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Real-Time Log Metrics Aggregator
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Real-Time Log Metrics Aggregator

HardPython

Problem

Given a stream of log lines, implement a function that parses each line and returns rolling performance metrics over the last window_seconds. Each valid log line has the format "<timestamp> <service> <latency_ms> <status>", where timestamp is a non-decreasing integer. Ignore malformed lines. For each processed line, output the current metrics for that line's service: total requests in the window, error count (status >= 500), and average latency rounded down.

Constraints

  • 1 <= len(logs) <= 10^5
  • 1 <= window_seconds <= 10^6
  • Timestamps are non-decreasing integers
  • 0 <= latency_ms <= 10^6
  • 100 <= status <= 599 for valid lines

Function Signature

def aggregate_log_metrics(logs, window_seconds):
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