Spring ReactorResourceFactory not working with CRaC onRefresh checkpoint

I have a spring boot 3.3.0 application running with embedded tomcat which uses WebClient. When I try out CRaC and generate a checkpoint with -Dspring.context.checkpoint=onRefresh I get errors during checkpoint creation. The cause is org.springframework.http.client.ReactorResourceFactory which is already started in afterPropertiesSet. I could prevent the errors by implementing a org.crac.Resource that stops the ReactorResourceFactory beforeCheckpoint. As I have some other problems I couldn't try if everything would be fine if I start it again in afterRestore. Errors during checkpoint creation:

Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=8 type=unknown path=anon_inode:[eventpoll]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=9 type=unknown path=anon_inode:[eventfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=10 type=unknown path=anon_inode:[timerfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=11 type=unknown path=anon_inode:[eventpoll]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=12 type=unknown path=anon_inode:[eventfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=13 type=unknown path=anon_inode:[timerfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=14 type=unknown path=anon_inode:[eventpoll]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=15 type=unknown path=anon_inode:[eventfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=16 type=unknown path=anon_inode:[timerfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=17 type=unknown path=anon_inode:[eventpoll]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=18 type=unknown path=anon_inode:[eventfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=19 type=unknown path=anon_inode:[timerfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=20 type=unknown path=anon_inode:[eventpoll]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=21 type=unknown path=anon_inode:[eventfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=22 type=unknown path=anon_inode:[timerfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=23 type=unknown path=anon_inode:[eventpoll]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=24 type=unknown path=anon_inode:[eventfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=25 type=unknown path=anon_inode:[timerfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=26 type=unknown path=anon_inode:[eventpoll]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=27 type=unknown path=anon_inode:[eventfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=28 type=unknown path=anon_inode:[timerfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=29 type=unknown path=anon_inode:[eventpoll]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=30 type=unknown path=anon_inode:[eventfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted
Suppressed: jdk.crac.impl.CheckpointOpenResourceException: FD fd=31 type=unknown path=anon_inode:[timerfd]
        at java.base/jdk.crac.Core.translateJVMExceptions(Core.java:122) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore1(Core.java:192) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:299) ~[na:na]
        at java.base/jdk.crac.Core.checkpointRestore(Core.java:278) ~[na:na]
        at java.base/javax.crac.Core.checkpointRestore(Core.java:73) ~[na:na]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.crac.Core$Compat.checkpointRestore(Core.java:141) ~[crac-1.4.0.jar!/:na]
        ... 17 common frames omitted

I don't know what the reason is that ReactorResourceFactory is already started in afterPropertiesSet. Either don't start it already in afterPropertiesSet or provide a org.crac.Resource implementation that stops it before a checkpoint (at least when the checkpoint is made onRefresh as later after start phase it is alrady stopped by the lifecycle implementation) and starts again after restore.

Comment From: sdeleuze

ReactorResourceFactory needs to be declared as bean to handle properly the lifecycle as it implements Lifecycle. I have not checked on Spring Boot side if that the case or not when it is used only in the client. Could you please double check if that's the case, and if you still think there is a potential Spring Framework issue involved, can you please provide a reproduced as an attached archive or a link to a repository?

Comment From: frederikz

The problem is that with -Dspring.context.checkpoint=onRefresh beans are not started so stop isn't called on Lifecyle beans. If you later after a start event do a manual jcmd JDK.checkpoint the lifecycle beans are stopped and everything is fine. So currently with -Dspring.context.checkpoint=onRefresh CracResourceAdapter in DefaultLifecycleProcessor calls stopForRestart which does nothing as this.running is false. So even though there is a ReactorResourceFactory lifecycle bean stop is never called on it which makes somewhat sense as we haven't reached the start event and Spring hasn't called start on the lifecycle beans. The problem is that ReactorResourceFactory itself already internally called the lifecycle method start in afterPropertiesSet. If you later manually do a JDK.checkpoint the application is already started so Sping called start on Lifcycle beans and the CracResourceAdapter with stopForRestart would also call stop on all Lifcycle beans including the ReactorResourceFactory.

