[PLC4X-50] Add a utility tool for massive polling from PLCs that do not support subscription

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.2.0
• Assignee: Julian Feinauer
• Reporter: Julian Feinauer
• Created: 14/Sep/18 12:49
• Updated: 12/Mar/19 12:42
• Resolved: 12/Mar/19 12:42

Description

For use cases where one wants to poll many informations from PLCs with low frequencies, a separate utility should be added on top of the PlcConnection / PlcDriver abstraction.
In this case the subscriber emulation PLC4X-49 is not ideal.

Features should be:

• Connection pooling and Thread safe reuse of connections
• Easy configuration
• Handling of connection losses and frequent request timeouts
• Monitoring of the scraping process, e.g., rate of failed requests in the last 1,5,60 minutes; mean response time; ...

Optional features

• Request collapsing
• Result Caching

See here for some discussion: https://mail-archives.apache.org/mod_mbox/plc4x-dev/201809.mbox/%3Cdc43d7f1-6e7f-b988-52e3-0ec45115b1c3%40codecentric.de%3E