Re: hadoop in the ETL process
On Wednesday 02 July 2008 19:51:57 David J. O'Dell wrote: > Is anyone using hadoop for any part of the ETL process? > > Given its ability to process large amounts of log files this seems like > a good fit. Well, we are doing the following data flow: 1.) webservers upload to S3 2.) hadoop jobs get started with a number of logfiles each. We use streaming.jar only, with a Python "framework" and a number of driver scripts for mapping, reducing (which is usually a completely generic behaviour assigned on a per job basis, e.g. FirstOnly, SumValues, CollectSet), and later on applying to MySQL. 3.) the results get written to MySQL. 4.) inside the hadoop cluster certain data from MySQL that is needed for efficient reducing (you cannot count persons by sex, if you do not know the sex of the person), are available as a REST-style http service. Each node has it's own squid, the http services create as much cachable content as possible, and the squids do ICP peering against all nodes. It works somehow find, although from time to time there are problems, e.g. my current one is that hadoop behaves really bad on long lines. (I know it's not exactly a trivial thing to read an arbitrary long line without knowing a limit beforehand, OTOH, Python does manage that for me, without me especially loosing to much sleep about it. Another of these situations where slow highlevel languages overwhelm the lowlevel optimization champions.) Andreas signature.asc Description: This is a digitally signed message part.
RE: hadoop in the ETL process
Hadoop is a great way to offload ETL jobs (especially aggregation) out of the DB. More than likely you would want to use Hadoop as a mechanism to create a file you can load into the database as a batch job (data pump or sql loader with Oracle for example) outside of Hadoop entirely. I would imagine establishing connections inside map/reduce jobs would not be ideal. Regards, Ryan -Original Message- From: Chris K Wensel [mailto:[EMAIL PROTECTED] Sent: Wednesday, July 02, 2008 11:31 AM To: core-user@hadoop.apache.org Subject: Re: hadoop in the ETL process If your referring to loading an RDBMS with data on Hadoop, this is doable. but you will need to write your own JDBC adapters to your tables. But you might review what you are using the RDBMS for and see if those jobs would be better off running on Hadoop entirely, if not for most of the processing. ckw On Jul 2, 2008, at 10:51 AM, David J. O'Dell wrote: > Is anyone using hadoop for any part of the ETL process? > > Given its ability to process large amounts of log files this seems > like > a good fit. > > -- > David O'Dell > Director, Operations > e: [EMAIL PROTECTED] > t: (415) 738-5152 > 180 Townsend St., Third Floor > San Francisco, CA 94107 > -- Chris K Wensel [EMAIL PROTECTED] http://chris.wensel.net/ http://www.cascading.org/
Re: hadoop in the ETL process
If your referring to loading an RDBMS with data on Hadoop, this is doable. but you will need to write your own JDBC adapters to your tables. But you might review what you are using the RDBMS for and see if those jobs would be better off running on Hadoop entirely, if not for most of the processing. ckw On Jul 2, 2008, at 10:51 AM, David J. O'Dell wrote: Is anyone using hadoop for any part of the ETL process? Given its ability to process large amounts of log files this seems like a good fit. -- David O'Dell Director, Operations e: [EMAIL PROTECTED] t: (415) 738-5152 180 Townsend St., Third Floor San Francisco, CA 94107 -- Chris K Wensel [EMAIL PROTECTED] http://chris.wensel.net/ http://www.cascading.org/
hadoop in the ETL process
Is anyone using hadoop for any part of the ETL process? Given its ability to process large amounts of log files this seems like a good fit. -- David O'Dell Director, Operations e: [EMAIL PROTECTED] t: (415) 738-5152 180 Townsend St., Third Floor San Francisco, CA 94107
