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From Robert Wille <rwi...@fold3.com>
Subject Re: Best Practise for Updating Index and Reporting Tables
Date Thu, 23 Jul 2015 18:33:16 GMT
My guess is that you don’t understand what an atomic batch is, give that you used the phrase
“updated synchronously”. Atomic batches do not provide isolation, and do not guarantee
immediate consistency. The only thing an atomic batch guarantees is that all of the statements
in the batch will eventually be executed. Both approaches are eventually consistent, so you
have to deal with inconsistency either way.

On Jul 23, 2015, at 11:46 AM, Anuj Wadehra <anujw_2003@yahoo.co.in<mailto:anujw_2003@yahoo.co.in>>
wrote:

We have a transaction table,3 manually created index tables and few tables for reporting.

One option is to go for atomic batch mutations so that for each transaction every index table
and other reporting tables are updated synchronously.

Other option is to update other tables async, there may be consistency issues if some mutations
drop under load or node goes down. Logic for rolling back or retrying idempodent updates will
be at client.

We dont have a persistent queue in the system yet and even if we introduce one so that transaction
table is updated and other updates are done async via queue, we are bothered about its throughput
as we go for around 1000 tps in large clusters. We value consistency but small delay in updating
index and reporting table is acceptable.

Which design seems more appropriate?

Thanks
Anuj

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