Hawkular Metrics has a REST API implemented with JAX-RS running on WildFly 10. Hawkular Metrics is deployed in OpenShift, and we are starting to see problems when the system comes under load. We are seeing a lot of:
Caused by: java.io.IOException: UT010029: Stream is closed at io.undertow.servlet.spec.ServletOutputStreamImpl.write(ServletOutputStreamImpl.java:136)
This is happening when writing the HTTP response. All of our REST endpoints are async, using @Suspended AsyncResponse. In addition to the exceptions, users are also reporting high cpu usage. We are using default settings for the I/O an Undertow subsystems. Can anyone suggest any setting that I may want to change? In one deployment nodes are AWS m4.xlarge instances with 4vCPUs and 16G of RAM; however, the nodes are shared with other processes.