I had an invalid URL for this property. The NodeManager output:
```
2023-07-13 10:14:58,397 ERROR logaggregation.AppLogAggregatorImpl: Error occurred while aggregating the log for the application application_1689169074550_0019
java.lang.NullPointerException
at org.apache.hadoop.yarn.logaggregation.AggregatedLogFormat$LogWriter.close(AggregatedLogFormat.java:566)
at org.apache.hadoop.yarn.logaggregation.filecontroller.tfile.LogAggregationTFileController.closeWriter(LogAggregationTFileController.java:99)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.AppLogAggregatorImpl.uploadLogsForContainers(AppLogAggregatorImpl.java:395)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.AppLogAggregatorImpl.doAppLogAggregation(AppLogAggregatorImpl.java:525)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.AppLogAggregatorImpl.run(AppLogAggregatorImpl.java:472)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.LogAggregationService$1.run(LogAggregationService.java:295)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:750)
2023-07-13 10:14:58,398 WARN logaggregation.AppLogAggregatorImpl: Log aggregation did not complete for application application_1689169074550_0019
```
This was caused by the initialise() function failing and not setting
`fsDataOStream`, with the exception being swallowed by a crash in the
crash handler.
After installing a `.jar` built using this patch, I got:
```
2023-07-13 10:15:34,175 ERROR logaggregation.AppLogAggregatorImpl: Error occurred while aggregating the log for the application application_1689169074550_0019
org.apache.hadoop.HadoopIllegalArgumentException: Uri without authority: hdfs:/var/log/yarn/<REMAINDER REMOVED FROM REPORT>
at org.apache.hadoop.fs.AbstractFileSystem.getUri(AbstractFileSystem.java:330)
at org.apache.hadoop.fs.AbstractFileSystem.<init>(AbstractFileSystem.java:282)
at org.apache.hadoop.fs.Hdfs.<init>(Hdfs.java:80)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.hadoop.fs.AbstractFileSystem.newInstance(AbstractFileSystem.java:143)
at org.apache.hadoop.fs.AbstractFileSystem.createFileSystem(AbstractFileSystem.java:181)
at org.apache.hadoop.fs.AbstractFileSystem.get(AbstractFileSystem.java:266)
at org.apache.hadoop.fs.FileContext$2.run(FileContext.java:347)
at org.apache.hadoop.fs.FileContext$2.run(FileContext.java:344)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1899)
at org.apache.hadoop.fs.FileContext.getAbstractFileSystem(FileContext.java:344)
at org.apache.hadoop.fs.FileContext.getFileContext(FileContext.java:471)
at org.apache.hadoop.yarn.logaggregation.AggregatedLogFormat$LogWriter$1.run(AggregatedLogFormat.java:477)
at org.apache.hadoop.yarn.logaggregation.AggregatedLogFormat$LogWriter$1.run(AggregatedLogFormat.java:474)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1899)
at org.apache.hadoop.yarn.logaggregation.AggregatedLogFormat$LogWriter.initialize(AggregatedLogFormat.java:474)
at org.apache.hadoop.yarn.logaggregation.filecontroller.tfile.LogAggregationTFileController.initializeWriter(LogAggregationTFileController.java:88)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.AppLogAggregatorImpl.uploadLogsForContainers(AppLogAggregatorImpl.java:326)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.AppLogAggregatorImpl.doAppLogAggregation(AppLogAggregatorImpl.java:525)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.AppLogAggregatorImpl.run(AppLogAggregatorImpl.java:472)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.LogAggregationService$1.run(LogAggregationService.java:295)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:750)
```
This is a much more useful error.