add filter to only load latest metricDef from bt idx
add filter to only load latest metricDef from bt idx

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