Debezium：無法在 Kafka-Connect Docker 容器上設置觀察程序。 獲取關聯 ID 為 2 的元數據時出錯……LEADER_NOT_AVAILABLE

Question

問題：

當對數據庫進行更改時，如何設置觀察者以實時觀察 Kafka-Connect stream？ Error while fetching metadata with correlation id 2: {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} 。 是什么導致了問題，我該如何解決？

語境：

這個問題與： Debezium How do I correct register the SqlServer connector with Kafka Connect - connection refused and https://github.com/debezium/debezium-examples/blob/master/tutorial/README.md#using-sql-服務器

在 Windows 10 中，我使用以下命令在各自獨立的 Docker 容器中設置了 Zookeeper、Kafka 和 Kafka-Connector：

docker run -it --rm --name zookeeper -p 2181:2181 -p 2888:2888 -p 3888:3888 debezium/zookeeper:1.1
docker run -it --rm --name kafka -p 9092:9092 -e KAFKA_ADVERTISED_HOST_NAME: kafka --link zookeeper:zookeeper debezium/kafka:1.1
docker run -it --rm --name connect -p 8083:8083 -e GROUP_ID=1 -e CONFIG_STORAGE_TOPIC=my_connect_configs -e OFFSET_STORAGE_TOPIC=my_connect_offsets -e STATUS_STORAGE_TOPIC=my_connect_statuses --link zookeeper:zookeeper --link kafka:kafka debezium/connect:1.1

然后，我將 Kafka 連接器設置到 SQL 服務器的實例，該服務器在 Docker 容器之外的 localhost 上運行。 日志顯示連接器可以連接到數據庫並獲取 CDC 數據。 到目前為止，我還可以。

但是，當我嘗試創建觀察者時，使用以下命令：

docker run -it --rm --name watcher --link zookeeper:zookeeper --link kafka:kafka debezium/kafka:1.1 

我收到以下錯誤。

watch-topic -a -k dbhistory.Test.Posts
WARNING: Using default BROKER_ID=1, which is valid only for non-clustered installations.
Using ZOOKEEPER_CONNECT=172.17.0.2:2181
Using KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://172.17.0.5:9092
Using KAFKA_BROKER=172.17.0.3:9092
Contents of topic dbhistory.Test.Posts:
[2020-04-08 15:18:39,373] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 2 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:41:20,501] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:41:20,605] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:41:20,807] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:41:21,262] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:41:22,120] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:41:23,330] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:41:24,189] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:41:59,826] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:04,051] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:07,121] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:08,024] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:09,354] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11570 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:09,458] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11572 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:09,571] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11574 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:09,677] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11576 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:09,786] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11578 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:09,895] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11580 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:10,002] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11582 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:10,112] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11584 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:10,220] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11586 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:10,326] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11588 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:10,435] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11590 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:10,537] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11592 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:10,648] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11594 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:10,751] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11596 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 16:42:10,854] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Error while fetching metadata with correlation id 11598 : {dbhistory.Test.Posts=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2020-04-08 17:08:48,268] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-08 17:09:55,602] WARN [Consumer clientId=consumer-console-consumer-3848-1, groupId=console-consumer-3848] Connection to node 1 (/172.17.0.3:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)

Answer 1

該問題很可能是由您定義環境變量的方式引起的。

代替：

-e KAFKA_ADVERTISED_HOST_NAME: kafka

和：

-e KAFKA_ADVERTISED_HOST_NAME=kafka

Answer 2

您可以嘗試在 docker 運行中添加 --network=host 一次。