)
[2020-09-28 10:32:42.191] [console] [warning] commWarning||72599-bZS6F-xGrtf-tjiyp-EwxFO (0)::sending message to tcp://127.0.0.1:23701
[2020-09-28 10:33:02.205] [console] [error] commERROR||72599-bZS6F-xGrtf-tjiyp-EwxFO (0)::zmq broker connection timed out after trying 5 times (2)
[2020-09-28 10:33:02.205] [console] [error] commERROR||72599-bZS6F-xGrtf-tjiyp-EwxFO (0)::receiver connection failure
Traceback (most recent call last):
  File "Battery.py", line 74, in <module>
    fed = h.helicsCreateValueFederateFromConfig("BatteryConfig.json")
  File "/Users/hard312/opt/anaconda3/envs/HELICS_UG_examples/lib/python3.8/site-packages/helics/capi.py", line 1512, in helicsCreateValueFederateFromConfig
    raise HelicsException("[" + str(err.error_code) + "] " + ffi.string(err.message).decode())
helics.capi.HelicsException: [-1] Unable to connect to broker->unable to register federate

[trevorhardy]

I've been able to get this working and I'm pretty sure it was related to similar problems I was having in Issue #1574. The working example is a part of the User Guide examples here.