Errno::EBADF: Bad file descriptor with ruby net/http - ruby

Question

What can cause while making an HTTP connection to return EBADF (Bad file descriptor).
Here is my following code wherein the HTTP connection is made. Although the error is very less now(happening very less) but before I put those error on rescue I need to understand what is the reason for the EBADF
def make_http_request(url, headers={})
uri = URI(url)
Net::HTTP.start(uri.host, uri.port) do |http|
req = Net::HTTP::Get.new(uri, headers)
resp = http.request(req)
if resp.code.to_i != 200
logger.error "Retrieve #{resp.code} with #{url} and #{headers}"
return false
end
return resp.body
end
rescue SocketError, Net::ReadTimeout, Errno::ECONNREFUSED => e
logger.error "make_http_request #{url} with #{headers} resulted in #{e.message} \n #{e.backtrace}"
return false
end
I have a feeling that connect syscall is receiving an FD which ain't valid at that given point in time. But still unable to understand how can that happens.
If it helps the code is used in an application that operates with multiple threads.
In a nutshell, the definition of the above method looks like this...
module Eval
def make_http_request(url, headers={})
...
...
..
end
def request_local_endpoint(url, headers)
response = make_http_request(url, headers)
response && response.fetch('bravo',nil)
end
def request_external_endpoint(url, headers)
response = make_http_request(url, headers)
response && response.fetch('token',nil)
end
end
class RequestBuilder
include Eval
attr_reader :data
def initialize(data)
#data = data
end
def start
token = request_external_endpoint('http://external.com/endpoint1',{'Content-Type'.freeze => 'application/json', 'Authorization' => 'abcdef'})
return unless token
result = request_local_endpoint('http://internal.com/endpoint1',{'Content-Type'.freeze => 'application/json'})
return result
end
end
10.times {
Thread.new { RequestBuilder.new('sample data').start }
}