tasks/online-compute/FlinkSQL/flinksql_008_en/task.md

metadata

id: online-compute_FlinkSQL_flinksql_008
name: Session Window User Behavior Aggregation
category: online-compute/FlinkSQL
timeout_seconds: 600
modality: pure-text
engine: flink-sql

Prompt

I need you to write a Flink SQL that uses a datagen built-in table to simulate a user behavior stream, performs session window aggregation to compute behavioral metrics per user within each session, and outputs the results to the console.

Business Background and Objective: Simulate a user behavior data stream using a datagen built-in table that generates 50 records per second, containing four fields: userId (user ID, string of length 6), action (action type, string of length 8), action_time (action occurrence time, timestamp), and ftime (event time, timestamp). Based on this datagen table, using ftime as the event time (with a 5-second watermark delay), perform a 30-minute session window (SESSION) aggregation grouped by userId. Compute the following metrics for each user within each session window: session start time, session end time, total action count, number of distinct action types, and the last action time (the maximum value of action_time). Output the results to a built-in console table.

Source Table Definition:

• user_source (user behavior stream, datagen connector):
  • userId VARCHAR: User ID, randomly generated, 6 characters in length
  • action VARCHAR: Action type, randomly generated, 8 characters in length
  • action_time TIMESTAMP(3): Action occurrence time
  • ftime: Uses LOCALTIMESTAMP to generate event time, with a WATERMARK delay of 5 seconds
  • Generation rate: rows-per-second = 50

Output Table Definition:

• console_output (print connector):
  • user_id VARCHAR: User ID
  • session_start TIMESTAMP: Session start time
  • session_end TIMESTAMP: Session end time
  • action_count BIGINT: Total action count
  • unique_actions BIGINT: Number of distinct action types
  • last_action_time TIMESTAMP: Last action time

Query Logic:

• Window: SESSION(ftime, INTERVAL '30' MINUTE) session window
• Grouping: Group by userId and the session window
• Aggregation: COUNT(*) for total action count, COUNT(DISTINCT action) for distinct action type count, MAX(action_time) for last action time
• Window functions: Use SESSION_START / SESSION_END to obtain the window start and end times

Output Requirements:

• Use INSERT INTO console_output to output the results.
• Output field order: user_id, session_start, session_end, action_count, unique_actions, last_action_time