[infinispan-dev] Single Port Client

[Sebastian Laskawiec]

On Tue, Dec 11, 2018 at 11:13 AM Radim Vansa <rvansa at redhat.com> wrote:

> I dislike having any logic based on the port number in some range; it's
> not common that behaviour would change if you set port to 9xxx instead
> of 8xxx.
>

That's not a problem with my approach, since you can always manually turn
the setting off or on. Here's how you do it:
ConfigurationBuilder cb = ...
cb.singlePort(SinglePortMode.ENABLED); // other options: DISABLED and AUTO


> Is there an (up-to-date) design doc?
>

No, this is just a proposal. I was hoping that you guys like it and then,
with some thumbs up, I could update the design doc.

Here's the most up-to-date version in case you were looking for it:
https://github.com/infinispan/infinispan-designs/blob/master/Single_port.adoc


>
> I don't fully follow, but if there's a problem in the HTTP handlers you
> can add a PING-detecting handler below...?
>

Thanks for the hint Radim!

Inspired by your idea I went ahead and checked how OpenShift Router
behaves. It turns out that it responds HTTP 400 if you throw Hotrod bytes
at it and then drops the connection. I also realized, there's one more
moving bit - TCP Keepalive. Luckily, we can control this setting over
configuration in our standalone.xml. However, it is perfectly legal what
I've seen in Netty (do not respond and keep the connection alive assuming
that TCP Keepalive is set to true).

The more I think about this, the more I'm convinced that the Single Port
support should be explicitly set in the client (or inferred from the
configuration). I do not know how Nginx, Linkerd or Envoy behaves in
situation when they expect HTTP and get a stream of bytes. Relying on this
partially unknown behavior for doing our upgrade procedure doesn't seem
right to me.

Just in case you're worried about the additional logic on the client side -
it's super small. Really, only 13 lines including brackets ;)
https://github.com/infinispan/infinispan/pull/6133/files#diff-684a10c939f31fcfef0f5f48d469393aR618


>
> Radim
>
> On 12/10/2018 03:27 PM, Sebastian Laskawiec wrote:
> > Hey guys,
> >
> > During Infinispan F2F, I had a short discussion with Tristan on Single
> > Port client-side implementation. Back then, we agreed that the client
> > should always send a Hotrod Ping request and if won't get any response
> > (or get some HTTP content back), it will try to upgrade to the Hotrod
> > protocol using Single Port.
> >
> > I've been playing with the implementation for a while, and
> > implementing it this way seems a bit "inconvenient" to me. The Ping
> > Operation uses 60s timeout, which seems to be a good fit as a default.
> > Unfortunately, for the Single Port functionality, this means we'd need
> > to wait 60s until we try to send HTTP request and do an upgrade. Also,
> > another problematic part is in Netty's HTTP handlers
> > (HttpObjectDecoder, HttpServerCodec and ByteToMessageDecoder). When
> > those classes fail to decode a message (REST expects HTTP rather than
> > a stream of bytes specific to Hotrod protocol), they just ignore it
> > and keep the channel in active state (which also makes sense for
> > HTTP/1.1 and HTTP/2).
> >
> > At this point, my intuition tells, that this doesn't look right and
> > seems to be a over-complicated. The whole HTTP upgrade idea seems to
> > work the other way around, use HTTP as a fallback and then upgrade to
> > other protocols. Forcing it to work a bit differently requires some
> > more effort.
> >
> > What if we preserved the Single Port setting in the client
> > configuration but implemented it as an enum with the following values
> > - true/false/auto. In automatic mode, the client would check if the
> > server port is set to 8\d{1,3} (this covers 80, 8080, 8081, 8443 and
> > friends). If that is true, we'd try to follow HTTP Upgrade procedure.
> > This looks very simple and I think this might actually work. Please
> > note, that we need the single port setting in the client configuration
> > to cover some corner cases like the Single Port exposed on different
> > port (like 4444) or Hot Rod exposed on port that starts with 8.
> >
> > What do you think about such simplification?
> >
> > Thanks,
> > Sebastian
> >
> >
> >
> >
> > _______________________________________________
> > infinispan-dev mailing list
> > infinispan-dev at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/infinispan-dev
>
>
> --
> Radim Vansa <rvansa at redhat.com>
> JBoss Performance Team
>
> _______________________________________________
> infinispan-dev mailing list
> infinispan-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/infinispan-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/infinispan-dev/attachments/20181212/8811b80f/attachment.html