If we search our spring boot 2.0.3 project source code (all files), there is no mention of nio.
According to the spring docs, nio is disabled by default, so we would expect to not be using nio.
However, when the app starts, it says "restartedMain org.apache.coyote.http11.Http11NioProtocol [] => Initializing ProtocolHandler ["http-nio-8080"]"
Does this mean that we Are using nio? If so, are the docs wrong about defaulting to not using it?
2024-10-23T09:10:56,001Z INFO restartedMain o.s.b.web.embedded.tomcat.TomcatWebServer [] => Tomcat initialized with port(s): 8080 (http)
2024-10-23T09:10:56,031Z INFO restartedMain org.apache.coyote.http11.Http11NioProtocol [] => Initializing ProtocolHandler ["http-nio-8080"]
2024-10-23T09:10:56,052Z INFO restartedMain org.apache.catalina.core.StandardService [] => Starting service [Tomcat]
2024-10-23T09:10:56,052Z INFO restartedMain org.apache.catalina.core.StandardEngine [] => Starting Servlet Engine: Apache Tomcat/8.5.31
Http11NioProtocol is the non-blocking IO (NIO) connector for Tomcat.
Tomcat 8 typically uses the http-nio protocol unless specifically configured to use the blocking I/O (BIO) protocol (Http11Protocol). Therefore, even if you haven't explicitly configured NIO in your project, Tomcat itself is using it by default.
Try:
server.tomcat.protocol=org.apache.coyote.http11.Http11Protocol
This would force the use of the blocking IO connector if you want to switch away from NIO.