logger.trace("processing new index repositories for state version [{}]", event.state().version());
Map<String, RepositoryHolder> survivors = newHashMap();
// First, remove repositories that are no longer there
for (Map.Entry<String, RepositoryHolder> entry : repositories.entrySet()) {
if (newMetaData == null || newMetaData.repository(entry.getKey()) == null) {
logger.debug("unregistering repository [{}]", entry.getKey());
closeRepository(entry.getKey(), entry.getValue());
} else {
survivors.put(entry.getKey(), entry.getValue());
}