Friday, October 21, 2011

Experience with Matlab's TMG

I have been playing with Matlab's TMG and here are my 2 cents from experience with the software

Pros: Easy to install, Easy to index a corpus and queries.
Cons: Proprietary code. Impossible to contribute modify or fix bugs in the code. Is not maintained well. Does not have any discussion forum where users and developers can communicate. Last citation was 2009

I was unable to even run some basic retrieval tasks due to bug in the code. norm2 does not work for sparse arrays and one needs to replace norm2 with normset, and I was unable to make the change because the code is protected and proprietary.

Thursday, July 14, 2011

Counter-intuitive results

I have been researching how restricting the vocabulary of a dataset affects retrieval results and I am seeing some really counter-intuitive results

This the format of the experiment:

I create a vocabulary using some percentage of the documents not all. The percentages I used was (10,20,30,40,50,60,70,80,90) and then performed retrieval and calculated MAP

There were two key observations that I found  interesting.

1) For software corpora, I found that even with 10% of documents, 45% of the original vocabulary was built. This means that software vocabulary tends to have a more uniform distribution of the terms/identifiers/variable-names across source files
2) With the Vector Space Model with tf-idf weighting, I found that with 10-30% of documents used to create the vocabulary (or dictionary) I got better performance as compared to original vocabulary. The only explanation I have for this result is that, some words are more important for retrieval than others. I do need to mention that the original vocabulary itself is a pruned version of the original raw vocabulary obtained by removing sparse terms in the document-term Matrix.


Tuesday, June 28, 2011

Back to Square one

I am lost here every time I come here. Its a maze and I cannot find a way out. Even if I do make a way out, I am unclear as to what happened back there.

I am now making a step by step plan on how I can tackle this gigantic problem I am facing.

What am I trying to do?
My main goal is to try and do distributed topic modeling using R on Amazon EMR.

The steps I need to take now to solve this problem

1) Install hadoop and run a single node hadoop cluster and basic mapper reducer scripts on it
2) Run R on hadoop using hive and try to do the same via R
3) Run distributed tm on R
4) Run Mahout on single node hadoop
5) Using hive try to convert data types between R and mahout

Do all of the above on the amazon emr cluster using its ruby client.

Loads of painful nights ahead, but hopefully rewarding too

Tuesday, May 10, 2011

The recovery from crash entry

I am penning down personal notes on how to recover from crash

setup auto rsync with cron tab and update everyday
Back up your scripts, that you used to fix issues with your computer. In my case

Sound issue fixing
 cheese webcam
gtalk video voice chat
auto ssh-passwordless login into most commonly used servers
svn for code
pdf annontator
eclipse IDE
perl, python, plugins for Eclipse IDE

Here is the link to the page on how to partition 

Tuesday, May 3, 2011

password-less ssh into multiple machines from a single machine

I have been trying to get password-less ssh login into two or more machines (servers). The tutorials that are available online are great but they do not cover one corner case.

The default private and public key are named id_rsa, so every time you attempt a password-less login, ssh looks for id_rsa private file and matches it with the ~/.ssh/authorized_keys . However, what happens when you want to login to multiple servers

1) put the same public key in all servers where you want password-less login
2) create a separate private-public key pair and use ssh-agent to add the private keys
for each public-private key pair (new_rsa and do the following

localuser@localmahine$scp ~/.ssh/ username@server:~/.ssh/ # copy to .ssh folder
localuser@localmahine$ssh username@server # login to the server
username@server$cat ~/.ssh/ >> ~/.ssh/authorized_keys  # append to existing aurhotized keys

localuser@localmahine$ssh-agent bash
localuser@localmahine$ssh-add ~/.ssh/new_rsa

Tuesday, April 26, 2011

R tips and tricks

1) R.setenv() and R.getenv() can help you set environment variables for packages like rJava from within R.

print(Sys.setenv(R_TEST="testit", "A+C"=123))  # `A+C` could also be used
Sys.unsetenv("R_TEST")  # may warn and not succeed

2) R has no bound checking for lists or arrays, so one has to take care of it manually. For example:

arr[length(arr)+1] simply yeilds a NA
This becomes an issue in running for loops

for (i in (2:length(arr))) will not work out well if length(arr)<2

Friday, April 22, 2011

Using gensim... the basics

Thanks to the extremely active community of gensim, I have made way through some basic commands in python and gensim

