neo4j won't start: Failed to get local hostname / Name or service not known

Question

I am attempting to start neo4j community version 1.8.2 on a test machine. This machine has a custom host name for the local network only.

I was able to start the neo4j server once (about 2 weeks ago) but never since. I know it started because I was able to access the web interface on port 7474.

I can't seem to figure out why not having a host name which valid could be a problem for starting the service now, since I didn't encounter that issue before.

Below is the back trace printed when I attempt to start neo4j (either as root from the working directory or as when I start it using the service in /etc/init.d/ , back traces are exactly the same).

Any input is useful. Thank in advance.

Solution:

This isn't much of a solution per se. What I did is simply start from scratch my neo4j installation, since I didn't have any important data stored. I suppose it was due to corrupted data (probably too many machine hibernations without proper neo4j shutdown).

WARNING: Max 1024 open files allowed, minimum of 40 000 recommended. See the Neo4j manual. WARNING! You are using an unsupported Java runtime. Please use Oracle(R) Java(TM) Runtime Environment 6. Starting Neo4j Server...00:05:28,335 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback.groovy] 00:05:28,336 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback-test.xml] 00:05:28,336 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Found resource [logback.xml] at [jar:file:/home/chris/Software/neo4j-community-1.8.2/system/lib/neo4j-server-1.8.2.jar!/logback.xml] 00:05:28,351 |-INFO in ch.qos.logback.core.joran.spi.ConfigurationWatchList@3c41068b - URL [jar:file:/home/chris/Software/neo4j-community-1.8.2/system/lib/neo4j-server-1.8.2.jar!/logback.xml] is not of type file 00:05:28,396 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - debug attribute not set 00:05:30,521 |-ERROR in ch.qos.logback.core.util.ContextUtil@5114ae94 - Failed to get local hostname java.net.UnknownHostException: acer.lap: acer.lap: Name or service not known at java.net.UnknownHostException: acer.lap: acer.lap: Name or service not known at at java.net.InetAddress.getLocalHost(InetAddress.java:1438) at at ch.qos.logback.core.util.ContextUtil.getLocalHostName(ContextUtil.java:30) at at ch.qos.logback.core.util.ContextUtil.addHostNameAsProperty(ContextUtil.java:39) at at ch.qos.logback.classic.joran.action.ConfigurationAction.begin(ConfigurationAction.java:48) at at ch.qos.logback.core.joran.spi.Interpreter.callBeginAction(Interpreter.java:277) at at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:149) at at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:131) at at ch.qos.logback.core.joran.spi.EventPlayer.play(EventPlayer.java:50) at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:148) at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:134) at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:97) at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:56) at at ch.qos.logback.classic.util.ContextInitializer.configureByResource(ContextInitializer.java:77) at at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:150) at at org.slf4j.impl.StaticLoggerBinder.init(StaticLoggerBinder.java:85) at at org.slf4j.impl.StaticLoggerBinder.(StaticLoggerBinder.java:55) at at org.slf4j.LoggerFactory.bind(LoggerFactory.java:128) at at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:108) at at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:279) at at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:252) at at org.apache.commons.logging.impl.SLF4JLogFactory.getInstance(SLF4JLogFactory.java:156) at at org.apache.commons.logging.impl.SLF4JLogFactory.getInstance(SLF4JLogFactory.java:132) at at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:685) at at org.apache.commons.configuration.AbstractFileConfiguration.(AbstractFileConfiguration.java:121) at at org.apache.commons.configuration.AbstractFileConfiguration.(AbstractFileConfiguration.java:154) at at org.apache.commons.configuration.PropertiesConfiguration.(PropertiesConfiguration.java:252) at at org.neo4j.server.configuration.PropertyFileConfigurator.loadPropertiesConfig(PropertyFileConfigurator.java:142) at at org.neo4j.server.configuration.PropertyFileConfigurator.(PropertyFileConfigurator.java:76) at at org.neo4j.server.storemigration.PreStartupStoreUpgrader.getConfigurator(PreStartupStoreUpgrader.java:135) at at org.neo4j.server.storemigration.PreStartupStoreUpgrader.run(PreStartupStoreUpgrader.java:78) at at org.neo4j.server.storemigration.PreStartupStoreUpgrader.main(PreStartupStoreUpgrader.java:57) Caused by: java.net.UnknownHostException: acer.lap: Name or service not known at at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method) at at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:866) at at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1258) at at java.net.InetAddress.getLocalHost(InetAddress.java:1434) at ... 30 common frames omitted 00:05:30,521 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender] 00:05:30,525 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT] 00:05:30,544 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property 00:05:30,589 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to INFO 00:05:30,589 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [STDOUT] to Logger[ROOT] 00:05:30,591 |-INFO in ch.qos.logback.core.joran.util.ConfigurationWatchListUtil@45828b22 - Adding [file:/home/chris/Software/neo4j-community-1.8.2/conf/custom-logback.xml] to configuration watch list. 00:05:30,596 |-INFO in ch.qos.logback.classic.joran.JoranConfigurator@7d7c88d4 - Registering current configuration as safe fallback point

Answer 1

The solution was to start the neo4j installation from scratch. I didn't have much data stored on this test machine so it was not a problem.

I suppose it was due to corrupted data (probably too many machine hibernations without proper neo4j shutdown).

Answer 2

I think the key line in that stack trace is this:

UnknownHostException: acer.lap: Name or service not known

Let me guess, you're running this on an Acer laptop? Anyway, no one can know why that host is being looked for or not found, except you. You must have changed something in those 2 weeks.

In your shoes, I'd be grepping every config file I can find (neo4j files, /etc/hosts, and so on) for acer.lap.