Unable to set up my own Stanford CoreNLP server with error "Could not delete shutdown key file" - nlp

Question

I try to set up my own Stanford CoreNLP server following the official guide. However, I am not able to start the server using the following command:
java -mx4g -cp "*" edu.stanford.nlp.pipeline.StanfordCoreNLPServer -port 9000 -timeout 15000
I paste the error messages below:
my_server_name$ java -mx4g -cp "*" edu.stanford.nlp.pipeline.StanfordCoreNLPServer -port 9000 -timeout 15000
[main] INFO CoreNLP - --- StanfordCoreNLPServer#main() called ---
[main] INFO CoreNLP - setting default constituency parser
[main] INFO CoreNLP - warning: cannot find edu/stanford/nlp/models/srparser/englishSR.ser.gz
[main] INFO CoreNLP - using: edu/stanford/nlp/models/lexparser/englishPCFG.ser.gz instead
[main] INFO CoreNLP - to use shift reduce parser download English models jar from:
[main] INFO CoreNLP - http://stanfordnlp.github.io/CoreNLP/download.html
Exception in thread "main" java.lang.IllegalStateException: Could not delete shutdown key file
at edu.stanford.nlp.pipeline.StanfordCoreNLPServer.<init>(StanfordCoreNLPServer.java:195)
at edu.stanford.nlp.pipeline.StanfordCoreNLPServer.main(StanfordCoreNLPServer.java:1323)
[Thread-0] INFO CoreNLP - CoreNLP Server is shutting down.
The main problem is the IllegalSstateException: Could not delete shutdown key file. I just wonder whether the cause of this problem is the sudo access. The official guide doesn't explicitly state this command needs sudo access.
I want to ask 1) whether the above command requires the sudo access and 2) if that command doesn't need sudo access, what could be the potential error for my IllegalSstateException.
Thanks.
PS: I am running on a server with Ubuntu 16.04.3 LTS.

Answer 1

This error happens when the shutdown key file already exists on your filesystem, you're starting a new CoreNLP server instance, and it can't delete the old shutdown key file. Are you running the server as two different users?
More generally, do you have permissions to the directory stored in java property java.io.tmpdir? This is, traditionally, /tmp on Linux machines. The shutdown key is stored in:
System.getProperty("java.io.tmpdir") + File.separator + "corenlp.shutdown"
So, for a Linux system:
/tmp/corenlp.shutdown
The error says that this file exists, and cannot be deleted by Java. You should check your permissions on this file, and that should help you debug what's wrong.
An easy workaround, in the worst case, is to set the tmpdir yourself when starting the server. For example:
java -Djava.io.tmpdir=/path/to/tmp -mx4g edu.stanford.nlp.pipeline.StanfordCoreNLPServer 9000