Unable to get Neo4j to run - neo4j

I searched for an answer to this, but was unable to find anyone else having the same problem.
This is the first time I've tried to use Neo4j.
I'm running on Windows Server 2008 R2 Standard.
I downloaded and unzipped Neo4j Community 1.8.2 for Windows.
In a command window, I switched to the bin folder and ran Neo4j.bat.
I received the following message in the command window: Unable to locate jvm. Could not find HKLM\SOFTWARE\JavaSoft\Java Runtime Environment/CurrentVersion entry in windows registry.
I verified that I have the latest JVM.
I verified that the above registry key is not present in the location shown, but I did find it at HKLM\Wow6432Node\JavaSoft\Java Runtime Environment/CurrentVersion.
How should I proceed?
Thanks for any direction!

I Fixed this problem by making a new environment variable JAVA_HOME and pointing it to my Java installation folder
C:\Program Files (x86)\Java\jre7\bin

try to set up the java PATH variable to the correct path. tutorial here:
http://java.com/en/download/help/path.xml
than, newest java are i think by 2 version newer than the original java for neo4j 1.8.2. a remind myself some problems with such versioning few months ago - i solved it by running neo4j in the newest versions of 1.9.0x

I installed JRE version 6 on my machine and this cleared the problem. (I previously had version 7 on the machine.)

Set the JAVA_HOME path in your environment variables.

Related

Neo4J Community 4.1.6 Stops after starting

I try to run Neo4J Community Edition 4.1.6 and need a hint. I have downloaded the winzip-package and unzipped it on a Windows 10 PC. I created a folder for the Neo4j files and another for the current JDK 15 package. The path for JDK has been put into system path variables. The log-flags in the neo4j conf has been set to DEBUG for HTPP. JAVA version throws the correct "15.0.2". No JAVA error message while starting.
I can start the service and the status gives back "Neo4j Service started...". After roughly 10 seconds the status shows that Neo4j has stopped without any further notice.
I can't see any logs in the \logs folder - the folder is empty.
I do not see a graphdb been created under neo4j-community-4.1.6\data\databases - the folder is empty
I cannot access the DB by localhost:7474
I do not see any error messages in the cmd windows.
I restarted the system several times but I still have the same outcome. Any hints?
Thank you
I believe we only support JDK 11 when using Neo4j 4.x.
https://neo4j.com/docs/operations-manual/current/installation/requirements/#deployment-requirements-java
Your errors may be because you are using JDK 15.
When diagnosing issues, it also helps to check the neo4j.log and debug.log files in the logs directory.

Installing Jenkins on mac o/s Catalina with Java 13 already installed

I installed java 13 prior and now need to install java 8 on my mac. As a newbie can I have 2 java versions on my machine and if yes then how can I make Jenkins installed for which java 8 is must OR is there a way to install Jenkins with java 13.
You can have multiple JRE or JDK installed in your machine (standard BE practice) but you can refer only one with your environment variable (usually the latest).
That means that **when you want to run something with java8 you will have to call it using the full path instead of just 'java' **.
I strongly recommend you to use docker and the container to run jenkins , mapping the home folder to a folder in your machine. This will give you full portability and easier upgrades / rollbacks. link
PS: welcome to SO !

neo4j 3.4.0 ubuntu: could not find or load main class org.neo4j.server.CommunityEntryPoint

I downloaded neo4j 3.4.0 Community edition on Ubuntu 16.04 and installed it.
I launched it successfully once with command ./neo4j console
But after I restarted the system, I used the same command ./neo4j console in /bin/, there is an error: could not find or load main class org.neo4j.server.CommunityEntryPoint
Anyone knows how to solve it?
the neo4j have been based on java. please check jdk path in env.
After trying many things (and no success).
I reinstalled the app by deleting ~/.configs/Neo4j-desktop and running again the Appimage file.
consider by this action you will lose license-key (and if you use Appimage version also all Db-data) so backup first if you have important data.

