docker / libkv

Distributed key/value store abstraction library
Apache License 2.0
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can not get zookeeper path data, node cannot be discovery. #199

Open rl5c opened 6 years ago

rl5c commented 6 years ago

zookeeper version: 3.4.6 this problem description: If you use the zk store lib, you will find that when the same node repeatedly goes online and offline, the node can no longer be discovery. After the investigation, it is found that the node path exists in zk, but the data cannot be obtained and the data is empty.

Previous code:store/zookeeper/zookeeper.go line 68.

func (s *Zookeeper) Get(key string) (pair *store.KVPair, err error) {
    resp, meta, err := s.client.Get(s.normalize(key))

    if err != nil {
        if err == zk.ErrNoNode {
            return nil, store.ErrKeyNotFound
        }
        return nil, err
    }

    // FIXME handle very rare cases where Get returns the
    // SOH control character instead of the actual value
    if string(resp) == SOH {
        return s.Get(store.Normalize(key))
    }

    pair = &store.KVPair{
        Key:       key,
        Value:     resp,
        LastIndex: uint64(meta.Version),
    }

    return pair, nil
}

Modified code, the problem disappears, hope to adopt.

func (s *Zookeeper) Get(key string) (pair *store.KVPair, err error) {
    resp, meta, err := s.client.Get(s.normalize(key))

    if err != nil {
        if err == zk.ErrNoNode {
            return nil, store.ErrKeyNotFound
        }
        return nil, err
    }

    // FIXME handle very rare cases where Get returns the
    // SOH control character instead of the actual value
    if string(resp) == SOH || string(resp) == "" {  //If the data is empty, you can get it again.
        return s.Get(key)  //get by original key
    }

    pair = &store.KVPair{
        Key:       key,
        Value:     resp,
        LastIndex: uint64(meta.Version),
    }

    return pair, nil
}