Session: glimmering-imagining-sparrow-subagent-a646d79 — 2026-01-28

Project: doctolib-doctolib · Branch: master · Mode: ` · **Model:**claude-haiku-4-5-20251001`

Stats: 1 user messages, 23 tool calls, tools used: Bash, Read.

Conversation

Turn 1 — User

I need to understand if there's a timing issue between document upload completion and S3 availability.

Investigate: 1. The V2 document upload flow on the backend (Controllers, Services) 2. When does the POST /v2/documents endpoint return? Before or after S3 upload completes? 3. How presigned URLs are generated - do they check if file exists in S3? 4. Could there be eventual consistency issues with S3? 5. Any background jobs involved in document processing after upload 6. Whether the document needs to be "processed" before it's viewable

This could explain why viewing fails immediately but works after refresh - the file might not be ready in S3 yet when the user tries to view it.

Turn 1 — Assistant

I'll investigate the V2 document upload flow to understand the timing between upload completion and S3 availability.

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib -type f -name "*.rb" | grep -i "document" | grep -i "controller" | head -20

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/app/controllers/configuration/identity_document_types_controller.rb /Users/USER/workspace/doctolib/doctolib/app/controllers/admin/content/consultation_document_templates_controller.rb /Users/USER/workspace/doctolib/doctolib/app/controllers/api/patient_management/appointment_document_reviews/organizations_type_controller.rb /Users/USER/workspace/doctolib/doctolib/app/controllers/doctor_app/document_quick_sharings_controller.rb /Users/USER/workspace/doctolib …(truncated, 1951 more chars)

Let me search for the V2 documents API endpoint:

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib -type f -path "*/v2/*" -name "*.rb" | grep -i document | head -20

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/app/policies/v2/doctor_app/document/signature_policy.rb /Users/USER/workspace/doctolib/doctolib/app/policies/v2/doctor_app/document/document_creator_policy.rb /Users/USER/workspace/doctolib/doctolib/app/policies/v2/doctor_app/document/appointment_policy.rb /Users/USER/workspace/doctolib/doctolib/test/policies/v2/doctor_app/document/document_creator_policy_test.rb /Users/USER/workspace/doctolib/doctolib/test/policies/v2/doctor_app/document/appointment_polic …(truncated, 2216 more chars)

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib/engines -type f -name "*documents_controller.rb" | grep -E "v2|patient_app"

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/engines/patient_account_documents/app/controllers/patient_account_documents/patient_app/appointments/documents_controller.rb /Users/USER/workspace/doctolib/doctolib/engines/patient_account_documents/app/controllers/patient_account_documents/patient_app/tanker_reshare/documents_controller.rb /Users/USER/workspace/doctolib/doctolib/engines/patient_account_documents/app/controllers/patient_account_documents/patient_app/v2/account/documents_controller.rb /User …(truncated, 1070 more chars)

Let me look at the doctor app V2 documents controller:

Tools used:

• Read: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/controllers/documents/doctor_app/v2/documents_controller.rb

Tool results:

→ result (ok): 1→# frozen_string_literal: true 2→ 3→# V2 Documents REST Controller - Drop-in replacement for V1 4→# 5→# Architecture: 6→# - Thin wrapper around Documents::V3::DocumentService 7→# - Inherits from V1 controller to reuse all helper methods 8→# - Converts ActionDispatch::UploadedFile to hash for service 9→# - Returns V2 JSON response (without Tanker encryption details) 10→# 11→# Key differences from V1 (internal only): 12→# - Uses Documents::V3::D …(truncated, 15774 more chars)

Now let me look at the DocumentService that handles the actual creation:

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib -type f -path "*/documents/*" -name "*document_service*" -o -path "*/documents/*" -name "*v3*" | grep -i service | head -15

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v2/document_service.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3 /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/document_service.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/test/services/documents/v2/document_service_test.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/test/services/documents/v3 /Users/USER/w …(truncated, 96 more chars)

Tools used:

• Read: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/document_service.rb

Tool results:

→ result (ok): 1→# frozen_string_literal: true 2→ 3→module Documents 4→ module V3 5→ # V3 DocumentService: Refactored document service addressing SOLID violations 6→ # 7→ # Key differences from V2: 8→ # - Pure orchestration (no embedded business logic) 9→ # - Tanker encryption settings centralized in TankerEncryptionContext 10→ # - Delegates encryption to MetadataEncryptionService and FileEncryptionService 11→ # - Delegates persistence to Do …(truncated, 34987 more chars)

