Retry when getting an EOF on HEAD/GET requests because of a Golang bug

[lebauce]

When running a 30 minutes testsuite (https://github.com/lebauce/distribution), I faced a weird issue : I sometimes got a url.Error : "Head https://my.swift.server/v1/AUTH_abcdb3abcda34a1c8d618164d99eb53e/test/myobject : EOF". I'm using the 1.4.2 version of Go.

The issue seems to be in the net/http library and is described in both tickets :
golang/go#4677
golang/go#8946

A fix on net/http is under review : https://golang.org/cl/3210

A fix for this problem is simply to send the request again when the request was a HEAD or a GET

[ncw]

That fix looks safe to me.

What do you think about retrying on any error on a HEAD or GET? These requests are idempotent in the swift API so there should be no problems with that.

[vtolstov]

this can helps me with my issue when i'm upload file and can't get it back

[ncw]

@vtolstov probably not since we are just talking about HEAD/GET requests not PUT/POST which would be used to upload data.

[vtolstov]

@ncw i'm also have issues in head requests, but file present and after 1,3,5 -10 seconds displayed

[ncw]

@vtolstov that sounds like it could be swift's eventual consistency in action? Is your swift server very busy?

[vtolstov]

@ncw yes, sometimes my swift servers very busy (backends have massive loading by container replicator)

[lebauce]

@ncw Something like :

        resp, err = c.doTimeoutRequest(timer, req)
        if err != nil {
            if urlError, ok := err.(*url.Error); ok {
                if p.Operation == "HEAD" || p.Operation == "GET" {
                    retries--;
                    continue
                }
            }
            return
        }

?

[ncw]

@lebauce Or maybe even this?

        resp, err = c.doTimeoutRequest(timer, req)
        if err != nil {
                if p.Operation == "HEAD" || p.Operation == "GET" {
                    retries--;
                    continue
                }
                return
        }

[lebauce]

@ncw Indeed, it's better. I updated the PR

[ncw]

Thank you very much for that.

-- Nick