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From Tyler Hobbs <ty...@datastax.com>
Subject Re: new "nodetool ring" output and unbalanced ring?
Date Thu, 06 Sep 2012 18:17:12 GMT
To minimize the impact on the cluster, I would bootstrap a new 1d node at
(42535295865117307932921825928971026432 - 100), then decommission the 1c
node at 42535295865117307932921825928971026432 and run cleanup on your
us-east nodes.

On Thu, Sep 6, 2012 at 1:11 PM, William Oberman <oberman@civicscience.com>wrote:

> 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
>



-- 
Tyler Hobbs
DataStax <http://datastax.com/>

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