注：只有在升级的时候有用。

使用下面的命令查看任务信息，

kubectl get cm {xstore}-task -o yaml

结构为:

type ExecutionContext struct {
    // Topologies in uses.
    Topologies map[int64]*xstore.Topology `json:"topologies,omitempty"`

    // Generation.
    Generation int64 `json:"generation,omitempty"`

    // Current running nodes.
    Running map[string]model.PaxosNodeStatus `json:"running,omitempty"`

    // Tracking nodes. This is the tracking set of the paxos node configuration.
    Tracking map[string]model.PaxosNodeStatus `json:"tracking,omitempty"`

    // Expected nodes.
    Expected map[string]model.PaxosNode `json:"expected,omitempty"`

    // Current usable volumes.
    Volumes map[string]model.PaxosVolume `json:"volumes,omitempty"`

    // Plan.
    Plan *plan.Plan `json:"plan,omitempty"`

    // StepIndex of the plan.
    StepIndex int `json:"step_index,omitempty"`

    PodFactory factory.ExtraPodFactory `json:"-"`
}