I have a directory of text documents that I want indexed and topic
model built on
Each file in the directory is a document containing plain text.
Lets assume that the text is pruned for stopwords and special
characters etc.
I will need to write custom over-rides of the get_text() function of textcorpus and this is how I achieve it

def split_line(text):
    words = text.split()
    out = []
    for word in words:
    return out

import gensim
class MyCorpus(gensim.corpora.TextCorpus):
    def get_texts(self):
        for filename in self.input:
            yield split_line(open(filename).read())

if b is a list of files then

myCorpus = MyCorpus(b)

will create the corpus and

myCorpus.dictionary has all the unique words

myCorpus.dictionary.token2id.items()  gives the word-id pairs

myCorpus.dictionary.token2id.keys() gives the unique words

myCorpus.dictionary.token2id.values() gives the corresponding ids

One can save it in Matrix Market format using the following command

`gensim.corpora.MmCorpus.serialize('', myCorpus)`

In order to add new documents, just extend the list b to include the file names and redo all of the above. Internally the implementation takes off from where it left

I still need to work on indexing, lsi based and lda based modeling of the corpus using the above framework and I am hoping to add more posts as I learn about them.

Wednesday, April 13, 2011

Hadoop streaming blues

I am facing trouble using hadoop streaming in order to  solve a simple nearest neighbor problem.

Input data is in the following format

key is the imageid for which nearest neighbor will be computed
the value is 100 dimensional  vector of floating point values separated by space or tab

The mapper reads in the query (the query is a 100 dimensional vector) and each line of the input and outputs a
where key2 is a floating point value indicating the distance, and value2 is the imageid

The number of reducers is set to 1. And the reducer is set to be the identity reducer.

I tried to use the following command

bin/hadoop jar ./mapred/contrib/streaming/
hadoop-0.21.0-streaming.jar -files /home/shivani/research/toolkit/mathouttuts/nearestneighbor/code/IdentityMapper.R#file1 -input datain/comparedata -output dataout5 -mapper file1 -reducer org.apache.hadoop.mapred.lib.IdentityReducer -verbose

This is the output stream is as below. The failure is in the mapper itself, more specifically the TEXTOUTPUTREADER. I am not sure how to fix this. The logs are attached below:

