When all io-threads are occupied the CPU usage is very high - Wildfly 29

[Yashaswini Adiga]

Hi All,

We are seeing a scenario when busy task thread count reaches the io thread count we see the CPU is being blocked. The reason we have these threads busy is because our call to once of our backend server takes time. this is SOAP call over http. However, we are wondering why would the CPU usage spike.

This is our configuration 

            <worker name="default" io-threads="200" task-max-threads="200"/>

Any insights appreciated

[Bartosz Baranowski]

Id bet that it might be due to thread starvation and aggressive attempts to reclaim blocked resources? Better question is - why all IO threads become occupied by SOAP call? This does look like flaw in design/bottle neck.