Jenkins running on WAS 8.5.5 with JDK 1.7

We have Jenkins installed and running on a WebSphere Application Server. We recently upgraded the server to version 8.5.5 and switched the profile to use JDK version 1.7. Doing this Jenkins Crashes the WebSphere Application Server and we cannot tell why. Any hints or suggestions on things to look at? Switching the server back to JDK 1.6 seems to work just fine, can Jenkins not run on JDK 1.7 or is it something else?
I'll assume that by crash the websphere application server you mean either a fatal error at startup or a java process crash. Those can have many causes.
Just to give some ideas, it may be related to the fact that you had somewhat customized your JDK install and forgot to re-apply those customization to your new JDK. Or that switching SDK requires you to switch command line options, or that you indeed hit an incompatible class in the stack, or that your process crash because of bad luck, etc.
So please find more information in the logs, either the corresponding stack traces in your WAS server logs or the javacores crash files.
Please also report your jenkins version.
As for JDK 7 compatibility, latest jenkins itself should be compatible, yet some plugins are not
You may also want to read this: https://stackoverflow.com/questions/17411717/jenkins-on-websphere-reports-java-lang-noclassdeffounderror-jenkins-model-jenki. Maybe you have the same issue.
If you indeed find out an incompatibility, please report an issue in jenkins issue tracker and consider updating the Jenkins Websphere wiki.

Neo4j unsupported Java runtime. use JDK 6. ubuntu 12.04

I am a new user to Neo4j usage and my OS is 32bit Ubuntu12.04. You need to start the server from Terminal by entering into the directory of Neo and then type
bin/neo4j start
which is all set and correct was until yesterday, there is some problem now and I get this
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 JDK 6.Neo4j Server already running with pid 3527
I am clueless to why this error occured suddenly.
When I run
localhost:7474
on my browser it doesn't recognise it any more.I tried to update my version following Install JDK6 on Ubuntu 12.04 link, but doesn't seem to work.Still gives the same error.
After checking for the version from terminal
java -version
I recieve
java version "1.6.0_27"
OpenJDK Runtime Environment (IcedTea6 1.12.3) (6b27-1.12.3-0ubuntu1~12.04.1)
OpenJDK Server VM (build 20.0-b12, mixed mode)
How do make localhost:7474 work on my machine?
Thanks.
For some licensing issues, Ubuntu does no longer ship Oracle/Sun JDKs directly, blame Oracle for that!
There is https://github.com/flexiondotorg/oab-java6 which automatically fetches Oracle/Sun JDKs, build local deb packages from them and puts them in a local apt repository.
Using update-java-alternatives you can set your system's default jdk.
Regarding the "open file" warning see http://docs.neo4j.org/chunked/stable/configuration-linux-notes.html#_setting_the_number_of_open_files.
We are using Ubuntu 12.04 as well. We use OpenJDK 1.6.0_24.
We ran into similar problems when we initially used Neo4j. Here are the instructions to get pass those hurdles.
You need to be able to open more files.
Edit /etc/security/limits.conf and add these two lines:
root soft nofile 40000
root hard nofile 40000
Edit /etc/pam.d/su and uncomment or add the following line:
session required pam_limits.so
Finally check that limit was changed. You might need to reboot.
ulimit -n
Returns 40000
Next in order to be able to use the webadmin on Ubuntu. You need to change one of the properties files inside neo4j. It works without this change on a Mac, I know.
Edit the neo4j-server.properties file:
cd [neo4j installation]/conf/
vim neo4-server.properties
Change this line
org.neo4j.server.webserver.address=0.0.0.0
The default is set to only listen for connections from localhost (that's why it works on a Mac). This way you can access the webadmin from anywhere. This can be a security problem though.
Hope this helps.
This seems to be a bug in neo4j about detection of running instance. By the reported pid there was some script about gnome and proxy, which after being killed (including parent lens script) let me start neo4j with OpenJDK. I guess they made it too smart.

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