How to pull data in the Map/Reduce functions?
Hi, Normally the Hadoop framework calls the map()/reduce() for each record in the input split. I read in the 'Hadoop : The Definitive Guide' that that data can be pulled using the new MR API. What is the new API for pulling the data in the map()/reduce() or is there a sample code? Thanks, Praveen
RE: How to pull data in the Map/Reduce functions?
Praveen, Functionality wise you don't gain much from using the new API and most would actually recommend that you stay with the old API as it will not be officially deprecated until 0.22 / 0.23 (I can't remember which one). If you want to take a look at the classes dig into the packages for org.apache.hadoop.mapred.* (old) and org.apache.hadoop.mapreduce.* (new). Also, I thought that Definitive Guide second edition and Hadoop In Action covered the new api. Matt From: Praveen Sripati [mailto:praveensrip...@gmail.com] Sent: Saturday, September 24, 2011 8:43 AM To: mapreduce-user@hadoop.apache.org Subject: How to pull data in the Map/Reduce functions? Hi, Normally the Hadoop framework calls the map()/reduce() for each record in the input split. I read in the 'Hadoop : The Definitive Guide' that that data can be pulled using the new MR API. What is the new API for pulling the data in the map()/reduce() or is there a sample code? Thanks, Praveen This e-mail message may contain privileged and/or confidential information, and is intended to be received only by persons entitled to receive such information. If you have received this e-mail in error, please notify the sender immediately. Please delete it and all attachments from any servers, hard drives or any other media. Other use of this e-mail by you is strictly prohibited. All e-mails and attachments sent and received are subject to monitoring, reading and archival by Monsanto, including its subsidiaries. The recipient of this e-mail is solely responsible for checking for the presence of Viruses or other Malware. Monsanto, along with its subsidiaries, accepts no liability for any damage caused by any such code transmitted by or accompanying this e-mail or any attachment. The information contained in this email may be subject to the export control laws and regulations of the United States, potentially including but not limited to the Export Administration Regulations (EAR) and sanctions regulations issued by the U.S. Department of Treasury, Office of Foreign Asset Controls (OFAC). As a recipient of this information you are obligated to comply with all applicable U.S. export laws and regulations.
Re: How to pull data in the Map/Reduce functions?
Matt, Neither of the books have much information about the new MR API. I was reading the 'Hadoop - The Definitive Guide' and came across a single pager on new API. I wanted to try the new MR, but could not find much information neither in the book nor on the internet. Thanks, Praveen On Sat, Sep 24, 2011 at 8:20 PM, GOEKE, MATTHEW (AG/1000) matthew.go...@monsanto.com wrote: Praveen, ** ** Functionality wise you don’t gain much from using the new API and most would actually recommend that you stay with the old API as it will not be “officially” deprecated until 0.22 / 0.23 (I can’t remember which one). If you want to take a look at the classes dig into the packages for org.apache.hadoop.mapred.* (old) and org.apache.hadoop.mapreduce.* (new). Also, I thought that Definitive Guide second edition and Hadoop In Action covered the new api. ** ** Matt ** ** *From:* Praveen Sripati [mailto:praveensrip...@gmail.com] *Sent:* Saturday, September 24, 2011 8:43 AM *To:* mapreduce-user@hadoop.apache.org *Subject:* How to pull data in the Map/Reduce functions? ** ** Hi, Normally the Hadoop framework calls the map()/reduce() for each record in the input split. I read in the 'Hadoop : The Definitive Guide' that that data can be pulled using the new MR API. What is the new API for pulling the data in the map()/reduce() or is there a sample code? Thanks, Praveen This e-mail message may contain privileged and/or confidential information, and is intended to be received only by persons entitled to receive such information. If you have received this e-mail in error, please notify the sender immediately. Please delete it and all attachments from any servers, hard drives or any other media. Other use of this e-mail by you is strictly prohibited. All e-mails and attachments sent and received are subject to monitoring, reading and archival by Monsanto, including its subsidiaries. The recipient of this e-mail is solely responsible for checking for the presence of Viruses or other Malware. Monsanto, along with its subsidiaries, accepts no liability for any damage caused by any such code transmitted by or accompanying this e-mail or any attachment. The information contained in this email may be subject to the export control laws and regulations of the United States, potentially including but not limited to the Export Administration Regulations (EAR) and sanctions regulations issued by the U.S. Department of Treasury, Office of Foreign Asset Controls (OFAC). As a recipient of this information you are obligated to comply with all applicable U.S. export laws and regulations.
