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The "HttpAuthenticationSchemes" page has been changed by susam. http://wiki.apache.org/nutch/HttpAuthenticationSchemes?action=diff&rev1=18&rev2=19 -------------------------------------------------- === Important Points === 1. For <authscope> tag, 'host' and 'port' attribute should always be specified. 'realm' and 'scheme' attributes may or may not be specified depending on your needs. If you are tempted to omit the 'host' and 'port' attribute, because you want the credentials to be used for any host and any port for that realm/scheme, please use the 'default' tag instead. That's what 'default' tag is meant for. 1. One authentication scope should not be defined twice as different <authscope> tags for different <credentials> tag. However, if this is done by mistake, the credentials for the last defined <authscope> tag would be used. This is because, the XML parsing code, reads the file from top to bottom and sets the credentials for authentication-scopes. If the same authentication scope is encountered once again, it will be overwritten with the new credentials. However, one should not rely on this behavior as this might change with further developments. - 1. Do not define multiple authscope tags with the same host, port but different realms if the server requires NTLM authentication. This means there should not be multiple tags with same host, port, scheme="NTLM" but different realms. If you are omitting the scheme attribute and the server requires NTLM authentication, then there should not be multiple tags with same host, port but different realms. This is discussed more in the next section. + 1. Do not define multiple authscope tags with the same host, port but different realms if the server requires NTLM authentication. This means there should not be multiple authscope tags with same host, port, scheme="NTLM" but different realms. If you are omitting the scheme attribute and the server requires NTLM authentication, then there should not be multiple tags with same host, port but different realms. This is discussed more in the next section. 1. If you are using NTLM scheme, you should also set the 'http.agent.host' property in conf/nutch-site.xml === A note on NTLM domains === NTLM does not use the concept of realms. Therefore, multiple realms for a web-server can not be defined as different authentication scopes for the same web-server requiring NTLM authentication. There should be exactly one authscope tag for NTLM scheme authentication scope for a particular web-server. The authentication domain should be specified as the value of the 'realm' attribute. NTLM authentication also requires the name of IP address of the host on which the crawler is running. Thus, 'http.agent.host' should be set properly. == Underlying HttpClient Library == - 'protocol-httpclient' is based on [[http://jakarta.apache.org/httpcomponents/httpclient-3.x/|Jakarta Commons HttpClient]]. Some servers support multiple schemes for authenticating users. Given that only one scheme may be used at a time for authenticating, it must choose which scheme to use. To accompish this, it uses an order of preference to select the correct authentication scheme. By default this order is: NTLM, Digest, Basic. For more information on the behavior during authentication, you might want to read the [[http://jakarta.apache.org/httpcomponents/httpclient-3.x/authentication.html|HttpClient Authentication Guide]]. + 'protocol-httpclient' is based on [[http://hc.apache.org/httpclient-3.x/|Jakarta Commons HttpClient]]. Some servers support multiple schemes for authenticating users. Given that only one scheme may be used at a time for authenticating, it must choose which scheme to use. To accomplish this, it uses an order of preference to select the correct authentication scheme. By default this order is: NTLM, Digest, Basic. For more information on the behavior during authentication, you might want to read the [[http://hc.apache.org/httpclient-3.x/authentication.html|HttpClient Authentication Guide]]. == Need Help? == If you need help, please feel free to post your question to the [[http://lucene.apache.org/nutch/mailing_lists.html#Users|nutch-user mailing list]]. The author of this work, Susam Pal, usually responds to mails related to authentication problems. The DEBUG logs may be required to troubleshoot the problem. You must enable the debug log for 'protocol-httpclient' before running the crawler. To enable debug log for 'protocol-httpclient', open 'conf/log4j.properties' and add the following line:
