[Design] Reports From Druid

Introduction:

This document describes the design to generate the data for the portal dashboards from Druid OLAP data store and export the report data to cloud storage. This mainly consists of following modules

1. Configure Report API - This API will be used to submit a request for configuration of a new report.
2. Job Scheduler Engine - This Scheduler will submit the reports for execution based on execution frequency.
3. Disable Report API - This API will mark an existing report as disabled and will be excluded from the list of reports to be executed.
4. Report Data Generator - The report data generator will be a spark job which will generate report data file by executing the query configured in the report configuration against the druid data store. The report data file will then be exported to cloud storage to complete the report execution.

Configure Report API:

• Input:

  • ReportName
  • QueryEngine - druid/cassandra/ES
  • ExecutionFrequency - Daily/Weekly/Monthly
  • ChannelId
  • ReportInterval
  • JsonQuery
  • OutputFormat - json/csv

  Request Object

   {
      "id":"sunbird.analytics.report.submit",
      "ver":"1.0",
      "ts":"2019-03-07T12:40:40+05:30",
      "params":{
         "msgid":"4406df37-cd54-4d8a-ab8d-3939e0223580",
         "client_key":"analytics-team"
      },
      "request":{
         "channel_id":"in.ekstep",
         "report_name":"avg_collection_downloads",
         "query_engine": "druid",
         "execution_frequency": "Daily",
         "report_interval":"LAST_7_DAYS",
         "output_format": "json"
         "query_json":{
            "queryType":"groupBy",
            "dataSource":"telemetry-events",
            "granularity":"day",
            "dimensions":[
               "eid"
            ],
            "aggregations":[
               { "type":"count", "name":"context_did", fieldName":"context_did" }
            ],
            "filter":{
               "type":"and",
               "fields":[
                  { "type":"selector", "name":"eid", fieldName":"IMPRESSION" },
                  { "type":"selector", "name":"edata_type", fieldName":"detail" },
                  { "type":"selector", "name":"edata_pageid", fieldName":"collection-detail" },
                  { "type":"selector", "name":"context_pdata_id", fieldName":"prod.diksha.app" }
               ]
            },
            "postAggregations":[
               {
                  "type":"arithmetic",
                  "name":"avg__edata_value",
                  "fn":"/",
                  "fields":[
                     { "type":"fieldAccess", "name":"total_edata_value", "fieldName":"total_edata_value" },
                     { "type":"fieldAccess", "name":"rows", "fieldName":"rows" }
                  ]
               }
            ],
            "intervals":[
               "2019-02-20T00:00:00.000/2019-01-27T23:59:59.000"
            ]
         }
      }
   }
  

• Output:

  The individual report configurations can be saved to a Cassandra table. The druid query JSON will be saved to Azure blob storage and the following will be the fields in the report configuration table.

   # Schema of table
  
   TABLE platform_db.druid_report_config (
     report_id text,
     report_name text,
     report_interval text,
     query_engine text,
     execution_frequency text,
     is_enabled boolean,
     report_query_location text,
     report_output_format text,
     report_output_location text,
     report_output_filename text,
     PRIMARY KEY (report_id) );
   )
  

• Output location and file format of query:

   /druid-reports/query/druid/report-id.json
   /druid-reports/query/cassandra/report-id.cql
  

• Report Intervals:

   YESTERDAY
   LAST_7_DAYS
   LAST_30_DAYS
   LAST_MONTH
   LAST_6_MONTHS
   LAST_YEAR
   StartDate(DD/MM/YYYY)-EndDate(DD/MM/YYYY)
  

Job Scheduler Engine:

• Input:

  • druid_report_config cassandra table

• Output:

  • Based on execution_frequency in platform_db.druid_report_config submits a request for execution by inserting a record in platform_db.job_request Cassandra table.

Disable Report API:

• Input:

  • report-id

• Output:

  • The report will be disabled in the platform_db.druid_report_config Cassandra table

Report Data Generator Data Product:

• Input:

  • Set of Requests

    i.e All records in platform_db.job_request where status=SUBMITTED and job_name=druid-reports

• Output:

  • Report data file will be saved in Azure with specified format
  • platform_db.job_request table will be updated with job status and output file details will be updated in platform_db.druid_report_config

• Output location and file format in Azure:

  Once a request has been submitted and processing complete, the report data file with the name of the file being the report name suffixed with genaration date saved under :

   /druid-reports/report-id/report-name-mmddyyyy.csv
   /druid-reports/report-id/report-name-mmddyyyy.json