Neo4j WARNING: Max 1024 open files allowed, minimum of 40 000 recommended. See the Neo4j manual

Question

I installed Neo4j on Ubuntu 12.04 using these instructions: http://www.neo4j.org/download/linux

wget -O - http://debian.neo4j.org/neotechnology.gpg.key | apt-key add - 
echo 'deb http://debian.neo4j.org/repo stable/' > /etc/apt/sources.list.d/neo4j.list
apt-get update
apt-get install neo4j

I made sure to have the right jdk:

root@precise64:~# java -version
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)

And when I startup neo4j I get this error:

WARNING: Max 1024 open files allowed, minimum of 40 000 recommended. See the Neo4j manual.

So I follow the instructions here: http://docs.neo4j.org/chunked/1.6.2/configuration-linux-notes.html

And add these contents to /etc/security/limits.conf

neo4j   soft    nofile  40000
neo4j   hard    nofile  40000

And uncomment this line in /etc/pam.d/su

session    required   pam_limits.so

After I restart the server I validate the new limit

neo4j@precise64:~$ ulimit -n
40000

Then I restart my server. I still get the same error when starting up.

root@precise64:~# service neo4j-service start
WARNING: Max 1024 open files allowed, minimum of 40 000 recommended. See the Neo4j manual.
Using additional JVM arguments:  -server -XX:+DisableExplicitGC -Dorg.neo4j.server.properties=conf/neo4j-server.properties -Djava.util.logging.config.file=conf/logging.properties -Dlog4j.configuration=file:conf/log4j.properties -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled
Starting Neo4j Server...WARNING: not changing user
process [3161]... waiting for server to be ready....... OK.
http://localhost:7474/ is ready.

Even though the service is running as the neo4j user:

