cube.js dremio driver基于补偿机制提升查询速度

默认cube.js 的dremio driver 在设计的时候，为了进行状态处理的请求使用了循环处理，同时添加了一个1s的延迟处理

原始参考代码

async query(query, values) {
    const queryString = applyParams(
      query,
      (values || []).map(s => (typeof s === 'string' ? {
        toSqlString: () => SqlString.escape(s).replace(/\\\\\\([_%])/g, '\\$1').replace(/\\'/g, '\'\'')
      } : s))
    );
 
    await this.getToken();
    const jobId = await this.executeQuery(queryString);
 
    for (;;) {
      const { data } = await this.getJobStatus(jobId);
 
      console.log(data.jobState, jobId);
 
      if (data.jobState === 'FAILED') {
        throw new Error(data.errorMessage);
      } else if (data.jobState === 'CANCELED') {
        throw new Error(`Job ${jobId} has been canceled`);
      } else if (data.jobState === 'COMPLETED') {
        let rows = [];
        const querys = [];
 
        for (let i = 0; i < data.rowCount; i += dremioJobLimit) {
          querys.push(this.getJobResults(jobId, dremioJobLimit, i));
        }
 
        const parts = await Promise.all(querys);
        parts.forEach((e) => {
          rows = rows.concat(e.data.rows);
        });
 
        return rows;
      }
     //   此处延迟1s执行，真是因为这个，所以会发现dremio 的查询都比较慢
      await this.sleep(1000);
    }
  }

解决方法

基于线性补偿机制，参考了bigquery driver

async query(query, values) {
    const queryString = applyParams(
      query,
      (values || []).map(s => (typeof s === 'string' ? {
        toSqlString: () => SqlString.escape(s).replace(/\\\\([_%])/g, '\\$1').replace(/\\'/g, '\'\'')
      } : s))
    );
 
    await this.getToken();
    const jobId = await this.executeQuery(queryString);
 
    // do some query like bigquery links  https://github.com/cube-js/cube.js/blob/master/packages/cubejs-bigquery-driver/driver/BigQueryDriver.js#L224
 
    const startedTime = Date.now();
 
    for (let i = 0; Date.now() - startedTime <= this.config.pollTimeout; i++) {
      const { data } = await this.getJobStatus(jobId);
      console.log(data.jobState, jobId);
      if (data.jobState === 'FAILED') {
        throw new Error(data.errorMessage);
      } else if (data.jobState === 'CANCELED') {
        throw new Error(`Job ${jobId} has been canceled`);
      } else if (data.jobState === 'COMPLETED') {
        let rows = [];
        const querys = [];
 
        for (let j = 0; j < data.rowCount; j += dremioJobLimit) {
          querys.push(this.getJobResults(jobId, dremioJobLimit, j));
        }
 
        const parts = await Promise.all(querys);
        parts.forEach((e) => {
          rows = rows.concat(e.data.rows);
        });
 
        return rows;
      }
 
      await this.sleep(
        Math.min(this.config.pollMaxInterval, 200 * i),
      );
    }
  }

说明

经过以上的调整cube.js 与dremio 的查询结合dremio 的数据反射能力，基本都可以在1s内响应了

参考资料

https://github.com/cube-js/cube.js/blob/master/CONTRIBUTING.md
https://github.com/cube-js/cube.js/pull/2475
https://github.com/cube-js/cube.js/blob/master/packages/cubejs-bigquery-driver/driver/BigQueryDriver.js#L60

posted on 2021-04-01 20:49  荣锋亮  阅读(118)  评论(0)  编辑  收藏  举报

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