Re: Add node to balanced cluster?

[ruslan usifov]

2011/3/25 Eric Gilmore 

> Ruslan, I'm not sure exactly what risks you are referring to -- can you be
> more specific?
>
> Do the CPU-intensive operations one at a time, including doing the cleanup
> when it will not interfere with other operations, and I think you should be
> fine, from my understanding.
>

I afraid about disk IO.

I think that move and cleanup opperations consume many IO, so when they run
- throughput of the cluster can degrade seriously? And this nut problem if
this operations took 5-10 minutes, but they cant run hours (1,5 - 2)  - and
this is on one node, so fully rebalance can took days with the seriouse
problems in throuput at that period.

Or i exaggerate?

Re: Add node to balanced cluster?

[Eric Gilmore]

Ruslan, I'm not sure exactly what risks you are referring to -- can you be
more specific?

Do the CPU-intensive operations one at a time, including doing the cleanup
when it will not interfere with other operations, and I think you should be
fine, from my understanding.


   1. Start the new nodes in staggered fashion, allowing at least two
   minutes between each node startup for the gossip protocol to perform
   important inter-node communication. You can monitor the startup and data
   streaming process to its completion using *nodetool
netstats*
   .
   2. After the new nodes are fully bootstrapped, run nodetool move
on each existing node, one node at a time, where 
   is the value you calculated for the node. Only the first node in the ring,
   whose token value is zero, does not need to be moved.


   1. Run *nodetool
cleanup*on
each of the previously existing nodes to remove the keys no longer
   belonging to those nodes. This operation is as disk-intensive as a major
   compaction, so run only one cleanup command at a time. Cleanup may be safely
   postponed for low-usage hours.





On Fri, Mar 25, 2011 at 10:39 AM, ruslan usifov wrote:

>
>
> 2011/3/25 Eric Gilmore 
>
>> Also:
>> http://www.datastax.com/docs/0.7/operations/clustering#adding-capacity
>>
>> Can do that about i represent, but i afraid that when i begin balance
> cluster with new node this will be a big stress for it. Mey be exists some
> strategies how to do that?
>

Re: Add node to balanced cluster?

[ruslan usifov]

2011/3/25 Eric Gilmore 

> Also:
> http://www.datastax.com/docs/0.7/operations/clustering#adding-capacity
>
> Can do that about i represent, but i afraid that when i begin balance
cluster with new node this will be a big stress for it. Mey be exists some
strategies how to do that?

Re: Add node to balanced cluster?

[Eric Gilmore]

Also: http://www.datastax.com/docs/0.7/operations/clustering#adding-capacity

On Thu, Mar 24, 2011 at 5:20 PM, Jonathan Ellis  wrote:

> http://wiki.apache.org/cassandra/Operations
>
> On Thu, Mar 24, 2011 at 5:15 PM, ruslan usifov 
> wrote:
> > Hello
> >
> > Which strategy should i use to and new node to fully balanced cluster
> (nodes
> > tokens are generated by python script:
> >
> > def tokens(nodes):
> >   for x in xrange(nodes):
> > print 2 ** 127 / nodes * x
> >
> > tokens(3);
> > )
> >
> > How to get balanced cluster after adding ne node without big stress for
> > current cluster?
> >
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of DataStax, the source for professional Cassandra support
> http://www.datastax.com
>

Re: Add node to balanced cluster?

[Jonathan Ellis]

http://wiki.apache.org/cassandra/Operations

On Thu, Mar 24, 2011 at 5:15 PM, ruslan usifov  wrote:
> Hello
>
> Which strategy should i use to and new node to fully balanced cluster (nodes
> tokens are generated by python script:
>
> def tokens(nodes):
>   for x in xrange(nodes):
>     print 2 ** 127 / nodes * x
>
> tokens(3);
> )
>
> How to get balanced cluster after adding ne node without big stress for
> current cluster?
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com

Add node to balanced cluster?

[ruslan usifov]

Hello

Which strategy should i use to and new node to fully balanced cluster (nodes
tokens are generated by python script:

def tokens(nodes):
  for x in xrange(nodes):
print 2 ** 127 / nodes * x

tokens(3);
)

How to get balanced cluster after adding ne node without big stress for
current cluster?