hadoop最基本配置及build(ant代理)

网上的大多数都是hadoop-site.xml
20的版本，分成了3个配置文件，core-site.xml,hdfs-site.xml,mapred-site.xml，
默认的在core.jar里面，源码在
hadoop-0.20.2\src\core\core-default.xml
hadoop-0.20.2\src\mapred\mapred-default.xml
hadoop-0.20.2\src\hdfs\hdfs-default.xml
core.jar里面还打了个hadoop-metrics.properties不知道干什么的
bin.tgz是把bin目录下的东西打包了，这样就能用了？
还有两个slaves，masters也相关
5个最基本的比较重要
1.fs.default.name
2.hadoop.tmp.dir
3.mapred.job.tracker
4.dfs.name.dir
5.dfs.data.dir
6.dfs.http.address


core-site.xml中hadoop.tmp.dir为临时目录，如果hdfs-site.xml中不配置namenode和datanode的存放位置，默认就放在这个hadoop.tmp.dir中了

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
        <property>
                <name>fs.default.name</name>
                <value>hdfs://192.168.200.12:8888</value>
        </property>
        <property>
                <name>dfs.replication</name>
                <value>1</value>
        </property>
        <property>
                <name>hadoop.tmp.dir</name>
                <value>/home/Administrator/tmp</value>
        </property>
</configuration>

hdfs-site.xml中
dfs.http.address提供web页面显示的地址和端口默认是50070，ip是namenode的ip
dfs.data.dir是datanode机器上data数据存放的位置，没有则放到core-site.xml的tmp目录中
dfs.name.dir是namenode机器上name数据粗放的位置，没有则放到core-site.xml的tmp目录中
<property>
    <name>dfs.hosts.exclude</name>
    <value>conf/excludes</value>
</property>这个不知道是啥，放上报错就去掉了

<configuration>
  <property>
    <name>dfs.http.address</name>
    <value>192.168.200.12:50071</value>
  </property>
  <property>
    <name>dfs.balance.bandwidthPerSec</name>
    <value>12582912</value>
  </property>
  <property>
    <name>dfs.block.size</name>
    <value>134217728</value>
    <final>true</final>
  </property>
  <property>
    <name>dfs.data.dir</name>
    <value>/home/Administrator/data/</value>
    <final>true</final>
  </property>
  <property>
    <name>dfs.datanode.du.reserved</name>
    <value>1073741824</value>
    <final>true</final>
  </property>
  <property>
    <name>dfs.datanode.handler.count</name>
    <value>10</value>
    <final>true</final>
  </property>
  <property>
    <name>dfs.name.dir</name>
    <value>/home/Administrator/name/</value>
    <final>true</final>
  </property>
  <property>
    <name>dfs.namenode.handler.count</name>
    <value>64</value>
    <final>true</final>
  </property>
  <property>
    <name>dfs.permissions</name>
    <value>True</value>
    <final>true</final>
  </property>
  <property>
    <name>dfs.replication</name>
    <value>3</value>
  </property>
</configuration>

mapred-site.xml内容为，mapred.job.tracker为jobtracker的ip和端口

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
        <property>
                <name>mapred.job.tracker</name>
                <value>192.168.200.12:9999</value>
        </property>
</configuration>

常见问题：
一。防火墙在学习阶段就全关了吧，iptables -L查看 ，网络问题1.互信；2.iptables
二。如果调用./bin/hadoop namenode -format前最好清空/tmp目录和基本配置中的目录（否则有可能运行后dfsadmin -report显示全0）
三。logs很重要，没事就看看，job那个总出问题


看到hadoop中用了ivy，下了个apache-ivy-2.2.0
需要把ivy-2.2.0.jar放到ant的lib目录，比如D:\oracle\apache-ant-1.8.1\lib
可以用apache-ivy-2.2.0\src\example\hello-ivy下ant看ivy是否好使
参考http://www.iteye.com/wiki/ivy/1945-ivy-tutorials-quick-start

----------------★★---------------
因为有代理，所以ant配合ivy有问题
上网找的http://liu-hliang.iteye.com/blog/456664
改了之后不好使啊
又找到https://issues.apache.org/jira/browse/IVY-529
拿apache-ivy-2.2.0\src\example\hello-ivy>apache-ivy-2.2.0\src\example\hello-ivy为例子
在<ivy:retrieve/>前加入proxy，并加depends="proxy"解决

<target name="proxy">
	<property name="proxy.host" value="代理的ip地址"/>
	<property name="proxy.port" value="8080"/>
	<input message="Please enter proxy username" addproperty="proxy.user" />
	<input message="Please enter proxy password - NOTE: CLEAR TEXT" addproperty="proxy.pass"/>
	<setproxy proxyhost="${proxy.host}" proxyport="${proxy.port}" proxyuser="${proxy.user}" proxypassword="${proxy.pass}"/>
</target>
<target name="resolve" depends="proxy" description="--> retreive dependencies with ivy">
	<ivy:retrieve/>
</target>

