Canary Test Tool and write sniffing

[Lars George]

Hi,

Looking at the Canary tool, it tries to ensure that all canary test
table regions are spread across all region servers. If that is not the
case, it calls:

if (numberOfCoveredServers < numberOfServers) {
  admin.balancer();
}

I doubt this will help with the StochasticLoadBalancer, which is known
to consider per-table balancing as one of many factors. In practice,
the SLB will most likely _not_ distribute the canary regions
sufficiently, leaving gap in the check. Switching on the per-table
option is discouraged against to let it do its thing.

Just pointing it out for vetting.

Lars