Go ZooKeeper 客户端

  Create 已存在 → zk: node already exists | errors.Is(err, zk.ErrNodeExists) = true
  Get 不存在 → zk: node does not exist
  Set 用旧 version → zk: version conflict
  临时节点下建子节点 → zk: ephemeral nodes may not have children
  FlagSequence 返回的路径 → /g/seq-0000000000 <nil>

  第一次变化收到: EventNodeDataChanged /g
  第二次变化(没有重新 GetW)收到: Unknown (读到零值事件:watch 的 channel 触发一次后就被关闭)
  循环里重新 GetW:连续 Set 200 次,收到 170 次事件;最终值 r199

  顺序 326 个/s(6.13 s);64 goroutine 11709 个/s(0.17 s);35.9 倍

  Multi(建 /m1, 建已存在的 /m2) → zk: node already exists | /m1 存在 = false
  Multi(建 /m3, 建 /m4) → <nil> | /m3 = true /m4 = true

  最终 200 / 200,用时 1.8 s;/glock 下现在的子节点数 0
  持有锁时的锁节点名: _c_a1570903446f6a2122ed5ffffd14af4f-lock-0000000000

  0.0s StateConnecting
  0.0s StateConnected
  0.0s StateHasSession
  0.9s StateDisconnected
  0.9s StateConnecting
  1.9s 调用 Get → zk: could not connect to a server(耗时 661 ms)
  1.9s StateConnecting
  2.9s StateConnecting
  2.9s 调用 Get → zk: could not connect to a server(耗时 302 ms)
  3.9s 调用 Get → zk: could not connect to a server(耗时 300 ms)
  3.9s StateConnecting
  4.9s StateConnecting
  5.9s StateConnected
  6.0s StateHasSession
  10.6s 服务端恢复后 Get → <nil>(耗时 6 ms)