问题
I'm trying to install nutch 1.12 on a windows 2012 server based on cygwin64 2.874. Due to limited skills with java and linux I followed the step by step introduction at https://wiki.apache.org/nutch/NutchTutorial#Step-by-Step:_Seeding_the_crawldb_with_a_list_of_URLs. The command
bin/nutch inject crawl/crawldb urls
throws an error because winutils.exe couldn't be found. Here is the hadoop log:
2016-07-01 09:22:25,660 ERROR util.Shell - Failed to locate the winutils binary in the hadoop binary path
java.io.IOException: Could not locate executable null\bin\winutils.exe in the Hadoop binaries.
at org.apache.hadoop.util.Shell.getQualifiedBinPath(Shell.java:318)
at org.apache.hadoop.util.Shell.getWinUtilsPath(Shell.java:333)
at org.apache.hadoop.util.Shell.<clinit>(Shell.java:326)
at org.apache.hadoop.util.GenericOptionsParser.preProcessForWindows(GenericOptionsParser.java:432)
at org.apache.hadoop.util.GenericOptionsParser.parseGeneralOptions(GenericOptionsParser.java:478)
at org.apache.hadoop.util.GenericOptionsParser.<init>(GenericOptionsParser.java:170)
at org.apache.hadoop.util.GenericOptionsParser.<init>(GenericOptionsParser.java:153)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:64)
at org.apache.nutch.crawl.Injector.main(Injector.java:441)
2016-07-01 09:22:25,832 INFO crawl.Injector - Injector: starting at 2016-07-01 09:22:25
2016-07-01 09:22:25,832 INFO crawl.Injector - Injector: crawlDb: crawl/crawldb
2016-07-01 09:22:25,832 INFO crawl.Injector - Injector: urlDir: urls
2016-07-01 09:22:25,832 INFO crawl.Injector - Injector: Converting injected urls to crawl db entries.
2016-07-01 09:22:26,050 WARN util.NativeCodeLoader - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2016-07-01 09:22:26,394 ERROR crawl.Injector - Injector: java.lang.NullPointerException
at java.lang.ProcessBuilder.start(Unknown Source)
at org.apache.hadoop.util.Shell.runCommand(Shell.java:445)
at org.apache.hadoop.util.Shell.run(Shell.java:418)
at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:650)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:739)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:722)
at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:633)
at org.apache.hadoop.fs.FilterFileSystem.setPermission(FilterFileSystem.java:467)
at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:456)
at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:424)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:906)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:887)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:849)
at org.apache.hadoop.fs.FileSystem.createNewFile(FileSystem.java:1149)
at org.apache.nutch.util.LockUtil.createLockFile(LockUtil.java:58)
at org.apache.nutch.crawl.Injector.inject(Injector.java:357)
at org.apache.nutch.crawl.Injector.run(Injector.java:467)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.nutch.crawl.Injector.main(Injector.java:441)
I found several hints here and downloaded winutils.exe from https://codeload.github.com/srccodes/hadoop-common-2.2.0-bin/zip/master. I unpacked the folder on the server and set the environment variable NUTCH_OPTS=-Dhadoop.home.dir=[winutils_folder]. Now the winutils error is gone but the nutch call fails with a different error:
2016-07-01 13:24:09,697 INFO crawl.Injector - Injector: starting at 2016-07-01 13:24:09
2016-07-01 13:24:09,697 INFO crawl.Injector - Injector: crawlDb: crawl/crawldb
2016-07-01 13:24:09,697 INFO crawl.Injector - Injector: urlDir: urls
2016-07-01 13:24:09,697 INFO crawl.Injector - Injector: Converting injected urls to crawl db entries.
2016-07-01 13:24:09,885 WARN util.NativeCodeLoader - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2016-07-01 13:24:10,307 ERROR crawl.Injector - Injector: org.apache.hadoop.util.Shell$ExitCodeException:
at org.apache.hadoop.util.Shell.runCommand(Shell.java:505)
at org.apache.hadoop.util.Shell.run(Shell.java:418)
at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:650)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:739)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:722)
at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:633)
at org.apache.hadoop.fs.FilterFileSystem.setPermission(FilterFileSystem.java:467)
at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:456)
at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:424)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:906)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:887)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:849)
at org.apache.hadoop.fs.FileSystem.createNewFile(FileSystem.java:1149)
at org.apache.nutch.util.LockUtil.createLockFile(LockUtil.java:58)
at org.apache.nutch.crawl.Injector.inject(Injector.java:357)
at org.apache.nutch.crawl.Injector.run(Injector.java:467)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.nutch.crawl.Injector.main(Injector.java:441)
After updating .bashrc (added the following lines) the hadoop log only shows warnings.
