[ 
https://issues.apache.org/jira/browse/NUTCH-475?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12491882
 ] 

Enis Soztutar commented on NUTCH-475:
-------------------------------------

we can use a formula like : 

delay = alpha * delay + (1 - alpha) * (k * t)

where 0 < alpha <= 1

so that the waiting time is less sensitive to varying reply times of the 
server. 


> Adaptive crawl delay
> --------------------
>
>                 Key: NUTCH-475
>                 URL: https://issues.apache.org/jira/browse/NUTCH-475
>             Project: Nutch
>          Issue Type: Improvement
>          Components: fetcher
>            Reporter: Doğacan Güney
>             Fix For: 1.0.0
>
>         Attachments: adaptive-delay_draft.patch
>
>
> Current fetcher implementation waits a default interval before making another 
> request to the same server (if crawl-delay is not specified in robots.txt). 
> IMHO, an adaptive implementation will be better. If the server is under 
> little load and can server requests fast, then fetcher can ask for more pages 
> in a given interval. Similarly, if the server is suffering from heavy load, 
> fetcher can slow down(w.r.t that host), easing the load on the server.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
Nutch-developers mailing list
Nutch-developers@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nutch-developers

Reply via email to