11/04/13 13:22:15 INFO security.Groups: Group mapping; cacheTimeout=300000
11/04/13 13:22:15 WARN conf.Configuration: mapred.used.genericoptionsparser is deprecated. Instead, use mapreduce.client.genericoptionsparser.used
STREAM: addTaskEnvironment=
STREAM: shippedCanonFiles_=[]
STREAM: shipped: false /usr/local/hadoop/file1
STREAM: cmd=file1
STREAM: cmd=null
STREAM: shipped: false /usr/local/hadoop/org.apache.hadoop.mapred.lib.IdentityReducer
STREAM: cmd=org.apache.hadoop.mapred.lib.IdentityReducer
11/04/13 13:22:15 WARN conf.Configuration: is deprecated. Instead, use
STREAM: Found runtime classes in: /usr/local/hadoop-hadoop/hadoop-unjar7358684340334149267/
packageJobJar: [/usr/local/hadoop-hadoop/hadoop-unjar7358684340334149267/] [] /tmp/streamjob2923554781371902680.jar tmpDir=null
JarBuilder.addNamedStream META-INF/MANIFEST.MF
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesWritable.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesRecordOutput$1.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesWritableOutput$1.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesRecordOutput.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesOutput.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesOutput$1.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesInput$1.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesWritableOutput.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesRecordInput$TypedBytesIndex.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesWritableInput$2.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesWritableInput.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesRecordInput.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/Type.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesWritableInput$1.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesRecordInput$1.class
JarBuilder.addNamedStream org/apache/hadoop/typedbytes/TypedBytesInput.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/StreamUtil$TaskId.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/PipeMapRed$1.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/StreamJob.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/StreamUtil.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/Environment.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/io/RawBytesOutputReader.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/io/TypedBytesInputWriter.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/io/TextInputWriter.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/io/InputWriter.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/io/TextOutputReader.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/io/IdentifierResolver.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/io/RawBytesInputWriter.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/io/TypedBytesOutputReader.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/io/OutputReader.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/PipeMapRed.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/PathFinder.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/LoadTypedBytes.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/StreamXmlRecordReader.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/UTF8ByteArrayUtils.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/JarBuilder.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/StreamUtil$StreamConsumer.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/PipeMapRed$MRErrorThread.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/StreamKeyValUtil.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/PipeCombiner.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/PipeReducer.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/StreamInputFormat.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/PipeMapRunner.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/PipeMapRed$MROutputThread.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/HadoopStreaming.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/DumpTypedBytes.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/AutoInputFormat.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/PipeMapper.class
