我在RHEL 6.6中安装了forecastIO。但是当我用pio-start启动pio时，我得到的错误如下
$ pio-start-all
Starting Elasticsearch...
Starting HBase...
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/hadoop/hbase/util/HBaseConfTool : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:643)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:323)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:268)
Could not find the main class: org.apache.hadoop.hbase.util.HBaseConfTool. Program will exit.
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/hadoop/hbase/zookeeper/ZKServerTool : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:643)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:323)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:268)
Could not find the main class: org.apache.hadoop.hbase.zookeeper.ZKServerTool. Program will exit.
starting master, logging to /home/itdevel/PredictionIO/vendors/hbase-1.0.0/bin/../logs/hbase-itdevel-master-Puget-129416.out
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/hadoop/hbase/master/HMaster : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:643)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:323)
starting regionserver, logging to /home/itdevel/PredictionIO/vendors/hbase-1.0.0/bin/../logs/hbase-itdevel-1-regionserver-Puget-129416.out
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/hadoop/hbase/regionserver/HRegionServer : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:643)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:323)
Waiting 10 seconds for HBase to fully initialize...
Starting PredictionIO Event Server...
毕竟pio服务器没有启动。我已经为该用户创建了一个新用户并安装了java，因为系统范围的java安装是1.6。我已成功为新用户安装了Java 1.8
$java -version
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)
我已经在pio-start-all中编辑了路径，指向我的java安装，因为pio-start-all找不到jdp。我检查了我的java路径。
$echo $JAVA_HOME
/home/me/jdk1.8.0_45/bin
将pio-start-all中的路径从/home/me/jdk1.8.0_45/bin/bin更改为/home/me/jdk1.8.0_45/bin后，jdp错误已修复，但我对当前错误感到震惊。我已经在几台ubuntu机器和服务器中安装了pio，定制了pio以满足我的自定义引擎模板要求，并且它运行没有问题。 predictIO支持Redhat吗？希望这是您需要的所有错误跟踪。提前谢谢：）
答案 0 :(得分：2)
我已经解决了这个问题。在我的情况下，hbase指向错误的java安装。在JAVA_HOME更新/home/me/PredictionIO/vendors/hbase-1.0.0/bin/hbase后，hbase启动并运行，我的问题已修复。感谢您的支持：）
答案 1 :(得分：0)
当java.lang.UnsupportedClassVersionError或其运行的其他脚本仍然使用早期版本的Java时，pio-start-all肯定会抛出predictionIO，而不是root所要求的。您必须彻底检查使用的Java版本。
其中一种方法是尝试alternatives --config java
：
There are 2 choices for the alternative java (providing /usr/bin/java).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/lib/jvm/java-7-oracle/jre/bin/java 1062 auto mode
1 /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java 1061 manual mode
2 /usr/lib/jvm/java-7-oracle/jre/bin/java 1062 manual mode
Press enter to keep the current choice[*], or type selection number:
你会有这样的东西
JAVA_HOME选择最新的Java版本。
您也可以配置- (void)methodThatNeedsAClassOfSpecialTypeAsInput:(Class)inClass;
。请check the instructions for RedHat。