hive udf 执行一次调用多次问题

sql 复制代码

SELECT AppMktApi(
      'http://xx.xx.xx.xx:8282/uph/sou',
      'POST',
      concat('{','"topicId": "', 'RZRQ', '",','"auditorId": "','ngw', '",','"channels": "', 'ol', '",','"content": "', '融资融券业务指标变动提醒","longtext":"尊敬的投资者您好！您信用账户持有的科泰电源(300153)折算率已调整，敬请关注', '",','"destIds": ', '[11500435,11500433,11304133,11000126,11000619,11504802]', ',','"destType": "', '1', '",','"priority": "', '5','",','"providerId": "','ngw', '",','"rTopic": "', 'Push_Result','",','"ack": "','1','"}'),
    -- '{"topicId":"RZRQ","auditorId":"ngw","channels":"ol","content":"融资融券业务指标变动提醒","longtext":"尊敬的投资者您好！您信用账户持有的科泰电源(300153)折算率已调整，敬请关注","destIds":[11500435,11500433,11304133,11000126,11000619,11504802],"destType":"1","priority":"5","providerId":"ngw","rTopic":"Push_Result","ack":"1"}',
      'Content-Type: application/json'
    ) AS result

执行一次调用了两次，查看执行计划

sql 复制代码

explain extended SELECT AppMktApi(
      'http://xx.xx.xx.xx:8282/uph/sou',
      'POST',
        '{\"topicId\":\"RZRQ\",\"auditorId\":\"ngw\",\"channels\":\"ol\",\"content\":\"融资融券业务指标变动提醒\",\"longtext\":\"尊敬的投资者您好！您信用账户持有的科泰电源(300153)折算率已调整，敬请关注\",\"destIds\":[11500435,11500433,11304133,11000126,11000619,11504802],\"destType\":\"1\",\"priority\":\"5\",\"providerId\":\"ngw\",\"rTopic\":\"Push_Result\",\"ack\":\"1\"}',
      'Content-Type: application/json'
    ) AS result

结果显示

sql 复制代码

STAGE DEPENDENCIES:
Stage-0 is a root stage
STAGE PLANS:
Stage: Stage-0
Fetch Operator
limit: -1
Processor Tree:
TableScan
alias: _dummy_table
Row Limit Per Split: 1
GatherStats: false
Select Operator
expressions: '{"response":"{\"errcode\":\"0\",\"msgId\":\"2025090239116000001\"}","curlCommand":"curl -X POST -H \"Content-Type: application/json\" -d '{\"topicId\":\"RZRQ\",\"auditorId\":\"ngw\",\"channels\":\"ol\",\"content\":\"融资融券业务指标变动提醒\",\"longtext\":\"尊敬的投资者您好！您信用账户持有的科泰电源(300153)折算率已调整，敬请关注\",\"destIds\":[11500435,11500433,11304133,11000126,11000619,11504802],\"destType\":\"1\",\"priority\":\"5\",\"providerId\":\"ngw\",\"rTopic\":\"Push_Result\",\"ack\":\"1\"}' http://xx.xx.xx.xx:8282/uph/sou"}' (type: string)
outputColumnNames: _col0
ListSink

执行计划里仅显示 Stage-0 （属于客户端本地阶段，无分布式计算），且扫描的是 dummy_table （Hive 虚拟表，仅用于返回固定值，无需 MapReduce 处理）。

原因：

Hive 执行计划的"预执行 + 实际执行"

Hive 在解析含 UDF（这里 AppMktApi; 可理解为自定义函数逻辑）的查询时，可能会先做语法/类型校验，执行计划中的 (type: string)，触发一次接口调用；实际执行查询（扫描 _dummy_table; 后处理数据）时，再触发一次。尤其当 UDF 里有固定参数拼接（像你 SQL 里构造固定请求体），Hive 校验阶段可能会提前执行 UDF 逻辑，导致额外调用。

2 解决方案

方案 1：避免 UDF 在校验阶段执行

Hive 校验阶段会执行 UDF（因固定参数/语法验证），可通过延迟 UDF 逻辑执行规避：

方法：参数化请求体（从固定值改为表字段）

把 UDF 里固定拼接的请求体，改成从表中读取字段动态生成。这样 Hive 校验阶段无实际参数，不会触发接口调用。

示例改造：

原 SQL（固定请求体，触发校验调用）：

sql 复制代码

SELECT AppMktApi(
      'http://xx.xx.xx.xx:8282/uph/sou',
      'POST',
      concat('{','"topicId": "', 'RZRQ', '",','"auditorId": "','ngw', '",','"channels": "', 'ol', '",','"content": "', '融资融券业务指标变动提醒","longtext":"尊敬的投资者您好！您信用账户持有的科泰电源(300153)折算率已调整，敬请关注', '",','"destIds": ', '[11500435,11500433,11304133,11000126,11000619,11504802]', ',','"destType": "', '1', '",','"priority": "', '5','",','"providerId": "','ngw', '",','"rTopic": "', 'Push_Result','",','"ack": "','1','"}'),
    -- '{"topicId":"RZRQ","auditorId":"ngw","channels":"ol","content":"融资融券业务指标变动提醒","longtext":"尊敬的投资者您好！您信用账户持有的科泰电源(300153)折算率已调整，敬请关注","destIds":[11500435,11500433,11304133,11000126,11000619,11504802],"destType":"1","priority":"5","providerId":"ngw","rTopic":"Push_Result","ack":"1"}',
      'Content-Type: application/json'
    ) AS result

改造后（请求体存表，动态读取）：

建辅助表存请求体（一次插入，复用）：

sql 复制代码

create table tmp.request_body(
name string
)

insert into table tmp.request_body 
select '{"topicId": "RZRQ","auditorId": "ngw","channels": "ol","content": "融资融券业务指标变动提醒","longtext":"尊敬的投资者您好！您信用账户持有的科泰电源(300153)折算率已调整，敬请关注","destIds": [11500435,11500433,11304133,11000126,11000619,11504802],"destType": "1","priority": "5","providerId": "ngw","rTopic": "Push_Result","ack": "1"}
' as name;

关联查询动态传参（Hive 校验阶段仅解析逻辑，不执行 UDF）：

sql 复制代码

SELECT AppMktApi(
      'http://xx.xx.xx.xx:8282/uph/sou',
      'POST',
    --   concat('{','"topicId": "', 'RZRQ', '",','"auditorId": "','ngw', '",','"channels": "', 'ol', '",','"content": "', '融资融券业务指标变动提醒","longtext":"尊敬的投资者您好！您信用账户持有的科泰电源(300153)折算率已调整，敬请关注', '",','"destIds": ', '[11500435,11500433,11304133,11000126,11000619,11504802]', ',','"destType": "', '1', '",','"priority": "', '5','",','"providerId": "','ngw', '",','"rTopic": "', 'Push_Result','",','"ack": "','1','"}'),
    -- '{"topicId":"RZRQ","auditorId":"ngw","channels":"ol","content":"融资融券业务指标变动提醒","longtext":"尊敬的投资者您好！您信用账户持有的科泰电源(300153)折算率已调整，敬请关注","destIds":[11500435,11500433,11304133,11000126,11000619,11504802],"destType":"1","priority":"5","providerId":"ngw","rTopic":"Push_Result","ack":"1"}',
    name,
      'Content-Type: application/json'
    ) AS resul from tmp.request_body

原理：Hive 校验阶段仅检查表字段引用，不会实际执行 AppMktApi ，仅实际执行阶段（扫描表时）触发 1 次调用。