JarBuilder.addNamedStream org/apache/hadoop/streaming/StreamBaseRecordReader.class
STREAM: ==== JobConf properties:
STREAM: dfs.block.access.key.update.interval=600
STREAM: dfs.block.access.token.enable=false
STREAM: dfs.block.access.token.lifetime=600
STREAM: dfs.blockreport.initialDelay=0
STREAM: dfs.blockreport.intervalMsec=21600000
STREAM: dfs.blocksize=67108864
STREAM: dfs.bytes-per-checksum=512
STREAM: dfs.client-write-packet-size=65536
STREAM: dfs.client.block.write.retries=3
STREAM: dfs.client.https.keystore.resource=ssl-client.xml
STREAM: dfs.client.https.need-auth=false
STREAM: dfs.datanode.address=
STREAM: dfs.datanode.balance.bandwidthPerSec=1048576
STREAM: dfs.datanode.directoryscan.interval=21600
STREAM: dfs.datanode.directoryscan.threads=1
STREAM: dfs.datanode.dns.interface=default
STREAM: dfs.datanode.dns.nameserver=default
STREAM: dfs.datanode.du.reserved=0
STREAM: dfs.datanode.failed.volumes.tolerated=0
STREAM: dfs.datanode.handler.count=3
STREAM: dfs.datanode.http.address=
STREAM: dfs.datanode.https.address=
STREAM: dfs.datanode.ipc.address=
STREAM: dfs.default.chunk.view.size=32768
STREAM: dfs.heartbeat.interval=3
STREAM: dfs.https.enable=false
STREAM: dfs.https.server.keystore.resource=ssl-server.xml
STREAM: dfs.namenode.accesstime.precision=3600000
STREAM: dfs.namenode.backup.address=
STREAM: dfs.namenode.backup.http-address=
STREAM: dfs.namenode.checkpoint.dir=file://${hadoop.tmp.dir}/dfs/namesecondary
STREAM: dfs.namenode.checkpoint.edits.dir=${dfs.namenode.checkpoint.dir}
STREAM: dfs.namenode.checkpoint.period=3600
STREAM: dfs.namenode.checkpoint.size=67108864
STREAM: dfs.namenode.decommission.interval=30
STREAM: dfs.namenode.decommission.nodes.per.interval=5
STREAM: dfs.namenode.delegation.key.update-interval=86400
STREAM: dfs.namenode.delegation.token.max-lifetime=604800
STREAM: dfs.namenode.delegation.token.renew-interval=86400
STREAM: dfs.namenode.edits.dir=${}
STREAM: dfs.namenode.handler.count=10
STREAM: dfs.namenode.http-address=
STREAM: dfs.namenode.https-address=
STREAM: dfs.namenode.logging.level=info
STREAM: dfs.namenode.max.objects=0
STREAM: dfs.namenode.replication.considerLoad=true
STREAM: dfs.namenode.replication.interval=3
STREAM: dfs.namenode.replication.min=1
STREAM: dfs.namenode.safemode.extension=30000
STREAM: dfs.namenode.safemode.threshold-pct=0.999f
STREAM: dfs.namenode.secondary.http-address=
STREAM: dfs.permissions.enabled=true
STREAM: dfs.permissions.superusergroup=supergroup
STREAM: dfs.replication=1
STREAM: dfs.replication.max=512
STREAM: dfs.web.ugi=webuser,webgroup
STREAM: file.blocksize=67108864
STREAM: file.bytes-per-checksum=512
STREAM: file.client-write-packet-size=65536
STREAM: file.replication=1
STREAM: fs.AbstractFileSystem.file.impl=org.apache.hadoop.fs.local.LocalFs
STREAM: fs.AbstractFileSystem.hdfs.impl=org.apache.hadoop.fs.Hdfs
STREAM: fs.automatic.close=true
STREAM: fs.checkpoint.dir=${hadoop.tmp.dir}/dfs/namesecondary
STREAM: fs.checkpoint.edits.dir=${fs.checkpoint.dir}
STREAM: fs.checkpoint.period=3600
STREAM: fs.checkpoint.size=67108864
STREAM: fs.defaultFS=hdfs://localhost:54310
STREAM: fs.df.interval=60000
STREAM: fs.file.impl=org.apache.hadoop.fs.LocalFileSystem
STREAM: fs.ftp.impl=org.apache.hadoop.fs.ftp.FTPFileSystem
STREAM: fs.har.impl=org.apache.hadoop.fs.HarFileSystem
STREAM: fs.har.impl.disable.cache=true
STREAM: fs.hdfs.impl=org.apache.hadoop.hdfs.DistributedFileSystem
STREAM: fs.hftp.impl=org.apache.hadoop.hdfs.HftpFileSystem
STREAM: fs.hsftp.impl=org.apache.hadoop.hdfs.HsftpFileSystem
STREAM: fs.kfs.impl=org.apache.hadoop.fs.kfs.KosmosFileSystem
STREAM: fs.ramfs.impl=org.apache.hadoop.fs.InMemoryFileSystem
STREAM: fs.s3.block.size=67108864
STREAM: fs.s3.buffer.dir=${hadoop.tmp.dir}/s3
STREAM: fs.s3.impl=org.apache.hadoop.fs.s3.S3FileSystem
STREAM: fs.s3.maxRetries=4
STREAM: fs.s3.sleepTimeSeconds=10
STREAM: fs.s3n.block.size=67108864
STREAM: fs.s3n.impl=org.apache.hadoop.fs.s3native.NativeS3FileSystem
STREAM: fs.trash.interval=0
STREAM: ftp.blocksize=67108864
STREAM: ftp.bytes-per-checksum=512
