# Watchers We support to use distributed messaging systems like[etcd](https://github.com/coreos/etcd)to keep consistence between multiple Casbin enforcer instances. 因此，我们的用户可以同时使用多个Casbin enforcers来处理大量的权限检查请求。 与策略存储 adapters类似，我们没有把watcher的代码放在主库中。 任何对新消息系统的支持都应该作为atcher程序来实现。 完整的Casbin watchers列表如下所示。 欢迎任何第三方对 watcher 进行新的贡献，如果有请告知我们，我将把它放在这个列表中:) | Watcher | Type | Author | Description | | --- | --- | --- | --- | | [Etcd Watcher](https://github.com/casbin/etcd-watcher) | KV store | Casbin | Watcher for[etcd](https://github.com/coreos/etcd) | | [NATS Watcher](https://github.com/Soluto/casbin-nats-watcher) | Messaging system | [Soluto](https://github.com/Soluto) | Watcher for[NATS](https://nats.io/) | | [ZooKeeper Watcher](https://github.com/grepsr/casbin-zk-watcher) | KV store | [Grepsr](https://github.com/grepsr) | Watcher for[Apache ZooKeeper](https://zookeeper.apache.org/) | | [Redis Watcher](https://github.com/billcobbler/casbin-redis-watcher) | KV store | [@billcobbler](https://github.com/billcobbler) | Watcher for[Redis](http://redis.io/) | | [GCP Pub/Sub Watcher](https://github.com/livingpackets/cloudpubsub-watcher) | Messaging system | [LivingPackets](https://github.com/livingpackets) | Watcher for[Google Cloud Platform PUB/SUB](https://cloud.google.com/pubsub/) |