[appengine-java] Re: NullPointerException while running a new app
Help anyone...the key here is the stack trace but it points to a line in the generated .java file that came from the .jsp. I am also getting a null pointer but when I check the line number using the generated .java on my local system, it does NOT make sense. Hence, the line number in production is NOT matching the line numbers locally!!! How do we affectively trouble-shoot a JSP stack dump on GAE? On Mar 13, 3:07 pm, anjolight anjoli...@gmail.com wrote: Hi I am getting the same NullPointerException. The challenge is that my app runs fine in my local eclipse but it gives me this error when it's deployed to app engine. And the error gives me very little information as to what went wrong. What's the best way to debug the nullpointerexception with JSP? On Feb 24, 5:05 pm, Ikai L (Google) ika...@google.com wrote: What's your application ID? On Fri, Feb 19, 2010 at 12:05 AM, Alberty Pascal alberty.pas...@gmail.comwrote: Hi all, while updating my application, I got the following stack for all request made on it. I try to deploy a really simple new application (created with Eclipse and its plugin) and got the same stack. Any idea ? Thanks Pascal java.lang.NullPointerException at com.google.appengine.runtime.Request.process-7d335e6a040b96cc(Request.java) at org.apache.jsp.index_jsp._jspService(index_jsp.java:44) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94) at javax.servlet.http.HttpServlet.service(HttpServlet.java:806) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java: 487) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java: 362) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java: 216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java: 181) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java: 712) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java: 405) at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:268) at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:126) at javax.servlet.http.HttpServlet.service(HttpServlet.java:693) at javax.servlet.http.HttpServlet.service(HttpServlet.java:806) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java: 487) at org.mortbay.jetty.servlet.ServletHandler $CachedChain.doFilter(ServletHandler.java:1093) at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java: 97) at org.mortbay.jetty.servlet.ServletHandler $CachedChain.doFilter(ServletHandler.java:1084) at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java: 35) at org.mortbay.jetty.servlet.ServletHandler $CachedChain.doFilter(ServletHandler.java:1084) at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java: 43) at org.mortbay.jetty.servlet.ServletHandler $CachedChain.doFilter(ServletHandler.java:1084) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java: 360) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java: 216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java: 181) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java: 712) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java: 405) at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java: 238) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java: 139) at org.mortbay.jetty.Server.handle(Server.java:313) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java: 506) at org.mortbay.jetty.HttpConnection $RequestHandler.headerComplete(HttpConnection.java:830) at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java: 76) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381) at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java: 135) at com.google.apphosting.runtime.JavaRuntime.handleRequest(JavaRuntime.java: 235) at com.google.apphosting.base.RuntimePb$EvaluationRuntime $6.handleBlockingRequest(RuntimePb.java:5485) at com.google.apphosting.base.RuntimePb$EvaluationRuntime $6.handleBlockingRequest(RuntimePb.java:5483) at
[appengine-java] Re: How to upload pics in appengine java
Also this guy Vince has a package that not only helps with uploads but also then allowing your app to generate pages that use the photos including delta checks - really neat stuff! See GAEVFS mentioned in this thread. Please post your results so the rest of us can benefit from your experience. http://groups.google.com/group/google-appengine-java/browse_thread/thread/a4ee0a7c54453586/b1f2984b43c920a1?hl=en#b1f2984b43c920a1 On Mar 14, 12:51 am, seleronm seler...@gmail.com wrote: Hi, I think that the following links are useful.http://stackoverflow.com/questions/1513603/ Please try. thanks. AFAIK almost any file can be apart of the docs that you upload (images, css, html, js, jsp, ico). I haven't had any trouble uploading images. Are you talking about accepting images from an input form? In that case you can store them as a blob type in the datastore. Hope this helps On Sun, Mar 14, 2010 at 12:12 AM, nag nagarjuna...@gmail.com wrote: Hi I am trying to build online reg form can u help me how to upload image files to app engine. First: is there any way to upload images in app engine? thanks Nag -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.comgoogle-appengine-java% 2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en. -- -Pav -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+ unsubscr...@googlegroups.com. For more options, visit this group athttp://groups.google.com/group/google- appengine-java?hl=en. ---html-part included links--- mailto:nagarjuna...@gmail.com mailto:google-appengine-java@googlegroups.com mailto:google-appengine-java%2bunsubscr...@googlegroups.com http://groups.google.com/group/google-appengine-java?hl=en- Hide quoted text - - Show quoted text - -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: Why is it called Google App Engine for Java ?
I agree with Ravi and Bryce...we have other fish to fry (threads to answer) and Java is a programming language reference which doesn't imply every library under the sun (pun intended). On Dec 1, 4:19 am, bryce cottam bcot...@gmail.com wrote: the GAE isn't cross-compiling, javac is doing the compiling (the real java compiler), so it's kind of a moot argument. The point is, the system runs java, not g-java, not pseudo-java, it's java. It just doesn't have all the libraries you want. That's all. It's written in the Java programming language (or Scala, or Groovy JRuby or anything else that runs on the JVM) and runs on a JVM... it's Java. On Tue, Dec 1, 2009 at 2:18 AM, Bobby bobbysoa...@gmail.com wrote: Suppose someone writes an app in C and wishes to cross compile to Java. In that scenario, if some C class is unsupported by the cross- compiler, then does the C app stop being a C app? No. Bobby On Dec 1, 4:10 am, Bobby bobbysoa...@gmail.com wrote: Maybe for terminology's sake it would make sense to detach the GAE from any language associations and just indicate that there are cross- compilers from Java/Python to GAE. Then there would be no question on whether it's technically Java - one does write in Java, it's just that the cross-compiler has its own requirements and limitations. Is that any better? :) Bobby On Nov 30, 2:58 pm, Nicolas Melendez nmelen...@getsense.com.ar wrote: if we are going to collaborate each other, we need the right names because communication is critical. On Mon, Nov 30, 2009 at 4:37 PM, Jess Evans laphroai...@gmail.com wrote: There are innovators who attempt to advance the field and be the first. They appeal to the desperate and the early adopters with nothing to loose and much to gain. There are guardians with deep experience who strive to ensure reliability and predictability. They appeal to those upon whom many are dependent; those with everything to lose and little to gain. Both camps are invaluable. Incorrectly categorizing a technology, or failing to understand who you're employed to represent, are personal problems. On Nov 30, 2009 12:22 PM, Jeff Schnitzer j...@infohazard.org wrote: I, for one, am sick and tired of Sun's domineering, suffocating stranglehold on what is and isn't Java. GAE is a breath of fresh air. JavaME and JavaEE also impose a variety of limitations on Java. What's the difference between those and GAE? The difference is that Sun got a committee of big company representatives with their own vested interests in a closed room and argued about how the official specs should work for years... and ultimately produced a bunch of crap that is barely useful to anyone. Just *try* out Websphere sometime, I dare you. For the first time ever, someone has produced a shared application service model for Java that's even easier than PHP. This could never have come out of the JCP. If this is destroying java, then GOOD RIDDANCE! Jeff -- You received this message because you are subscribed to the Google Groups Google App Engine fo... -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.comgoogle-appengine-java%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en. -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group athttp://groups.google.com/group/google-appengine-java?hl=en.- Hide quoted text - - Show quoted text - -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: Why is it called Google App Engine for Java ?
