Github user bbende commented on the issue:
https://github.com/apache/nifi-registry/pull/29
@kevdoran I looked into the issue with the app not shutting down cleanly...
taking a thread dump showed:
```
" (ldap-user-group-provider) - background sync thread" #28 prio=5
os_prio=31 tid=0x00007f86f06f2000 nid=0x140b waiting on condition
[0x0000700002cf5000]
java.lang.Thread.State: TIMED_WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000007a1560750> (a
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at
java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078)
at
java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1093)
at
java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:809)
at
java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
```
Digging in further, I realized we don't have a concept of shutting down
extensions, even though the authorizer, user/group provider, and policy
providers do have a preDestruction method which would have shutdown that thread
if we called it.
Tested a change where I made AuthorizerFactory extend DisposableBean and
added:
```
@Override
public void destroy() throws Exception {
if (authorizers != null) {
authorizers.entrySet().stream().forEach(e ->
e.getValue().preDestruction());
}
if (accessPolicyProviders != null) {
accessPolicyProviders.entrySet().stream().forEach(e ->
e.getValue().preDestruction());
}
if (userGroupProviders != null) {
userGroupProviders.entrySet().stream().forEach(e ->
e.getValue().preDestruction());
}
}
```
This appears to work, so if you can add that for AuthorizerFactory and
LoginIdentityProviderFactory then we should be good for that one.
---
