revert change in metricname Len()
revert change in metricname Len()

replay/metrictank,raintank/metrictank,replay/metrictank,raintank/raintank-metric,raintank/raintank-metric,replay/metrictank,raintank/metrictank,raintank/metrictank,raintank/raintank-metric,replay/metrictank,raintank/metrictank