Socket connection aborted while uploading

[josuegomes]

FileZilla Pro development here.

Customer consistently sees 'ECONNABORTED' errors while trying to upload a large file. See log excerpt below:

Command: POST /2/files/upload_session/start HTTP/1.1
Command: Authorization: *********************************************************************************************************************************************************
Command: Connection: keep-alive
Command: Content-Length: 5242880
Command: Content-Type: application/octet-stream
Command: Date: Tue, 05 Dec 2023 15:23:14 GMT
Command: Dropbox-API-Arg: { "close": false }
Command: Dropbox-API-Path-Root: {".tag": "namespace_id", "namespace_id": "<REMOVED>"}
Command: Host: content.dropboxapi.com
Command: Keep-Alive: 300
Command: User-Agent: FileZilla/3.66.2
Response: HTTP/1.1 200 OK
Response: Cache-Control: no-cache
Response: X-Content-Type-Options: nosniff
Response: X-Server-Response-Time: 908
Response: Content-Type: application/json
Response: Accept-Encoding: identity,gzip
Response: Date: Tue, 05 Dec 2023 15:22:47 GMT
Response: Server: envoy
Response: Content-Length: 87
Response: Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
Response: X-Robots-Tag: noindex, nofollow, noimageindex
Response: X-Dropbox-Response-Origin: far_remote
Response: X-Dropbox-Request-Id: cc19db53be50431a942701b9e2a367e8
Command: POST /2/files/upload_session/append_v2 HTTP/1.1
Command: Authorization: *********************************************************************************************************************************************************
Command: Connection: keep-alive
Command: Content-Length: 80248163
Command: Content-Type: application/octet-stream
Command: Date: Tue, 05 Dec 2023 15:23:16 GMT
Command: Dropbox-API-Arg: {"cursor":{"offset":5242880,"session_id":"pid_upload_session:<REMOVED>"}}
Command: Dropbox-API-Path-Root: {".tag": "namespace_id", "namespace_id": "<REMOVED>"}
Command: Host: content.dropboxapi.com
Command: Keep-Alive: 300
Command: User-Agent: FileZilla/3.66.2
Error: Socket error: ECONNABORTED - Connection aborted

Any idea of possible causes?

[Greg-DB]

Are you only seeing this reported by one customer? This issue doesn't reproduce for me, even when using the same request body sizes, and I'm not seeing any other reports of this error.

I'm not aware of any issues on the Dropbox side that should be causing this. Is there anything on the customer's network connection, such as a firewall, VPN, proxy, anti-virus, or other such software that may be interfering with the connections?

I also notice that the failing request uses a substantially larger request body size than the successful request before it (80248163 versus 5242880). While the Dropbox API supports accepting 80248163 bytes in a request (and that is working for me), there may be something on the customer's network connection that is failing on the larger size.

[Здравко]

Such an error indicates that the socket has felled in undefined state and the system (socket controlling libraries) cannot recover it. It's not related to the HTTP query performed directly. There are wide variety of reasons for such thing and cannot be pointed something mandatory as a source.

@josuegomes, To figure out what's going out you need to debug the particular system and see what's the exact wrong in the socket state. After that, what directs socket to this state. If you have some doubts that something in responses from Dropbox causes it, you need to provide more detailed log of communication causing such a state, so be able issue reproduction (it's NOT on HTTP level but lower in protocol stack). Most probably it's some bug in some part of the particular system - system update (especially related to communication) may fix it without you deal with details.

Good luck.

[josuegomes]

Thank you for your reply.

Yes, this is the only customer experiencing the issue. With other customer and on tests done by our team, we see no errors.

I'll ask if there is something in the customer's network that could interfere with the communication.