Building Neo4j

The instructions provided below specify the steps to build Neo4j 2.3 on Linux on the IBM z Systems for RHEL 7, SLES 12 and Ubuntu 16.04.

General Notes: i) When following the steps below, please use a standard permission user unless otherwise specified.

ii) A directory /<source_root>/ will be referred to in these instructions, this is a temporary writeable directory anywhere you'd like to place it.

1. Install the Build Dependencies

   RHEL 7.2

   sudo yum install git gcc-c++ make java-1.8.0-ibm java-1.8.0-ibm-devel graphviz maven rpm git unzip bzip2
   

   SLES 12.1

   sudo zypper install java-1.8.0-ibm java-1.8.0-ibm-devel  git gcc-c++ make graphviz rpm wget tar unzip bzip2
   

   Ubuntu 16.04

   Install IBM Java 8 Download IBM Java 8 sdk binary from IBM Java 8 and follow the instructions as per given in the link

   sudo apt-get install git gcc g++ make graphviz rpm wget maven tar unzip bzip2 npm nodejs nodejs-legacy devscripts debhelper rpm openjdk-8-jdk-headless
   

2. Download and Install Node.js (Only for RHEL 7.1 and SLES 12.1)

   cd <source_root> 
   git clone https://github.com/andrewlow/node.git
   cd node/
   ./configure
   make 
   sudo make install
   

3. Install grunt-cli (Only for SLES 12.1)

   sudo /usr/local/bin/npm install -g grunt-cli
   

4. Download maven binary executable (Only for SLES 12.1)

   cd <source_root> 
   wget https://archive.apache.org/dist/maven/maven-3/3.0.5/binaries/apache-maven-3.0.5-bin.tar.gz
   tar -zxvf apache-maven-3.0.5-bin.tar.gz
   export PATH=<source_root>/apache-maven-3.0.5/bin:$PATH
   

5. Set Enviroment variables

For RHEL 7.1 and SLES 12.1
  ```
 export MAVEN_OPTS="-Xmx512m -XX:MaxPermSize=128m"
 export JAVA_HOME=/etc/alternatives/java_sdk_1.8.0_ibm
 export PATH=$JAVA_HOME/bin:$PATH
 ```

For Ubuntu 16.04

Set JAVA_HOME to location where IBM Java 8 sdk binary is downloaded


 ```
 export MAVEN_OPTS="-Xmx1024m -XX:MaxPermSize=512m"
 export JVM_ARGS="-Xms1024m -Xmx1024m"
 export PATH=$JAVA_HOME/bin:$PATH
 ```

6. Download and unzip Neo4j source code

   cd <source_root>
   wget https://github.com/neo4j/neo4j/archive/2.3.zip 
   unzip 2.3.zip
   cd <source_root>/neo4j-2.3
   

7. Ignore testcases that fail persistently(Only for RHEL 7.1 and SLES 12.1)

```
 sed -i '26i import org.junit.Ignore;'  community/kernel/src/test/java/org/neo4j/helpers/HostnamePortTest.java
 sed -i '488i @Ignore'  community/kernel/src/test/java/org/neo4j/helpers/HostnamePortTest.java
 sed -i '50i @Ignore'  community/kernel/src/test/java/org/neo4j/qa/tooling/DumpProcessInformationTest.java
 sed -i '22i import org.junit.Ignore;'  community/kernel/src/test/java/org/neo4j/qa/tooling/DumpProcessInformationTest.java
```

8. Build the source

   To build individual jar files and execute test cases run the following command

   mvn clean install -DskipBrowser -fn
   

   To build without running test cases execute the following

   mvn clean install -DskipBrowser -DskipTests -fn
   

9. Running Neo4j

   cd <source_root>/neo4j-2.3/community/server
   mvn clean compile exec:java
   

10. Additional Notes

i) If build fails due to the error "Too many open files" try increasing the limit for number of open files.
	```
	ulimit -n 4096
	```

ii) Some of the test cases might fail due to time-out. In such a case you will have to increase the timeout and re-run the test case.
 
For example
 
 ```
 At Line 465 change SEMI_LONG_TIMEOUT_MILLIS to LONG_TIMEOUT_MILLIS in file <source_root>/neo4j2.3/community/io/src/test/java/org/neo4j/io/pagecache/PageCacheTest.java
 At Line 533 change SHORT_TIMEOUT_MILLIS to LONG_TIMEOUT_MILLIS in file <source_root>/neo4j2.3/community/io/src/test/java/org/neo4j/io/pagecache/PageCacheTest.java
 ```

**NOTE:** *After building Neo4j it will be running on `localhost:7474`.*