It can happen with erroneous clients which do not send `Host:`
header until 4k worth of header bytes have been read. This can lead
to Peek() method of bufio to fail with ErrBufferFull.
To avoid this we should make sure that Peek buffer is as large as
our maxHeaderBytes count.
Without this PR minio server is writing an erroneous
response to clients on an idle connections which ends
up printing following message
```
Unsolicited response received on idle HTTP channel
```
This PR would avoid sending responses on idle connections
.i.e routine network errors.
An issue was reproduced when minio-js client functional
tests are setting lower case http headers, in our current
master branch we specifically look for canonical host header
which may be not necessarily true for all http clients.
This leads to a perpetual hang on the *net.Conn*.
This PR fixes regression caused by #6206 by handling the
case insensitivity.
This package provide customizable TCP net.Listener with various
performance-related options:
* SO_REUSEPORT. This option allows linear scaling server performance
on multi-CPU servers.
See https://www.nginx.com/blog/socket-sharding-nginx-release-1-9-1/ for details.
* TCP_DEFER_ACCEPT. This option expects the server reads from the accepted
connection before writing to them.
* TCP_FASTOPEN. See https://lwn.net/Articles/508865/ for details.
Peek could fail legitimately when clients abruptly close connection. So,
io.EOF and network timeout errors are not logged while all other errors
will be logged.
* Refactor HTTP server to address bugs
* Remove unnecessary goroutine to start multiple TCP listeners.
* HTTP server waits for shutdown to maximum of Server.ShutdownTimeout
than per serverShutdownPoll.
* Handles new connection errors properly.
* Handles read and write timeout properly.
* Handles error on start of HTTP server properly by exiting minio
process.
Fixes#4494#4476 & fixed review comments
Harshavardhana