fiware-cygnus | persisting context data sources | Database library

Assuming that you have exposed the ports of your container to the underlying host, then the application is accessible via the IP address of the underlying host.

The 172.19.0.3 IP address is an IP address that exists inside the Docker network on the host: it's not available externally. If your remote host has IP 1.2.3.4 and your application port has been exposed, e.g. in your compose file you have something like:

According to the docs, your environment should look like this:

Before sending measures you need to do a provision operation for the device using the IOTA-UL API. That provision operation "creates" the device in the IOTA-UL and map it with the corresponding entity at CB. Then, you can start sending measures using MQTT.

You can have a look to this piece of documentation for more detail.

can you post your piece of code ? This looks like some auth mechanism or credentials sent are not Valid.

authMechanism= can be "PLAIN" or "KERBEROS" as per your setup .

Not fully sure, but of the 3 I think the one you need to work with Orion Context Broker (i.e. subscribing to Orion so it sends notifications to Cygnus) is cygnus-ngsi.

With regards to configuration, I think that the approach is not editing .conf files inside the docker container on execution. You should inject configuration as environment variables. The ENV marks in the Dockerfile mean configurabe parameters.

I guess that both docker run and docker-compose should allow to set environment variables to the container, but that's a docker generic question not directly related with this question. There should be a lot of literature out there about this :)

You don't have to be worried about the num_takes_failed if you see that the number of processed_events is the same than the number of persisted_events. The numb_takes_filed is the result of the subtraction between the values of the flume methods EventTakeAttemptCount and EventTakeSuccessCount where the EventTakeAttemptCount is the total number of times the sink(s) attempted to read the events from the channel. This doesn't mean that the events were returned each time since sinks might poll and the channel might not have any data, On the other hand,EventTakesuccessCount is the total number of events that were successfully taken by the sink(s).

Moreover, if you want to know more about how the events are processed by the channels and sinks, you can run Cygnus on debug mode and see the log output for ensuring that every event is processed and persisted in the correct way

The page you used to install cygnus belongs to an older version of Cygnus. Please, visit the latest version here: http://fiware-cygnus.readthedocs.io/en/latest/cygnus-ngsi/quick_start_guide/

The caveat here is that yum install cygnus will install a quite old version of cygnus. You should install yum install cygnus-ngsi instead which is a newer version.

However, I like better to follow the github page: https://github.com/telefonicaid/fiware-cygnus/tree/master/cygnus-ngsi and installing cygnus-ngsi and creating the configuration files /usr/cygnus/conf/agent_1.conf and /usr/cygnus/conf/cygnus_instance_1.conf as shown in github. Cygnus can then be started a service.

The notification.sh script in http://fiware-cygnus.readthedocs.io/en/latest/cygnus-ngsi/quick_start_guide/ is usefull and you can use it once cygnus is running.

You need java, maven and Flume correctly installed before starting.

export APACHE_FLUME_HOME_BIN=/usr/local/flume to your shell

I recommend following the install from source, which guide you through all the steps.

For docker start with the cygnus-common Dockerfile which uses centos6 as base.

The error you were facing was because the user has no permission to perform that operation on the specified directory.

The solution, in this case, is use sudo: