👀 Views: 404 💬 Answers: 1 📅 Created: 2025-06-09

GCP Dataflow Apache Beam Pub/Sub JSON Python

I've encountered a strange issue with I'm trying to implement I need some guidance on I tried several approaches but none seem to work... I keep running into I'm currently working on a GCP Dataflow job that processes messages from a Pub/Sub topic using Apache Beam (version 2.34.0). However, I'm working with an 'Invalid JSON' behavior when trying to parse incoming messages. The behavior occurs at runtime and looks like this: ``` behavior: Invalid JSON: ' "field1": "value1", "field2": value2 ' ``` I have implemented the following code to read messages from Pub/Sub and transform the JSON: ```python import json from apache_beam import Pipeline from apache_beam.io import ReadFromPubSub from apache_beam.pvalue import WithKeys from apache_beam.transforms import Map def parse_json(message): return json.loads(message.data.decode('utf-8')) with Pipeline() as p: (p | 'Read from Pub/Sub' >> ReadFromPubSub(subscription='projects/my-project/subscriptions/my-subscription') | 'Parse JSON' >> Map(parse_json) | 'Process Data' >> Map(lambda x: print(x))) ``` I've double-checked the data being sent to the Pub/Sub topic, and it's indeed valid JSON. However, in some cases, it seems certain messages are getting corrupted or not formatted correctly as demonstrated in the behavior message. I've also tried adding a try-except block around the JSON parsing to log the messages that unexpected result to parse, but it still doesn't give clear insights on why these specific messages are failing. Here’s what I tried: 1. Validating the JSON format using external tools before sending. 2. Logging raw messages before parsing to see if there's any pattern. 3. Adding behavior handling to skip bad messages. Despite these efforts, the scenario continues. Has anyone encountered a similar question with Dataflow and Pub/Sub? Any insights on how to handle or debug this situation would be greatly appreciated. My development environment is Ubuntu. Is this even possible? I recently upgraded to Python latest. The project is a mobile app built with Python.