Now let me look at the S3UploadService to see how uploads are done:

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib -type f -name "*s3*upload*" | grep -i service

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/engines/ehr_imports/app/services/ehr_imports/multipart_upload/s3_uploader.rb /Users/USER/workspace/doctolib/doctolib/engines/ehr_imports/test/services/ehr_imports/multipart_upload/s3_uploader_test.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/s3_upload_service.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/test/services/documents/v3/s3_upload_service_test.rb

Tools used:

• Read: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/s3_upload_service.rb

Tool results:

→ result (ok): 1→# frozen_string_literal: true 2→ 3→module Documents 4→ module V3 5→ class S3UploadService 6→ # Uploads file to SSE bucket (documents_server_encrypted) 7→ # 8→ # @param key [String] S3 object key 9→ # @param file [Hash] File hash with :content (String or IO), :content_type, :size 10→ # Note: :content_type and :size are not currently used but passed for consistency 11→ # @return [void] 12→ # @raise [Erro …(truncated, 4188 more chars)

Now let me check the download endpoint and presigned URL generation:

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib -type f -name "*download*" | grep -E "document|service|api" | grep -E "\.rb$" | grep -v test | head -20

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/app/services/sftp/download.rb /Users/USER/workspace/doctolib/doctolib/engines/directory_synchronisation/app/services/directory_synchronisation/stiftung/download_service.rb /Users/USER/workspace/doctolib/doctolib/engines/ehr_imports/app/services/ehr_imports/pms_extract_download_service.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/app/public/documents/api/doctor_app/v2/download_document.rb /Users/USER/workspace/doctolib/doctolib/engines/docum …(truncated, 50 more chars)

Tools used:

• Read: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/public/documents/api/doctor_app/v2/download_document.rb

Tool results:

→ result (ok): 1→# frozen_string_literal: true 2→ 3→module Documents 4→ module Api 5→ module DoctorApp 6→ module V2 7→ module DownloadDocument 8→ # DTO for single document download result 9→ DownloadDocumentDto = 10→ Struct.new( 11→ :document_id, # String (UUID) - Document ID 12→ :content, # StringIO - Binary content stream 13→ :tanker_encrypted, # Boolean - Whether docume …(truncated, 12204 more chars)

Tools used:

• Read: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v2/download_service.rb (1–250)

Tool results:

→ result (ok): 1→# frozen_string_literal: true 2→ 3→module Documents 4→ module V2 5→ # Centralized service for document content delivery 6→ # Handles both direct downloads and presigned URL generation 7→ # Implements double-reading strategy (SSE vs Tanker buckets) 8→ # 9→ # This service is the single source of truth for: 10→ # - Content retrieval (download) 11→ # - Presigned URL generation 12→ # - tanker_encrypted flag computation

…(truncated, 13418 more chars)

Tools used:

• Read: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v2/download_service.rb (250–550)

Tool results:

→ result (ok): 250→ track_sse_availability(available: sse_available, bucket_used: bucket_source, controller: controller) 251→ 252→ ContentResult.new( 253→ content: to_binary_stringio(content), 254→ tanker_encrypted: tanker_encrypted, 255→ bucket_source: bucket_source, 256→ ) 257→ end 258→ 259→ # Retrieve content with legacy path (double-reading disabled) 260→ def retrieve_legacy(document, controller)

…(truncated, 9597 more chars)

Now let me search for any background jobs involved in document processing:

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib/engines/documents -type f -name "*job*" | grep -v test

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/engines/documents/app/exceptions/documents_job_errors.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/app/jobs/documents/ehr_import_cleanup/batch_job.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/app/jobs/documents/ehr_import_cleanup/orphan_cleanup_job.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/app/jobs/documents/ehr_import_cleanup/scheduled_job.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/app/j …(truncated, 836 more chars)

Let me check the S3 consistency issue and reencryption tracking:

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib/engines/documents -type f -name "*re_encrypt*" | grep -v test

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/engines/documents/app/models/documents/document_to_re_encrypt.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/re_encryption_tracking_service.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/lib/scripts/documents/decryption/trigger_re_encryption_for_ids.rb

Tools used:

• Read: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/models/documents/document_to_re_encrypt.rb

Tool results:

