// first node. The following is required to serialize (the effects of)
	// concurrent rebalance-start commands.
	if ep := globalEndpoints[0].Endpoints[0]; !ep.IsLocal {
		for nodeIdx, proxyEp := range globalProxyEndpoints {
			if proxyEp.Host == ep.Host {
				if proxied, success := proxyRequestByNodeIndex(ctx, w, r, nodeIdx, false); proxied && success {
					return
				}
			}

	for poolIdx, doRebalance := range participants {
		if !doRebalance {
			continue
		}
		// nothing to do if this node is not pool's first node (i.e pool's rebalance 'leader').
		if !globalEndpoints[poolIdx].Endpoints[0].IsLocal {
			continue
		}

		go func(idx int) {
			stopfn := globalRebalanceMetrics.log(rebalanceMetricRebalanceBuckets, idx)
			err := z.rebalanceBuckets(ctx, idx)
			stopfn(0, err)
		}(poolIdx)
	}
}