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From "Mullen, Robert" <robert.mul...@pearson.com>
Subject Re: nodetool status owns % calculation after upgrade to 2.0.2
Date Sat, 04 Jan 2014 19:10:13 GMT
Hey Rob,
Thanks for the reply.

First, why would you upgrade to 2.0.2 when higher versions exist?
I upgraded a while ago when 2.0.2 was the latest version, haven't upgraded
since then as I'd like to figure out what's going on here before upgrading
again.  I was on vacation for a while too, so am just revisiting this after
the holidays now.

I am running in production but under very low usage with my API in "alpha"
state, so I don't mind a bumpy road with <5 of the Z version, as the API
matures to beta->GA I'll keep that info in mind.

What do you mean by "the counts are different across the nodes now"?
I have a column family called "topics" which has a count of 47 on one node,
59 on another and 49 on another node. It was my understanding with a
replication factor of 3 and 3 nodes in each ring that the nodes should be
equal so I could lose a node in the ring and have no loss of data.  Based
upon that I would expect the counts across the nodes to all be 59 in this
case.

thanks,
Rob



On Fri, Jan 3, 2014 at 5:14 PM, Robert Coli <rcoli@eventbrite.com> wrote:

> On Fri, Jan 3, 2014 at 3:33 PM, Mullen, Robert <robert.mullen@pearson.com>wrote:
>
>> I have a multi region cluster with 3 nodes in each data center, ec2
>> us-east and and west.  Prior to upgrading to 2.0.2 from 1.2.6, the owns %
>> of each node was 100%, which made sense because I had a replication factor
>> of 3 for each data center.  After upgrading to 2.0.2 each node claims to
>> own about 17% of the data now.
>>
>
> First, why would you upgrade to 2.0.2 when higher versions exist?
>
> Second, are you running in production? If so, read this :
> https://engineering.eventbrite.com/what-version-of-cassandra-should-i-run/
>
>
>> So a couple of questions:
>> 1.  Any idea why the owns % would have changed from 100% to 17% per node
>> after upgrade?
>>
>
> Because the display of this information has changed repeatedly over the
> years, including for bugfixes.
>
> https://issues.apache.org/jira/browse/CASSANDRA-3412
> https://issues.apache.org/jira/browse/CASSANDRA-5076
> https://issues.apache.org/jira/browse/CASSANDRA-4598
> https://issues.apache.org/jira/browse/CASSANDRA-6168
> https://issues.apache.org/jira/browse/CASSANDRA-5954
>
> etc.
>
> 2. Is there anything else I can do to get the data back in sync between
>> the nodes other than nodetool repair?
>>
>
> What do you mean by "the counts are different across the nodes now"?
>
> It is pretty unlikely that you have lost any data, from what you have
> described.
>
> =Rob
>
>

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