eclipse-vertx/vert.x · error · IllegalArgumentException

Missing QLog path configuration

Error message

Missing QLog path configuration

What it means

Incomplete QLog configuration in QuicServerImpl.createCodecBuilder: a QLogConfig object was supplied but its path field is null, so qlog output cannot be written. The input at fault is QLogConfig.path on the server's QuicConfig.

Source

Thrown at vertx-core/src/main/java/io/vertx/core/net/impl/quic/QuicServerImpl.java:257

/*

        public void channelInactive(ChannelHandlerContext ctx) {
          // OK
          ((QuicChannel) ctx.channel()).collectStats().addListener(f -> {
//            if (f.isSuccess()) {
//              System.out.println("Connection closed: " + f.getNow());
//            }
            //only test for first connection
//            ctx.channel().parent().close();
          });
        }
*/
      });

    QLogConfig qlogCfg = config.getQLogConfig();
    if (qlogCfg != null) {
      if (qlogCfg.getPath() == null) {
        throw new IllegalArgumentException("Missing QLog path configuration");
      }
      if (qlogCfg.getTitle() == null) {
        throw new IllegalArgumentException("Missing QLog title configuration");
      }
      if (qlogCfg.getDescription() == null) {
        throw new IllegalArgumentException("Missing QLog description configuration");
      }
      QLogConfiguration qLogConfiguration = new QLogConfiguration(qlogCfg.getPath(),
        qlogCfg.getTitle(),
        qlogCfg.getDescription());
      builder.option(QuicChannelOption.QLOG, qLogConfiguration);
    }
    return builder;
  }

  private class QuicDispatcher extends QuicCodecDispatcher implements Shareable {

    private final ServerID serverID;

View on GitHub (pinned to fb308bd8c3)

Solutions

1. Set a writable directory path on QLogConfig
2. Or remove the QLogConfig to disable qlogging

When it happens

Trigger: Thrown at vertx-core/src/main/java/io/vertx/core/net/impl/quic/QuicServerImpl.java:257 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of eclipse-vertx/vert.x@fb308bd8c3 (2026-09-06). Data as JSON: /api/errors/f1631c3f2ab20cbb. Report an issue: GitHub.