12:00:01 INFO  api-gateway  Request received for /checkout
12:00:01 INFO  checkout     Calling payment-service
12:00:02 WARN  payment      Slow response from database
12:00:03 ERROR payment      Database query timeout
12:00:03 WARN  checkout     Payment service timeout
12:00:04 ERROR checkout     Request failed
12:00:04 WARN  api-gateway  Upstream service error
12:00:05 ERROR api-gateway  502 Bad Gateway