I'm curious which classes you are referring to that are missing and are NOT considered a stability risk running under a shared app server environment. We are developing in Java with this solution so I don't mind the naming...I have yet to need a class not offered, guess I have been lucky :) So, what would you recommend calling it? On Nov 27, 12:04 pm, jago java.j...@gmail.com wrote: Hi, this is not Java! The whitelist is ridiculous:http://code.google.com/appengine/docs/java/jrewhitelist.html There is so much missing I don't even know where to start. Is there an issue I can star that extends the whitelist to the full Java6 lib? This is destroying the Java standard and shouldn't be called Java. Every other company that tries to do an implementation of Java and call it Java gets a massive punch from Sun. Why is Google allowed to use Java6 with a whitelist and still call it Java? -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: Why is it called Google App Engine for Java ?
Jago...in shared environments you can't let apps launch their own threads, you can't let apps takeover file systems, etc...these are basic principles for shared resources such as GAE and, for example, contradicts J2EE specs such as EJB and so on. Such apps belong on dedicated servers. Also, loading of images to datastore is possible with VFS...as far as editing images, I don't know. Ted... java.lang.Thread, you want to launch new processes from within your app server...that's a job for URLFetch. Anyhow, I was just curious at what you couldn't do...good to share that with the community in case they know something you don't. As far as the naming goes, you may be the first to raise this concern in GAE's existence (2 years or so). On Nov 27, 6:07 pm, marksea mark...@gmail.com wrote: In the end all they support is Java syntax and a couple of classes. I count 1332. Since you're so particular about your terminology, you may want to look up a couple. -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: GAE status / availalbility problems?
Excellent news. How long did it take to resolve this matter and what was the impact to your Users? I assume you would agree we could avoid this type of problem by only using the data types listed here right? http://code.google.com/appengine/docs/java/datastore/dataclasses.html#Core_Value_Types On Nov 18, 3:27 pm, Dmitry Anipko dmitry.ani...@gmail.com wrote: Thanks Jason for help. In our case the problem was caused by usage of byte[] field in a persisted class. Somehow though, it wasn't causing any problems immediately, but only after a few objects have been saved. Per Jason, usage of byte[] in JDO on GAE isn't supported. On Wed, Nov 18, 2009 at 1:00 PM, Diana Cruise diana.l.cru...@gmail.com wrote: What's the latest here Dmitry...can GAE handle more than 100 request or not? Please update where you are with this problem. Thanks. On Nov 9, 5:15 pm, Dmitry Anipko dmitry.ani...@gmail.com wrote: Following up offline and will update with resolution later. On Mon, Nov 9, 2009 at 9:50 AM, Jason (Google) apija...@google.com wrote: As always, I need your application ID in order to help troubleshoot app-specific issues. Please provide that and any stack traces or other error messages you see in your application's logs. - Jason On Fri, Nov 6, 2009 at 9:47 PM, Dmitry Anipko dmitry.ani...@gmail.com wrote: After some more experimentation, it looks like there is something in the data store that is surfaced by our application: if I clean up the store for the application completely, using the web interface, then for the first ~100 request it works fine, but after some time, it starts producing those errors I wrote before - it can't query objects by index (and that problem persists until I clean the store again). The second observation - although I don't know if it is related or not - is when the store for my app is in such state, and I try to view objects through the web interface, the web interfaces crashes with the error 500: Server Error A server error has occurred. Return to Applications screen » GAE folks, can someone please take a look - this is a blocking issue for my team, and I don't know how to proceed here without your help. Everything works just fine when I run it on a local development server. Thank you. On Nov 6, 11:05 am, Diana Cruise diana.l.cru...@gmail.com wrote: I see NO reply from GAE here regarding such a critical issue!!! Is your app still down, what is the status of your app? How are we supposed to put an application in production with GAE if such a problem can occur with NO response for 3 days? Is there another channel to raise such high-priority issues to get proper helpdesk response? On Nov 4, 1:58 am, Dmitry Anipko dmitry.ani...@gmail.com wrote: It is 11:56 Pacific 11/3/2009, are there any known issues withGAE right now? My application that has been working for a couple of months now today started producing failures for some queries from the data store (basically an object which has just been stored cannot be retrieved after that by key), and after some time started producing even htmlhead meta http-equiv=content-type content=text/html;charset=utf-8 title500 Server Error/title /head body text=#00 bgcolor=#ff h1Error: Server Error/h1 h2The server encountered an error and could not complete your request.pIf the problem persists, please A HREF=http:// code.google.com/appengine/support/report/A your problem and mention this error message and the query that caused it./h2 h2/h2 /body/html The same application executes just fine in the localGAEdevelopment environment. Can folks fromGAEcomment if there is any maintenance going on right now or how could I get more details on what causing the failures (again the same code worked for quite some time now, so I think it is unlikely the code is the issue here). Thanks for your help.- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group athttp://groups.google.com/group/google-appengine-java?hl=en.- Hide quoted text - - Show quoted text - -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group
[appengine-java] Re: JDO/JPA Snippets That Work - Updating a bidirectional, owned, one-to-many relationship with a new child
Max Ross, I took time to review and enter discussion relating to your
snippet. In that thread above I raised questions, but never heard
back...please have a look.
On Nov 2, 12:55 pm, Max Ross (Google) maxr+appeng...@google.com
wrote:
Looking in the debugger is not a good indication of what is and is not set
because jdo-enhanced classes perform lazy loading when the fields are
accessed. If you call a getter method and System.out.println() the result
is it still null? Feel free to send me your model objects and your
persistence code with some println()s showing me the problem and I'll have a
look.
Max
On Tue, Oct 27, 2009 at 5:28 PM, stanlick stanl...@gmail.com wrote:
Hey Max --
At what point are you validating this? I am breaking after the commit
and also after a subsequent query.execute(). Dude, it is about to
make me jump off a bridge.
P.S. I'm not a good swimmer, so please throw me a clue.