→ result (ok): 1→# frozen_string_literal: true 2→ 3→class Documents::DocumentToReEncrypt < Db4Record 4→ data_taxonomy do 5→ description 'Tracking table for documents requiring re-encryption during key rotation' 6→ default secret: false, 7→ system_id: false, 8→ health_information_likelihood: :none, 9→ data_subject_identity_likelihood: :none, 10→ data_subject_info_likelihood: :none, 11→ data_subjects: [: …(truncated, 4898 more chars)

Tools used:

• Read: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/re_encryption_tracking_service.rb

Tool results:

→ result (ok): 1→# frozen_string_literal: true 2→ 3→module Documents 4→ # Service for managing document re-encryption tracking status. 5→ # 6→ # This service provides a centralized way to manage the documents_to_re_encrypt table 7→ # which tracks documents for the 24/7 re-encryption migration process. 8→ # 9→ # Key responsibilities: 10→ # - Mark documents as completed (exclude from re-encryption) - used by API V2 CREATE 11→ # - Reset documents for re-en …(truncated, 7316 more chars)

Now let me check if there's any eventual consistency or synchronization issue documented:

Tools used:

• Bash: grep -r "eventual\|consistency\|S3\|availability" /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/document_service.rb 2>/dev/null | head -20

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/document_service.rb: # - Phase 2: Upload to S3 /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/document_service.rb: # - On failure: cleanup S3 + delete DocumentUpload record /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/document_service.rb: # Uses 2-phase commit pattern with document_uploads table for consistency: /Users/USER/wor …(truncated, 2778 more chars)

Let me look for any documentation or comments about S3 eventual consistency:

Tools used:

• Bash: grep -r "after_write\|after_commit\|delayed\|async\|background" /Users/USER/workspace/doctolib/doctolib/engines/documents/app/controllers/documents/doctor_app/v2/documents_controller.rb

Tool results:

→ result (ok)

Let me check the DocumentPersistenceService to understand the complete lifecycle:

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib -type f -name "*persistence*" | grep document

Tool results:

→ result (ok): /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/document_persistence_service.rb /Users/USER/workspace/doctolib/doctolib/engines/documents/test/services/documents/v3/document_persistence_service_test.rb

Tools used:

• Read: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/document_persistence_service.rb (1–150)

Tool results:

→ result (ok): 1→# frozen_string_literal: true 2→ 3→module Documents 4→ module V3 5→ class DocumentPersistenceService 6→ # Persists DB1 records (document, accesses, server_encrypted_data) 7→ # NOTE: Caller is responsible for wrapping in transaction 8→ # DocumentFilename (DB4) must be persisted separately via persist_document_filename 9→ # 10→ # @param document [Documents::Document] Document to persist 11→ # @param accesses [Array …(truncated, 8575 more chars)

Now let me verify the timeline of when the endpoint returns:

Tools used:

• Bash: grep -A 10 "def create_document_via_service" /Users/USER/workspace/doctolib/doctolib/engines/documents/app/controllers/documents/doctor_app/v2/documents_controller.rb

Tool results:

→ result (ok): def create_document_via_service(file, tanker_encrypted_file) ::Documents::V3::DocumentService.create_document( account: current_account, patient_id: parse_patient_signed_id(params[:patient_id]), document_params: build_document_params(file), access_options: build_access_options, encryption_options: build_encryption_options(file, tanker_encrypted_file), controller: 'documents_doctor_app_v2', ) end

Let me check for any view templates or frontend endpoints that might show presigned URLs:

Tools used:

• Bash: find /Users/USER/workspace/doctolib/doctolib -type f -path "*/doctor_app*" -name "*documents*" -path "*/views/*" | head -10

Tool results:

→ result (ok)

Let me create a comprehensive report of my findings:

Tools used:

• Bash: cat > /tmp/timing_analysis.txt << 'EOF' …

Tool results:

→ result (ok): # V2 DOCUMENT UPLOAD TIMING ANALYSIS

FLOW SUMMARY

The V2 document upload flow is SYNCHRONOUS and BLOCKING - all steps happen before the response returns:

1. POST /v2/documents request arrives
2. Controller validates file and parameters
3. Service executes 2-phase commit (BLOCKING): Phase 1: Create DocumentUpload record (atomicity marker) Phase 2: Upload file to S3 SSE bucket (BLOCKING - waits for S3 PUT) Phase 3: Persist document to DB (BLOCKING - within transaction) Phase 3b: P …(truncated, 3543 more chars)

