cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Nikolay KŠ¾vshov <nkovs...@yandex.ru>
Subject nodetool move causes summary load to grow
Date Mon, 23 Jul 2012 14:46:20 GMT
I have a testing cluster cassandra 1.1.2 with default memory and cache settings, 1 CF, 1 KS,
RF = 2

This is an empty cluster

10.111.1.141    datacenter1 rack1       Up     Normal  43.04 KB        100.00%           
 0                                           
10.111.1.142    datacenter1 rack1       Up     Normal  26.95 KB        100.00%           
 85070591730234615865843651857942052864 

Then I fill it with 200 MB of random data

10.111.1.141    datacenter1 rack1       Up     Normal  153.34 MB       100.00%           
 0                                           
10.111.1.142    datacenter1 rack1       Up     Normal  76.94 MB        100.00%           
 85070591730234615865843651857942052864

Though second token is something that your python script calculates for equal token distribution
and keys were random, well, this is still looks reasonable

Now I start moving nodes. I wish them change places

nodetool -h d-st-n2 move 1
nodetool -h d-st-n2 cleanup
Here I expect for the second node to have a load of almost 0, but this does not happen

10.111.1.141    datacenter1 rack1       Up     Normal  195.53 MB       100.00%           
 0                                           
10.111.1.142    datacenter1 rack1       Up     Normal  249.82 MB       100.00%           
 1  

nodetool -h d-st-n1 move 85070591730234615865843651857942052864
nodetool -h d-st-n1 cleanup

Nodes did not change places, but the memory grows bigger 

10.111.1.142    datacenter1 rack1       Up     Normal  271.2 MB        100.00%           
 1                                           
10.111.1.141    datacenter1 rack1       Up     Normal  195.53 MB       100.00%           
 85070591730234615865843651857942052864

nodetool -h d-st-n1 move z
nodetool -h d-st-n2 move a
nodetool -h d-st-n1 move 0
nodetool -h d-st-n2 move 85070591730234615865843651857942052864
nodetool -h d-st-n1 cleanup && nodetool -h d-st-n2 cleanup

Here I come to the original cluster, but now it is much bigger

10.111.1.141    datacenter1 rack1       Up     Normal  353.09 MB       100.00%           
 0                                           
10.111.1.142    datacenter1 rack1       Up     Normal  195.58 MB       100.00%           
 85070591730234615865843651857942052864

Could you help me understand the effect of nodetool move ? I see no logic in these results.

Mime
View raw message