<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Some food for thought regarding "Java" support on the Google App Engine.<br><div><br><div>Begin forwarded message:</div><blockquote type="cite"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div><blockquote type="cite"><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>From: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">David Pollak </font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Date: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">April 17, 2009 11:57:57 PM CEDT</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>To: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">liftweb</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Subject: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica"><b>[Lift] Lift works on Google App Engine (within the confines of what's possible)</b></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" color="#000000" size="3"><span class="Apple-style-span" style="font-size: 12px;"><b><br></b></span></font></div> </div>Folks,<br><br>I've just committed a version of Lift (including the Lift Example) that runs on the Google App Engine. You can see the running demo at:<br><a href="http://liftdemo.appspot.com/">http://liftdemo.appspot.com/</a><br> <br>What's missing:<br><ul><li>Mapper and Mapper-related stuff. You can use JPA.</li><li>Comet. GAE's lack of thread or message queue support is a huge limitation. <br></li><li>Actor-based session-shutdown notification is disabled on GAE.</li> <li>There's no session affinity guarantee, so there may be problems with migrating sessions (I'll be working with the Google folks on this issue)<br></li></ul>Okay... so you can build apps on GAE... I have to wonder... who would want to?<br> <br>GAE gives you a highly scalable platform to build CRUD apps. Without a back-end messaging infrastructure, long running processes, threads, inter-session messaging, etc. there's not much in the way of exciting apps to build. Here are a list of apps that could not be built with GAE:<br> <ul><li>Twitter (requires a message bus and back-ground processing)</li><li>Facebook (has many of Twitter's requirements)</li><li>GoogleTalk</li><li>A travel site (the 30 second request duration means that looking stuff up on a back end service is not possible)</li> <li>A multi-player game<br></li></ul>So... on a $100/mo box from CalPop, I can run a service that will scale to 20M requests per day. If I'm doing 20M requests per day, I've got a business where I want more control over my infrastructure than GAE gives me. That might be Amazon EC2 where I can power-up and down boxes at will. There are also a number of different scalable storage solutions on Amazon. I just can't for the life of me figure out why anyone would want to put a Java/Scala app on GAE.<br> <br>Thanks,<br><br>David<br><br>-- <br>Lift, the simply functional web framework <a href="http://liftweb.net">http://liftweb.net</a><br>Beginning Scala <a href="http://www.apress.com/book/view/1430219890">http://www.apress.com/book/view/1430219890</a><br> Follow me: <a href="http://twitter.com/dpp">http://twitter.com/dpp</a><br>Git some: <a href="http://github.com/dpp">http://github.com/dpp</a><br><br> --~--~---------~--~----~------------~-------~--~----~<br> You received this message because you are subscribed to the Google Groups "Lift" group. <br> To post to this group, send email to <a href="mailto:liftweb@googlegroups.com">liftweb@googlegroups.com</a> <br> To unsubscribe from this group, send email to <a href="mailto:liftweb+unsubscribe@googlegroups.com">liftweb+unsubscribe@googlegroups.com</a> <br> For more options, visit this group at <a href="http://groups.google.com/group/liftweb?hl=en">http://groups.google.com/group/liftweb?hl=en</a><br> -~----------~----~----~----~------~----~------~--~---<br> <br></blockquote></div><br></div></div></blockquote></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>Jason Lee, SCJP</div><div>Senior Java Developer, Sun Microsystems</div><div>Mojarra and Mojarra Scales Dev Team</div><div><a href="https://mojarra.dev.java.net">https://mojarra.dev.java.net</a></div><div><a href="https://scales.dev.java.net">https://scales.dev.java.net</a></div><div><a href="http://blogs.steeplesoft.com">http://blogs.steeplesoft.com</a></div><div><br></div></div></div></div></div></div></span><br class="Apple-interchange-newline"> </div><br></body></html>