Scott
On Oct 27, 12:25 pm, Max Ross (Google)
maxr+appeng...@google.commaxr%2bappeng...@google.com
wrote:
At what point are you checking to see if the parent property of the child
is
populated? I see that the newly created Chapter's Book property is
populated when addChapterToBook() completes.
Max
On Tue, Oct 27, 2009 at 8:31 AM, stanlick stanl...@gmail.com wrote:
This code saves the child for me, however, the parent property of the
child (in your case book) is null in the child. I have tried
deliberately setting this child parent property myself to the parent
prior to commit, but nothing seems to work.
On Sep 28, 6:45 pm, Max Ross
maxr+appeng...@google.commaxr%2bappeng...@google.com
maxr%2bappeng...@google.com maxr%252bappeng...@google.com
wrote:
Hello again and welcome to Episode 3 of JDO/JPA Snippets That Work.
Today's
episode is called..
Updating A Bidrectional Owned One-To-Many With A New Child
All the way back in episode one we demonstrated how to create both a
parent
and a child of a bidirectional, owned, one-to-many relationship
at the same time. This week we're going to see how to add a child to
an
existing parent. We'll use the same model objects we used in episode
one:
JPA:
@Entity
public class Book {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Key id;
private String title;
@OneToMany(mappedBy = book, cascade = CascadeType.ALL)
private ListChapter chapters = new ArrayListChapter();
// getters and setters
}
@Entity
public class Chapter {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Key id;
private String title;
private int numPages;
@ManyToOne(fetch = FetchType.LAZY)
private Book book;
// getters and setters
}
Now let's assume we've already created a book with a few chapters in
the
datastore and we want to add a brand new chapter to a Book with a
given
id
(we'll assume someone else is creating and closing an EntityManager
named
'em' for us):
public void addChapterToBook(EntityManager em, Key bookKey, Chapter
chapter)
{
em.getTransaction().begin();
try {
Book b = em.find(Book.class, bookKey);
if (b == null) {
throw new RuntimeException(Book + bookKey + not
found!);
}
b.getChapters().add(chapter);
em.getTransaction().commit();
} finally {
if (em.getTransaction().isActive()) {
em.getTransaction().rollback();
}
}
}
JDO:
@PersistenceCapable(identityType = IdentityType.APPLICATION,
detachable =
true)
public class Book {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key id;
private String title;
@Persistent(mappedBy = book)
@Element(dependent = true)
@Order(extensions = @Extension(vendorName=datanucleus, key=
list-ordering, value=id asc))
private ListChapter chapters = new ArrayListChapter();
// getters and setters
}
@PersistenceCapable(identityType = IdentityType.APPLICATION,
detachable =
true)
public class Chapter {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key id;
private String title;
private int numPages;
@Persistent
private Book book;
// getters and setters
}
Now let's assume we've already created a book with a few chapters in
the
datastore and we want to add a brand new chapter to a Book with a
given
id
(we'll assume someone else is creating and closing a
PersistenceManager
named 'pm' for us):
public void
[appengine-java] Re: GAE status / availalbility problems?
Thanks Phil, but this scheduled downtime was advertised for 11/3 at 5pm and was actually between 5:17-6:12. Dmitry clearly states his problem was at 11:56 that day...not to mention, he is still having the problem! We would just like to see more answers in the forum in order to be successful with GAE. On Nov 8, 8:06 pm, philburk p...@softsynth.com wrote: Your problem started on 11/3. There was a scheduled downtime that day. It may be related. Here is a thread that announces scheduled downtime. It is not very well advertised. http://groups.google.com/group/google-appengine-downtime-notify/brows... Phil (not from Google) On Nov 7, 7:29 am, Diana Cruise diana.l.cru...@gmail.com wrote: I'm troubled by this lack of help for GAE apps...I see MANY forum entries with NO reply lately whereas in earlier months there seemed to be more quality responses. Who are the Google reps assisting with- Hide quoted text - - Show quoted text - --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: Which datastore exceptions are appropriate for Re-try
WSouza, what scenario triggers UnknownException?
On Nov 9, 3:24 am, leszek leszek.ptokar...@gmail.com wrote:
http://code.google.com/intl/pl/appengine/docs/java/datastore/transact...
for (int i = 0; i NUM_RETRIES; i++) {
pm.currentTransaction().begin();
ClubMembers members = pm.getObjectById(ClubMembers.class,
k12345);
members.incrementCounterBy(1);
try {
pm.currentTransaction().commit();
break;
} catch (JDOCanRetryException ex) {
if (i == (NUM_RETRIES - 1)) {
throw ex;
}
}
}
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[appengine-java] Re: Which datastore exceptions are appropriate for Re-try
Leszek, thanks much!
On Nov 9, 11:20 am, Diana Cruise diana.l.cru...@gmail.com wrote:
WSouza, what scenario triggers UnknownException?
On Nov 9, 3:24 am, leszek leszek.ptokar...@gmail.com wrote:
http://code.google.com/intl/pl/appengine/docs/java/datastore/transact...
