Neo4j WARNING: Max 1024 open files allowed, minimum of 40 000 recommended. See the Neo4j manual
linux, neo4j, ubuntu
Solution
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.
Problem
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?