How to Catch Errno::Econnreset Class in "Case When"

How to catch Errno::ECONNRESET class in case when?

This is because of how the === operator works on the class Class

The case statement internally calls the === method on the object you are evaluating against. If you want to test for e class, you just test against e, not e.class. That's because e.class would fall into the when Class case, because, well, e.class is a Class.

rescue Exception => e
    case e
        when Errno::ECONNRESET
            p 1
        when Errno::ECONNRESET,Errno::ECONNABORTED,Errno::ETIMEDOUT
            p 2
        else
            p 3
    end
end

Yeah, Ruby can have weird semantics sometimes

Ruby UDPSocket throws ERRNO:ECONNRESET

If there is an error on the socket recv will not block, but remove and return the error. In this case the packet probably was sent, but no receiver was set up at localhost:7000, so it got back an ICMP unreachable. So set the the socket error to ECONNRESET.

How to rescue all exceptions under a certain namespace?

All the Errno exceptions subclass SystemCallError:

Module Errno is created dynamically to map these operating system errors to Ruby classes, with each error number generating its own subclass of SystemCallError. As the subclass is created in module Errno, its name will start Errno::.

So you could trap SystemCallError and then do a simple name check:

rescue SystemCallError => e
  raise e if(e.class.name.start_with?('Errno::'))
  # do your thing...
end

ERROR Errno::ECONNRESET: Connection reset by peer

My quick guess is this looks like you have a problem with your sessions and protect_from_forgery is kicking in.

I had a similar problem and smashed my head against the wall for a few days, it turned out to be I was assigning an entire object to a session object instead of just the id. A quick note, non-GET requests are the ones that trigger the protect_from_forgery.

What’s the best way to handle exceptions from Net::HTTP?

I agree it is an absolute pain to handle all the potential exceptions. Look at this to see an example:

Working with Net::HTTP can be a pain. It's got about 40 different ways
to do any one task, and about 50 exceptions it can throw.

Just for the love of google, here's what I've got for the "right way"
of catching any exception that Net::HTTP can throw at you:

begin
  response = Net::HTTP.post_form(...) # or any Net::HTTP call
rescue Timeout::Error, Errno::EINVAL, Errno::ECONNRESET, EOFError,
       Net::HTTPBadResponse, Net::HTTPHeaderSyntaxError, Net::ProtocolError => e
  ...
end

Why not just rescue Exception => e? That's a bad habit to get into, as
it hides any problems in your actual code (like SyntaxErrors, whiny
nils, etc). Of course, this would all be much easier if the possible
errors had a common ancestor.

The issues I've been seeing in dealing with Net::HTTP have made me
wonder if it wouldn't be worth it to write a new HTTP client library.
One that was easier to mock out in tests, and didn't have all these
ugly little facets.

What I've done, and seen most people do, is move away from Net::HTTP and move to 3rd party HTTP libraries such as:

httparty and faraday

Ruby class types and case statements

You must use:

case item
when MyClass
...

I had the same problem:
How to catch Errno::ECONNRESET class in "case when"?

npm not working - read ECONNRESET

use

npm config set registry http://registry.npmjs.org/

so that npm requests for http url instead of https.

and then try the same npm install command

How do I debug error ECONNRESET in Node.js?

A simple tcp server I had for serving the flash policy file was causing this. I can now catch the error using a handler:

# serving the flash policy file
net = require("net")

net.createServer((socket) =>
  //just added
  socket.on("error", (err) =>
    console.log("Caught flash policy server socket error: ")
    console.log(err.stack)
  )

  socket.write("<?xml version=\"1.0\"?>\n")
  socket.write("<!DOCTYPE cross-domain-policy SYSTEM \"http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd\">\n")
  socket.write("<cross-domain-policy>\n")
  socket.write("<allow-access-from domain=\"*\" to-ports=\"*\"/>\n")
  socket.write("</cross-domain-policy>\n")
  socket.end()
).listen(843)

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