On Wed, Jan 6, 2010 at 7:17 AM, Paul Sandoz <[email protected]> wrote:
> > On Jan 6, 2010, at 3:22 PM, David Pollak wrote: > > > > On Wed, Jan 6, 2010 at 5:23 AM, Timothy Perrett > <[email protected]>wrote: > >> Yes, if you constantly change containers, then there is value in >> Atmosphere for that as it does leverage the native APIs for the container. >> We [lift] are waiting for servlet 3.0 to standardise the comet API - whilst >> its debatable if that will prove as an api standardisation solution, it >> should level the playing field somewhat - right now the different containers >> are all doing different things in different ways. >> > > Marius is actively working on an abstraction of the thread dropping so that > other containers that use different APIs can be plugged into Lift (or vice > versa) because the Servlet 3.0 spec is taking forever. > > > OK. Servlet 3.0 spec is now finalized, meaning there is at least one > implementation (in GlassFish v3) but i guess it may take time for others to > arrive. > > Are the async features of Servlet 3.0 sufficient for lift's requirements? > Yes and it will be supported by the work Marius is currently doing. > > > > >> >> Essentially lift uses special classes within Jetty (the continuation API) >> to make comet scalable... there is nothing stopping comet working in other >> containers with lift, the only restriction is that it does not use the >> native container API so it's essentially thread based - to that end, if you >> have a lot of connections things could get sticky. >> >> Lift has things that Atmosphere does not have (yet) like the multiplex >> support, and object delta'ing... perhaps other comet frameworks will get >> this in the future, but right now, using Jetty is not a deal breaker for >> most of our users. I guess its only really an issue if you have a heavy >> investment in something that is not jetty. However, I would stress that lift >> is an excellent framework even if your not using comet and that would of >> course deploy without any issues in any container. >> > > As Tim points out, Lift has a number of advantages in its Comet support: > > - Multiplexing -- you can have many Comet components on a given page > and they all talk over a single long poll. You can see this at > http://demo.liftweb.com. Both the clock and the chat component are > Comet. Neither piece of code was special or required knowledge of the > other. > - Connection saturation detection -- Lift will avoid connection > saturation by only allowing a single long poll to be active at once. If a > second connection (this is tunable and it's on my to-do list to make it > browser tunable as Chrome has more than 2 connections per server) is opened > from the browser, Lift will automatically terminate the long poll. > - DNS wildcard support -- To avoid the connection saturation issue, you > can have the long poll done on a DNS wildcarded server and tune the long > poll connection termination logic. This allows many different browser tabs > to have open long polls. The server name is automatically changed on each > page reload and the actual client-side and server-side components are > unchanged (that means the app developer doesn't have to worry about this > part of the plumbing.) > > > > I am not suggesting Atmosphere can or should be utilized as a replacement > for the useful features you enumerate. I think the area where Atmosphere can > provide value to lift is scalable async support for many Web/App servers. > To date, the large Lift comet users have been using Jetty with success. If there is demand for Lift's Comet support on non-Servlet 3.0 platforms, we'll look into Atmosphere integration. Thanks, David > > Paul. > > -- > You received this message because you are subscribed to the Google Groups > "Lift" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<liftweb%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/liftweb?hl=en. > > -- Lift, the simply functional web framework http://liftweb.net Beginning Scala http://www.apress.com/book/view/1430219890 Follow me: http://twitter.com/dpp Surf the harmonics--
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