集群监控

Overview

本指南向您展示如何使用 Go 驱动程序监控 MongoDB 实例、副本集或分片集群中的拓扑事件。当您连接到的实例或集群的状态发生任何变化时，驱动程序会创建拓扑结构事件，也称为服务器发现和监控 (SDAM) 事件。

您可以使用有关应用程序中的拓扑结构事件的信息来了解集群更改、评估集群运行状况或执行容量规划。

提示

日志记录

您还可以在应用程序中配置日志记录，以了解有关驱动程序事件的更多信息。要了解更多信息，请参阅日志记录。

订阅事件

您可以通过在应用程序中订阅 SDAM 事件来访问有关这些事件的详细信息。以下示例演示了如何通过实例化ServerMonitor并连接到部署来订阅ServerClosed事件：

var eventArray []*event.ServerClosedEventsrvMonitor := &event.ServerMonitor{    ServerClosed: func(e *event.ServerClosedEvent) {        eventArray = append(eventArray, e)    },}clientOpts := options.Client().ApplyURI(uri).SetServerMonitor(srvMonitor)client, err := mongo.Connect(context.TODO(), clientOpts)

事件描述

您可以通过指定ServerMonitor实例的属性来订阅以下 SDAM 事件：

事件名称	说明
`ServerDescriptionChangedEvent`	在实例状态更改（例如从节点变为主节点）时创建。
`ServerOpeningEvent`	在服务器初始化时创建。
`ServerClosedEvent`	在服务器关闭时创建。
`TopologyDescriptionChangedEvent`	在拓扑结构发生变化时创建，例如选举新的主节点或断开`mongos`代理。
`TopologyOpeningEvent`	在初始化拓扑结构时创建。
`TopologyClosedEvent`	在拓扑结构闭合时创建。
`ServerHeartbeatStartedEvent`	在 heartbeat 启动时创建。
`ServerHeartbeatSucceededEvent`	当心跳成功时创建。
`ServerHeartbeatFailedEvent`	当 heartbeat 失败时创建。

示例事件文档

以下部分显示了每种类型的 SDAM 事件的输出示例。

ServerDescriptionChangedEvent

*event.ServerDescriptionChangedEvent{    "Address": "...",    "TopologyID": "...",    "PreviousDescription": {        "Addr": "...",        "Arbiters": null,        "AverageRTT": 0,        "AverageRTTSet": false,        "Compression": null,        "CanonicalAddr": "...",        "ElectionID": "...",        "HeartbeatInterval": 0,        "HelloOK": false,        "Hosts": null,        "LastError": null,        "LastUpdateTime": "...",        "LastWriteTime": "...",        "MaxBatchCount": 0,        "MaxDocumentSize": 0,        "MaxMessageSize": 0,        "Members": null,        "Passives": null,        "Passive": false,        "Primary": "...",        "ReadOnly": false,        "ServiceID": null,        "SessionTimeoutMinutes": 0,        "SetName": "...",        "SetVersion": 0,        "Tags": null,        "TopologyVersion": null,        "Kind": 0,        "WireVersion": null    },    "NewDescription": {        "Addr": "...",        "Arbiters": null,        "AverageRTT": ...,        "AverageRTTSet": true,        "Compression": null,        "CanonicalAddr": "...",        "ElectionID": "...",        "HeartbeatInterval": ...,        "HelloOK": true,        "Hosts": [...],        "LastError": null,        "LastUpdateTime": "...",        "LastWriteTime": "...",        "MaxBatchCount": ...,        "MaxDocumentSize": ...,        "MaxMessageSize": ...,        "Members": [...],        "Passives": null,        "Passive": false,        "Primary": "...",        "ReadOnly": false,        "ServiceID": null,        "SessionTimeoutMinutes": 30,        "SetName": "...",        "SetVersion": 9,        "Tags": [...],        "TopologyVersion": {...},        "Kind": 10,        "WireVersion": {...}    }}

`Kind` 字段值

事件文档中的Kind字段表示拓扑结构中单个服务器的类型，可以具有以下值：

值	说明
`0`	未知实例
`1`	独立运行的实例
`2`	副本集成员
`6`	主实例
`10`	从节点实例
`18`	仲裁节点实例
`34`	副本集虚影（无法查询的成员）
`256`	`mongos` 代理实例
`512`	负载均衡器实例

ServerOpeningEvent

*event.ServerOpeningEvent{    "Address": "...",    "TopologyID": "..."}

ServerClosedEvent

*event.ServerClosedEvent{    "Address": "...",    "TopologyID": "..."}

TopologyDescriptionChangedEvent

重要

由于驱动程序在部署拓扑结构锁定时调用TopologyDescriptionChangedEvent ，因此此事件的回调（函数参数）不得尝试在同一客户端上进行任何需要选择服务器的操作。

*event.TopologyDescriptionChangedEvent{    "TopologyID": "...",    "PreviousDescription": {        "Servers": [            {                "Addr": "...",                "Arbiters": null,                "AverageRTT": 0,                "AverageRTTSet": false,                "Compression": null,                "CanonicalAddr": "...",                "ElectionID": "...",                "HeartbeatInterval": 0,                "HelloOK": false,                "Hosts": null,                "LastError": null,                "LastUpdateTime": "...",                "LastWriteTime": "...",                "MaxBatchCount": 0,                "MaxDocumentSize": 0,                "MaxMessageSize": 0,                "Members": null,                "Passives": null,                "Passive": false,                "Primary": "...",                "ReadOnly": false,                "ServiceID": null,                "SessionTimeoutMinutes": 0,                "SetName": "...",                "SetVersion": 0,                "Tags": null,                "TopologyVersion": null,                "Kind": 0,                "WireVersion": null            },            ...        ],        "SetName": "...",        "Kind": 10,        "SessionTimeoutMinutes": 30,        "CompatibilityErr": null    },    "NewDescription": {        "Servers": [...],        "SetName": "...",        "Kind": 10,        "SessionTimeoutMinutes": 30,        "CompatibilityErr": null    }}

要解释 Kind 字段的值，请参阅“种类字段值”部分。

TopologyOpeningEvent

*event.TopologyOpeningEvent{    "TopologyID": "..."}

TopologyClosedEvent

*event.TopologyClosedEvent{    "TopologyID": "..."}

ServerHeartbeatStartedEvent

*event.ServerHeartbeatStartedEvent{    "ConnectionID": "...",    "Awaited": true}

ServerHeartbeatSucceededEvent

*event.ServerHeartbeatSucceededEvent{ "DurationNanos": ...,    "Reply": {        "Addr": "...",        "Arbiters": null,        "AverageRTT": 0,        "AverageRTTSet": false,        "Compression": null,        "CanonicalAddr": "...",        "ElectionID": "...",        "HeartbeatInterval": 0,        "HelloOK": true,        "Hosts": [...],        "LastError": null,        "LastUpdateTime": "...",        "LastWriteTime": "...",        "MaxBatchCount": ...,        "MaxDocumentSize": ...,        "MaxMessageSize": ...,        "Members": [...],        "Passives": null,        "Passive": false,        "Primary": "...",        "ReadOnly": false,        "ServiceID": null,        "SessionTimeoutMinutes": 30,        "SetName": "...",        "SetVersion": 9,        "Tags": [...],        "TopologyVersion": {...},        "Kind": 6,        "WireVersion": {...}    },    "ConnectionID": "...",    "Awaited": true}