Monday, June 12, 2017

JavaOptions to pass to Spark driver and Snappy native library to pass to Java program

/usr/hdp

JavaOptions to pass to Spark driver:  Here is a Hortonworks example:

JavaOptions=-Dhdp.version=2.4.2.0-258 -Dspark.driver.extraJavaOptions=-Dhdp.version=2.4.2.0-258

Snappy native library to pass to Java program.  Here is an example for CDH5:

1. Copy /opt/cloudera/parcels/CDH-5.5.1-1.cdh5.5.1.p0.11/lib/hadoop/lib/native/* to your java program machine and put them to any directory such as /opt/native
2. Run your Java program with following Java options:
JavaOptions=-Djava.library.path=/opt/native

Wednesday, May 10, 2017

Search anything from a bugzilla bug given a range of bug numbers

[root@centos my-data-set]# for ((i=13420;i<13500;i++)); do echo $i >> /tmp/search_result.txt; curl http://192.168.5.105/bugzilla/show_bug.cgi?id=$i | grep "passed to DE constructor may be null" >> /tmp/search_result.txt; done;

Tuesday, May 2, 2017

A simple way to clone 10,000 files to cluster


# Generate 10,000 files from one seed and put them into 100 subdirectories

[hdfs@cdh1 tmp]$ for((i=1;i<=100;i++));do mkdir -p 10000files/F$i; for((j=1;j<=100;j++));do echo $i-$j; cp 1000line.csv 10000files/F$i/$i-$j.csv;done;done;

# Move them to cluster.  One sub-directory at one time.

[hdfs@cdh1 tmp]$ for((i=1;i<=100;i++));do echo $i; hadoop fs -mkdir /JohnZ/10000files/F$i; hadoop fs -copyFromLocal 10000files/F$i/* /JohnZ/10000files/F$i/.;done;

Tuesday, April 25, 2017

Prepare Python machine learning environment on Centos 6.6 to train data

# major points: 1. Has to use Python 2.7, not 2.6.  But Centos 6.6 uses Python 2.6 for OS so upgrading to 2.7 is not a solution.  Need to install Python 2.7 in addition to 2.6.  2. Use setuptool to install pip and use pip to install rest.

# Download dependency files
yum groupinstall "Development tools"
yum -y install gcc gcc-c++ numpy python-devel scipy
yum install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel

# Compile and install Python 2.7.13
wget https://www.python.org/ftp/python/2.7.13/Python-2.7.13.tgz
tar xzf Python-2.7.13.tgz
cd Python-2.7.13
./configure
# make altinstall is used to prevent replacing the default python binary file /usr/bin/python.
make altinstall

# Download setuptools using wget:
wget --no-check-certificate https://pypi.python.org/packages/source/s/setuptools/setuptools-1.4.2.tar.gz
# Extract the files from the archive:
tar -xvf setuptools-1.4.2.tar.gz
# Enter the extracted directory:
cd setuptools-1.4.2

# Install setuptools using the Python we've installed (2.7.6)
# python2.7 setup.py install
/opt/python-2.7.13/Python-2.7.13/python ./setup.py install

# install pip
curl https://raw.githubusercontent.com/pypa/pip/master/contrib/get-pip.py | python2.7 -

or (following works for me)

[root@centos python-2.7.13]# /opt/python-2.7.13/Python-2.7.13/python ./setuptools/setuptools-1.4.2/easy_install.py pip

# install numpy
[root@centos python-2.7.13]# /opt/python-2.7.13/Python-2.7.13/python -m pip install numpy

# Install SciPy
[root@centos python-2.7.13]# /opt/python-2.7.13/Python-2.7.13/python -m pip install scipy

# Install Scikit
[root@centos python-2.7.13]# /opt/python-2.7.13/Python-2.7.13/python -m pip install scikit-learn

# Install nltk
[root@centos python-2.7.13]# /opt/python-2.7.13/Python-2.7.13/python -m pip install nltk

# Download nltk data (will be stored under /root/nltk_data)
[root@centos SVM]# /opt/python-2.7.13/Python-2.7.13/python -m nltk.downloader all

Tuesday, March 21, 2017

Mapreduce logs have weird behavior on HDP 2.3 Tez

When launching map reduce on Tez, we will not see our logs from HDP UI.  Click ‘History’ and got nothing although we can see Hadoop system logs.

But if you use following command, you will get map reduce logs from system stdout:

sudo -u hdfs yarn logs -applicationId application_1490133530166_0002

But the format is modified:

2017-03-21 15:04:24,708 [ERROR] [TezChild] |common.FindAndExitMapRunner|: caught throwable when run mapper: java.lang.UnsupportedOperationException: Input only available on map

The ‘source’ is changed to ‘TezChild’. 
Our package name is truncated to only have last part so our Java class name is not full name anymore. On this example, “com.xxx.hadoop.common.FindAndExitMapRunner” is changed to “common.FindAndExitMapRunner”

          To be compare with normal log (i.e. without Tez), here is what we should have from map reduce log (you see full package name and class name):


      2017-03-20 14:29:54,778 INFO [main] com.xxx.hadoop.common.ColumnMap: Columnar Mapper

Important! Important! Important! ---->
To review the log, you have to use exact user who launched such application: sudo -u hdfs"
Otherwise, you will see following error:
"Log aggregation has not completed or is not enabled."

Monday, March 6, 2017

Additional jar files when running Spark under Hadoop YARN mode (CDH 5.10.0 with Scala 2.10 and Spark 1.6.0)



lrwxrwxrwx 1 root root     91 Feb 23 15:02 spark-core_2.10-1.6.0-cdh5.10.0.jar -> /opt/cloudera/parcels/CDH-5.10.0-1.cdh5.10.0.p0.41/jars/spark-core_2.10-1.6.0-cdh5.10.0.jar
lrwxrwxrwx 1 root root     80 Feb 23 15:15 scala-library-2.10.6.jar -> /opt/cloudera/parcels/CDH-5.10.0-1.cdh5.10.0.p0.41/jars/scala-library-2.10.6.jar
lrwxrwxrwx 1 root root     37 Mar  6 14:06 commons-lang3-3.3.2.jar -> ../../../jars/commons-lang3-3.3.2.jar
-rw-r--r-- 1 root root 185676 Mar  6 14:11 typesafe-config-2.10.1.jar
lrwxrwxrwx 1 root root     55 Mar  6 14:26 akka-actor_2.10-2.2.3-shaded-protobuf.jar -> ../../../jars/akka-actor_2.10-2.2.3-shaded-protobuf.jar
lrwxrwxrwx 1 root root     56 Mar  6 14:28 akka-remote_2.10-2.2.3-shaded-protobuf.jar -> ../../../jars/akka-remote_2.10-2.2.3-shaded-protobuf.jar
lrwxrwxrwx 1 root root     55 Mar  6 14:29 akka-slf4j_2.10-2.2.3-shaded-protobuf.jar -> ../../../jars/akka-slf4j_2.10-2.2.3-shaded-protobuf.jar
lrwxrwxrwx 1 root root     70 Mar  6 14:40 spark-assembly-1.6.0-cdh5.10.0-hadoop2.6.0-cdh5.10.0.jar -> ../../../jars/spark-assembly-1.6.0-cdh5.10.0-hadoop2.6.0-cdh5.10.0.jar
[root@john2 lib]# pwd
/opt/cloudera/parcels/CDH-5.10.0-1.cdh5.10.0.p0.41/lib/hadoop-yarn/lib