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From Neha Trivedi <nehajtriv...@gmail.com>
Subject Re: Cassandra Maintenance Best practices
Date Tue, 16 Dec 2014 17:35:54 GMT
thanks Ryan.. We will get a new node and add it in the cluster. I will mail
if I have any question regarding the same.

On Tue, Dec 16, 2014 at 10:52 PM, Ryan Svihla <rsvihla@datastax.com> wrote:
>
> you'll have to run repair and that will involve some load and streaming,
> but this is a normal use case for cassandra..and your cluster should be
> sized load wise to allow repair, and bootstrapping of new nodes..otherwise
> when you're over whelmed you won't be able to add more nodes easily.
>
> If you need to reduce the cost of streaming to the existing cluster, just
> set streaming throughput on your existing nodes to a lower number like 50
> or 25.
>
> On Tue, Dec 16, 2014 at 11:10 AM, Neha Trivedi <nehajtrivedi@gmail.com>
> wrote:
>>
>> Thanks Ryan.
>> So, as Jonathan recommended, we should have RF=3 with Three nodes.
>> So Quorum = 2 so, CL= 2 (or I need the CL to be set to two) and I will
>> not need the  downgrading retry policy, in case if my one node goes down.
>>
>> I can dynamically add a New node to my Cluster.
>> Can I change my RF to 3, dynamically without affecting my nodes ?
>>
>> regards
>> Neha
>>
>> On Tue, Dec 16, 2014 at 10:32 PM, Ryan Svihla <rsvihla@datastax.com>
>> wrote:
>>>
>>>
>>> CL quorum with RF2 is equivalent to ALL, writes will require
>>> acknowledgement from both nodes, and reads will be from both nodes.
>>>
>>> CL one will write to both replicas, but return success as soon as the
>>> first one responds, read will be from one node ( load balancing strategy
>>> determines which one).
>>>
>>> FWIW I've come around to dislike downgrading retry policy. I now feel
>>> like if I'm using downgrading, I'm effectively going to be using that
>>> downgraded policy most of the time under server stress, so in practice that
>>> reduced consistency is the effective consistency I'm asking for from my
>>> writes and reads.
>>>
>>>
>>>
>>> On Tue, Dec 16, 2014 at 10:50 AM, Neha Trivedi <nehajtrivedi@gmail.com>
>>> wrote:
>>>>
>>>> Hi Jonathan,QUORUM = (sum_of_replication_factors / 2) + 1, For us
>>>> Quorum = (2/2) +1 = 2.
>>>>
>>>> Default CL is ONE and RF=2 with Two Nodes in the cluster.(I am little
>>>> confused, what is my read CL and what is my WRITE CL?)
>>>>
>>>> So, does it mean that for every WRITE it will write in both the nodes?
>>>>
>>>> and For every READ, it will read from both nodes and give back to
>>>> client?
>>>>
>>>> DOWNGRADERETRYPOLICY will downgrade the CL if a node is down?
>>>>
>>>> Regards
>>>>
>>>> Neha
>>>>
>>>> On Wed, Dec 10, 2014 at 1:00 PM, Jonathan Haddad <jon@jonhaddad.com>
>>>> wrote:
>>>>>
>>>>> I did a presentation on diagnosing performance problems in production
>>>>> at the US & Euro summits, in which I covered quite a few tools &
>>>>> preventative measures you should know when running a production cluster.
>>>>> You may find it useful:
>>>>> http://rustyrazorblade.com/2014/09/cassandra-summit-recap-diagnosing-problems-in-production/
>>>>>
>>>>> On ops center - I recommend it.  It gives you a nice dashboard.  I
>>>>> don't think it's completely comprehensive (but no tool really is) but
it
>>>>> gets you 90% of the way there.
>>>>>
>>>>> It's a good idea to run repairs, especially if you're doing deletes or
>>>>> querying at CL=ONE.  I assume you're not using quorum, because on RF=2
>>>>> that's the same as CL=ALL.
>>>>>
>>>>> I recommend at least RF=3 because if you lose 1 server, you're on the
>>>>> edge of data loss.
>>>>>
>>>>>
>>>>> On Tue Dec 09 2014 at 7:19:32 PM Neha Trivedi <nehajtrivedi@gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Hi,
>>>>>> We have Two Node Cluster Configuration in production with RF=2.
>>>>>>
>>>>>> Which means that the data is written in both the clusters and it's
>>>>>> running for about a month now and has good amount of data.
>>>>>>
>>>>>> Questions?
>>>>>> 1. What are the best practices for maintenance?
>>>>>> 2. Is OPScenter required to be installed or I can manage with
>>>>>> nodetool utility?
>>>>>> 3. Is is necessary to run repair weekly?
>>>>>>
>>>>>> thanks
>>>>>> regards
>>>>>> Neha
>>>>>>
>>>>>
>>>
>>> --
>>>
>>> [image: datastax_logo.png] <http://www.datastax.com/>
>>>
>>> Ryan Svihla
>>>
>>> Solution Architect
>>>
>>> [image: twitter.png] <https://twitter.com/foundev> [image: linkedin.png]
>>> <http://www.linkedin.com/pub/ryan-svihla/12/621/727/>
>>>
>>> DataStax is the fastest, most scalable distributed database technology,
>>> delivering Apache Cassandra to the world’s most innovative enterprises.
>>> Datastax is built to be agile, always-on, and predictably scalable to any
>>> size. With more than 500 customers in 45 countries, DataStax is the
>>> database technology and transactional backbone of choice for the worlds
>>> most innovative companies such as Netflix, Adobe, Intuit, and eBay.
>>>
>>>
>
> --
>
> [image: datastax_logo.png] <http://www.datastax.com/>
>
> Ryan Svihla
>
> Solution Architect
>
> [image: twitter.png] <https://twitter.com/foundev> [image: linkedin.png]
> <http://www.linkedin.com/pub/ryan-svihla/12/621/727/>
>
> DataStax is the fastest, most scalable distributed database technology,
> delivering Apache Cassandra to the world’s most innovative enterprises.
> Datastax is built to be agile, always-on, and predictably scalable to any
> size. With more than 500 customers in 45 countries, DataStax is the
> database technology and transactional backbone of choice for the worlds
> most innovative companies such as Netflix, Adobe, Intuit, and eBay.
>
>

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