final DiscoveryNodes nodes = clusterState.nodes();
if (nodes.localNodeMaster() || localExecute(request)) {
// check for block, if blocked, retry, else, execute locally
final ClusterBlockException blockException = checkBlock(request, clusterState);
if (blockException != null) {
if (!blockException.retryable()) {
listener.onFailure(blockException);
return;
}
logger.trace("can't execute due to a cluster block: [{}], retrying", blockException);
observer.waitForNextChange(