for (int i = 0; i NUM_RETRIES; i++) {
pm.currentTransaction().begin();
ClubMembers members = pm.getObjectById(ClubMembers.class,
k12345);
members.incrementCounterBy(1);
try {
pm.currentTransaction().commit();
break;
} catch (JDOCanRetryException ex) {
if (i == (NUM_RETRIES - 1)) {
throw ex;
}
}
}
- Hide quoted text -
- Show quoted text -
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-~--~~~~--~~--~--~---
[appengine-java] Re: GAE Performance
Relating to entity groups, how can we determine what entity group each entity belongs to? Using the Data Viewer, I would think we could examine this type of setup info for each entity but I have NOT found how to do that. Thanks! On Oct 23, 1:50 pm, Jason (Google) apija...@google.com wrote: Hi Diana. As others have stated, App Engine can write to multiple entity groups in parallel, so if each User entity is a root entity or is otherwise placed in a different entity group, then there shouldn't be any issues. Regarding performance, all apps should generally be able to handle up to 30 simultaneous dynamic requests assuming a 75ms processing time for each (average load), for a throughput of 400 qps or so: http://code.google.com/appengine/docs/java/runtime.html#Quotas_and_Li... If you want any other performance or cost-related numbers, let me know. For updates to the same entity or entity group, App Engine uses optimistic concurrency as opposed to locking. If an entity is already being updated, then the second request will fail and will automatically get retried on the server. After consistent failures, an exception will be thrown which you can catch to either handle gracefully. Datastore writes will fail from time to time, generally about 0.1 to 0.2 percent of the time, but the failure rate will be higher when there is contention, i.e. a high rate of simultaneous writes to the same entity/entity group. http://code.google.com/appengine/articles/scaling/contention.html - Jason On Thu, Oct 22, 2009 at 8:04 AM, Diana Cruise diana.l.cru...@gmail.comwrote: I'm glad to hear that the 1-10 requests/second is per User root entity...in my case this means that huge number of Users logged in around the world should expect sub-second response even if tens of thousands clicked the Update button at the same instance in time! The only problem is we do NOT hear from anyone outside of Google to confirm performance of large volume for specific applications and what the real costs are!!! Regarding deadlock, I hear GAE does NOT both with lock timeouts so as soon as a transaction trys to retrieve a record that is already locked, it will receive an error and have to retry. On Oct 19, 5:50 pm, Dr. Flufenstein michael.brink...@gmail.com wrote: Preface: Please note, I'm not speaking for google at all in this note and a lot of what I've written is speculation based on what I've read in various GAE docs as well as some meager knowledge of how relational DBs generally work. And yes, I know datastore isn't a relational DB, but I believe that their indexing implementation likely runs into many of the same problems you have with indexing relational data although that assumption could be completely wrong. From what I can tell, the update bottleneck you're referring to is for updating what you would often think of as a single record if you were persisting one instance of your User as a single denormalized record in a relational schema. I suspect this bottleneck is due to the datastore architecture and the way that data updates are accumulated (possibly grouped/keyed by PK) in a queue, which is probably read from like a cache if read requests come in before the data has been flushed into the actual storage medium and replicated to the other datacenters. So if each of your users were updating their own User records, I don't believe you'd experience that limitation which may be an artifact of how those in-memory queue/cache structures are managed/locked during updates (i.e. a new update for a record may be held until it's been flushed from the queue to the storage medium to prevent having to merge/reconcile records in the queue). If they were all updating a single shared record, then I think you'd hit this pretty quick. Let's say though that your users are updating separate records...as your data size grows, you will probably see your update throughput decrease as other factors become dominant, and I believe this will primarily be dependent on the number and composition of the indexes on your data as well as the number of entities persisted. To me, this is the much riskier unknown because your average index structure is harder to update piecewise in parallel because the index must allow you to order/search all of the records' indexed columns. In an RDBMS like SQL Server or Oracle, you'd see some level of index locking take place during each transaction (maybe one page of an index) to allow concurrent updates to different sections of an index before the updates are committed, the transaction is ended and the locks are released. In relational persistence systems, this gets slower as the indexes become larger and is usually overcome with a technique like partitioning which, if you aren't familiar with it, sort of gives you a top level of your index tree where
[appengine-java] Re: Photo and Video services
In terms of performance does gaevfs accmmodate http resource timestamp checks to avoid re-downloading repeated requests for the same images? On Oct 22, 8:22 pm, Vince Bonfanti vbonfa...@gmail.com wrote: That's the most GAE will let you upload in one request (for now). Again, there's a Service for storing and serving large files feature on the roadmap, but the details of this feature have not be revealed. Vince On Thu, Oct 22, 2009 at 7:40 PM, Diana Cruise diana.l.cru...@gmail.com wrote: What is the nature of the 10Mb limit again? On Oct 22, 6:38 pm, Diana Cruise diana.l.cru...@gmail.com wrote: Yes, that worked ok from another system so it must be an IE7 problem...good catch! On Oct 22, 5:55 pm, Vince Bonfanti vbonfa...@gmail.com wrote: Can you try a different browser? From the logs it looks like you're using IE7. I just tried with IE8, Chrome, and Firefox 3 (all on Windows) and they all worked fine. Something about the path being sent by the browser is causing the error--if we can narrow it to IE7 then I can investigate further. The only degradation I've ever seen is that larger files take longer to download, which you'd expect. However, I've never done any real load or stress testing. Vince On Thu, Oct 22, 2009 at 6:07 PM, Diana Cruise diana.l.cru...@gmail.com wrote: Actually, I tried simple files without spaces also and they failed too. When I hit your photo I noticed execellent response time...have you noticed any particular degradation when displaying lists of photos, for example? On Oct 22, 3:58 pm, Diana Cruise diana.l.cru...@gmail.com wrote: Thanks Baz. Vince, I hit your demo site and just entered a path like /gaevfs/mypic or /gaevfs/images/mypic, then selected a local small photo. On submitting the form, received the 500 error...perhaps the photo had spaces in the name? On Oct 22, 3:10 pm, Vince Bonfanti vbonfa...@gmail.com wrote: You were unable to upload a small photo on my demo site, or in your development environment? I just successfully uploaded an image to the demo site, which you can download from here: http://gaevfs.appspot.com/gaevfs/images/ Yes, the images get stored in blocks of 1MB or less. GaeVFS implements a virtual file system, so you refer to the file using URL links, just as you would for a static file. For example, here's an image I just uploaded: http://gaevfs.appspot.com/gaevfs/images/img4.jpg The GaeVfsServlet handles both upload and download, and demonstrates how this is done: http://code.google.com/p/gaevfs/source/browse/trunk/src/com/newatlant... The GaeVfsServlet also handles setting the content type for the response. Vince On Thu, Oct 22, 2009 at 3:04 PM, Diana Cruise diana.l.cru...@gmail.com wrote: Vince, I was unable to upload small photos...getting error code 500! What is the basic principle behind this solution? It appears you are storing the file in datastore in increments of 1M or less...along the lines of what Raphael was getting at. How do you display a list of images from the datastore on a webpage? On Oct 22, 1:33 pm, Vince Bonfanti vbonfa...@gmail.com wrote: Hi Diana, I've created GaeVFS to solve this problem: http://code.google.com/p/gaevfs/ You can view a demonstration here: http://gaevfs.appspot.com/ Note that the current released version (0.3) will only upload about 2.0MB before timing out; the latest code in SVN will support the full 10.0MB allowed by Google App Engine. There's a feature on the roadmap called Service for storing and serving large files, but there's apparently no additional information available on this feature: http://code.google.com/appengine/docs/roadmap.html Vince On Thu, Oct 22, 2009 at 1:55 PM, Diana Cruise diana.l.cru...@gmail.com wrote: What options do I have in GAE to allow Users to upload, store, and view media (photos, video, audio, etc) from my within my application? Is there a special data type in datastore that would be used to store media? If I store a media item in datastore then how do I display it to the User? In a regular app server, I would do this as a static file reference where I first transfer the data from the database to a file accessible under webroot (if it is not already present). But in GAE the application can NOT create files in the static area due to permissions...so is there another technique to accomplish this? Would videos best be served indirectly via youtube? If so, how do I know they will NOT be removed prematurely by youtube
