Improve logging robustness

[jpenilla]

This fixes a race where a late log message to the async appender could cause console reinitialization during shutdown

Also fixes issues when plugin log messages with classloader scoped context tries to print after the plugin classloader is closed by flushing the async appender as a part of disabling plugins.

[papermc-pr-publishing]

Last updated for: 17a34a8bc08925b4c2f6c413b2f2013b7f64a390.

Download the Paperclip jar for this pull request: paper-13622.zip

Maven Publication

The artifacts published by this PR:

• 📦 io.papermc.paper:dev-bundle:1.21.11-R0.1-SNAPSHOT
• 📦 io.papermc.paper:paper-api:1.21.11-R0.1-SNAPSHOT

Repository Declaration

In order to use the artifacts published by the PR, add the following repository to your buildscript:

repositories {
    maven("https://maven-prs.papermc.io/Paper/pr13622") {
        name = "Maven for PR #13622" // https://github.com/PaperMC/Paper/pull/13622
        mavenContent {
            includeModule("io.papermc.paper", "dev-bundle")
            includeModule("io.papermc.paper", "paper-api")
        }
    }
}

[Copilot]

Pull request overview

Improves shutdown-time logging behavior to avoid races with Log4j async logging and plugin-classloader-scoped log messages during plugin disable/unload.

Changes:

• Adds an explicit flush(timeout, unit) API to Log4j’s AsyncAppender via a Paper patch.
• Flushes Log4j async appenders during plugin disable before unloading plugin classloaders.
• Moves/removes some shutdown-time logging cleanup steps from MinecraftServer shutdown flow into LogManagerShutdownThread.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
paper-server/src/main/java/io/papermc/paper/util/LogManagerShutdownThread.java	Adds additional shutdown cleanup (force reset + terminal console close) around Log4j shutdown.
paper-server/src/main/java/io/papermc/paper/plugin/manager/PaperPluginInstanceManager.java	Flushes Log4j async appenders during plugin disable to prevent late log processing after classloader close.
paper-server/patches/sources/net/minecraft/server/MinecraftServer.java.patch	Removes terminal console close + log manager reset from the server’s shutdown routine.
paper-server/patches/features/0032-Add-explicit-flush-support-to-Log4j-AsyncAppender.patch	Introduces explicit flush support to Log4j async logging internals.
paper-server/patches/features/0028-Optimize-Hoppers.patch	Patch metadata/index adjustment only.
paper-server/patches/features/0025-Optimise-EntityScheduler-ticking.patch	Patch metadata/index adjustment only.
paper-server/patches/features/0020-Incremental-chunk-and-player-saving.patch	Patch metadata/index adjustment only.
paper-server/patches/features/0001-Moonrise-optimisation-patches.patch	Patch metadata/index adjustment only.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.