Quick Start

Joule is part of the Wattsworth software stack. See http://wattsworth.net/install.html for installation details. Before continuing make sure Joule is installed and the jouled service is running:

# ensure the joule CLI is installed $> joule --version joule, version 0.9 # authorize local user access to joule server $> sudo -E joule admin authorize Access to node [xxxx] granted to user [xxxx] # confirm the local joule server is running $> joule node info Server Version: 0.9.x Status: online

This guide will step through the implementation of the three stage pipeline shown below:

_images/getting_started_pipeline.png

The Data Source

The first module is a data reader. Reader modules "read" data into the Joule pipeline. This data can come from embedded sensors, HTTP API's, system logs, or any other timeseries data source.

Our reader will simply produce random values. Joule provides a built-in module specifically for this purpose. Stubbing pipeline inputs with a random data source can simplify unit testing and expose logic errors. See the Module Documentation page for more details on this and other Joule modules.

Try out joule-random-reader on the command line:

$> joule-random-reader -h # ... module documentation (available at http://docs.wattsworth.net/modules) $> joule-random-reader --width 2 --rate 10 1485188853650944 0.32359053067687582 0.70028608966895545 1485188853750944 0.72139550945715136 0.39218791387411422 1485188853850944 0.40728044378612194 0.26446072057019654 1485188853950944 0.61021957330250398 0.27359526775709841 # output continues, hit ctrl-c to stop

When a reader module is run from the command line its output stream is sent to standard output (the screen). Now let's add this module to our pipeline. We need to create a Module Configuration file to tell Joule how to execute the module and where to connect its output. To do this create the following file:

: /etc/joule/module_configs/data_source.conf [Main] exec_cmd = joule-random-reader name = Data Source [Arguments] width = 2 rate = 10 [Outputs] output = /demo/random:float32[x,y]

This connects the module to the stream /demo/random. The stream is configured inline after the colon (:). This specifies a float32 datatype and two elements named x and y. To control other stream options create a Stream Configuration file in /etc/joule/stream_configs. Now the pipeline is ready to execute. Restart joule and check that the new module is running:

# restart joule to use the new configuration files $> sudo service joule restart # check pipeline status using the joule CLI $> joule module list -s ╒═════════════╤══════════╤══════════════╤═════════╤═════════════╕ │ Name │ Inputs │ Outputs │ CPU % │ Mem (KiB) │ ╞═════════════╪══════════╪══════════════╪═════════╪═════════════╡ │ Data Source │ │ /demo/random │ 0 │ 62868 │ ╘═════════════╧══════════╧══════════════╧═════════╧═════════════╛ # check module logs for any errors $> joule module logs "Data Source" [2018-09-12T15:51:38.845242]: ---starting module--- # confirm the pipeline is producing data $> joule stream info /demo/random Name: random Description: — Datatype: float32 Keep: all data Decimate: yes Status: ● [active] Start: 2018-09-12 15:51:39.811572 End: 2018-09-12 15:52:59.711573 Rows: 800 ╒════════╤═════════╤════════════╤═══════════╕ │ Name │ Units │ Display │ Min,Max │ ╞════════╪═════════╪════════════╪═══════════╡ │ x │ — │ continuous │ auto │ ├────────┼─────────┼────────────┼───────────┤ │ y │ — │ continuous │ auto │ ╘════════╧═════════╧════════════╧═══════════╛ # view live data stream $> joule data read -l /demo/random 1485188853650944 0.32359053067687582 0.70028608966895545 1485188853750944 0.72139550945715136 0.39218791387411422 1485188853850944 0.40728044378612194 0.26446072057019654 1485188853950944 0.61021957330250398 0.27359526775709841 # output continues, hit ctrl-c to stop

The Data Processor

Now let's add a filter to smooth out the random data produced by the reader. Joule provides a built-in moving average filter, mean, that does exactly this. See the Module Documentation page for more details on this and other Joule modules.