[appengine-java] Re: Photo and Video services
Vince, I was unable to upload small photos...getting error code 500! What is the basic principle behind this solution? It appears you are storing the file in datastore in increments of 1M or less...along the lines of what Raphael was getting at. How do you display a list of images from the datastore on a webpage? On Oct 22, 1:33 pm, Vince Bonfanti vbonfa...@gmail.com wrote: Hi Diana, I've created GaeVFS to solve this problem: http://code.google.com/p/gaevfs/ You can view a demonstration here: http://gaevfs.appspot.com/ Note that the current released version (0.3) will only upload about 2.0MB before timing out; the latest code in SVN will support the full 10.0MB allowed by Google App Engine. There's a feature on the roadmap called Service for storing and serving large files, but there's apparently no additional information available on this feature: http://code.google.com/appengine/docs/roadmap.html Vince On Thu, Oct 22, 2009 at 1:55 PM, Diana Cruise diana.l.cru...@gmail.com wrote: What options do I have in GAE to allow Users to upload, store, and view media (photos, video, audio, etc) from my within my application? Is there a special data type in datastore that would be used to store media? If I store a media item in datastore then how do I display it to the User? In a regular app server, I would do this as a static file reference where I first transfer the data from the database to a file accessible under webroot (if it is not already present). But in GAE the application can NOT create files in the static area due to permissions...so is there another technique to accomplish this? Would videos best be served indirectly via youtube? If so, how do I know they will NOT be removed prematurely by youtube? Thanks.- Hide quoted text - - Show quoted text - --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: Photo and Video services
Actually, I tried simple files without spaces also and they failed too. When I hit your photo I noticed execellent response time...have you noticed any particular degradation when displaying lists of photos, for example? On Oct 22, 3:58 pm, Diana Cruise diana.l.cru...@gmail.com wrote: Thanks Baz. Vince, I hit your demo site and just entered a path like /gaevfs/mypic or /gaevfs/images/mypic, then selected a local small photo. On submitting the form, received the 500 error...perhaps the photo had spaces in the name? On Oct 22, 3:10 pm, Vince Bonfanti vbonfa...@gmail.com wrote: You were unable to upload a small photo on my demo site, or in your development environment? I just successfully uploaded an image to the demo site, which you can download from here: http://gaevfs.appspot.com/gaevfs/images/ Yes, the images get stored in blocks of 1MB or less. GaeVFS implements a virtual file system, so you refer to the file using URL links, just as you would for a static file. For example, here's an image I just uploaded: http://gaevfs.appspot.com/gaevfs/images/img4.jpg The GaeVfsServlet handles both upload and download, and demonstrates how this is done: http://code.google.com/p/gaevfs/source/browse/trunk/src/com/newatlant... The GaeVfsServlet also handles setting the content type for the response. Vince On Thu, Oct 22, 2009 at 3:04 PM, Diana Cruise diana.l.cru...@gmail.com wrote: Vince, I was unable to upload small photos...getting error code 500! What is the basic principle behind this solution? It appears you are storing the file in datastore in increments of 1M or less...along the lines of what Raphael was getting at. How do you display a list of images from the datastore on a webpage? On Oct 22, 1:33 pm, Vince Bonfanti vbonfa...@gmail.com wrote: Hi Diana, I've created GaeVFS to solve this problem: http://code.google.com/p/gaevfs/ You can view a demonstration here: http://gaevfs.appspot.com/ Note that the current released version (0.3) will only upload about 2.0MB before timing out; the latest code in SVN will support the full 10.0MB allowed by Google App Engine. There's a feature on the roadmap called Service for storing and serving large files, but there's apparently no additional information available on this feature: http://code.google.com/appengine/docs/roadmap.html Vince On Thu, Oct 22, 2009 at 1:55 PM, Diana Cruise diana.l.cru...@gmail.com wrote: What options do I have in GAE to allow Users to upload, store, and view media (photos, video, audio, etc) from my within my application? Is there a special data type in datastore that would be used to store media? If I store a media item in datastore then how do I display it to the User? In a regular app server, I would do this as a static file reference where I first transfer the data from the database to a file accessible under webroot (if it is not already present). But in GAE the application can NOT create files in the static area due to permissions...so is there another technique to accomplish this? Would videos best be served indirectly via youtube? If so, how do I know they will NOT be removed prematurely by youtube? Thanks.- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: Photo and Video services
Yes, that worked ok from another system so it must be an IE7 problem...good catch! On Oct 22, 5:55 pm, Vince Bonfanti vbonfa...@gmail.com wrote: Can you try a different browser? From the logs it looks like you're using IE7. I just tried with IE8, Chrome, and Firefox 3 (all on Windows) and they all worked fine. Something about the path being sent by the browser is causing the error--if we can narrow it to IE7 then I can investigate further. The only degradation I've ever seen is that larger files take longer to download, which you'd expect. However, I've never done any real load or stress testing. Vince On Thu, Oct 22, 2009 at 6:07 PM, Diana Cruise diana.l.cru...@gmail.com wrote: Actually, I tried simple files without spaces also and they failed too. When I hit your photo I noticed execellent response time...have you noticed any particular degradation when displaying lists of photos, for example? On Oct 22, 3:58 pm, Diana Cruise diana.l.cru...@gmail.com wrote: Thanks Baz. Vince, I hit your demo site and just entered a path like /gaevfs/mypic or /gaevfs/images/mypic, then selected a local small photo. On submitting the form, received the 500 error...perhaps the photo had spaces in the name? On Oct 22, 3:10 pm, Vince Bonfanti vbonfa...@gmail.com wrote: You were unable to upload a small photo on my demo site, or in your development environment? I just successfully uploaded an image to the demo site, which you can download from here: http://gaevfs.appspot.com/gaevfs/images/ Yes, the images get stored in blocks of 1MB or less. GaeVFS implements a virtual file system, so you refer to the file using URL links, just as you would for a static file. For example, here's an image I just uploaded: http://gaevfs.appspot.com/gaevfs/images/img4.jpg The GaeVfsServlet handles both upload and download, and demonstrates how this is done: http://code.google.com/p/gaevfs/source/browse/trunk/src/com/newatlant... The GaeVfsServlet also handles setting the content type for the response. Vince On Thu, Oct 22, 2009 at 3:04 PM, Diana Cruise diana.l.cru...@gmail.com wrote: Vince, I was unable to upload small photos...getting error code 500! What is the basic principle behind this solution? It appears you are storing the file in datastore in increments of 1M or less...along the lines of what Raphael was getting at. How do you display a list of images from the datastore on a webpage? On Oct 22, 1:33 pm, Vince Bonfanti vbonfa...