[appengine-java] Re: Is the any limitation on entity group size?

On Apr 12, 4:18 pm, "Ikai L (Google)" wrote: > No, it should be fine UNLESS you want to load all these child objects in a > single request. As a rule of thumb, load as little data as possible. You may > need to denormalize (the datastore isn't relational anyway) for additional > read performance

[appengine-java] changes regarding 1000-result query limit

hi, Does the 1000-query result limit still hold for an individual query? (I know that the use of query cursors now allows > 1000 results total to be fetched). Comments such as this: http://groups.google.com/group/google-appengine-java/browse_thread/thread/88bb6df3d8cf5f78/5a98f713e9bc665f?lnk=gst

Re: [appengine-java] App Engine SDK 1.3.2 is out!

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[appengine-java] Re: error in the GAE/J transaction docs?

Interesting! Thanks, that's helpful. On Mar 25, 2:19 pm, "Max Ross (Google)" wrote: > We could perhaps be a bit more precise in our language here.  You can run > any query you want inside a transaction but the results are only guaranteed > to be transactionally consistent if the query is an ances

[appengine-java] error in the GAE/J transaction docs?

hi, The documentation on transactions says: "An app can perform a query during a transaction, but only if it includes an ancestor filter." () This does not seem to be the case-- it seems tha

[appengine-java] JDO 'lifecycle' events-- bug in App Engine implementation?

hi, I have been looking into using the JDO LifecycleListener and InstanceCallback features. (, ) I've run into something that seems like it might be a bug in the App Engine implementation of these features. Spe

[appengine-java] Re: a question about transactional tasks

On Mar 21, 6:45 pm, "Max Ross (Google)" wrote: > Hi AJ, > > Your understanding is correct and I don't quite know what we meant when we > said "same level of isolation and consistency."  I'll get this sorted out. thanks, I appreciate the reply! --

[appengine-java] a question about transactional tasks

hi, I could use a clarification about transactional tasks. My understanding was that a transactional task is enqueued if and only if the transaction succeeds, but is performed outside the transaction (so, is not restricted to objects in the same entity group as the transaction, and does not share

[appengine-java] using JDO level 2 caching

I'm interested to hear from people who have enabled the datanucleus JDO level 2 caching for App Engine-- how has that worked out? This thread: http://groups.google.com/group/google-appengine-java/browse_thread/thread/13cb942ceb97dc/3ab7518edf6a8bc6 suggests that at least one person had the expe

[appengine-java] JDO - PM object 'involvement' in transaction

I am seeing some transaction-related behavior, using JDO and GAE 1.3.1, that puzzles me. I get an exception if I do something like the following. All entities below are in (their own) separate entity groups: PersistenceManager pm = PMF.get().getPersistenceManager(); //... fetch entity a1 of

[appengine-java] JDO Lifecycle Listeners and transactions

I have a question about JDO Lifecycle Listeners and transactions. Suppose that I have set a StoreLifecycleListener for a PersistenceManager, then initiated a transaction. When I call commit(), this triggers some saves to the Datastore, and the preStore() and postStore() methods get called. My q

Re: [appengine-java] log4j init fails

lasses whenever Eclipse > performs a build of your project; you should not have to copy it over > manually. > > I'm not sure why you're getting the error with regard to > Datanucleus.Connection; I've added Don to this thread; he may have some > insight into this. &g

Re: [appengine-java] log4j init fails

I have the default log4j.properties in WEB-INF/classes dir. but the warning always comes up. the file is visible because I can change the log level to ERROR to get rid of the warning. -aj On Fri, Feb 19, 2010 at 7:24 PM, Rusty Wright wrote: > I think you can simply put the log4j.properties f

[appengine-java] transaction 'scope', unexpected behaviour

I am seeing some transaction-related behaviour, using JDO and GAE 1.3.1, that puzzles me. I get an exception if I do something like the following. All entities below are in separate entity groups: PersistenceManager pm = PMF.get().getPersistenceManager(); //... fetch entity a1 of kind A, mo

Re: [appengine-java] Re: GAE Alternatives?

. Hope GAE grows up faster. -aj On Wed, Feb 24, 2010 at 3:20 PM, Larry Cable wrote: > I have to concur with Corby on this ... I was initially attracted to > the end-to-end > solution that GAE offered integrated as it is with Eclipse. > > In practice I have found it very frus

Re: [appengine-java] Re: High latency issue

I see the same latency problem for my new app and have started to find solutions. there are some good tips in this thread<http://groups.google.com/group/google-appengine/browse_thread/thread/866b3640995e05c/d6e7bd547d845564?lnk=gst&q=realmon9#d6e7bd547d845564>I started yesterday. -aj O

Re: [appengine-java] Re: How to handle schema change on JDO data model class?

