High Replication -- Writes Way Higher Than Reads

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James Gilliam

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Sep 13, 2011, 10:44:45 AM9/13/11
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I frequently have way more writes (billing history) than reads on the
datastore and this seems very strange to me.

Typically, .3 million writes (300,000) and .06 million reads (60,000).

And I don't think I am writing to the datastore nearly the amount I am
reading from it -- I would think they would be the other way around.

This is like I read an entity and then write it 5 times. Am I being
charged for writing a record to multiple datacenters? Gives an
entirely new meaning to high replication.

What am I missing?

Plus, it would be great if we had more insights into these I/O
operations -- are they to service indexes?

Thanks

Simon Knott

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Sep 13, 2011, 11:04:26 AM9/13/11
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Have you read this thread - https://groups.google.com/d/msg/google-appengine/mjnSqQWOfqU/cgPVeHbrR8oJ?

It explains what happens at the datastore when an entity is put, and how this converts into datastore writes.

Francois Masurel

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Sep 13, 2011, 11:07:05 AM9/13/11
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Hi James,

The new GAE 1.5.4 SDK shows in the local dev DatastoreViewer how many write ops were needed to create each entity (check screenshot attached).

You will probably be suprised.

François
screenshot.jpg

objectuser

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Sep 13, 2011, 12:49:04 PM9/13/11
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That's very useful ... and, yes, surprising to me for sure!

Thanks for pointing that out, Francois.
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