So currently when you do a checkpoint with -Dspring.context.checkpoint=onRefresh Lifcycle beans don't take part in the beforeCheckpoint and afterRestore process of CRaC as we haven't reached the start point of Lifcycle.

Hope this helps to understand the problem without providing an example project?

Comment From: sdeleuze

Thanks for the detailed explanation, but a repro is still welcomed, especially for this kind of issue where the devil is usually in the details.

Comment From: frederikz

I did a fork of your spring-boot-crac-demo: https://github.com/frederikz/spring-boot-crac-demo Added a spring-boot-starter-webflux dependency and a WebClient needs to be created (but doesn't has to be a Bean like in the example). Changed your checkpoint.sh so that it executes in the foreground and you can see the error. Thanks for investigating.

Comment From: jhoeller

@sdeleuze looking at the ReactorResourceFactory implementation, it was made lifecycle-aware after initially relying on init and destroy methods... and in the course of that revision, the init/destroy methods were retained as internally delegating to start/stop. This seems suboptimal since the container lifecycle management is not aware of these internal calls.

Could we simply remove the InitializingBean/DisposableBean methods there and rather implement SmartLifecycle which implies an auto-startup call within the container's lifecycle management?

Comment From: jhoeller

A new ReactorResourceFactory revision will be available in the upcoming 6.1.9 snapshot, participating in standard lifecycle management when running within an ApplicationContext. Feel free to give it an early try!