在hadoop-0.20.2\build.xml中
找到<target name="ivy-download" ...
修改为

<target name="proxy">
	<property name="proxy.host" value="代理的ip地址"/>
	<property name="proxy.port" value="8080"/>
	<input message="Please enter proxy username" addproperty="proxy.user" />
	<input message="Please enter proxy password - NOTE: CLEAR TEXT" addproperty="proxy.pass"/>
	<setproxy proxyhost="${proxy.host}" proxyport="${proxy.port}" proxyuser="${proxy.user}" proxypassword="${proxy.pass}"/>
</target>
<target name="ivy-download" depends="proxy" description="To download ivy" unless="offline">
    <get src="${ivy_repo_url}" dest="${ivy.jar}" usetimestamp="true"/>
</target>

---------------★★------------------
ant之后
\hadoop-0.20.2\src\hdfs，hadoop-0.20.2\src\mapred，hadoop-0.20.2\src\core下的所有代码会变成hadoop-0.20.2\build\hadoop-0.20.3-dev-core.jar替换原来的hadoop-0.20.2-core.jar即可
如果用eclipse创建工程，build path--source--Link Source选上面三个目录(如果看例子可以引个examples目录)，lib引用\hadoop-0.20.2\lib下的所有jar和外面的除了core.jar，还需要个ant.jar,
-------------★★----------------------
hadoop还用到了这个东西The JR Concurrent Programming Language
http://www.cs.ucdavis.edu/~olsson/research/jr/
安装http://www.cs.ucdavis.edu/~olsson/research/jr/versions/2.00602/install.html
这有个helloworld
http://developer.51cto.com/art/201006/208197.htm
尝试一下jr windows上跑需要perl，放redhat5上测试，把jr.zip解压到/usr/local/hadoop/
设置环境变量

export CLASSPATH=$CLASSPATH:/usr/local/hadoop/jr/classes/jrt.jar:/usr/local/hadoop/jr/classes/jrx.jar:.
export JR_HOME=/usr/local/hadoop/jr
export PATH=$PATH:/usr/local/hadoop/jr/bin:/usr/local/hadoop/jr/jrv

cd /usr/local/hadoop/jr/vsuite

[root@122226 vsuite]# jrv quick
Starting JRV
JR_HOME= /usr/local/hadoop/jr
JRC=     perl "/usr/local/hadoop/jr/bin/jrc"
JRRUN=   perl "/usr/local/hadoop/jr/bin/jrrun"
JAVAC=   "/usr/java/jdk1.6.0_23/bin/javac"
JAVA=    "/usr/java/jdk1.6.0_23/bin/java"
ccr2jr=  perl "/usr/local/hadoop/jr/bin/ccr2jr"
csp2jr=  perl "/usr/local/hadoop/jr/bin/csp2jr"
m2jr=    perl "/usr/local/hadoop/jr/bin/m2jr"
WHICH=   /usr/bin/which
CMP=     perl "/usr/local/hadoop/jr/bin/cmp.pl"
GREP=    perl "/usr/local/hadoop/jr/bin/grep.pl"
SORT=    perl "/usr/local/hadoop/jr/bin/sort.pl"
TAIL=    perl "/usr/local/hadoop/jr/bin/tail.pl"
jr compiler version "2.00602 (Mon Jun 1 10:59:20 PDT 2009)"
jr rts      version "2.00602 (Mon Jun 1 10:59:25 PDT 2009)"
HOST= 122226
Start Directory= /usr/local/hadoop/jr/vsuite
JR.JRT = /usr/local/hadoop/jr/classes/jrt.jar 
  -rw-r--r--   1 root     root       2090324 Jun  2  2009 /usr/local/hadoop/jr/classes/jrt.jar
JR.JRX = /usr/local/hadoop/jr/classes/jrx.jar 
  -rw-r--r--   1 root     root        227198 Jun  2  2009 /usr/local/hadoop/jr/classes/jrx.jar
Operating System= 
original CLASSPATH= /usr/java/jdk1.6.0_23/lib:/usr/local/hadoop/jr/classes/jrt.jar:/usr/local/hadoop/jr/classes/jrx.jar:.
jrv sets CLASSPATH= .:/usr/local/hadoop/jr/classes/jrt.jar:/usr/local/hadoop/jr/classes/jrx.jar
DATE= Thu Oct 14 20:14:21 2010
quick/baby:
    expected 0, got 1 from jrrun <null
quick/fact_2:
    expected 0, got 1 from jrrun <null
quick/misc_invocation_count_st_by_0:
    expected 0, got 1 from jrrun <null
DATE= Thu Oct 14 20:14:34 2010
Elapsed time (hh:mm:ss)= 00:00:13
[root@122226 vsuite]# pwd
/usr/local/hadoop/jr/vsuite