mail extension - socket was closed unexpected when shutting down the app

[rsvoboda]

Describe the bug

mail extension - socket was closed unexpectedwhen shutting down the app

2022-09-13 17:03:59,937 ERROR [io.ver.ext.mai.imp.SMTPConnection] (vert.x-eventloop-thread-0) socket was closed unexpected. [Error Occurred After Shutdown]
2022-09-13 17:03:59,938 ERROR [io.ver.ext.mai.imp.SMTPConnection] (vert.x-eventloop-thread-1) socket was closed unexpected. [Error Occurred After Shutdown]

Based on the discussion with @cescoffier

• we keep a connection opened with the SMTP server
• we are closing the connection, but the server didn't say BYE (yet)
• so, we abruptly cut it (as we are shutting down)

AIs:

• have a note in mailer reference guide
• update the error message to mention that the remote server didn't reply when closing the connection

Expected behavior

More context in guide / error message.

Actual behavior

Not clear that the errors can occur.

How to Reproduce?

• use mailer-quickstart
• adjust application.properties and "To:" in MailResource.java
  • was using Gmail to send the emails
• build the app - mvn clean package -DskipTests
• run the app - java -jar target/quarkus-app/quarkus-run.jar
• run curl localhost:8080/mail twice
• hit Ctrl+C and check the logs

Output of uname -a or ver

macOS Monterey

Output of java -version

Java 17

GraalVM version (if different from Java)

No response

Quarkus version or git rev

Quarkus main

Build tool (ie. output of mvnw --version or gradlew --version)

No response

Additional information

No response

[quarkus-bot]

/cc @cescoffier

[gaol]

It relates to vert-x3/vertx-mail-client#185

[cescoffier]

Thanks, @gaol, it's exactly that issue. Do you have an ETA?

[gaol]

@cescoffier these cases are inevitable IMO, when the connections are idle for a while, the SMTP server will close the connection, which will lead to this logging.

It does not break sending of emails, but it is a noisy message, so I proposed a fix of changing the log level back to debug like what it was in v3. vert-x3/vertx-mail-client#188

[cescoffier]

Probably a good idea to reduce the level.

I can also filter out the message in our logging configuration.

[cescoffier]

Issue fixed upstream.

[rsvoboda]

Thanks, tried the latest Quarkus main and the error message is no longer present when shutting down the app.