About mokkan

mokkan · ‎12-01-2021

I have seen some of my jobs are using only one reducer in the end. Does it mean we have one output file? Or it depends?

mokkan · ‎12-01-2021

Our user is running a job and which is a hive query and number of mapper is always 6 and not changing even the data size change. It is a insert query. How do I change number of mappers ? Which parameter determine number of mappers?

mokkan · ‎10-13-2021

I can do query through spark using spark.sql, but when I tried via beeline ranger is blocking the access because of the policy. How does it work via spark query? Doesn't it check HDFS level permission? I

mokkan · ‎11-16-2019

Thank you for the info. Yes, I have created with backup with another directory and I was about to boot restart the namenode from that image.

mokkan · ‎11-16-2019

Thank you for the information. If I have multiple directories configured for dfs.namenode.name.dir. Defualt: /hadoop/hdfs/namenode I can configure /backup/namenode /goldbackup/namenode In this case I will have multiple copy of FSimage and Editlog and in case one the directory is corrupted, I can use another one. Does it make sense?

mokkan · ‎11-15-2019

Hello, I have a basic question about about namenode format. If we perform namenode format, will clean up all the metadata info in namenode like directory structure, etc. After it completed, if we restart namenode, would it rebuild the directory structure from datanode information? Or we are lost.

mokkan · ‎05-25-2018

Hello, When NN writes data(block) to DN or when DN send block over to next DN, what protocol they use? RPC or HTTP?

mokkan · ‎05-24-2018

Thanks a lot.

mokkan · ‎05-24-2018

Thanks a lot for giving great explanation. Just a last question, delegation token is given by NN, from NN what package or what tool provides the delegation token. Is it part of namenode package?

mokkan · ‎05-24-2018

Thank you very much, we are using centos we should be able to install using yum?

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Cloudera Community

Re: namenode format question

Reducer 1 question

Number of mapper is not changing

Spark query vs beeline query

Re: namenode format question

Re: namenode format question

namenode format question

hdfs block protocol

Re: delegation token and block token question

Re: delegation token and block token question

Re: Edge node or utility node packages