Flow Example

This is an example of a fully configured Retry Flow that retries failed API requests based on status codes, with exponential backoff.

/etc/lunar-proxy/flows/flow.yaml

name: RetryFlow

filter:
  url: "api.com/resource/{id}"

processors:
  RetryProcessor:
    processor: Retry
    parameters:
      - key: attempts
        value: 5
      - key: cooldown_between_attempts_seconds
        value: 5
      - key: cooldown_multiplier
        value: 1.5
    metrics:
      enabled: true
      labels:
        - flow_name
        - processor_key
        - http_method
        - host
        - status_code
        - consumer_tag


  FilterProcessor:
    processor: Filter
    parameters:
      - key: status_code_range
        value: 400-500
    metrics:
      enabled: true
      labels:
        - flow_name
        - processor_key
        - http_method
        - host
        - status_code
        - consumer_tag

flow:
  request:
    - from:
        stream:
          name: globalStream
          at: start
      to:
        stream:
          name: globalStream
          at: end

  response:
    - from:
        stream:
          name: globalStream
          at: start
      to:
        processor:
          name: FilterProcessor
    - from: 
        processor:
          name: FilterProcessor
          condition: miss
      to:
        stream:
          name: globalStream
          at: end

    - from:
        processor:
          name: FilterProcessor
          condition: hit
      to:
        processor:
          name: RetryProcessor

    - from:
        processor:
          name: RetryProcessor
          condition: retry
        
      to:
        stream:
          name: globalStream
          at: end

    - from:
        processor:
          name: RetryProcessor
          condition: failed
      to:
        stream:
          name: globalStream
          at: end

Troubleshooting

1. Retries Not Triggering:
   • Verify that status_code_range is correctly configured.
   • Ensure the API response status code falls within the specified range.
2. Excessive Retry Attempts:
   • Check the attempts parameter and reduce it if necessary.
   • Adjust the cooldown_multiplier to increase wait times between retries.
   • Make sure that in case of long cooldown the value of LUNAR_RETRY_REQUEST_TIMEOUT_SEC is also increased. the default is 100

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