root@precise64:~# ps -ef | grep 3161
neo4j     3161     1  2 17:43 pts/0    00:00:10 /usr/bin/java -cp /var/lib/neo4j/lib/concurrentlinkedhashmap-lru-1.3.1.jar:/var/lib/neo4j/lib/geronimo-jta_1.1_spec-1.1.1.jar:/var/lib/neo4j/lib/lucene-core-3.6.2.jar:/var/lib/neo4j/lib/neo4j-cypher-2.0.0.jar:/var/lib/neo4j/lib/neo4j-cypher-commons-2.0.0.jar:/var/lib/neo4j/lib/neo4j-cypher-compiler-1.9-2.0.0.jar:/var/lib/neo4j/lib/neo4j-cypher-compiler-2.0-2.0.0.jar:/var/lib/neo4j/lib/neo4j-graph-algo-2.0.0.jar:/var/lib/neo4j/lib/neo4j-graph-matching-2.0.0.jar:/var/lib/neo4j/lib/neo4j-jmx-2.0.0.jar:/var/lib/neo4j/lib/neo4j-kernel-2.0.0.jar:/var/lib/neo4j/lib/neo4j-lucene-index-2.0.0.jar:/var/lib/neo4j/lib/neo4j-shell-2.0.0.jar:/var/lib/neo4j/lib/neo4j-udc-2.0.0.jar:/var/lib/neo4j/lib/org.apache.servicemix.bundles.jline-0.9.94_1.jar:/var/lib/neo4j/lib/parboiled-core-1.1.6.jar:/var/lib/neo4j/lib/parboiled-scala_2.10-1.1.6.jar:/var/lib/neo4j/lib/scala-library-2.10.3.jar:/var/lib/neo4j/lib/server-api-2.0.0.jar:/var/lib/neo4j/system/lib/asm-3.1.jar:/var/lib/neo4j/system/lib/bcprov-jdk16-140.jar:/var/lib/neo4j/system/lib/commons-beanutils-1.8.0.jar:/var/lib/neo4j/system/lib/commons-beanutils-core-1.8.0.jar:/var/lib/neo4j/system/lib/commons-collections-3.2.1.jar:/var/lib/neo4j/system/lib/commons-compiler-2.6.1.jar:/var/lib/neo4j/system/lib/commons-configuration-1.6.jar:/var/lib/neo4j/system/lib/commons-digester-1.8.1.jar:/var/lib/neo4j/system/lib/commons-io-1.4.jar:/var/lib/neo4j/system/lib/commons-lang-2.4.jar:/var/lib/neo4j/system/lib/commons-logging-1.1.1.jar:/var/lib/neo4j/system/lib/jackson-core-asl-1.9.7.jar:/var/lib/neo4j/system/lib/jackson-jaxrs-1.9.7.jar:/var/lib/neo4j/system/lib/jackson-mapper-asl-1.9.7.jar:/var/lib/neo4j/system/lib/janino-2.6.1.jar:/var/lib/neo4j/system/lib/javax.servlet-3.0.0.v201112011016.jar:/var/lib/neo4j/system/lib/jcl-over-slf4j-1.6.1.jar:/var/lib/neo4j/system/lib/jersey-core-1.9.jar:/var/lib/neo4j/system/lib/jersey-multipart-1.9.jar:/var/lib/neo4j/system/lib/jersey-server-1.9.jar:/var/lib/neo4j/system/lib/jetty-http-9.0.5.v20130815.jar:/var/lib/neo4j/system/lib/jetty-io-9.0.5.v20130815.jar:/var/lib/neo4j/system/lib/jetty-security-9.0.5.v20130815.jar:/var/lib/neo4j/system/lib/jetty-server-9.0.5.v20130815.jar:/var/lib/neo4j/system/lib/jetty-servlet-9.0.5.v20130815.jar:/var/lib/neo4j/system/lib/jetty-util-9.0.5.v20130815.jar:/var/lib/neo4j/system/lib/jetty-webapp-9.0.5.v20130815.jar:/var/lib/neo4j/system/lib/jetty-xml-9.0.5.v20130815.jar:/var/lib/neo4j/system/lib/jsr311-api-1.1.2.r612.jar:/var/lib/neo4j/system/lib/logback-access-1.0.9.jar:/var/lib/neo4j/system/lib/logback-classic-1.0.9.jar:/var/lib/neo4j/system/lib/logback-core-1.0.9.jar:/var/lib/neo4j/system/lib/mimepull-1.6.jar:/var/lib/neo4j/system/lib/neo4j-browser-2.0.0.jar:/var/lib/neo4j/system/lib/neo4j-server-2.0.0-static-web.jar:/var/lib/neo4j/system/lib/neo4j-server-2.0.0.jar:/var/lib/neo4j/system/lib/rhino-1.7R3.jar:/var/lib/neo4j/system/lib/rrd4j-2.0.7.jar:/var/lib/neo4j/system/lib/slf4j-api-1.6.2.jar:/var/lib/neo4j/conf/ -server -XX:+DisableExplicitGC -Dorg.neo4j.server.properties=conf/neo4j-server.properties -Djava.util.logging.config.file=conf/logging.properties -Dlog4j.configuration=file:conf/log4j.properties -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -Dneo4j.home=/var/lib/neo4j -Dneo4j.instance=/var/lib/neo4j -Dfile.encoding=UTF-8 org.neo4j.server.Bootstrapper
root      3238  2056  0 17:49 pts/0    00:00:00 grep --color=auto 3161

So I think that maybe starting the service as root is the issue, so I shut it down and start it up as the neo4j user.

root@precise64:~# service neo4j-service stop
root@precise64:~# su - neo4j 
neo4j@precise64:~$ service neo4j-service start
Using additional JVM arguments:  -server -XX:+DisableExplicitGC -    Dorg.neo4j.server.properties=conf/neo4j-server.properties -Djava.util.logging.config.file=conf/logging.properties -Dlog4j.configuration=file:conf/log4j.properties -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled
Starting Neo4j Server...WARNING: not changing user
process [3435]... waiting for server to be ready....... OK.
http://localhost:7474/ is ready.
cp: cannot create regular file `/var/run/neo4j.pid': Permission denied

And it fails because the pid file cannot be created. Which I assume means this is not the correct approach, but I go ahead and edit /etc/init.d/neo4j-service to change the location of the pid file to the home folder of the neo4j user:

#PIDFILE=/var/run/$NAME.pid
PIDFILE=/var/lib/neo4j/$Name.pid

And then things startup without error when I run the service as the Neo4j user.

So, my question is: What is the intended behavior? Should starting the service as root work as long as the neo4j user has the correct ulimit permissions, or do I need to modify the startup script/permissions to allow the neo4j user to create it's PID file?

Answer 1

As mentioned in this issue comment and fixed by this commit, since Neo4J 3.1,

you can add a line in /etc/default/neo4j:

NEO4J_ULIMIT_NOFILE=60000

to set the ulimit setting (60000 open files) for the service.

There is no need anymore to use /etc/security/limits.conf on debian to set the number of open files.