@gmail.com wrote: Hi Diana, I've created GaeVFS to solve this problem: http://code.google.com/p/gaevfs/ You can view a demonstration here: http://gaevfs.appspot.com/ Note that the current released version (0.3) will only upload about 2.0MB before timing out; the latest code in SVN will support the full 10.0MB allowed by Google App Engine. There's a feature on the roadmap called Service for storing and serving large files, but there's apparently no additional information available on this feature: http://code.google.com/appengine/docs/roadmap.html Vince On Thu, Oct 22, 2009 at 1:55 PM, Diana Cruise diana.l.cru...@gmail.com wrote: What options do I have in GAE to allow Users to upload, store, and view media (photos, video, audio, etc) from my within my application? Is there a special data type in datastore that would be used to store media? If I store a media item in datastore then how do I display it to the User? In a regular app server, I would do this as a static file reference where I first transfer the data from the database to a file accessible under webroot (if it is not already present). But in GAE the application can NOT create files in the static area due to permissions...so is there another technique to accomplish this? Would videos best be served indirectly via youtube? If so, how do I know they will NOT be removed prematurely by youtube? Thanks.- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: Photo and Video services
What is the nature of the 10Mb limit again? On Oct 22, 6:38 pm, Diana Cruise diana.l.cru...@gmail.com wrote: Yes, that worked ok from another system so it must be an IE7 problem...good catch! On Oct 22, 5:55 pm, Vince Bonfanti vbonfa...@gmail.com wrote: Can you try a different browser? From the logs it looks like you're using IE7. I just tried with IE8, Chrome, and Firefox 3 (all on Windows) and they all worked fine. Something about the path being sent by the browser is causing the error--if we can narrow it to IE7 then I can investigate further. The only degradation I've ever seen is that larger files take longer to download, which you'd expect. However, I've never done any real load or stress testing. Vince On Thu, Oct 22, 2009 at 6:07 PM, Diana Cruise diana.l.cru...@gmail.com wrote: Actually, I tried simple files without spaces also and they failed too. When I hit your photo I noticed execellent response time...have you noticed any particular degradation when displaying lists of photos, for example? On Oct 22, 3:58 pm, Diana Cruise diana.l.cru...@gmail.com wrote: Thanks Baz. Vince, I hit your demo site and just entered a path like /gaevfs/mypic or /gaevfs/images/mypic, then selected a local small photo. On submitting the form, received the 500 error...perhaps the photo had spaces in the name? On Oct 22, 3:10 pm, Vince Bonfanti vbonfa...@gmail.com wrote: You were unable to upload a small photo on my demo site, or in your development environment? I just successfully uploaded an image to the demo site, which you can download from here: http://gaevfs.appspot.com/gaevfs/images/ Yes, the images get stored in blocks of 1MB or less. GaeVFS implements a virtual file system, so you refer to the file using URL links, just as you would for a static file. For example, here's an image I just uploaded: http://gaevfs.appspot.com/gaevfs/images/img4.jpg The GaeVfsServlet handles both upload and download, and demonstrates how this is done: http://code.google.com/p/gaevfs/source/browse/trunk/src/com/newatlant... The GaeVfsServlet also handles setting the content type for the response. Vince On Thu, Oct 22, 2009 at 3:04 PM, Diana Cruise diana.l.cru...@gmail.com wrote: Vince, I was unable to upload small photos...getting error code 500! What is the basic principle behind this solution? It appears you are storing the file in datastore in increments of 1M or less...along the lines of what Raphael was getting at. How do you display a list of images from the datastore on a webpage? On Oct 22, 1:33 pm, Vince Bonfanti vbonfa...@gmail.com wrote: Hi Diana, I've created GaeVFS to solve this problem: http://code.google.com/p/gaevfs/ You can view a demonstration here: http://gaevfs.appspot.com/ Note that the current released version (0.3) will only upload about 2.0MB before timing out; the latest code in SVN will support the full 10.0MB allowed by Google App Engine. There's a feature on the roadmap called Service for storing and serving large files, but there's apparently no additional information available on this feature: http://code.google.com/appengine/docs/roadmap.html Vince On Thu, Oct 22, 2009 at 1:55 PM, Diana Cruise diana.l.cru...@gmail.com wrote: What options do I have in GAE to allow Users to upload, store, and view media (photos, video, audio, etc) from my within my application? Is there a special data type in datastore that would be used to store media? If I store a media item in datastore then how do I display it to the User? In a regular app server, I would do this as a static file reference where I first transfer the data from the database to a file accessible under webroot (if it is not already present). But in GAE the application can NOT create files in the static area due to permissions...so is there another technique to accomplish this? Would videos best be served indirectly via youtube? If so, how do I know they will NOT be removed prematurely by youtube? Thanks.- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google
[appengine-java] Re: GAE Performance
Shawn, the docs link you site is riddled with numbers (easy to get lost in them and what they truely mean)...which is why I included a simplest of scenarios above, that being to simply add a home addressbook entry attached to a User. Surely someone has a sizeable production system today in GAE that could share load results and real costs. If noone does, then that is also very troubling. Gaurav, I assume too that reading is NOT the problem and by this post am hoping to get real-world numbers to a simple update transaction. But, we need production app feedback from the most popular apps out there. Is there such a list for Java for GAE yet? Surely, there are large production apps by now? On Oct 19, 2:17 am, Gaurav ano...@gmail.com wrote: GAE performs best for simultaneous read operations. So there could be virtually any no. of users reading at the same time, no issue. But when it comes to making updates performance degradation is significant. To get a better understanding of how gae performs under heavy load, I recommend this video :http://www.youtube.com/watch?v=AgaL6NGpkB8 On Oct 19, 7:09 am, Shawn Brown big.coffee.lo...@gmail.com wrote: Hi, I have read that a particular User can process 1-10 request per second. Is this a limit of the free quota or does paid quota also have this limitation. Where and what did you read? That doesn't seem consistent with the published limits. I guess it depends on what they were doing with the app.http://code.google.com/appengine/docs/quotas.html Shawn- Hide quoted text - - Show quoted text - --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: My recommendation: Use Low-Level API instead of JDO/JPA
Could you supply some briefs on your findings? This is exactly the type of feedback we need in this forum to help us who are starting new projects to best decide on what APIs and designs to use. For example, if you could summarize your handling of this simple relation that is in ALL apps: Entity A and B are related to each other via C. So, A is 1-many with C and B is 1-many with C...so C is a many-to-many. Surely, you have this in your app. How do you compare your JDO implementation of these 3 Entities with your low- level API implementation? Perhaps you could include some simple code to illustrate your points. Seems I've only seen very basic examples like Hello World. Really, nothing beyond 1 relation...which is very limited and thus, ALL THE PERSISTENCE CONFUSION around here... Thanks. On Sep 23, 4:40 am, dflorey daniel.flo...@gmail.com wrote: I've just refactored my app to use Low-Level API instead of JDO and it's much cleaner, works more reliable etc. If you are not really forced to use JDO/JPA I'd strongly recommend to use the very simple, elegant and clean Low-Level API. BigTable simply is not a relational db, so it is highly misleading to fake a relational wrapper and to me it caused lots of pain. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: Type Owned by Two Different Types?
