我有一个主题post_users_t
,在上面使用PRINT
命令时
rowtime: 4/2/20 2:03:48 PM UTC, key: <null>, value: {"userid": 6, "id": 8, "title": "testest", "body": "Testingmoreand more"}
rowtime: 4/2/20 2:03:48 PM UTC, key: <null>, value: {"userid": 7, "id": 11, "title": "testest", "body": "Testingmoreand more"}
然后我用以下方法创建一个流:
CREATE STREAM userstream (userid INT, id INT, title VARCHAR, body VARCHAR)
WITH (KAFKA_TOPIC='post_users_t',
VALUE_FORMAT='JSON');
但是我无法从中选择任何内容,当我DESCRIBE EXTENDED
时,所有消息都失败了。
consumer-messages-per-sec: 1.06 consumer-total-bytes: 116643 consumer-total-messages: 3417 last-message: 2020-04-02T14:08:08.546Z
consumer-failed-messages: 3417 consumer-failed-messages-per-sec: 1.06 last-failed: 2020-04-02T14:08:08.56Z
我在做什么错了?
其他信息!
从头开始打印主题:
ksql> print 'post_users_t' from beginning limit 2;
Key format: SESSION(AVRO) or HOPPING(AVRO) or TUMBLING(AVRO) or AVRO or SESSION(PROTOBUF) or HOPPING(PROTOBUF) or TUMBLING(PROTOBUF) or PROTOBUF or SESSION(JSON) or HOPPING(JSON) or TUMBLING(JSON) or JSON or SESSION(JSON_SR) or HOPPING(JSON_SR) or TUMBLING(JSON_SR) or JSON_SR or SESSION(KAFKA_INT) or HOPPING(KAFKA_INT) or TUMBLING(KAFKA_INT) or KAFKA_INT or SESSION(KAFKA_BIGINT) or HOPPING(KAFKA_BIGINT) or TUMBLING(KAFKA_BIGINT) or KAFKA_BIGINT or SESSION(KAFKA_DOUBLE) or HOPPING(KAFKA_DOUBLE) or TUMBLING(KAFKA_DOUBLE) or KAFKA_DOUBLE or SESSION(KAFKA_STRING) or HOPPING(KAFKA_STRING) or TUMBLING(KAFKA_STRING) or KAFKA_STRING
Value format: AVRO or KAFKA_STRING
rowtime: 4/2/20 1:04:08 PM UTC, key: <null>, value: {"userid": 1, "id": 1, "title": "loremit", "body": "loremit heiluu ja paukkuu"}
rowtime: 4/2/20 1:04:08 PM UTC, key: <null>, value: {"userid": 2, "id": 2, "title": "lorbe", "body": "larboloilllaaa"}
答案 0 :(得分:2)
根据ksqlDB对主题的检查输出,您的数据在Avro中进行了序列化:
Value format: AVRO or KAFKA_STRING
,但是您已经创建了STREAM
并指定了VALUE_FORMAT='JSON'
。这将导致反序列化错误,如果您运行docker-compose logs -f ksqldb-server
,当您尝试查询流时,将看到已被注销。
由于使用的是Avro,因此无需指定架构。请尝试以下方法:
CREATE STREAM userstream
WITH (KAFKA_TOPIC='post_users_t',
VALUE_FORMAT='AVRO');