Joule filters can execute as standalone programs but require extra configuration to do so because they can have multiple inputs and outputs. For now let's just run it in the Joule environment. To add the module to the pipeline create the following file:

: /etc/joule/module_configs/data_processor.conf [Main] exec_cmd = joule-mean-filter name = Data Processor [Arguments] window = 11 [Inputs] input = /demo/random [Outputs] output = /demo/smoothed:float32[x,y]

The input stream is already configured by the producer module. The output will have the same datatype and number of elements. Now the pipeline is fully configured. Restart joule and check that both modules are running:

# restart joule to use the new configuration files $> sudo service joule restart # check pipeline status using the joule CLI $> joule module list ╒════════════════╤══════════════╤════════════════╤═════════╤═════════════╕ │ Name │ Inputs │ Outputs │ CPU % │ Mem (KiB) │ ╞════════════════╪══════════════╪════════════════╪═════════╪═════════════╡ │ Data Processor │ /demo/random │ /demo/smoothed │ 0 │ 63880 │ ├────────────────┼──────────────┼────────────────┼─────────┼─────────────┤ │ Data Source │ │ /demo/random │ 0 │ 63172 │ ╘════════════════╧══════════════╧════════════════╧═════════╧═════════════╛ $> joule module logs "Data Processor" [2018-09-12T16:00:34.298364]: ---starting module--- # confirm the pipeline is producing data (check /demo/random as well) $> joule stream info /demo/smoothed Name: smoothed Description: — Datatype: float32 Keep: all data Decimate: yes Status: ● [active] Start: 2018-09-12 16:00:35.788668 End: 2018-09-12 16:02:29.688669 Rows: 1140 ╒════════╤═════════╤════════════╤═══════════╕ │ Name │ Units │ Display │ Min,Max │ ╞════════╪═════════╪════════════╪═══════════╡ │ x │ — │ continuous │ auto │ ├────────┼─────────┼────────────┼───────────┤ │ y │ — │ continuous │ auto │ ╘════════╧═════════╧════════════╧═══════════╛

The Data App

Finally let's add a Data App to complete our pipeline with a user interface. Joule provides a simple built-in module to visualize recent values and historic highs and lows of stream elements. See the Module Documentation page for more details on the visualizer and other Joule modules.

Add the following file to the configuration directory to add the module to the pipeline.

: /etc/joule/module_configs/data_app.conf [Main] exec_cmd = joule-visualizer-filter name = Data App is_app = yes [Arguments] title = Quick Start Data Pipeline [Inputs] smoothed = /demo/smoothed random = /demo/random

Restart Joule and confirm that the new module is active

# restart joule to use the new configuration files $> sudo service joule restart # check pipeline status using the joule CLI $> joule module list ╒════════════════╤════════════════╤════════════════╤═════════╤═════════════╕ │ Name │ Inputs │ Outputs │ CPU % │ Mem (KiB) │ ╞════════════════╪════════════════╪════════════════╪═════════╪═════════════╡ │ Data Processor │ /demo/random │ /demo/smoothed │ 2 │ 63924 │ ├────────────────┼────────────────┼────────────────┼─────────┼─────────────┤ │ Data App │ /demo/smoothed │ │ 0 │ 64548 │ │ │ /demo/random │ │ │ │ ├────────────────┼────────────────┼────────────────┼─────────┼─────────────┤ │ Data Source │ │ /demo/random │ 0 │ 62748 │ ╘════════════════╧════════════════╧════════════════╧═════════╧═════════════╛ # check the module info to find the interface URL $> joule module info "Data App" --connecting to [joule_node]-- This is module is a Data App Name: Data App Inputs: smoothed: /demo/smoothed random: /demo/random Outputs: --none-- CPU Usage: 0.00% Memory Usage: 3.95% Uptime: 0:18:25.660176

Viewing Data Apps

Data Apps can be accessed through the Lumen webserver. First, link Joule to the local Lumen server using the command below. Note if the Lumen server is already activated you will need an authorization key to add additional Joule nodes. See Lumen Documentation for more details.

# connect joule to the local lumen server $> joule master add lumen 127.0.0.1 # ...follow prompts to create a user account

Now open a browser and point it to http://127.0.0.1 if you are on the target machine or use the IP address of the machine if you want to access it from another device. Log in with the user credentials you just added. From the main page, expand the local Joule node and click the Data App to open the visualizer or select one of the stream elements to view data in the plotting interface.

For more details on modules and streams read Using Joule or visit the Lumen Documentation for details on visualizing and plotting data.