Bug #14466: Errno::ECONNRESET or Errno::EPIPE raised instead of HTTPResponse returned when POSTing with large body

• Status: Closed
• Assignee: naruse (Yui NARUSE)
• Target version: -
• ruby -v: ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-linux], ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-linux]
• Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN

[sk (SK Liew)]

Using net/http, when trying to POST to an endpoint with a large body, Errno::ECONNRESET or Errno::EPIPE would be raised.

How to reproduce:

1. In a terminal, run ruby -run -e httpd -- -p 3000 . to run a HTTP webserver.
2. In another terminal, run the code below:

require 'net/http'
def post_with_size(dest_url, size)
  string_to_send = ' ' * size

  uri_to_post = URI(dest_url)
  request = Net::HTTP::Post.new(uri_to_post)
  request.body = string_to_send

  http_client = Net::HTTP.new(uri_to_post.host, uri_to_post.port)
  http_client.use_ssl = (uri_to_post.scheme == 'https')
  response = http_client.request(request)
  puts response.body
  puts response.code
  puts response
end

dest_url = 'http://localhost:3000'
size = 6000000
post_with_size(dest_url, size)

Expected: HTTPResponse with status code of 404.
Observed: Errno::ECONNRESET or Errno::EPIPE error.

[carl.hoerberg (Carl Hörberg)]

sk (SK Liew) wrote:

Expected: HTTPResponse with status code of 404.
Observed: Errno::ECONNRESET or Errno::EPIPE error.

are you sure it's not the server that's aborting the connection before returning a 404? use eg. wireshark to confirm.

[sk (SK Liew)]

I have just confirmed with wireshark that a 404 is returned before the connection aborts.

[jeremyevans0 (Jeremy Evans)]

• File net-http-epipe.patch net-http-epipe.patch added
• Status changed from Open to Assigned
• Assignee set to naruse (Yui NARUSE)

I tried this example against an nginx instance, and received normal HTTP error codes (413 or 404 depending on payload size). However, on some other webservers (OpenBSD httpd and Webrick), I did see EPIPE failures in write_nonblock. Ignoring Errno::EPIPE when sending the request allows the request to complete and return results for those webservers. Attached is a patch that does that.

I don't know about handling Errno::ECONNRESET. That implies the socket is no longer usable and you should not be able to read from it. I wasn't able to trigger that condition in the webservers I tested, and don't feel comfortable trying to ignore it as well.

• Status changed from Assigned to Closed

Applied in changeset git|2b6a9f3a1ffcdb00bf89798979d475c6d189d419.

---

Ignore Errno::EPIPE when sending requests in net/http

An EPIPE when sending the request should be ignored. Even if you
cannot write more data, you may still be able to read the server's
response.

Fixes [Bug #14466]