(accumulo) branch main updated: fixes NPE in ServiceLockPaths (#5778)

[kturner]

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kturner pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/accumulo.git


The following commit(s) were added to refs/heads/main by this push:
     new 836f0ec928 fixes NPE in ServiceLockPaths (#5778)
836f0ec928 is described below

commit 836f0ec92825eb4390a8af2c264a9852c89d0040
Author: Keith Turner <ktur...@apache.org>
AuthorDate: Wed Aug 6 10:35:03 2025 -0400

    fixes NPE in ServiceLockPaths (#5778)
    
    UserFateOpsCommandsIT was failing because of the following error in the
    Manager.  Modified ServiceLockPaths to avoid the NPE.
    
    ```
    Critical thread CompactionCoordinator Thread died
    java.lang.NullPointerException
            at 
org.apache.accumulo.core.lock.ServiceLockPaths.get(ServiceLockPaths.java:456)
            at 
org.apache.accumulo.core.lock.ServiceLockPaths.getCompactor(ServiceLockPaths.java:290)
            at 
org.apache.accumulo.core.util.compaction.ExternalCompactionUtil.getCompactionsRunningOnCompactors(ExternalCompactionUtil.java:206)
            at 
org.apache.accumulo.manager.compaction.coordinator.CompactionCoordinator.getCompactionsRunningOnCompactors(CompactionCoordinator.java:1212)
            at 
org.apache.accumulo.manager.compaction.coordinator.CompactionCoordinator.run(CompactionCoordinator.java:409)
            at 
org.apache.accumulo.core.util.threads.Threads.lambda$createCriticalThread$0(Threads.java:76)
            at 
org.apache.accumulo.core.trace.TraceWrappedRunnable.run(TraceWrappedRunnable.java:52)
            at java.base/java.lang.Thread.run(Thread.java:829)
    ```
---
 .../main/java/org/apache/accumulo/core/lock/ServiceLockPaths.java | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git 
a/core/src/main/java/org/apache/accumulo/core/lock/ServiceLockPaths.java 
b/core/src/main/java/org/apache/accumulo/core/lock/ServiceLockPaths.java
index 729fb03af3..ab266636fd 100644
--- a/core/src/main/java/org/apache/accumulo/core/lock/ServiceLockPaths.java
+++ b/core/src/main/java/org/apache/accumulo/core/lock/ServiceLockPaths.java
@@ -447,7 +447,13 @@ public class ServiceLockPaths {
             }
             addressPredicate = s -> true;
           } else {
-            servers = zooCache.getChildren(typePath + "/" + group);
+            var children = zooCache.getChildren(typePath + "/" + group);
+            if (children == null) {
+              // resource group no longer exist
+              servers = List.of();
+            } else {
+              servers = children;
+            }
             addressPredicate = addressSelector.getPredicate();
           }