使用Microsoft Flow创建DocuSign信封时超时报错的问题咨询

Let’s break down why you’re seeing this timeout discrepancy between Microsoft Flow and Postman, along with actionable fixes to resolve the issue:

Possible Root Causes #

• Inefficient Large Data Transfer in Flow: Unlike Postman, Microsoft Flow might handle large Base64-encoded document data with less optimized transfer logic. If your documents are sizable, Flow could be sending data slower or failing to use chunked transfer encoding properly. This leads DocuSign to only receive partial data before its internal timeout triggers a BadRequest, and Flow waits the full 2 minutes before timing out.
• Hidden Flow Timeout Constraints: Even if you’ve set a 2-minute overall timeout, Flow’s underlying infrastructure might have lower-level (TCP/HTTP) timeouts that kick in earlier. For large requests, these hidden limits can interrupt the transfer before the full payload reaches DocuSign.
• Base64 Formatting Issues in Flow: Flow might be introducing unintended artifacts (like extra newlines or whitespace) into the Base64 strings during processing. DocuSign can’t parse this malformed partial data, so it stops accepting the request, leaving Flow hanging until its timeout expires. Postman handles Base64 cleanly without these errors.

Recommended Fixes #

• Split Document Uploads: Instead of sending all documents in one POST request, use DocuSign’s draft envelope workflow:
  1. Create a draft envelope with minimal metadata (no documents)
  2. Add each document to the draft via separate PUT requests to /accounts/{accountId}/envelopes/{envelopeId}/documents/{documentId}
  3. Update the envelope status to "Sent" once all documents are added
     This reduces the size of each request, making transmission faster and less prone to timeouts.
• Optimize Flow’s HTTP Request Settings:
  • Enable chunked transfer encoding in Flow’s HTTP action configuration (look for a setting like "Enable chunked transfer") to improve large data transfer efficiency.
  • Verify that Flow isn’t routing through a proxy that limits bandwidth or adds latency.
• Clean Up Base64 Data: Add a step in your Flow to sanitize the Base64 strings—remove any newline characters, spaces, or padding errors. Use an expression like replace(variables('documentBase64'), decodeUriComponent('%0A'), '') to strip unwanted newlines.
• Adjust Flow’s Timeout Parameters: Check if your Flow’s HTTP action has separate connection and read timeout settings (not just the overall retry timeout). Increase these values to give more time for large data transfers to complete.
• Engage Microsoft Support: If none of the above work, submit a support ticket to Microsoft with your request details, Flow run logs, and DocuSign error logs. There might be a platform-specific limitation or bug affecting large request transmission in Flow.

Note: Your Postman test confirms the core request payload is valid when transmitted efficiently—so the issue is almost certainly related to how Flow handles the request transfer, not the payload itself.

内容的提问来源于stack exchange，提问作者Ivan Wilson