Run a workflow based on output from a different database

[clonedapple]

There are two processes that are run and their statuses are updated on a database. What I want to do is read the statuses of the processes and based on that, run another workflow which accesses a different database. How can I implement this?
Thank you!

[mlauber71]

@clonedapple you could take a look at this example

Start a Workflow, e. g. a database query, after a certain time

@USCHUKN1ME I tried to build a system you might be able to expand and use. The idea is to have a workflow that would iterate a number of times (v_number_of_intervals) with a set interval (of seconds) between (v_seconds_interval) them. The workflow looks for a trigger_file.csv if this file has changed from the last time the loop has run a component would be executed. If the file has not changed nothing would happen. Admittedly not the most elegant way but you could build a small automatic execu…

Otherwise the knime server offers a lot of possibilities

[clonedapple]

Hey, I noticed that you wrote “(please download the complete workflow group)” in that answer. Is the workflow group you are referring to the system you tried to build? Where can I download it?

[mlauber71]

This si the workflow group in question. It consists of two workflows and a /data/ folder containing the files and the database. It is meant as an inspiration about how you could iterate a loop and when something changes trigger an action (in this case do something in a database).

mlauber71/Public – kn_example_db_wait_execute_advanced

[clonedapple]

Thank you! I will look into this

[ipazin]

Hello @clonedapple,

if I got it right you can simply connect to database and read statuses from it. Then build your logic based on your readings (using Rule Engine and Switches for example) to call another workflow(s) using Call Workflow nodes

Does it help or you need help with logic, Call Workflow nodes maybe?

Br,
Ivan

[clonedapple]

That is exactly what I am implemented yesterday and it worked. I am looking into how to loop and check after fixed intervals now. I believe @mlauber71’s workflow would serve as a good point of reference. This is just to get familiar with KNIME. I will be using the KNIME server for scheduling.

[clonedapple]

How can I use KNIME server here? I was able to create a workflow(workflow A) which checks if the processes have finished or not and calls the other workflow based on this. Can I schedule the execution of this workflow A at certain intervals such that it keeps checking and executing till the condition is met? I want it to execute till the condition is met and stop after that.