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Merge branch '3.2.x'

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Closes gh-39738
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Andy Wilkinson
2024-02-23 09:40:01 +00:00
parent f3f7acc8fb 490161c0ed
commit 9acd5376c8
1 changed files with 4 additions and 5 deletions
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spring-boot-project/spring-boot-docs/src/docs/asciidoc/features/spring-application.adoc
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@@ -387,11 +387,10 @@ If you're running on Java 21 or up, you can enable virtual threads by setting th
Before turning on this option for your application, you should consider https://docs.oracle.com/en/java/javase/21/core/virtual-threads.html[reading the official Java virtual threads documentation]. Before turning on this option for your application, you should consider https://docs.oracle.com/en/java/javase/21/core/virtual-threads.html[reading the official Java virtual threads documentation].
In some cases, applications can experience lower throughput because of "Pinned Virtual Threads"; this page also explains how to detect such cases with JDK Flight Recorder or the `jcmd` CLI. In some cases, applications can experience lower throughput because of "Pinned Virtual Threads"; this page also explains how to detect such cases with JDK Flight Recorder or the `jcmd` CLI.
WARNING: One side effect of virtual threads is that these threads are daemon threads. WARNING: One side effect of virtual threads is that they are daemon threads.
A JVM will exit if there are no non-daemon threads. A JVM will exit if all of its threads are daemon threads.
This behavior can be a problem when you rely on, e.g. `@Scheduled` beans to keep your application alive. This behavior can be a problem when you rely on `@Scheduled` beans, for example, to keep your application alive.
If you use virtual threads, the scheduler thread is a virtual thread and therefore a daemon thread and won't keep the JVM alive. If you use virtual threads, the scheduler thread is a virtual thread and therefore a daemon thread and won't keep the JVM alive.
This does not only affect scheduling, but can be the case with other technologies, too! This not only affects scheduling and can be the case with other technologies too.
To keep the JVM running in all cases, it is recommended to set the property configprop:spring.main.keep-alive[] to `true`. To keep the JVM running in all cases, it is recommended to set the property configprop:spring.main.keep-alive[] to `true`.
This ensures that the JVM is kept alive, even if all threads are virtual threads. This ensures that the JVM is kept alive, even if all threads are virtual threads.