google-app-engine

ClassNotPersistenceCapableException

I'm getting ClassNotPersistenceCapableException when trying to persist the following JDO class. package com.xxx.cms.model; import javax.jdo.annotations.IdGeneratorStrategy; import javax.jdo.annotations.PersistenceCapable; import javax.jdo.annotations.Persistent; import javax.jdo.annotations.PrimaryKey; import com.google.appengine.api....

Google application engine Datastore - any alternatives to aggregate functions and group by?

Hi All, As is mentioned in the doc for google app engine, it does not support group by and other aggregation functions. Is there any alternatives to implement the same functionality? I am working on a project where I need it on urgent basis, being a large database its not efficient to iterate the result set and then perform the logic. ...

Many-to-many relationships in Google AppEngine - efficient?

Hi, I'm using Google Appengine to store a list of favorites, linking a Facebook UserID to one or more IDs from Bing. I need function calls returning the number of users who have favorited an item, and the number of times an item has been favorited (and by whom). My question is, should I resolve this relationship into two tables for eff...

RestrictedPython on Google AppEngine (GAE)

I'm looking for a way to execute user submitted python code in GAE in a secure fashion (much stricter then the GAE sandbox). RestrictedPython would certainly fit the shoe, being used in Zope for the exakt same purpose. But RestrictedPython relies on modifying the AST (abstract syntax tree) which means loading modules from the compiler ...

How fast Google App Engine is?

I am experimenting with GAE for last 2 Months. I am saving records to the bigtable by uploading CSV file. My Test File's size is 300 KB. Here what i found Local system Upload take less than 1 second Process 2500 records in 3 seconds On Google Sandbox Upload takes 5-7 seconds. Processing file gives timeout. It only save 60-18...

Google Geocoding API - REQUEST_DENIED

Hi, Apparently I do not need a 'Maps API key' to use the 'Google Geocoding API' according to: http://code.google.com/apis/maps/documentation/geocoding/index.html However, I obtain this: { "status": "REQUEST_DENIED", "results": [ ] } Does this mean that my IP is blocked? What can I do to overcome this? Thanks. Christian ...

Google App Engine: appcfg.py rollback

I'm using Windows 7 and for the life of me I cannot figure out how to call the rollback function on appcfg.py. All I want to know is what to type into the command prompt so I can rollback my app. ...

how to write a georss that can be used for "google.maps.KmlLayer"

1.the atom is : <?xml version="1.0" encoding="utf-8"?> <feed xmlns="http://www.w3.org/2005/Atom"&gt; <title>Example Feed</title> <subtitle>A subtitle.</subtitle> <link href="http://example.org/feed/" rel="self" /> <link href="http://example.org/" /> <id>urn:uuid:60a76c80-d399-11d9-b91C-0003939e0af6</id> <update...

Is GAE a viable platform for my application? (if not, what would be a better option?)

Here's the requirement at a very high level. We are going to distribute desktop agents (or browser plugins) to collect certain information from tons of users (in thousands or possibly millions down the road). These agents collect data and periodically upload it to a server app. The server app will allow for analyzing collected data...

Caching a page so it doesn't have to be regenerated?

Hi, I have a app engine app (java) which renders a page. It fetches data to generate the page, something like: // index.jsp <% List<Horse> horses = datastore.getHorses(PMF.get()); List<Horse> cows = datastore.getCows(PMF.get()); List<Horse> goats = datastore.getGoats(PMF.get()); for (Horse it : horses) { %> <div><%...

Still wondering about directed graphs drawn from AppEngine

With reference to another case of pretty much the same question I have, Brightside asked: http://stackoverflow.com/questions/2264157/library-to-render-directed-graphs-similar-to-graphviz-on-google-app-engine The accepted answer was "canvis", which looks very cool from a rendering perspective, but canvis just does the drawing. It still n...

Basic caching strategy for a simple page ?

Hi, I'm starting to work with memcache and app engine (java). I have a page where I can cache results fetched from the datastore. Example: // index.jsp <% List<Horse> horses = datastore.getHorses(PMF.get()); for (Horse it : horses) { %> <div><%= it.getName() %></div> <% } %> I can put the horse list into memcache, but wo...

Caching contents of a page?

Hi, I'm generating page content like: // index.jsp <% List<Horse> horses = database.getHorses(); for (Horse it : horses) { %> <div><%= it.getName() %></div> <% } %> is it possible to grab the entire page content at the end of the jsp file, and dump it into a String, like: String page = this.getPrin...

In the python version of Google App Engine, how can you override the db.Model class to save to a temp datastore rather than big table?

In Singapore, we are teaching students python using Singpath (singpath.appspot.com). In addition to letting students practice writing software in python, we would like to familiarize students with the google.appengine.ext.db API used to access big table. What is the easiest way to modify db.Model settings in an App Engine app so that a...

Import large chunk of data into Google App Engine Data Store at one go...

Hi I have a large CSV file, approx 10 MB in size, which contains all the data which need to be imported in the Google App Engine DataStore. I tried following approaches to perform import but all the times it failed in half way. Import using mapping a command to url and then executing url, failed because of request time out... Import...

GAE datastore export_transform

Bulkload automatic configuration bulkload.yaml. How to export reference property for key reference field back to datastore from csv. - property: datacenter external_name: datacenter # Type: Key Stats: 2 properties of this type in this kind. import_transform: transform.create_foreign_key('DataCenter') export_transform: transform....

Does Google uses AppEngine for its own products?

I've been wondering: does Google uses AppEngine for its own products? ...

Can a app engine task get a count of the number of times it's been run?

I am running thousands of tasks per hour in Google App Engine and around .1% of them are failing even after multiple retries. Ideally, I want them to stop trying and exit. However, due to app engine's design they seem to be just trying again and again. I know there is a backoff time which increases with every unsuccessful execution, but ...

Store user name as separate first/last name, or as a single full name String?

Hi, I have a web app, I'd like the user to supply their real name, for friend searches. I'm not sure whether to store this as two separate fields in my user class, or as a single field: class User { @Persistent private String mFirstName; @Persistent private String mLastName; } .. or .. class User { @Persisten...

Google wave authentication login on 3rd party website

Hey, im trying to figure out how to make a user authenticate with my web app using google accounts and be recognized as an active session with google wave. Currently when i use google accounts login, everything works fine but embedded google wave widgets dont recognize the users session and asks him to relogin. The only way i found aro...