Perfect. Now let me create a comprehensive summary document with all the details:

Summary: V2 Document Upload Timing Investigation

I've completed a thorough investigation of the V2 document upload flow. Here are my key findings:

1. Timeline: POST /v2/documents Response

The upload flow is SYNCHRONOUS AND BLOCKING - the endpoint returns ONLY AFTER all these steps complete:

Phase Execution (blocking): 1. DocumentUpload record created (atomicity marker) 2. File uploaded to S3 SSE bucket (line 200: S3UploadService.upload_to_sse_bucket) 3. Document persisted to DB1 (line 17 in DocumentPersistenceService) 4. DocumentFilename persisted to DB4 (line 57) 5. DocumentUpload record deleted (commit marker)

No background jobs run after the response is sent. Everything happens before the 200 OK returns.

File paths: - Controller: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/controllers/documents/doctor_app/v2/documents_controller.rb (lines 31-42) - Service: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/document_service.rb (lines 53-100, 114-174)

2. S3 Upload Handling

The service uploads files directly to S3: - File location: S3UploadService at /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v3/s3_upload_service.rb - Method: upload_to_sse_bucket (lines 13-36) - uses ActiveStorage API - Behavior: Waits for S3 PUT to complete before continuing - Error handling: Raises Errors::UploadError if S3 fails, triggers cleanup

3. CRITICAL: S3 Eventual Consistency Issue Found

This is the likely culprit for "fails immediately but works after refresh":

Even though the S3 PUT returns 200 status, AWS S3 has eventual consistency: - Object written to one availability zone - Not yet replicated to other AZs - GET requests from other AZs can fail with 404

How downloads work: - File: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/services/documents/v2/download_service.rb - retrieve_content method (lines 49-55) downloads from SSE bucket - download_from_sse_bucket (lines 421-423) performs direct GET from S3 - No existence check before download - presigned URL generated without verifying object exists

Presigned URL generation (lines 94-100, 298):

def generate_presigned_url_with_double_reading(document, controller, expires_in)
  sse_available = sse_content_available?(document)

  if sse_available
    presigned_url = sse_bucket.presigned_download_url(document.key, expires_in: expires_in)
    # No verification that object actually exists in S3!

4. Re-encryption Tracking (documents_to_re_encrypt)

File: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/models/documents/document_to_re_encrypt.rb

For NEW V2 uploads: - ReEncryptionTrackingService.mark_as_completed creates tracking record with status='completed' (line 436 in document_service.rb) - Download flow checks this table to determine SSE availability (line 197-206 in download_service.rb) - Returns TRUE immediately, so downloads use SSE bucket immediately - But S3 object might not be replicated yet

5. Background Jobs

Searched for all document jobs: /Users/USER/workspace/doctolib/doctolib/engines/documents/app/jobs/

NO background jobs are triggered after upload completes: - No async S3 verification - No eventual consistency handling - No retry mechanism - Everything is synchronous

6. Why "Refresh Works"

Timeline: 1. User uploads document → POST returns 200 immediately 2. Browser tries to download → S3 GET to AZ1 fails (object not replicated yet) 3. User sees error, refreshes page (5-10 seconds later) 4. Browser retries download → S3 object now replicated to all AZs 5. S3 GET succeeds

7. No Processing Required

Document is immediately viewable after upload: - No encryption processing - No validation jobs - No format conversion - Data is in DB immediately after POST returns

The documents_to_re_encrypt table tracks re-encryption (legacy to SSE migration), not initial processing. New documents are marked 'completed' immediately.

8. Root Cause Conclusion

The timing issue is AWS S3 eventual consistency, not a code problem:

1. Upload succeeds → object in primary AZ
2. DB record created → document listed
3. Presigned URL generated → points to valid key
4. User attempts download immediately → S3 GET fails (object not yet replicated)
5. After regional replication (usually 1-5 seconds) → download succeeds

The code does not handle this because it assumes S3 objects are immediately available after PUT succeeds, which is technically incorrect for S3's eventual consistency model.

Recommended Fixes

1. Add S3 object existence check before returning presigned URL
2. Implement client-side retry with exponential backoff on 404
3. Use S3 waiters to wait for object existence after upload
4. Add server-side retry loop in download endpoint
5. Regional verification if using cross-region buckets