First of all, I HAVE got thinks to work  - check out
mybharatbyrail.appspot.com.

My questions first:
Does the general Google infrastructure also have these hard limits in
place ? meaning do your developers of your pride and joy -the
magnificently fast search engine work to these limits ?
Are these limits arbitrary or in some sense necessary for your great
scalability - of your OWN apps.

RE: my experience

Its an application of some complexity. I'm developing it for fun - -
not for commercial use  I'm retired. I first did it using Java on my
local machine against MS-SQL-Server then set about transferring to
google-app-engine. What a pullava !

1. Does the app-engine development group realize the efforts
developers have to put in to get across the hard limits as detailed in
the subject field ? Those hard limits, especially in x-referencing
data structures cause significant redesign efforts. Its a cascading
thing guys ! the 30 second rule means I have to optimise by caching
but caches( and data stores)  can only be written to 1Mb at a time ! -
but to break things up into 1Mb chunks and retrieve them in that size
means that addressing context is lost, meaning Xreferencing structure
Map<V,H> to List<V>  ( in Java - I have no idea how it works in
Python). must have the Vs as the same address in both data structures
- when retrieved via serialization and deserialization but they won't
if written in different incarnations of a VM ( i.e. tasks executed on
a queue) .. unless you redesign carefully to ensure this.

2. I often of course can only find out it doesn't work when I deploy -
it works fine in Eclipse/SDK/debug of course. A particular difficulty
is that when deployed I get messages like "String property too large -
exceed 1,000000 bytes ) - but when I want to really figure out how BIG
that data element is, using Java Instrumentation, I'm told that the
java instrumentation interface( implementation is a different issue )
is not supported by the app-engine. So, apart from trial and error -
how am I supposed to figure out the size of an object when deployed.

3. The reason I can only find out things when they are deployed  is
because my database - the datastore in the development environment is
a lot smaller than the one in "production". There are no tools for me
- this is JAVA remember - to transfer the production DB to my dev
engine.

4. I have to use Python tools to load the production environment with
the full data - I had to learn Python enough to do that as it
happens :-) . But those same tools will not produce the same datastore
in my JAVA+Eclipse development environment. So I cannot fully check
out things in my dev environment before deploying.

Like I said - I have got things to work ( famous last words :-) - but
honestly if it wasn't for the significant relearning issues and no
certainty of things being any better - I've definitely thought of
moving it over to Amazon, Azure or even back to MY-OWN-MACHINE(s) !

This reminds of the early days of Oracle - 1984 version 3.x - mannnn
what a pullava THAT was - and look where they are now - commercially
for sure at least.
I look forward to watching the next 25 years of google. As we used to
say at DEC/digital - keep the faith.

-skk

-- 
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.

Reply via email to