STREAM: ftp.client-write-packet-size=65536
STREAM: ftp.replication=3
STREAM: hadoop.common.configuration.version=0.21.0
STREAM: hadoop.hdfs.configuration.version=1
STREAM: hadoop.logfile.count=10
STREAM: hadoop.logfile.size=10000000
STREAM: hadoop.tmp.dir=/usr/local/hadoop-${}
STREAM: hadoop.util.hash.type=murmur
STREAM: io.bytes.per.checksum=512
STREAM: io.file.buffer.size=4096
STREAM: io.mapfile.bloom.error.rate=0.005
STREAM: io.mapfile.bloom.size=1048576
STREAM: io.native.lib.available=true
STREAM: io.seqfile.compress.blocksize=1000000
STREAM: io.seqfile.lazydecompress=true
STREAM: io.seqfile.local.dir=${hadoop.tmp.dir}/io/local
STREAM: io.seqfile.sorter.recordlimit=1000000
STREAM: io.skip.checksum.errors=false
STREAM: ipc.client.connect.max.retries=10
STREAM: ipc.client.connection.maxidletime=10000
STREAM: ipc.client.idlethreshold=4000
STREAM: ipc.client.kill.max=10
STREAM: ipc.client.tcpnodelay=false
STREAM: ipc.server.listen.queue.size=128
STREAM: ipc.server.tcpnodelay=false
STREAM: kfs.blocksize=67108864
STREAM: kfs.bytes-per-checksum=512
STREAM: kfs.client-write-packet-size=65536
STREAM: kfs.replication=3
STREAM: map.sort.class=org.apache.hadoop.util.QuickSort
STREAM: mapred.input.format.class=org.apache.hadoop.mapred.TextInputFormat
STREAM: mapred.mapper.class=org.apache.hadoop.streaming.PipeMapper
STREAM: mapred.output.format.class=org.apache.hadoop.mapred.TextOutputFormat
STREAM: mapred.reducer.class=org.apache.hadoop.mapred.lib.IdentityReducer
STREAM: mapreduce.client.completion.pollinterval=5000
STREAM: mapreduce.client.genericoptionsparser.used=true
STREAM: mapreduce.client.output.filter=FAILED
STREAM: mapreduce.client.progressmonitor.pollinterval=1000
STREAM: mapreduce.client.submit.file.replication=10
STREAM: mapreduce.cluster.local.dir=${hadoop.tmp.dir}/mapred/local
STREAM: mapreduce.cluster.temp.dir=${hadoop.tmp.dir}/mapred/temp
STREAM: mapreduce.input.fileinputformat.inputdir=hdfs://localhost:54310/user/hadoop/datain/comparedata
STREAM: mapreduce.input.fileinputformat.split.minsize=0
STREAM: mapreduce.job.cache.symlink.create=yes
STREAM: mapreduce.job.committer.setup.cleanup.needed=true
STREAM: mapreduce.job.complete.cancel.delegation.tokens=true
STREAM: mapreduce.job.end-notification.retry.attempts=0
STREAM: mapreduce.job.end-notification.retry.interval=30000
STREAM: mapreduce.job.jar=/tmp/streamjob2923554781371902680.jar
STREAM: mapreduce.job.jvm.numtasks=1
STREAM: mapreduce.job.maps=2
STREAM: mapreduce.job.maxtaskfailures.per.tracker=4
STREAM: mapreduce.job.queuename=default
STREAM: mapreduce.job.reduce.slowstart.completedmaps=0.05
STREAM: mapreduce.job.reduces=1
STREAM: mapreduce.job.speculative.slownodethreshold=1.0
STREAM: mapreduce.job.speculative.slowtaskthreshold=1.0
STREAM: mapreduce.job.speculative.speculativecap=0.1
STREAM: mapreduce.job.split.metainfo.maxsize=10000000
STREAM: mapreduce.job.userlog.retain.hours=24
STREAM: mapreduce.job.working.dir=hdfs://localhost:54310/user/hadoop
STREAM: mapreduce.jobtracker.address=localhost:54311
STREAM: mapreduce.jobtracker.expire.trackers.interval=600000
STREAM: mapreduce.jobtracker.handler.count=10
STREAM: mapreduce.jobtracker.http.address=
STREAM: mapreduce.jobtracker.instrumentation=org.apache.hadoop.mapred.JobTrackerMetricsInst
STREAM: mapreduce.jobtracker.jobhistory.block.size=3145728
STREAM: mapreduce.jobtracker.jobhistory.lru.cache.size=5
STREAM: mapreduce.jobtracker.maxtasks.perjob=-1
STREAM: mapreduce.jobtracker.persist.jobstatus.dir=/jobtracker/jobsInfo
STREAM: mapreduce.jobtracker.persist.jobstatus.hours=1
STREAM: mapreduce.jobtracker.restart.recover=false
STREAM: mapreduce.jobtracker.retiredjobs.cache.size=1000
STREAM: mapreduce.jobtracker.staging.root.dir=${hadoop.tmp.dir}/mapred/staging
STREAM: mapreduce.jobtracker.system.dir=${hadoop.tmp.dir}/mapred/system
STREAM: mapreduce.jobtracker.taskcache.levels=2
STREAM: mapreduce.jobtracker.taskscheduler=org.apache.hadoop.mapred.JobQueueTaskScheduler
STREAM: mapreduce.jobtracker.tasktracker.maxblacklists=4
STREAM: mapreduce.output.fileoutputformat.compress=false
STREAM: mapreduce.output.fileoutputformat.compression.type=RECORD
