On Wed, Dec 7, 2011 at 10:44 AM, Andrius A <[email protected]> wrote:
> In docs it says that HRD is more costly "The High Replication Datastore
> costs more due to the additional replication (see billing page for pricing
> details). Due to the higher cost, we recommend High Replication Datastore
> primarily for those developers building critical App Engine applications
> that require the highest availability".

I've filed a bug against this documentation.

> It also says "queries on a single guestbook to be strongly consistent, but
> also limits changes to the guestbook to 1 write per second (the supported
> limit for entity groups). Therefore, writing to a single entity group per
> guestbook is not ideal when high usage is expected. If your app is likely to
> encounter heavy write usage, consider using another means. For example, you
> can put recent posts in memcache with an expiration, and then display a mix
> of recent posts from memcache and posts retrieved from the datastore."
> How could we trust by putting data to memcache if we know it can be evicted
> any time?

You wouldn't as definitive storage but it is reasonable to cache
recent posts there.

> To use HRD is not viable for applications which need strong
> consistency for high rate of puts.

You may have to think about how your organize your data in order to
satisfy your consistency and throughput requirements but I am very
skeptical when you say that it is simply not viable.

Google, for example, has been successful using the same technology for
many of its own high-volume properties.

> At the moment MS is perfect what it does
> but bloody thing keeps dying..

That is an architectural problem that is very hard to fix with making
the same kinds of trade-offs that we made when implementing HRD .

Cheers,
Brian

> I can't believe there is no way to improve MS
> and you are switching to HRD. In long term HRD can cause more problems for
> applications parts were it wasn't aticipating to receive higher rate of
> inserts, and having a limit of 1 write per second is a disastrous.
>
>
> On 6 December 2011 23:29, Gregory D'alesandre <[email protected]> wrote:
>>
>> Hi Kenneth,
>>
>> We are planning to add blobstore migration at some point but it won't
>> likely be until the middle of Q1 at the earliest.
>>
>> Greg
>>
>>
>> On Tue, Dec 6, 2011 at 3:27 PM, Kenneth <[email protected]>
>> wrote:
>>>
>>> Hi Greg,
>>>
>>> Can you give us some indication if the migration tool is ever going to
>>> include blobstore migration? That's the only thing holding me back. I know I
>>> can do it myself but I'd rather not. I see now that it has gone ga, have you
>>> stuck a fork in it and called it done?
>>>
>>> Thanks
>>>
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