It seems alarming to me that these basic relations are difficult to
code. Lets face it, applications are full of these relations...it
seems to me that too much developer time is required in the
Persistence layer of GAE apps. The Persistence and Presentation
layers needs to be a no brainer, so more focus can be where it needs
to be - the business layer. Does anyone feel the same?
On Sep 23, 7:51 pm, objectuser kevin.k.le...@gmail.com wrote:
Here's some code that reproduces my problem. Before the code, I think
it's interesting to note that I started making this example in JPA
(because I had an old test that used JPA) and I was not able to
reproduce the error. However, after converting to JDO, I get the
error. I'm not 100% sure the code is exactly the same, however, but
wanted to note it in case it's helpful to anyone.
LocalServiceTestCase is based on the examples from Google.
Does anyone see a problem with the code or is this a legit bug?
@PersistenceCapable(identityType = IdentityType.APPLICATION,
detachable = true)
public class ParentOfOne {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Long id;
@Persistent
private SharedChild child;
...
}
@PersistenceCapable(identityType = IdentityType.APPLICATION,
detachable = true)
public class ParentOfList {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Long id;
@Persistent
private ListSharedChild children;
...
}
@PersistenceCapable(identityType = IdentityType.APPLICATION,
detachable = true)
public class SharedChild {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key id;
@Persistent
private String name;
...
}
public class SharedChildTestCase extends LocalServiceTestCase {
private PersistenceManager persistenceManager;
@Before
public void openPersistenceManager() {
PersistenceManagerFactory persistenceManagerFactory =
JDOHelper
.getPersistenceManagerFactory(transactions-optional);
persistenceManager =
persistenceManagerFactory.getPersistenceManager
();
}
@After
public void closePersitenceManager() {
persistenceManager.close();
}
@Test
public void saveParents() {
ParentOfList pol = new ParentOfList();
ListSharedChild list = new ArrayListSharedChild();
SharedChild c1 = new SharedChild();
c1.setName(c1);
list.add(c1);
SharedChild c2 = new SharedChild();
c2.setName(c2);
list.add(c2);
pol.setChildren(list);
persistenceManager.makePersistent(pol);
ParentOfOne poo = new ParentOfOne();
SharedChild c3 = new SharedChild();
c1.setName(c3);
poo.setChild(c3);
persistenceManager.makePersistent(poo);
}
}
On Sep 22, 9:40 am, objectuser kevin.k.le...@gmail.com wrote:
Thanks, Marton. That's very unfortunate. The limitations still
surprise me. Is that documented somewhere? Need to go back and
reread that stuff I guess.
I'll see if I can come up with a simple test case for the collection.
On Sep 22, 3:28 am, Marton Papp mapr...@gmail.com wrote:
A class cannot have two different owned relationship to a single
class. For example if I have these two classes:
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class Parent3 {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Long id;
Child1 child1;
Child1 child2;
// ... get-set
}
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class Child1 {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key id;
// ... get-set
}
then this code will fail with an assertion error:
public void testMultiParent2() throws Exception {
PersistenceManager pm;
Parent3 p3 = null;
Parent3 p3Loaded = null;
pm = pmf.getPersistenceManager();
pm.currentTransaction().begin();
p3 = new Parent3();
p3.setChild1(new Child1());
p3.setChild2(new Child1());
pm.makePersistent(p3);
pm.currentTransaction().commit();
pm.close();
pm = pmf.getPersistenceManager();
pm.currentTransaction().begin();
p3Loaded = pm.getObjectById(Parent3.class,
[appengine-java] How-to view stack dumps in GAE
What does GAE do with standard dumps such as e.printStackTrace()?
Here is the Admin Console Log output in DEBUG mode for my test:
I 09-19 08:14AM 54.605 [app1-widget/1.336449820535414591].stdout:
hello, testMode=false
I 09-19 08:14AM 54.605 org.apache.jsp.test_jsp _jspService: hello2
I 09-19 08:14AM 54.606 [app1-widget/1.336449820535414591].stdout:
hello3
The output above comes from the code snippet below which tests Stdout,
Logger, and then a forced stack dump. As you can see the stack dump
identified with the message hello4 is NOT in the log output above.
How do I view this stack dump in GAE?
%@ page contentType=text/html;charset=UTF-8 language=java %
%@ page import=java.util.*,
widget.presentation.common.*
%
%
try {
UserSession userSess = UserSession.get(session, request, response);
System.out.println(hello, testMode= + userSess.isTestMode());
java.util.logging.Logger logger = java.util.logging.Logger.getLogger
(widget);
logger.log(java.util.logging.Level.INFO, hello2);
userSess.logInfo(hello3);
if (true) throw new Exception(hello4);
%
!DOCTYPE HTML PUBLIC -//W3C//DTD HTML 4.01 Transitional//EN
table border=0 cellpadding=0 cellspacing=0 width=100%
tr
td width=15% valign=top
table border=0 cellpadding=0 cellspacing=0
width=100%
...
/table
%
} catch (Exception e) { e.printStackTrace(); }
%
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[appengine-java] Re: JDO : How to make an unowned reference to an entity if we don't know its key yet ?
