case UNAVAILABLE:
assert err.infos instanceof UnavailableException;
if (metricsEnabled())
metrics().getErrorMetrics().getUnavailables().inc();
UnavailableException ue = (UnavailableException)err.infos;
retry = retryPolicy.onUnavailable(statement,
ue.getConsistencyLevel(),
ue.getRequiredReplicas(),
ue.getAliveReplicas(),
retriesByPolicy);
if (metricsEnabled()) {
if (retry.getType() == Type.RETRY)
metrics().getErrorMetrics().getRetriesOnUnavailable().inc();