From: jean.boussier@...
Date: 2017-04-03T11:32:21+00:00
Subject: [ruby-core:80542] [Ruby trunk Bug#13396] Net::HTTP has no write	timeout

Issue #13396 has been reported by byroot (Jean Boussier).

----------------------------------------
Bug #13396: Net::HTTP has no write timeout
https://bugs.ruby-lang.org/issues/13396

* Author: byroot (Jean Boussier)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: 
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
----------------------------------------
When sending a large request to an unresponsive server, `Net::HTTP` can hang pretty much forever.

```ruby
# server.rb
require 'socket'

server = TCPServer.new('localhost', 2345)
loop do
  socket = server.accept
end

```

```ruby
# client.rb
require 'net/http'

connection = Net::HTTP.new('localhost', 2345)
connection.open_timeout = 1
connection.read_timeout = 3
connection.start

post = Net::HTTP::Post.new('/')
body = (('a' * 1023) + "\n") * 5_000
post.body = body

puts "Sending #{body.bytesize} bytes"
connection.request(post)
```

The above code will hang forever on all system I tested it on (OSX / Linux 3.19).

The issue only trigger once the request body is above a certain threshold. That threshold depends on the system, I assume it's due to the system's TCP settings, but a request over 4MB will trigger the issue consistently.

I assume it happens when the request is bigger than the socket buffer. 

It's stuck on the following path:

```
/net/protocol.rb:211:in `write': Interrupt
/net/protocol.rb:211:in `write0'
/net/protocol.rb:185:in `block in write'
/net/protocol.rb:202:in `writing'
/net/protocol.rb:184:in `write'
/net/http/generic_request.rb:188:in `send_request_with_body'
/net/http/generic_request.rb:121:in `exec'
/net/http.rb:1435:in `block in transport_request'
/net/http.rb:1434:in `catch'
/net/http.rb:1434:in `transport_request'
/net/http.rb:1407:in `request'
```

I tried setting `setsockopt(Socket::SOL_SOCKET, Socket::SO_SNDTIMEO, ...)` on the client socket, but without success. However adding a `Timeout.timeout` call around `req.exec` did work.



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