需要根据某个关键字过滤掉Kafka记录

我有一个Kafka主题，有大约300万张唱片。我想从中选出一条有特定参数的记录。我一直试图用镜头来查询这个问题，但无法形成正确的查询。以下是1条消息的记录内容。

{
  "header": {
    "schemaVersionNo": "1",
  },
  "payload": {
    "modifiedDate": 1552334325212,
    "createdDate": 1552334325212,
    "createdBy": "A",
    "successful": true,
    "source_order_id": "1111111111111",
  }
}

现在我想筛选出一个具有特定源订单id的记录，但无法找到正确的方法。我们尝试过通过镜头以及Kafka工具。
下面是我们在镜头中尝试的一个示例查询：

SELECT * FROM `TEST`
WHERE _vtype='JSON' AND _ktype='BYTES'
AND _sample=2 AND _sampleWindow=200 AND payload.createdBy='A'

此查询有效，但是如果尝试使用如下所示的源id，则会出现错误：

SELECT * FROM `TEST`
WHERE _vtype='JSON' AND _ktype='BYTES'
AND _sample=2 AND _sampleWindow=200 AND payload.source_order_id='1111111111111'

 Error : "Invalid syntax at line=3 and column=41.Invalid syntax for 'payload.source_order_id'. Field 'payload' resolves to primitive type STRING.

通过一个定制消费者消费所有300万条记录，然后对其进行迭代，对我来说似乎不是一种优化的方法，因此，为这样的用例寻找任何可用的解决方案。

既然您说过您对其他解决方案持开放态度，那么下面是一个使用ksql构建的解决方案。
首先，让我们将一些示例记录放到源主题中：

$ kafkacat -P -b localhost:9092 -t TEST <<EOF
{ "header": { "schemaVersionNo": "1" }, "payload": { "modifiedDate": 1552334325212, "createdDate": 1552334325212, "createdBy": "A", "successful": true, "source_order_id": "3411976933214" } }
{ "header": { "schemaVersionNo": "1" }, "payload": { "modifiedDate": 1552334325412, "createdDate": 1552334325412, "createdBy": "B", "successful": true, "source_order_id": "3411976933215" } }
{ "header": { "schemaVersionNo": "1" }, "payload": { "modifiedDate": 1552334325612, "createdDate": 1552334325612, "createdBy": "C", "successful": true, "source_order_id": "3411976933216" } }
EOF

使用ksql，我们可以用 PRINT :

ksql> PRINT 'TEST' FROM BEGINNING;
Format:JSON
{"ROWTIME":1552476232988,"ROWKEY":"null","header":{"schemaVersionNo":"1"},"payload":{"modifiedDate":1552334325212,"createdDate":1552334325212,"createdBy":"A","successful":true,"source_order_id":"3411976933214"}}
{"ROWTIME":1552476232988,"ROWKEY":"null","header":{"schemaVersionNo":"1"},"payload":{"modifiedDate":1552334325412,"createdDate":1552334325412,"createdBy":"B","successful":true,"source_order_id":"3411976933215"}}
{"ROWTIME":1552476232988,"ROWKEY":"null","header":{"schemaVersionNo":"1"},"payload":{"modifiedDate":1552334325612,"createdDate":1552334325612,"createdBy":"C","successful":true,"source_order_id":"3411976933216"}}

然后在主题上声明一个模式，这使我们能够对其运行sql：

ksql> CREATE STREAM TEST (header STRUCT<schemaVersionNo VARCHAR>, 
                          payload STRUCT<modifiedDate BIGINT, 
                                        createdDate BIGINT, 
                                        createdBy VARCHAR, 
                                        successful BOOLEAN, 
                                        source_order_id VARCHAR>) 
                          WITH (KAFKA_TOPIC='TEST', 
                                VALUE_FORMAT='JSON');

Message
----------------
Stream created
----------------

告诉ksql处理主题中的所有数据：

ksql> SET 'auto.offset.reset' = 'earliest';
Successfully changed local property 'auto.offset.reset' to 'earliest'. Use the UNSET command to revert your change.

现在我们可以选择所有数据：

ksql> SELECT * FROM TEST;
1552475910106 | null | {SCHEMAVERSIONNO=1} | {MODIFIEDDATE=1552334325212, CREATEDDATE=1552334325212, CREATEDBY=A, SUCCESSFUL=true, SOURCE_ORDER_ID=3411976933214}
1552475910106 | null | {SCHEMAVERSIONNO=1} | {MODIFIEDDATE=1552334325412, CREATEDDATE=1552334325412, CREATEDBY=B, SUCCESSFUL=true, SOURCE_ORDER_ID=3411976933215}
1552475910106 | null | {SCHEMAVERSIONNO=1} | {MODIFIEDDATE=1552334325612, CREATEDDATE=1552334325612, CREATEDBY=C, SUCCESSFUL=true, SOURCE_ORDER_ID=3411976933216}
^CQuery terminated

或者我们可以使用 -> 访问架构中嵌套字段的符号：

ksql> SELECT * FROM TEST 
        WHERE PAYLOAD->CREATEDBY='A';
1552475910106 | null | {SCHEMAVERSIONNO=1} | {MODIFIEDDATE=1552334325212, CREATEDDATE=1552334325212, CREATEDBY=A, SUCCESSFUL=true, SOURCE_ORDER_ID=3411976933214}

除了选择所有记录外，还可以仅返回感兴趣的字段：

ksql> SELECT payload FROM TEST 
        WHERE PAYLOAD->source_order_id='3411976933216';
{MODIFIEDDATE=1552334325612, CREATEDDATE=1552334325612, CREATEDBY=C, SUCCESSFUL=true, SOURCE_ORDER_ID=3411976933216}

使用ksql，您可以编写任何 SELECT 语句，该语句使用所有现有消息以及根据声明的 SELECT 声明：

ksql> CREATE STREAM TEST_CREATED_BY_A AS
        SELECT * FROM TEST WHERE PAYLOAD->CREATEDBY='A';

Message
----------------------------
Stream created and running
----------------------------

Kafka集群的列表主题：

ksql> SHOW TOPICS;

Kafka Topic            | Registered | Partitions | Partition Replicas | Consumers | ConsumerGroups
----------------------------------------------------------------------------------------------------
orders                 | true       | 1          | 1                  | 1         | 1
pageviews              | false      | 1          | 1                  | 0         | 0
products               | true       | 1          | 1                  | 1         | 1
TEST                   | true       | 1          | 1                  | 1         | 1
TEST_CREATED_BY_A      | true       | 4          | 1                  | 0         | 0

打印新主题的内容：

ksql> PRINT 'TEST_CREATED_BY_A' FROM BEGINNING;
Format:JSON
{"ROWTIME":1552475910106,"ROWKEY":"null","HEADER":{"SCHEMAVERSIONNO":"1"},"PAYLOAD":{"MODIFIEDDATE":1552334325212,"CREATEDDATE":1552334325212,"CREATEDBY":"A","SUCCESSFUL":true,"SOURCE_ORDER_ID":"3411976933214"}}

需要根据某个关键字过滤掉Kafka记录

1条答案

相关问题

热门标签

最新问答