Running flows

After you have updated your Components Library as described in Manage components library documentation and written your first program you can execute the program using Cascades runtime's run command.

Running options

You can execute cascades run --help command to see all possible running options as shown below:

NAME:
   run - Runs a given graph defined in the .fbp or .json formats

USAGE:
   command run [command options] [arguments...]

OPTIONS:
   --port, -p '5000'	initial port to use for connections between nodes
   --dry		dry run (parses and validates the graph, exits without executing it)

Additionally you can specify the global command line flags:

GLOBAL OPTIONS:
   --file, -f 'library.json'	components library file
   --debug, -d			enable extra output for debug purposes

Validating a flow

In order to validate the flow without actually executing it you can run the following command (notice --debug and --dry flags):

$ cascades --debug run --dry examples/tick.fbp
--------- Properties ----------
---------- Inports -----------
---------- Outports -----------
---------- Processes ----------
Ticker (core/ticker)
Forward (core/passthru)
Log (core/console)
--------- Connections ---------
'5s' -> INTERVAL Ticker
Ticker OUT -> IN Forward
Forward OUT -> IN Log
-------------------------------

This indicates that a flow is valid.

If we try to validate a flow that uses a component not registered in Library an error will be shown:

$ cascades --debug run --dry examples/bad-tick.fbp
Failed to load/flatten graph: Component core/newticker not found in the library

Or if you have a syntax error in FBL DSL a corresponding error will be shown:

$ cascades --debug run --dry examples/tick.fbp
Failed to load/flatten graph: Failed to parse graph definition:
...

Running with/without debug option

Executing a flow with a --debug flag usually produces a lot of additional output in the stdout and it can give you a lot of insights on how the Cascades Runtime is manages the processes.

Example executing flow without --debug options

$ cascades run examples/tick.fbp
runtime | Starting processes...
runtime | Activating processes by sending IIPs...
runtime | Sending '5s' to socket 'tcp://127.0.0.1:5000'
Log     | IP: 1416347159
Log     | IP: 1416347164

...

^Cruntime | Shutdown...
runtime | sending SIGTERM to Forward
runtime | sending SIGTERM to Log
runtime | sending SIGTERM to Ticker
Forward | Stopped
Ticker  | Stopped
Log     | Stopped
runtime | Shutdown...
Stopped

Example executing flow with --debug options

$ cascades --debug run examples/tick.fbp
--------- Properties ----------
---------- Inports -----------
---------- Outports -----------
---------- Processes ----------
Ticker (core/ticker)
Forward (core/passthru)
Log (core/console)
--------- Connections ---------
'5s' -> INTERVAL Ticker
Ticker OUT -> IN Forward
Forward OUT -> IN Log
-------------------------------
Log.IN [tcp://127.0.0.1:5002]
Ticker.INTERVAL [tcp://127.0.0.1:5000]
Ticker.OUT [tcp://127.0.0.1:5001]
Forward.IN [tcp://127.0.0.1:5001]
Forward.OUT [tcp://127.0.0.1:5002]
--------- Executables ---------
Forward: "/Users/alex/Projects/OpenSource/Cascades/components/core/passthru" "-port.in=\"tcp://127.0.0.1:5001\" -port.out=\"tcp://127.0.0.1:5002\" -debug=\"true\" "
Log: "/Users/alex/Projects/OpenSource/Cascades/components/core/console" "-debug=\"true\" -port.in=\"tcp://127.0.0.1:5002\" "
Ticker: "/Users/alex/Projects/OpenSource/Cascades/components/core/ticker" "-debug=\"true\" -port.interval=\"tcp://127.0.0.1:5000\" -port.out=\"tcp://127.0.0.1:5001\" "
-------------------------------
runtime | Starting processes...
Ticker  | Wait for configuration IP...
Log     | Started...
Forward | Started...
runtime | Activating processes by sending IIPs...
runtime | Sending '5s' to socket 'tcp://127.0.0.1:5000'
Ticker  | Started...
Ticker  | Configured to tick with interval: 5s
Ticker  | 1416347216
Log     | IP: 1416347216
Ticker  | 1416347221
Log     | IP: 1416347221

...

^Cruntime | Shutdown...
runtime | sending SIGTERM to Log
runtime | sending SIGTERM to Ticker
runtime | sending SIGTERM to Forward
Log     | Error receiving message: interrupted system call
Ticker  | Give 0MQ time to deliver before stopping...
Log     | Give 0MQ time to deliver before stopping...
Forward | Give 0MQ time to deliver before stopping...
Forward | Error receiving message: interrupted system call
Forward | Stopped
Ticker  | Stopped
Log     | Stopped
Forward | Stopped
Ticker  | Stopped
Log     | Stopped
runtime | Shutdown...
Stopped