Is GAE team working on implementing the JDO feature (use default value for new field instead of throwing exception)? that will make data migration easier. -aj On Mon, Feb 22, 2010 at 8:02 AM, datanucleus wrote: > > For example, when adding a field that uses a primitve type to an object. &

Re: [appengine-java] update to sdk1.3.1

thanks. it works. -aj 2010/2/19 Miguel Méndez > No, it won't auto-update today. The following link explains how to switch > the SDK that a project is using: > http://code.google.com/eclipse/docs/using_sdks.html. > > On Thu, Feb 18, 2010 at 11:46 PM, AJ Chen wrote: >

[appengine-java] update to sdk1.3.1

I ran an update from eclipse. The sdk1.3.1 is installed in the eclipse/plugin dir, but the sdk in my existing GAE project still points to the old version 1.3.0. Should the update automatically update the existing project? if not, how to change it manually? thanks, -aj -- You received this

[appengine-java] log4j init fails

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[appengine-java] cloud computing event: Intelligence from the Cloud

how customers are applying the latest techniques to solve painful problems in an elegant and affordable way, that simply were not possible just a couple years ago. Wondering what's behind the Cloud? Aliens and Intelligence. Hope to see some of you on the event. Best, AJ -- AJ Chen, P

Re: [appengine-java] Re: how to do initialization at startup?

I'm hoping someone has an easy/reliable way to keep tracking a counter in memory within GAE. I'll appreciate any suggestion. -aj On Wed, Feb 17, 2010 at 1:56 PM, Stephan Hartmann wrote: > Hi AJ, > > Your consideration is not specific to GAE. You always have the potential > risk

Re: [appengine-java] Re: how to do initialization at startup?

coding for storage. Without knowing what exactly happens when GAE automatically shutdowns the app, my worry may be wrong. Does anyone see the similar issue? Any suggestion for safely keeping data in memory? -aj On Wed, Feb 17, 2010 at 10:00 AM, Vlad Skarzhevskyy wrote: > There is an Cus

Re: [appengine-java] how to do initialization at startup?

You should also implement ServletContextListener.contextDestroyed() to > perform cleanup of your data, if needed. > > Regards, > Stephan > > > 2010/2/17 AJ Chen > >> For standard web app, I use a context listener servlet to do >> initialization at startup. This also wo

[appengine-java] how to do initialization at startup?

restarts the context or something that triggers the call to the listener servlet. SO, the question is: what's the right way to do one-time initialization (e.g. pre-load data) in GAE? Maybe GAE does not have the concept of initialization. Any suggestion is appreciated. -aj -- AJ Chen, PhD

[appengine-java] unexpected execution of task queue

executed in 1 hour or so. And, the number of tasks keeps growing. I understand ETA is not exact, but 1 min actual is just too far from 60 min ETA. Any idea how to make the scheduled task more reliable? the app is at http://realmon9.appspot.com thanks, -aj-- AJ Chen, PhD Chair, Semantic Web SIG

Re: [appengine-java] Re: queue task timeout

This must be it since timeout occurs only when multiple tasks are fired at the same time. thanks, -aj On Thu, Feb 4, 2010 at 6:11 PM, cowper wrote: > I believe that this may be due to the fact that the URL you are > requesting is on the local SDK server, which is single threaded and as

[appengine-java] queue task timeout

at org.quartz.core.JobRunShell.run(JobRunShell.java:195) at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:520) -aj-- AJ Chen, PhD Chair, Semantic Web SIG, sdforum.org http://web2express.org @web2express on twitter Palo Alto, CA, USA 650-283-4091 *Monitoring social media in real time* --

[appengine-java] Re: issue with 1:1 JDO owned relationship

Yes, thanks -- that's it! On Jan 26, 1:40 am, Ian Marshall wrote: > Does datanucleus-appengine Issue 89 (assigning new value to child > field does not delete the old child entity) at > > http://code.google.com/p/datanucleus-appengine/issues/detail?id=89 > > describe your problem? -- You receive

[appengine-java] issue with 1:1 JDO owned relationship

The GAE JDO documentation says: - An owned relationship can be "dependent," meaning that the child cannot exist without its parent. ... Breaking an owned, dependent relationship by assigning a new value to the dependent field on the parent also deletes the old child. You can declare a

Re: [appengine-java] Re: A running app does not detect newly created files.

Since app engine does not allow file writing, it probably does not expect any new file during run time. That's why you see the new file only after restarting the server. To "write new file" in app engine, I would think it as "put new file content into datastore". -aj On

[appengine-java] question about detached object with bi-directional 1:m relationship, and adding new child

I ran across some unexpected behaviour with a bi-directional one-to- many relationship, in adding a new child to a collection, when the parent object was detached. I'd be interested if anyone could shed more light on why things work the way they do. My detached parent object appears to include ful