Issue
Fusion API calls occasionally fail with the following error message:
"error": "service-timeout",
"msg": "Did not observe any item or terminal signal within 15000ms in 'circuitBreaker' (and no fallback has been configured)"This indicates that a request was not completed within the default timeout of 15 seconds.
Environment
Fusion 5.9.0 (Self-Hosted)
Component: api-gateway
Relevant service: Resilience4j circuit breaker configuration
Cause
Fusion uses the Resilience4j library to implement circuit breakers and time limiters across microservices. By default, the API gateway applies a 15-second timeout for time-limited operations, including query-related requests. If no response is received within this time, the call fails with a service-timeout.
Resolution
To increase the timeout duration for query operations managed by the circuit breaker in the api-gateway, add the following JVM flag to the api-gateway microservice:
-Dresilience4j.timelimiter.instances.query.timeoutDuration=60sThis setting increases the timeout to 60 seconds. Apply this change by modifying the JAVA_TOOL_OPTIONS in your api-gateway deployment. The method for setting JVM options will vary depending on how your Fusion deployment is managed (e.g., Kubernetes deployment via Helm chart).
After updating the setting, restart the api-gateway pod to apply the configuration.