sample loader fails if there are multiple nodes in the cluster and bucket creation time takes more than few seconds

create bucket api returns immediately but that does not mean the bucket and db files are ready on all nodes.

sample loader only waits a few seconds until that happens.
it needs to wait for the bucket to be ready on all nodes either via checking with memcached or ns-server

Loading sample bucket beer-sample failed:

if you have a cluster with 2 buckets and 3 nodes and then click on sample loader you will see this behavior