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From William Oberman <ober...@civicscience.com>
Subject Re: new "nodetool ring" output and unbalanced ring?
Date Thu, 06 Sep 2012 18:11:53 GMT
Didn't notice the racks!  Of course....

If I change a 1c to a 1d, what would I have to do to make sure data
shuffles around correctly?  Repair everywhere?

will

On Thu, Sep 6, 2012 at 2:09 PM, Tyler Hobbs <tyler@datastax.com> wrote:

> The main issue is that one of your us-east nodes is in rack 1d, while the
> restart are in rack 1c.  With NTS and multiple racks, Cassandra will try
> use one node from each rack as a replica for a range until it either meets
> the RF for the DC, or runs out of racks, in which case it just picks nodes
> sequentially going clockwise around the ring (starting from the range being
> considered, not the last node that was chosen as a replica).
>
> To fix this, you'll either need to make the 1d node a 1c node, or make
> 42535295865117307932921825928971026432 a 1d node so that you're alternating
> racks within that DC.
>
>
> On Thu, Sep 6, 2012 at 12:54 PM, William Oberman <oberman@civicscience.com
> > wrote:
>
>> Hi,
>>
>> I recently upgraded from 0.8.x to 1.1.x (through 1.0 briefly) and
>> nodetool -ring seems to have changed from "owns" to "effectively owns".
>>  "Effectively owns" seems to account for replication factor (RF).  I'm ok
>> with all of this, yet I still can't figure out what's up with my cluster.
>>  I have a NetworkTopologyStrategy with two data centers (DCs) with
>> RF/number nodes in DC combinations of:
>> DC Name, RF, # in DC
>> analytics, 1, 2
>> us-east, 3, 4
>> So I'd expect 50% on each analytics node, and 75% for each us-east node.
>>  Instead, I have two nodes in us-east with 50/100??? (the other two are
>> 75/75 as expected).
>>
>> Here is the output of nodetool (all nodes report the same thing):
>> Address         DC          Rack        Status State   Load
>>  Effective-Ownership Token
>>
>>                  127605887595351923798765477786913079296
>> x.x.x.x   us-east     1c          Up     Normal  94.57 GB        75.00%
>>            0
>> x.x.x.x   analytics   1c          Up     Normal  60.64 GB        50.00%
>>            1
>> x.x.x.x   us-east     1c          Up     Normal  131.76 GB       75.00%
>>            42535295865117307932921825928971026432
>> x.x.x.x    us-east     1c          Up     Normal  43.45 GB        50.00%
>>              85070591730234615865843651857942052864
>> x.x.x.x    analytics   1d          Up     Normal  60.88 GB        50.00%
>>              85070591730234615865843651857942052865
>> x.x.x.x   us-east     1d          Up     Normal  98.56 GB        100.00%
>>             127605887595351923798765477786913079296
>>
>> If I use cassandra-cli to do "show keyspaces;" I get (and again, all
>> nodes report the same thing):
>> Keyspace: civicscience:
>>   Replication Strategy:
>> org.apache.cassandra.locator.NetworkTopologyStrategy
>>   Durable Writes: true
>>     Options: [analytics:1, us-east:3]
>> I removed the output about all of my column families (CFs), hopefully
>> that doesn't matter.
>>
>> Did I compute the tokens wrong?  Is there a combination of nodetool
>> commands I can run to migrate the data around to rebalance to 75/75/75/75?
>>  I routinely run repair already.  And as the release notes required, I ran
>> upgradesstables during the upgrade process.
>>
>> Before the upgrade, I was getting analytics = 0%, and us-east = 25% on
>> each node, which I expected for "owns".
>>
>> will
>>
>>
>
>
> --
> Tyler Hobbs
> DataStax <http://datastax.com/>
>
>


-- 
Will Oberman
Civic Science, Inc.
3030 Penn Avenue., First Floor
Pittsburgh, PA 15201
(M) 412-480-7835
(E) oberman@civicscience.com

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