Comment From: frederikz

It seems like calling the start method was required before the start lifecycle. For a quick test I directly replaced only the changed ReactorResourceFactory.class in my spring-web-6.1.8.jar and now I get this exception:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'webClientBuilder' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/function/client/WebClientAutoConfiguration.class]: Failed to instantiate [org.springframework.web.reactive.function.client.WebClient$Builder]: Factory method 'webClientBuilder' threw exception with message: Error creating bean with name 'webClientHttpConnectorCustomizer' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/function/client/ClientHttpConnectorAutoConfiguration.class]: Unsatisfied dependency expressed through method 'webClientHttpConnectorCustomizer' parameter 0: Error creating bean with name 'webClientHttpConnector' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/function/client/ClientHttpConnectorAutoConfiguration.class]: Failed to instantiate [org.springframework.http.client.reactive.ClientHttpConnector]: Factory method 'webClientHttpConnector' threw exception with message: ConnectionProvider not initialized yet
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:648) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:636) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1337) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1167) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:562) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:355) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:254) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1443) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1353) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:904) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:782) ~[spring-beans-6.1.8.jar!/:6.1.8]
        ... 24 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.reactive.function.client.WebClient$Builder]: Factory method 'webClientBuilder' threw exception with message: Error creating bean with name 'webClientHttpConnectorCustomizer' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/function/client/ClientHttpConnectorAutoConfiguration.class]: Unsatisfied dependency expressed through method 'webClientHttpConnectorCustomizer' parameter 0: Error creating bean with name 'webClientHttpConnector' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/function/client/ClientHttpConnectorAutoConfiguration.class]: Failed to instantiate [org.springframework.http.client.reactive.ClientHttpConnector]: Factory method 'webClientHttpConnector' threw exception with message: ConnectionProvider not initialized yet
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:177) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:644) ~[spring-beans-6.1.8.jar!/:6.1.8]
        ... 36 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webClientHttpConnectorCustomizer' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/function/client/ClientHttpConnectorAutoConfiguration.class]: Unsatisfied dependency expressed through method 'webClientHttpConnectorCustomizer' parameter 0: Error creating bean with name 'webClientHttpConnector' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/function/client/ClientHttpConnectorAutoConfiguration.class]: Failed to instantiate [org.springframework.http.client.reactive.ClientHttpConnector]: Factory method 'webClientHttpConnector' threw exception with message: ConnectionProvider not initialized yet
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:795) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:542) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1337) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1167) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:562) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:337) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:335) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:254) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1696) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1653) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1470) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1392) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory$DependencyObjectProvider.resolveStream(DefaultListableBeanFactory.java:2198) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory$DependencyObjectProvider.orderedStream(DefaultListableBeanFactory.java:2192) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration.webClientBuilder(WebClientAutoConfiguration.java:55) ~[spring-boot-autoconfigure-3.3.0.jar!/:3.3.0]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:140) ~[spring-beans-6.1.8.jar!/:6.1.8]
        ... 37 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'webClientHttpConnector' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/function/client/ClientHttpConnectorAutoConfiguration.class]: Failed to instantiate [org.springframework.http.client.reactive.ClientHttpConnector]: Factory method 'webClientHttpConnector' threw exception with message: ConnectionProvider not initialized yet
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:648) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:636) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1337) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1167) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:562) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:337) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:335) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:254) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1443) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1353) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:904) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:782) ~[spring-beans-6.1.8.jar!/:6.1.8]
        ... 57 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.http.client.reactive.ClientHttpConnector]: Factory method 'webClientHttpConnector' threw exception with message: ConnectionProvider not initialized yet
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:177) ~[spring-beans-6.1.8.jar!/:6.1.8]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:644) ~[spring-beans-6.1.8.jar!/:6.1.8]
        ... 71 common frames omitted
Caused by: java.lang.IllegalStateException: ConnectionProvider not initialized yet
        at org.springframework.util.Assert.state(Assert.java:76) ~[spring-core-6.1.8.jar!/:6.1.8]
        at org.springframework.http.client.ReactorResourceFactory.getConnectionProvider(ReactorResourceFactory.java:146) ~[spring-web-6.1.8.jar!/:6.1.8]
        at org.springframework.http.client.reactive.ReactorClientHttpConnector.createHttpClient(ReactorClientHttpConnector.java:107) ~[spring-web-6.1.8.jar!/:6.1.8]
        at org.springframework.http.client.reactive.ReactorClientHttpConnector.<init>(ReactorClientHttpConnector.java:101) ~[spring-web-6.1.8.jar!/:6.1.8]
        at org.springframework.boot.autoconfigure.web.reactive.function.client.ReactorClientHttpConnectorFactory.createClientHttpConnector(ReactorClientHttpConnectorFactory.java:68) ~[spring-boot-autoconfigure-3.3.0.jar!/:3.3.0]
        at org.springframework.boot.autoconfigure.web.reactive.function.client.ReactorClientHttpConnectorFactory.createClientHttpConnector(ReactorClientHttpConnectorFactory.java:44) ~[spring-boot-autoconfigure-3.3.0.jar!/:3.3.0]
        at org.springframework.boot.autoconfigure.web.reactive.function.client.ClientHttpConnectorFactory.createClientHttpConnector(ClientHttpConnectorFactory.java:32) ~[spring-boot-autoconfigure-3.3.0.jar!/:3.3.0]
        at org.springframework.boot.autoconfigure.web.reactive.function.client.ClientHttpConnectorAutoConfiguration.webClientHttpConnector(ClientHttpConnectorAutoConfiguration.java:57) ~[spring-boot-autoconfigure-3.3.0.jar!/:3.3.0]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:140) ~[spring-beans-6.1.8.jar!/:6.1.8]
        ... 72 common frames omitted

Comment From: jhoeller

We also got a similar phase mismatch with Boot's NettyWebServer. Reopening for another revision.

Comment From: jhoeller

I've pushed another revision. Please let me know whether the upcoming 6.1.9 snapshot works for your purposes now... either through upgrading the entire spring-web.jar or through patching ReactorResourceFactory as well as ReactorClientHttpConnector (which has corresponding changes as well now).

Comment From: frederikz

Thanks, works.