STREAM: mapreduce.output.fileoutputformat.outputdir=hdfs://localhost:54310/user/hadoop/dataout5
STREAM: mapreduce.reduce.input.buffer.percent=0.0
STREAM: mapreduce.reduce.log.level=INFO
STREAM: mapreduce.reduce.markreset.buffer.percent=0.0
STREAM: mapreduce.reduce.maxattempts=4
STREAM: mapreduce.reduce.merge.inmem.threshold=1000
STREAM: mapreduce.reduce.shuffle.connect.timeout=180000
STREAM: mapreduce.reduce.shuffle.input.buffer.percent=0.70
STREAM: mapreduce.reduce.shuffle.merge.percent=0.66
STREAM: mapreduce.reduce.shuffle.parallelcopies=5
STREAM: mapreduce.reduce.skip.maxgroups=0
STREAM: mapreduce.reduce.skip.proc.count.autoincr=true
STREAM: mapreduce.reduce.speculative=true
STREAM: mapreduce.task.files.preserve.failedtasks=false
STREAM: mapreduce.task.merge.progress.records=10000
STREAM: mapreduce.task.profile=false
STREAM: mapreduce.task.profile.maps=0-2
STREAM: mapreduce.task.profile.reduces=0-2
STREAM: mapreduce.task.skip.start.attempts=2
STREAM: mapreduce.task.timeout=600000
STREAM: mapreduce.task.tmp.dir=./tmp
STREAM: mapreduce.task.userlog.limit.kb=0
STREAM: mapreduce.tasktracker.cache.local.size=10737418240
STREAM: mapreduce.tasktracker.dns.interface=default
STREAM: mapreduce.tasktracker.dns.nameserver=default
STREAM: mapreduce.tasktracker.healthchecker.interval=60000
STREAM: mapreduce.tasktracker.healthchecker.script.timeout=600000
STREAM: mapreduce.tasktracker.http.address=
STREAM: mapreduce.tasktracker.http.threads=40
STREAM: mapreduce.tasktracker.indexcache.mb=10
STREAM: mapreduce.tasktracker.instrumentation=org.apache.hadoop.mapred.TaskTrackerMetricsInst
STREAM: mapreduce.tasktracker.local.dir.minspacekill=0
STREAM: mapreduce.tasktracker.local.dir.minspacestart=0
STREAM: mapreduce.tasktracker.outofband.heartbeat=false
STREAM: mapreduce.tasktracker.reduce.tasks.maximum=2
STREAM: mapreduce.tasktracker.taskcontroller=org.apache.hadoop.mapred.DefaultTaskController
STREAM: mapreduce.tasktracker.taskmemorymanager.monitoringinterval=5000
STREAM: mapreduce.tasktracker.tasks.sleeptimebeforesigkill=5000
STREAM: net.topology.script.number.args=100
STREAM: s3.blocksize=67108864
STREAM: s3.bytes-per-checksum=512
STREAM: s3.client-write-packet-size=65536
STREAM: s3.replication=3
STREAM: s3native.blocksize=67108864
STREAM: s3native.bytes-per-checksum=512
STREAM: s3native.client-write-packet-size=65536
STREAM: s3native.replication=3
STREAM: stream.addenvironment=
STREAM: stream.numinputspecs=1
STREAM: tmpfiles=file:/home/shivani/research/toolkit/mathouttuts/nearestneighbor/code/IdentityMapper.R#file1
STREAM: webinterface.private.actions=false
STREAM: ====
STREAM: submitting to jobconf: localhost:54311
11/04/13 13:22:17 INFO mapred.FileInputFormat: Total input paths to process : 1
11/04/13 13:22:17 WARN conf.Configuration: is deprecated. Instead, use mapreduce.job.maps
11/04/13 13:22:17 INFO mapreduce.JobSubmitter: number of splits:2
11/04/13 13:22:17 INFO mapreduce.JobSubmitter: adding the following namenodes' delegation tokens:null
11/04/13 13:22:17 INFO streaming.StreamJob: getLocalDirs(): [/usr/local/hadoop-hadoop/mapred/local]
11/04/13 13:22:17 INFO streaming.StreamJob: Running job: job_201104131251_0002
11/04/13 13:22:17 INFO streaming.StreamJob: To kill this job, run:
11/04/13 13:22:17 INFO streaming.StreamJob: /usr/local/hadoop/bin/hadoop job  -Dmapreduce.jobtracker.address=localhost:54311 -kill job_201104131251_0002
11/04/13 13:22:17 INFO streaming.StreamJob: Tracking URL: http://localhost:50030/jobdetails.jsp?jobid=job_201104131251_0002
11/04/13 13:22:18 INFO streaming.StreamJob:  map 0%  reduce 0%
11/04/13 13:23:19 INFO streaming.StreamJob:  map 100%  reduce 100%
11/04/13 13:23:19 INFO streaming.StreamJob: To kill this job, run:
11/04/13 13:23:19 INFO streaming.StreamJob: /usr/local/hadoop/bin/hadoop job  -Dmapreduce.jobtracker.address=localhost:54311 -kill job_201104131251_0002
11/04/13 13:23:19 INFO streaming.StreamJob: Tracking URL: http://localhost:50030/jobdetails.jsp?jobid=job_201104131251_0002
11/04/13 13:23:19 ERROR streaming.StreamJob: Job not Successful!
11/04/13 13:23:19 INFO streaming.StreamJob: killJob...
Streaming Command Failed!

