/**
* For a given list of metrics, figure out the shard and slot they belong to and for those shard
* and slot combinations, get all the locators from metrics_delayed_locator column family.
*
* @param metrics
* @return
* @throws IOException
*/
protected Set<Locator> retrieveLocatorsByShardAndSlot(List<IMetric> metrics) throws IOException {
Set<String> slotKeys = new HashSet<String>();
for (IMetric metric : metrics) {
int shard = Util.getShard(metric.getLocator().toString());
int slot = DELAYED_METRICS_STORAGE_GRANULARITY.slot(metric.getCollectionTime());
SlotKey slotKey = SlotKey.of(DELAYED_METRICS_STORAGE_GRANULARITY, slot, shard);
slotKeys.add(slotKey.toString());
}
Set<Locator> locatorsFromDB = new HashSet<Locator>();
for (String slotKeyStr : slotKeys) {
locatorsFromDB.addAll(delayedLocatorIO.getLocators(SlotKey.parse(slotKeyStr)));
}
return locatorsFromDB;
}
