NPE in websocket metrics #5574
Description
Version
5.0.0
Context
A simple http server that accepts websockets with metrics enabled (Micrometer) throws NPE when the client closes the socket.
Do you have a reproducer?
package test;
import io.micrometer.core.instrument.Metrics;
import io.vertx.core.Vertx;
import io.vertx.core.VertxOptions;
import io.vertx.micrometer.MicrometerMetricsFactory;
import io.vertx.micrometer.MicrometerMetricsOptions;
import java.util.concurrent.CountDownLatch;
public class Server2 {
public static void main(String[] args) throws InterruptedException {
var cdl = new CountDownLatch(3);
var vertx =
Vertx.builder()
.withMetrics(new MicrometerMetricsFactory(Metrics.globalRegistry))
.with(
new VertxOptions()
.setMetricsOptions(new MicrometerMetricsOptions().setEnabled(true)))
.build();
vertx
.createHttpServer()
.requestHandler(
r ->
r.toWebSocket()
.onSuccess(
ss -> {
ss.exceptionHandler(
e -> {
System.err.println("ss.exceptionHandler: " + e);
cdl.countDown();
});
ss.textMessageHandler(
msg -> {
System.out.println("server: received " + msg);
cdl.countDown();
});
ss.writeTextMessage("hello from server");
})
.onFailure(e -> System.err.println("toWebSocket: " + e)))
.listen(0, "localhost")
.onSuccess(
server -> {
for (var i = 0; i < 2; i++) {
var client = vertx.createWebSocketClient();
client
.connect(server.actualPort(), "localhost", "/")
.onSuccess(
socket -> {
socket.writeTextMessage("hello from client");
socket.textMessageHandler(
msg -> {
System.out.println("client: received " + msg);
socket.close();
cdl.countDown();
// Prevent the cleaner from kicking in and destroying the client
// socket immediately
System.out.println(client);
});
})
.onFailure(e -> System.err.println("connect failed: " + e));
}
});
cdl.await();
vertx.close();
}
}Steps to reproduce
- Create a minimal project
- Add dependencies to
io.vertx:vertx-coreandio.vertx:vertx-micrometer-metrics - Run the example above
- Note the output of
java.lang.NullPointerException: Cannot read field "bytesReceived" because "socketMetric" is null
Extra
- The example runs fine on 4.5.15
- I think this can be fixed by changing
towebSocketConn.metric(httpConn.metric());. The current code is a no-op and sets a null field to null again.
OS: Linux
JDK: Temurin 21.0.7