two main changes must be implemented to enable mass remote crawls:
- shift control of robots.txt to crawl queue (away from stacker). This is necessary since remote
crawls can contain unchecked urls. Each peer must check the robots to prevent that it is misused
as crawl agent for unwanted file retrieval
- implement new index files that control double-check of remotely crawled urls
After removal of robots.txt checking from stacker threads, the multi-threading of this process is void.
Multithreading has been removed. Also the thread pools for the crawl threads had been removed, since
creation of these threads is not resource-consuming, for a detailed explanation see svn 4106
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@4181 6c8d7289-2bf4-0310-a012-ef5d649a1542
search profiling showed, that a major amount of time is wasted by computing url hashes. The computation does an intranet-check, which needs a DNS lookup. This caused that each urlhash computation needed 100-200 milliseconds, which caused remote searches to delay at least 1 second more that necessary. The solution to this problem is to attach a URL hash to the URL data structure, because that means that the url hash value can be filled after retrieval of the URL from the database. The redesign of the url/urlhash management caused a major redesign of many parts of the software. Since some parts had been decided to be given up they had been removed during this change to avoid unnecessary maintenance of unused code.
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@4074 6c8d7289-2bf4-0310-a012-ef5d649a1542
