@Override
    public void close() {
        RUNNING.set(false);
        if (Objects.nonNull(executor)) {
            executor.shutdownNow();
            // help gc
            executor = null;
        }
    }
update local cache.

@param json the response from config server.
@return true: the local cache was updated. false: not updated.
shenyu-sync-data-center/shenyu-sync-data-http/src/main/java/org/apache/shenyu/sync/data/http/HttpSyncDataService.java