Salakhetdinov Shamil
mcp2004 at mail.ru
Thu Feb 21 13:44:30 CST 2013
Hi Jim -- Yes, the subject is very interesting and CQRS seems to be a good candidate software design pattern to be used with NoSQL and "Big Data". The issue is that I can't say I have currently a clear understanding how the subject (CQRS) design pattern should be applied to real life projects where there should be also traditional ORM and CRUD parts (partially) left. The DDD concepts of aggregate root etc. aren't the ones I'm using here everyday/at all. The concept of *eventual consistency and set validation* ( http://codebetter.com/gregyoung/2010/08/12/eventual-consistency-and-set-validation/ ) isn't yet clear how to apply... ... and then when I see coming the new information as the following: "AWS Launches OpsWorks, A Potential PaaS Disruptor, To Automate App Deployment To The Cloud" http://techcrunch.com/2013/02/19/aws-launches-opsworks-a-potential-paas-disruptor-to-automate-app-deployment-to-the-cloud/ I'm wondering does it makes sense to get "obsessed" by rather complicated design concepts when the mainstream cloud providers have proven highly scalable applications hosts where custom applications seems to be possible to build from "small bricks" and scale on demand... So the question is: "6*9 = 42, or KISS - 6*9 = 54 ?" Thank you. -- Shamil Четверг, 21 февраля 2013, 10:07 -08:00 от "Jim Lawrence" <accessd at shaw.ca>: >Hi Shamil: > >A very interesting subject. > >There are so many questions about how to properly manage data when data is >huge and the number of users are massive. This lends its self to the NoSQL >world of huge data where data can be spread across thousands of servers >being accessed and changed and added to by thousands of users. > >I have noticed this latency with Facebook where just running a refresh may >display one set of data then a new refresh and another slightly different >set is presented...and the data isn't new...but all the matching results are >not retrieved at any single time. Multiple refreshes, in a row, seems to >produce the best results. > >So what types of data and database will you use. It will be difficult to >emulate the same set of issues when a system only has limited users and >data...doesn't such tests require a high stressed environment? > >But do keep us posted on the scenario and products you will be using to test >these concepts and any significant results you subsequently observe. > >Jim > >-----Original Message----- >From: dba-tech-bounces at databaseadvisors.com >[mailto:dba-tech-bounces at databaseadvisors.com] On Behalf Of Salakhetdinov >Shamil >Sent: Wednesday, February 20, 2013 4:57 PM >To: Discussion of Hardware and Software issues >Subject: [dba-Tech] CQRS or 6*9 = 42 > > Hi All -- > >I'm considering to try to apply CQRS + ES ( Command & Query Responsibility >Segregation and Event Sourcing) architectural patterns > >http://www.udidahan.com/2009/12/09/clarified-cqrs/ > >http://www.udidahan.com/2010/05/07/cqrs-isnt-the-answer-its-just-one-of-the- >questions/ > >in one of my test projects. I'm still to find good practical info on CQRS + >ES drawbacks - do you have some? > >Thank you. > >-- Shamil > >