External interfaces

Optisim requires the following external services to operate correctly:

The services have to be installed locally or in remote hosts from the machine where Optisim runs. The following picture shows the interactions among the applications. Note how OutputDataManager does not interact effectively with Optisim. However, this section describes it as an important part of the simulator, which interacts both with RabbitMQ and InfluxDB.

images/external_interfaces_schema.svg — Interaction of *Optisim* with external applications

InfluxDB

InfluxDB is a powerful time-series database able to store and maintain significant amounts of data sets. As regards Optisim, it uses the InfluxDB service to download all the data required by the simulation (e.g. the profile of the external temperature). The data downloading, shown by the orange arrow in figure above, is actuated by Optisim at the beginning of the simulation, to load all the needed data before starting the simulation.

RabbitMQ

RabbitMQ is a message broking system, basically used to exchange data between different applications. Optisim uses it for two aims. The former, already described in subsection Loop with external controller, is to utilize the broker system to send, at every step, the simulation state to an external controller and then to receive from it the related commands to actuate in the next step. Regarding the latter, Optisim uses RabbitMQ to send the simulation results configured to be stored in InfluxDB. The effective saving in the database is performed by OutputDataManager, as described in the following subsection.

OutputDataManager

Unlike InfluxDB and RabbitMQ, OutputDataManager is a part of Optisim project. It acts with parallel and independent processes, one for each CPU, and is demanded to save the simulation results as shown in the figure above. The usage of this external script significantly improves the simulation velocity, leaving Optisim to run it without having to spend time to save data in InfluxDB.

The following BASH commands show how to launch OutputDataManager installed in a generic $ROOT/optisim folder (see section Installation and running for details).

cd $ROOT
source optisim/venv/bin/activate
(venv) python optisim/output_data_manager.py -c $CONNECTIONS_CONFIGURATION_FILE

Section (Configuration file structure) describes the main parts of $CONNECTIONS_CONFIGURATION_FILE file.