Now I'm confused...I thought an unowned relation was defined as being outside the Entity Group? If I have entity A and entity B who are both related to each other via entity C, I was under the impression that we had to decide whether C would be part of A's group or B's group, but NOT could not all be in 1 group. Perhaps that is a JDO limitation and you are using the lower level API? For the sake of my discussion I'll assume A owns C and B has unowned relation with C. According to Max Ross from the Google GAE Persistence Video, I am under the impression that we should denormalize data in order that the application get around the absence of Join capability. So the many-to-many entity C would contain extra data for each FK to A and B such that, for example, if the application is querying C based a particular A.key...then each record found will already contain fields from B instead of just having the key only (ie C.keyB). Otherwise, for each row the app would have to turn around and query B by primaryKey...hence encurring much overhead. Have I interpreted this fashion of persistence handling correctly as you understand it? Are you using this same denormalization in your designs? On Sep 19, 11:08 am, mlenormand mickael.lenorm...@gmail.com wrote: All the entities we are talking about are in the SAME entity group in order to create/update them in the same transaction. In addition to that, we declare an unowned relationship, using Key for example. I want to save all my entities in the same transaction. On Sep 19, 5:52 pm, objectuser kevin.k.le...@gmail.com wrote: Because your relationships are unowned (so the objects are in different entity groups, right?), you wouldn't be able to save them all in the same transaction anyway. So you're right: you'll have to save them, which means multiple transactions, and if one of them fails you'll have inconsistent data. On Sep 19, 8:47 am, mlenormand mickael.lenorm...@gmail.com wrote: Hi Everybody, Here's my problem with JDO and unowned relationships : I have several entities of the same kind that are organized in a hierarchical way, maintained with unowned relationships. JDO can generate keys for my entities when they are written to the datastore, but with this option, I can't know my entity's keys until they are saved to the datastore. If I want to make a reference to an entity A from an entity B, it seems to be impossible because at this time I don't know A's key, that will be generated when transaction is committed. One solution would be to use several transactions, each one would persist an entity, but it's not good because I want to persist all the entities in the same transaction. I know that defining keys myself could solve the problem, but maybe there is an other solution that would be better ? Thank you for your help. And thank you to the GAE team for the fantastic work you did !- Hide quoted text - - Show quoted text - --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] System.out.println behavior in production
I'm having difficulty debugging my application in production. According to the GAE docs, System.out.println output is directed as log level INFO. My home page generates such output when debugging in my test local environment. But, my deployment to production generates NO output. Using the Admin Console-Log I can see my Requests but NOT my standard output from println(). How can I see this output? Is it just NOT being flushed or is there a config for this? Thanks, Diana --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: System.out.println behavior in production
Yes, I tried all the levels in the Console. It must be the properties
file. I noticed the plugin created the log4j.properties in the src
folder and the contents are below. How do I set the default level in
this file? Thanks.
# A default log4j configuration for log4j users.
#
# To use this configuration, deploy it into your application's WEB-INF/
classes
# directory. You are also encouraged to edit it as you like.
# Configure the console as our one appender
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%d{HH:mm:ss,SSS} %-5p [%c]
- %m%n
# tighten logging on the DataNucleus Categories
log4j.category.DataNucleus.JDO=WARN, A1
log4j.category.DataNucleus.Persistence=WARN, A1
log4j.category.DataNucleus.Cache=WARN, A1
log4j.category.DataNucleus.MetaData=WARN, A1
log4j.category.DataNucleus.General=WARN, A1
log4j.category.DataNucleus.Utility=WARN, A1
log4j.category.DataNucleus.Transaction=WARN, A1
log4j.category.DataNucleus.Datastore=WARN, A1
log4j.category.DataNucleus.ClassLoading=WARN, A1
log4j.category.DataNucleus.Plugin=WARN, A1
log4j.category.DataNucleus.ValueGeneration=WARN, A1
log4j.category.DataNucleus.Enhancer=WARN, A1
log4j.category.DataNucleus.SchemaTool=WARN, A1
On Sep 18, 10:13 pm, Don Schwarz schwa...@google.com wrote:
Are you switch the logging level in the Admin Console to Info? By default
it only shows errors.
Do you have a logging.properties file? If so, what is your default .level
set to? System.out would be logged at INFO, so if you are specifying this
make sure it is INFO or lower.
Finally, I would recommend using java.util.logging instead of System.out.
It's a lot more flexible and is very easy to use.
On Fri, Sep 18, 2009 at 10:09 PM, Diana Cruise
diana.l.cru...@gmail.comwrote:
I'm having difficulty debugging my application in production.
According to the GAE docs, System.out.println output is directed as
log level INFO. My home page generates such output when debugging in
my test local environment. But, my deployment to production generates
NO output. Using the Admin Console-Log I can see my Requests but NOT
my standard output from println(). How can I see this output? Is it
just NOT being flushed or is there a config for this?
Thanks, Diana- Hide quoted text -
- Show quoted text -
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[appengine-java] Re: System.out.println behavior in production
I found the Logger docs for GAE at:
http://code.google.com/appengine/docs/java/runtime.html#Logging
I'm definitely getting output now from Stdout but I can't seem to get
logger.log() to work. I'll fiddle with it and log a separate issue if
I can't get it to work. Thanks for the help Don!
On Sep 18, 10:27 pm, Diana Cruise diana.l.cru...@gmail.com wrote:
Yes, I tried all the levels in the Console. It must be the properties
file. I noticed the plugin created the log4j.properties in the src
folder and the contents are below. How do I set the default level in
this file? Thanks.
# A default log4j configuration for log4j users.
#
# To use this configuration, deploy it into your application's WEB-INF/
classes
# directory. You are also encouraged to edit it as you like.
# Configure the console as our one appender
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%d{HH:mm:ss,SSS} %-5p [%c]
- %m%n
# tighten logging on the DataNucleus Categories
log4j.category.DataNucleus.JDO=WARN, A1
log4j.category.DataNucleus.Persistence=WARN, A1
log4j.category.DataNucleus.Cache=WARN, A1
log4j.category.DataNucleus.MetaData=WARN, A1
log4j.category.DataNucleus.General=WARN, A1
log4j.category.DataNucleus.Utility=WARN, A1
log4j.category.DataNucleus.Transaction=WARN, A1
log4j.category.DataNucleus.Datastore=WARN, A1
log4j.category.DataNucleus.ClassLoading=WARN, A1
log4j.category.DataNucleus.Plugin=WARN, A1
log4j.category.DataNucleus.ValueGeneration=WARN, A1
log4j.category.DataNucleus.Enhancer=WARN, A1
log4j.category.DataNucleus.SchemaTool=WARN, A1
On Sep 18, 10:13 pm, Don Schwarz schwa...@google.com wrote:
Are you switch the logging level in the Admin Console to Info? By default
it only shows errors.
Do you have a logging.properties file? If so, what is your default .level
set to? System.out would be logged at INFO, so if you are specifying this
make sure it is INFO or lower.
Finally, I would recommend using java.util.logging instead of System.out.
It's a lot more flexible and is very easy to use.
On Fri, Sep 18, 2009 at 10:09 PM, Diana Cruise
diana.l.cru...@gmail.comwrote:
I'm having difficulty debugging my application in production.
According to the GAE docs, System.out.println output is directed as
log level INFO. My home page generates such output when debugging in
my test local environment. But, my deployment to production generates
NO output. Using the Admin Console-Log I can see my Requests but NOT
my standard output from println(). How can I see this output? Is it
just NOT being flushed or is there a config for this?
Thanks, Diana- Hide quoted text -
- Show quoted text -- Hide quoted text -
- Show quoted text -
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