Re: Distribute crawling of a URL list using Flink

Posted by Eranga Heshan on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Distribute-crawling-of-a-URL-list-using-Flink-tp14873p15161.html

Thank you Aljoscha :-) I actually need it for a Kafka stream, so I use DataStream API anyway.

Regards,

On Fri, Aug 25, 2017 at 5:53 PM, Aljoscha Krettek <[hidden email]> wrote:

Hi,

It is not available for the Batch API, you would have to use the DataStream API.

Best,

Aljoscha

On 15. Aug 2017, at 01:16, Kien Truong <[hidden email]> wrote:

Hi,

Admittedly, I have not suggested this because I thought it was not available for batch API.

Regards,

Kien

On Aug 15, 2017, at 00:06, Nico Kruber <[hidden email]> wrote:

Hi Eranga and Kien,
Flink supports asynchronous IO since version 1.2, see [1] for details.

You basically pack your URL download into the asynchronous part and collect 
the resulting string for further processing in your pipeline.



Nico


[1] https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/stream/
asyncio.html

On Monday, 14 August 2017 17:50:47 CEST Kien Truong wrote:

 

   Hi,
  

  
 While this task is quite trivial to do with Flink Dataset API, using
  
 readTextFile to read the input and
  

  
 a flatMap function to perform the downloading, it might not be a good idea.
  

  
 The download process is I/O bound, and will block the synchronous
  
 flatMap function,
  

  
 so the throughput will not be very good.
  

  

  
 Until Flink supports asynchronous functions, I suggest you looks elsewhere.
  

  
 An example with master-workers architecture using Akka can be found here
  

  

  https://github.com/typesafehub/activator-akka-distributed-workers
  

  

  
 Regards,
  

  
 Kien
  

  
 On 8/14/2017 10:09 AM, Eranga Heshan wrote:
  

  

    Hi all,
   

   
 I am fairly new to Flink. I have this project where I have a list of
   
 URLs (In one node) which need to be crawled distributedly. Then for
   
 each URL, I need the serialized crawled result to be written to a
   
 single text file.
   

   
 I want to know if there are similar projects which I can look into or
   
 an idea on how to implement this.
   

   
 Thanks & Regards,
   

   

   

   

   
 Eranga Heshan
   
 /Undergraduate/
   
 Computer Science & Engineering
   
 University of Moratuwa
   
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