Azure Eventhub TS

Azure Event Hubs SDK for TypeScript

高吞吐量事件流和实时数据摄入。

安装

npm install @azure/event-hubs @azure/identity

使用消费者组进行检查点存储：

npm install @azure/eventhubs-checkpointstore-blob @azure/storage-blob

环境变量

EVENTHUB_NAMESPACE=<namespace>.servicebus.windows.net
EVENTHUB_NAME=my-eventhub
STORAGE_ACCOUNT_NAME=<storage-account>
STORAGE_CONTAINER_NAME=checkpoints

身份认证

import { EventHubProducerClient, EventHubConsumerClient } from "@azure/event-hubs";
import { DefaultAzureCredential } from "@azure/identity";

const fullyQualifiedNamespace = process.env.EVENTHUB_NAMESPACE!;
const eventHubName = process.env.EVENTHUB_NAME!;
const credential = new DefaultAzureCredential();

// Producer
const producer = new EventHubProducerClient(fullyQualifiedNamespace, eventHubName, credential);

// Consumer
const consumer = new EventHubConsumerClient(
  "$Default", // Consumer group
  fullyQualifiedNamespace,
  eventHubName,
  credential
);

核心工作流

发送事件

const producer = new EventHubProducerClient(namespace, eventHubName, credential);

// Create batch and add events
const batch = await producer.createBatch();
batch.tryAdd({ body: { temperature: 72.5, deviceId: "sensor-1" } });
batch.tryAdd({ body: { temperature: 68.2, deviceId: "sensor-2" } });

await producer.sendBatch(batch);
await producer.close();

发送到指定分区

// By partition ID
const batch = await producer.createBatch({ partitionId: "0" });

// By partition key (consistent hashing)
const batch = await producer.createBatch({ partitionKey: "device-123" });

接收事件（简单模式）

const consumer = new EventHubConsumerClient("$Default", namespace, eventHubName, credential);

const subscription = consumer.subscribe({
  processEvents: async (events, context) => {
    for (const event of events) {
      console.log(`Partition: ${context.partitionId}, Body: ${JSON.stringify(event.body)}`);
    }
  },
  processError: async (err, context) => {
    console.error(`Error on partition ${context.partitionId}: ${err.message}`);
  },
});

// Stop after some time
setTimeout(async () => {
  await subscription.close();
  await consumer.close();
}, 60000);

带检查点的接收（生产环境）

import { EventHubConsumerClient } from "@azure/event-hubs";
import { ContainerClient } from "@azure/storage-blob";
import { BlobCheckpointStore } from "@azure/eventhubs-checkpointstore-blob";

const containerClient = new ContainerClient(
  `https://${storageAccount}.blob.core.windows.net/${containerName}`,
  credential
);

const checkpointStore = new BlobCheckpointStore(containerClient);

const consumer = new EventHubConsumerClient(
  "$Default",
  namespace,
  eventHubName,
  credential,
  checkpointStore
);

const subscription = consumer.subscribe({
  processEvents: async (events, context) => {
    for (const event of events) {
      console.log(`Processing: ${JSON.stringify(event.body)}`);
    }
    // Checkpoint after processing batch
    if (events.length > 0) {
      await context.updateCheckpoint(events[events.length - 1]);
    }
  },
  processError: async (err, context) => {
    console.error(`Error: ${err.message}`);
  },
});

从指定位置接收

const subscription = consumer.subscribe({
  processEvents: async (events, context) => { /* ... */ },
  processError: async (err, context) => { /* ... */ },
}, {
  startPosition: {
    // Start from beginning
    "0": { offset: "@earliest" },
    // Start from end (new events only)
    "1": { offset: "@latest" },
    // Start from specific offset
    "2": { offset: "12345" },
    // Start from specific time
    "3": { enqueuedOn: new Date("2024-01-01") },
  },
});

Event Hub 属性

// Get hub info
const hubProperties = await producer.getEventHubProperties();
console.log(`Partitions: ${hubProperties.partitionIds}`);

// Get partition info
const partitionProperties = await producer.getPartitionProperties("0");
console.log(`Last sequence: ${partitionProperties.lastEnqueuedSequenceNumber}`);

批处理选项

const subscription = consumer.subscribe(
  {
    processEvents: async (events, context) => { /* ... */ },
    processError: async (err, context) => { /* ... */ },
  },
  {
    maxBatchSize: 100,           // Max events per batch
    maxWaitTimeInSeconds: 30,    // Max wait for batch
  }
);

核心类型

import {
  EventHubProducerClient,
  EventHubConsumerClient,
  EventData,
  ReceivedEventData,
  PartitionContext,
  Subscription,
  SubscriptionEventHandlers,
  CreateBatchOptions,
  EventPosition,
} from "@azure/event-hubs";

import { BlobCheckpointStore } from "@azure/eventhubs-checkpointstore-blob";

事件属性

// Send with properties
const batch = await producer.createBatch();
batch.tryAdd({
  body: { data: "payload" },
  properties: {
    eventType: "telemetry",
    deviceId: "sensor-1",
  },
  contentType: "application/json",
  correlationId: "request-123",
});

// Access in receiver
consumer.subscribe({
  processEvents: async (events, context) => {
    for (const event of events) {
      console.log(`Type: ${event.properties?.eventType}`);
      console.log(`Sequence: ${event.sequenceNumber}`);
      console.log(`Enqueued: ${event.enqueuedTimeUtc}`);
      console.log(`Offset: ${event.offset}`);
    }
  },
});

错误处理

consumer.subscribe({
  processEvents: async (events, context) => {
    try {
      for (const event of events) {
        await processEvent(event);
      }
      await context.updateCheckpoint(events[events.length - 1]);
    } catch (error) {
      // Don't checkpoint on error - events will be reprocessed
      console.error("Processing failed:", error);
    }
  },
  processError: async (err, context) => {
    if (err.name === "MessagingError") {
      // Transient error - SDK will retry
      console.warn("Transient error:", err.message);
    } else {
      // Fatal error
      console.error("Fatal error:", err);
    }
  },
});

最佳实践

1. 使用检查点 - 生产环境中始终使用检查点以确保精确一次处理
2. 批量发送 - 使用 createBatch() 进行高效发送
3. 分区键 - 使用分区键确保相关事件的顺序性
4. 消费者组 - 为不同的处理管道使用独立的消费者组
5. 优雅处理错误 - 处理失败时不要更新检查点
6. 关闭客户端 - 使用完毕后始终关闭 producer/consumer
7. 监控延迟 - 跟踪 lastEnqueuedSequenceNumber 与已处理序列号的差距

适用场景

本技能适用于执行概述中描述的工作流或操作。

限制

• 仅当任务明确匹配上述范围时才使用本技能。
• 不要将输出视为环境特定验证、测试或专家审查的替代方案。
• 如果缺少所需的输入、权限、安全边界或成功标准，请停止并请求澄清。