Hi Francois, I was just talking to Arie about this. So some implementation details (for anyone who is curious): The way the backup tool works is by iterating over all of your data in a mapper job. The number of shards is determined by the number of Kinds * Entities per kind. Entities are serialized ( entity.ToPb().SerializeToString() ), batched in a LevelDB format ( http://code.google.com/p/leveldb/) and written to the Blobstore ( http://code.google.com/p/appengine-mapreduce/source/browse/trunk/python/src/mapreduce/output_writers.py ).
What's happening in your case is that there are too many worker shards and the metadata required to describe the job is exceeding the entity size limit, and it's causing a mapreduce exception which is bubbling all the way up to the top. This is a bug in the API and will be fixed. I don't have an ETA for when the fix will go live, however - hopefully sometime in the next few days. In the meantime, do you have an application ID? Arie on the engineering team would like to take a look at your datastore to look at the metadata entity, but he needs your permission to do so. He might be able to recommend a workaround if there's something that jumps out at us. -- Ikai Lan Developer Programs Engineer, Google App Engine plus.ikailan.com On Wed, Feb 1, 2012 at 1:26 PM, Arie Ozarov <[email protected]> wrote: > We are looking into it. > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/google-appengine/-/roABfczfSxYJ. > > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/google-appengine?hl=en. > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