export JAVA_HOME='/cygdrive/c/Program Files/Java/jre1.8.0_92'
export PATH=$PATH:$JAVA_HOME/bin
But nutch still throws an error:
Injector: starting at 2016-07-01 17:25:22
Injector: crawlDb: crawl/crawldb
Injector: urlDir: urls
Injector: Converting injected urls to crawl db entries.
Exception in thread "main" java.lang.UnsatisfiedLinkError: org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z
at org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Native Method)
at org.apache.hadoop.io.nativeio.NativeIO$Windows.access(NativeIO.java:570)
at org.apache.hadoop.fs.FileUtil.canRead(FileUtil.java:977)
at org.apache.hadoop.util.DiskChecker.checkAccessByFileMethods(DiskChecker.java:173)
at org.apache.hadoop.util.DiskChecker.checkDirAccess(DiskChecker.java:160)
at org.apache.hadoop.util.DiskChecker.checkDir(DiskChecker.java:94)
at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.confChanged(LocalDirAllocator.java:285)
at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:344)
at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150)
at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131)
at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:115)
at org.apache.hadoop.mapred.LocalDistributedCacheManager.setup(LocalDistributedCacheManager.java:131)
at org.apache.hadoop.mapred.LocalJobRunner$Job.<init>(LocalJobRunner.java:163)
at org.apache.hadoop.mapred.LocalJobRunner.submitJob(LocalJobRunner.java:731)
at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:432)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1285)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1282)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Unknown Source)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1548)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:1282)
at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1303)
at org.apache.nutch.crawl.Injector.inject(Injector.java:376)
at org.apache.nutch.crawl.Injector.run(Injector.java:467)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.nutch.crawl.Injector.main(Injector.java:441)
I need hints what may be wrong configured or isn't it possible to run nutch with windows/cygwin?
回答1:
I spent about a week to find out what causes UnsatisfiedLinkError.
I think the main reason is that java cannot find its dependencies.
I solved this problem by commenting out some scripts in nutch file.
(located in {nutch_folder}\runtime\local\bin)
To be more specific, I commented out scripts setting -Djava.library.path.
I made java program to use original java.library.path instead.
Use below command to check original java.libary.path on your environment.
java -XshowSettings:properties -version
It will show many properties including java.library.path = ...
comment out below code:
# setup 'java.library.path' for native-hadoop code if necessary
# used only in local mode
JAVA_LIBRARY_PATH=''
if [ -d "${NUTCH_HOME}/lib/native" ]; then
JAVA_PLATFORM=`"${JAVA}" -classpath "$CLASSPATH" org.apache.hadoop.util.PlatformName | sed -e 's/ /_/g'`
if [ -d "${NUTCH_HOME}/lib/native" ]; then
if [ "x$JAVA_LIBRARY_PATH" != "x" ]; then
JAVA_LIBRARY_PATH="${JAVA_LIBRARY_PATH}:${NUTCH_HOME}/lib/native/${JAVA_PLATFORM}"
else
JAVA_LIBRARY_PATH="${NUTCH_HOME}/lib/native/${JAVA_PLATFORM}"
fi
fi
fi
if [ $cygwin = true -a "X${JAVA_LIBRARY_PATH}" != "X" ]; then
JAVA_LIBRARY_PATH="`cygpath -p -w "$JAVA_LIBRARY_PATH"`"
fi
also comment out below code:
if [ "x$JAVA_LIBRARY_PATH" != "x" ]; then
NUTCH_OPTS=("${NUTCH_OPTS[@]}" -Djava.library.path="$JAVA_LIBRARY_PATH")
fi
by doing this NUTCH_OPTS will not contain -Djava.library.path, so java will use original setting.
nutch command is running like in (pseudo)-distributed mode. I don't know why exactly.
Hope this helps.
回答2:
No need to comment anything in the nutch script. If you have placed the hadoop.dll and winutils.exe under a bin folder of your HADOOP_HOME make sure that the path to bin folder is also appended to your windows PATH env varable.
来源：https://stackoverflow.com/questions/38147431/nutch-on-windows-error-crawl-injector