I looked at the output of the mapper and it fails

ava.lang.NullPointerException at
java.lang.String.( at at
org.apache.hadoop.streaming.PipeMapRed.getContext( at
org.apache.hadoop.streaming.PipeMapRed.logFailure( at at at at
org.apache.hadoop.mapred.MapTask.runOldMapper( at at
org.apache.hadoop.mapred.Child$ at Method) at at at

Friday, April 8, 2011

Hadoop troubleshooting tips: Hadoop hangs before launching a job

Whenever a hadoop job hangs right after spitting out the following

11/04/08 13:52:59 INFO security.Groups: Group mapping; cacheTimeout=300000

After 6 hours of diagnoses, I realized there are two possible problems

1) namenode needs formatting. You do this by going to your hadoop-hadoop/ directory and deleting everything in there and running

bin/hdfs namenode format

2) examine the logs and look for exceptions in the datnode, tasktracker

Monday, February 21, 2011

R on amazon EMR

Seems like I found an opening.

This tutorial seems to be very relevant and useful to me.

If I intend to work on the cluster from my R, I need to tell R where the cluster is sitting

maybe this is the way

Thursday, February 17, 2011

ssh tunnelling blues

I have been meddling with ssh tunneling issues now and for the first time I have been able to set up an ssh session with the remote server
The nomenclature is explained in this beautiful tutorial

The real trick I got from this tutorial and another tutorial

Run the following on myPC
$ssh -t userid@gateway ssh remoteserver

Still gotta figure out how to do sftp through ssh tunneling

Wednesday, February 16, 2011

Hadoop vs Hadoop Streaming

What is the difference between Hadoop and Hadoop streaming?

Hadoop is a gigantic program that defines its mapper and reducer all in one code (or compiled as one) and all conf details are all in that one object file
With hadoop streaming, you can use the streaming option to run a mapper of any kind and a reducer of any kind and specify other details (conf etc) externally

Tuesday, February 15, 2011

algorithmic and algorithm

algorithm encapsulates algorithmic, and has options of being boxed ruled or plain. However once algorithm package is loaded, the option settings are global to the entire package


and then whenever you create an algorithm code



Monday, February 14, 2011

Finally figured the svn puzzle

Today is my lucky day. SVN has finally shown me some love. So this is what I wanted to do always

1) Have a data folder "research" that needs backing up , and checking out from either lab computer or home computer
2) Create two users on the server machine (where you run svnadmin commands)
3) From either the lab computer or the home machine use svn co svn+ssh://@/pathtorepos to check out files
4) the passwd file in /pathtorepos/conf/passwd is not of any use... this file really got me twisted. No matter what the contents of this file are, there needs to be a login on the machine for each user that wants to checkout any data
5) last but not the least. once the "research" folder is imported, one needs to check it back out on to the machine where modifications need to be made.

Sunday, February 13, 2011

Change the float page fraction

\renewcommand{\dbltopfraction}{0.9} % fit big float above 2-col. text
\renewcommand{\textfraction}{0.07} % allow minimal text w. figs
% Parameters for FLOAT pages (not text pages):
\renewcommand{\floatpagefraction}{0.7} % require fuller float pages
% N.B.: floatpagefraction MUST be less than topfraction !!
\renewcommand{\dblfloatpagefraction}{0.7} % require fuller float pages

Friday, February 11, 2011

svn version control tips and pitfalls

Here is a step by step procedure to do the following
1) svn repository to be created on a machine labpc (with your login name mylogin) with ipaddress lab_ipaddress at location /svnrepos

The data to be imported is in /media/data

There are two users on this machine lab_user home_user .These users modify or update the repository from two different locations labpc and homepc

All computers run Ubuntu OS

2) Prefer web access

I will update the post later on web access. For now I will post instructions on setting it up.

On labPC
1) run $ svnadmin create /svnrepos
svn import /media/data /svnrepos
2) Change /svnrepos/conf/svnserve.conf to look like this

anon-access = none
auth-access = write
password-db = passwd

3) Modify the pasword file /svnrepos/conf/passwd

User1 = passw1
User2 = pass2

4) on homepc
change /etc/hosts and add the following line


the could be changed to anything

5) on homepc, Add the following lines to .ssh/config

User mylogin
Port some_number

6) Finally try $svn list svn+ssh://

Common pitfalls

1) the svnserve.conf should have no leading spaces
2) the port number specified in step 5 should not be a port that is commonly used...

More to come later

Latex table of figures

\caption{Image 1}
\end{minipage} &
\caption{Image 2}
\end{minipage} \\
\caption{Image 3}
\end{minipage} &
\caption{Image 4}
\end{minipage} \\