[NUTCH-1613] Timeouts in protocol-httpclient when crawling same host with >2 threads and added cookie strings for both http protocols

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.2.1
• Fix Version/s: 2.3, 1.9
• Component/s: protocol
• Labels: patch
• Patch Info: Patch Available
• Assignee: Unassigned
• Reporter: Brian
• Created: 16/Jul/13 21:45
• Updated: 13/Mar/24 14:51
• Resolved: 12/May/14 12:59

Description

1.) When using protocol-httpclient to crawl a single website (the same host) I would always get a bunch of timeout errors during fetching and the pages with errors would not be fetched. E.g.:

2013-07-09 17:57:13,717 WARN fetcher.FetcherJob - fetch of http://www.... failed with: org.apache.commons.httpclient.ConnectionPoolTimeoutException: Timeout waiting for connection
2013-07-09 17:57:13,718 INFO fetcher.FetcherJob - fetching http://www.... (queue crawl delay=0ms)
2013-07-09 17:57:13,715 ERROR httpclient.Http - Failed with the following error:
org.apache.commons.httpclient.ConnectionPoolTimeoutException: Timeout waiting for connection
at org.apache.commons.httpclient.MultiThreadedHttpConnectionManager.doGetConnection(MultiThreadedHttpConnectionManager.java:497)
at org.apache.commons.httpclient.MultiThreadedHttpConnectionManager.getConnectionWithTimeout(MultiThreadedHttpConnectionManager.java:416)
at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:153)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
at org.apache.nutch.protocol.httpclient.HttpResponse.<init>(HttpResponse.java:95)
at org.apache.nutch.protocol.httpclient.Http.getResponse(Http.java:174)
at org.apache.nutch.protocol.http.api.HttpBase.getProtocolOutput(HttpBase.java:133)
at org.apache.nutch.fetcher.FetcherReducer$FetcherThread.run(FetcherReducer.java:518)

This is because by default the connection pool manager only allows 2 connections per host so if more than 2 threads are used the others will tend to time out waiting to get a connection. The code previously set max connections correctly but not connection per host.

2.) I also added at the same time simple modifications to both protocol-http and protocol-httpclient to allow specifying a cookie string in the conf file to include in request headers.

I use this to crawl site content requiring authentication - it is better for me to specify the cookie string for the authentication than go through the whole authentication process and specifying login info.

The nutch-site.xml property is the following:

<property>
<name>http.cookie_string</name>
<value>XX_AL=authorization_value_goes_here</value>
<description>String to use as the cookie value for HTTP requests</description>
</property>

Although I use it for authentication it can be used to specify any single cookie string for the crawl (httpclient does support different cookies for different hosts but I did not get into that).

Issue Links

• is related to: NUTCH-827 HTTP POST Authentication