解决Hadoop0.21.0 HDFS/MapReduce编译错误(ivy-resolve-common does not find hadoop-commo)
最近老大安排，要跟踪HDFS ConcatenateFile的前提条件；于是尝试用ant/ivy编译了一下hdfs，提示ivy找不到hadoop-common组件；于是又编译了一下mapreduce，提示ivy找不到hadoop-comm/hadoop-hdfs；编译hadoop-common，提示编译成功；在编译mapreduce错误如下：
ivy-resolve-common:
[ivy:resolve]
[ivy:resolve] :: problems summary ::
[ivy:resolve] :::: WARNINGS
[ivy:resolve] module not found: org.apache.hadoop#hadoop-common;0.21.0
[ivy:resolve] ==== apache-snapshot: tried
[ivy:resolve] https://repository.apache.org/content/repositories/snapshots/org/apache/hadoop/hadoop-common/0.21.0/hadoop-common-0.21.0.pom
[ivy:resolve] -- artifact org.apache.hadoop#hadoop-common;0.21.0!hadoop-common.jar:
[ivy:resolve] https://repository.apache.org/content/repositories/snapshots/org/apache/hadoop/hadoop-common/0.21.0/hadoop-common-0.21.0.jar
[ivy:resolve] ==== maven2: tried
[ivy:resolve] http://repo1.maven.org/maven2/org/apache/hadoop/hadoop-common/0.21.0/hadoop-common-0.21.0.pom
[ivy:resolve] -- artifact org.apache.hadoop#hadoop-common;0.21.0!hadoop-common.jar:
[ivy:resolve] http://repo1.maven.org/maven2/org/apache/hadoop/hadoop-common/0.21.0/hadoop-common-0.21.0.jar
[ivy:resolve] module not found: org.apache.hadoop#hadoop-common-test;0.21.0
[ivy:resolve] ==== apache-snapshot: tried
[ivy:resolve] https://repository.apache.org/content/repositories/snapshots/org/apache/hadoop/hadoop-common-test/0.21.0/hadoop-common-test-0.21.0.pom
[ivy:resolve] -- artifact org.apache.hadoop#hadoop-common-test;0.21.0!hadoop-common-test.jar:
[ivy:resolve] https://repository.apache.org/content/repositories/snapshots/org/apache/hadoop/hadoop-common-test/0.21.0/hadoop-common-test-0.21.0.jar
[ivy:resolve] ==== maven2: tried
[ivy:resolve] http://repo1.maven.org/maven2/org/apache/hadoop/hadoop-common-test/0.21.0/hadoop-common-test-0.21.0.pom
[ivy:resolve] -- artifact org.apache.hadoop#hadoop-common-test;0.21.0!hadoop-common-test.jar:
[ivy:resolve] http://repo1.maven.org/maven2/org/apache/hadoop/hadoop-common-test/0.21.0/hadoop-common-test-0.21.0.jar
[ivy:resolve] module not found: org.apache.hadoop#hadoop-hdfs;0.21.0
[ivy:resolve] ==== apache-snapshot: tried
[ivy:resolve] https://repository.apache.org/content/repositories/snapshots/org/apache/hadoop/hadoop-hdfs/0.21.0/hadoop-hdfs-0.21.0.pom
[ivy:resolve] -- artifact org.apache.hadoop#hadoop-hdfs;0.21.0!hadoop-hdfs.jar:
[ivy:resolve] https://repository.apache.org/content/repositories/snapshots/org/apache/hadoop/hadoop-hdfs/0.21.0/hadoop-hdfs-0.21.0.jar
[ivy:resolve] ==== maven2: tried
[ivy:resolve] http://repo1.maven.org/maven2/org/apache/hadoop/hadoop-hdfs/0.21.0/hadoop-hdfs-0.21.0.pom
[ivy:resolve] -- artifact org.apache.hadoop#hadoop-hdfs;0.21.0!hadoop-hdfs.jar:
[ivy:resolve] http://repo1.maven.org/maven2/org/apache/hadoop/hadoop-hdfs/0.21.0/hadoop-hdfs-0.21.0.jar
[ivy:resolve] ::::::::::::::::::::::::::::::::::::::::::::::
[ivy:resolve] :: UNRESOLVED DEPENDENCIES ::
[ivy:resolve] ::::::::::::::::::::::::::::::::::::::::::::::
[ivy:resolve] :: org.apache.hadoop#hadoop-common;0.21.0: not found
[ivy:resolve] :: org.apache.hadoop#hadoop-common-test;0.21.0: not found
[ivy:resolve] :: org.apache.hadoop#hadoop-hdfs;0.21.0: not found
[ivy:resolve] ::::::::::::::::::::::::::::::::::::::::::::::
[ivy:resolve]
[ivy:resolve] :: USE VERBOSE OR DEBUG MESSAGE LEVEL FOR MORE DETAILS
BUILD FAILED
/opt/hadoop-0.21.0/mapred/build.xml:1861: impossible to resolve dependencies:
resolve failed - see output for details
通过Google，发现原来这是Apache-Hadoop的BUG:
https://issues.apache.org/jira/browse/HDFS-1519(hdfs ivy配置bug)
主要原因是ivy配置问题：
hdfs的ivy在配置关联类库hadoop-common时候位置指定错误，具体修改如下：
hdfs/ivy.xml
<dependency org="org.apache.hadoop" name="hadoop-common"
----- rev="${hadoop-common.version}"
+++ rev="${hadoop-common.version}-SNAPSHOT"
conf="common->default"/>
hdfs/src/contrib/hdfsproxy/ivy.xml
<dependency org="org.apache.hadoop"
name="hadoop-common"
---- rev="${hadoop-common.version}"
+++ rev="${hadoop-common.version}-SNAPSHOT"
conf="common->default"/>
<dependency org="org.apache.hadoop"
name="hadoop-common-test"
--- rev="${hadoop-common.version}"
+++ rev="${hadoop-common.version}-SNAPSHOT"
conf="common->default"/>
hdfs/src/contrib/thriftfs/ivy.xml
<dependency org="org.apache.hadoop"
name="hadoop-common"
--- rev="${hadoop-common.version}"
+++ rev="${hadoop-common.version}-SNAPSHOT"
conf="common->default"/>
mapreduce的ivy在配置关联类库hadoop-common/hadoop-dfs时候位置指定错误，修改方法与hdfs类似：
1.修改mapreduce project里的ivy.xml(多个)
在eclipse里search file(ivy.xml):
(1)rev="${hadoop-common.version}" replace rev="${hadoop-common.version}-SNAPSHOT"
(2)rev="${hadoop-hdfs.version}" replace rev="${hadoop-hdfs.version}-SNAPSHOT"
2.修改buid.xml
<unzip
-- -- src="${common.ivy.lib.dir}/hadoop-hdfs-${hadoop-hdfs.version}.jar"
+++ src="${common.ivy.lib.dir}/hadoop-hdfs-${hadoop-hdfs.version}-SNAPSHOT.jar"
dest="${build.dir}">