Alex Osborne
1832c5ef89
dnsjava will create its global selector thread on first DNS lookup.
Since the first lookup occurs on a toe thread then this will cause the
selector thead to join the job's toe thread group. This is a problem
because when the job is terminated ToePool sends an interrupt to all
threads in the thread group which the dnsjava selector thread is
not expected and never clears. The interrupted state then causes
select() to return immediately instead of sleeping so it consumes
100% CPU.
So workaround this by doing a dummy lookup when FetchDNS is loaded,
this ensures the first lookup happens on the web server thread that
handles the job build action instead of a toe thread.
Fixes: 045b2516da ("Update to latest version of dnsjava")
Heritrix
Introduction
Heritrix is the Internet Archive's open-source, extensible, web-scale, archival-quality web crawler project. Heritrix (sometimes spelled heretrix, or misspelled or missaid as heratrix/heritix/heretix/heratix) is an archaic word for heiress (woman who inherits). Since our crawler seeks to collect and preserve the digital artifacts of our culture for the benefit of future researchers and generations, this name seemed apt.
Crawl Operators!
Heritrix is designed to respect the robots.txt exclusion directives† and META nofollow tags. Please consider the
load your crawl will place on seed sites and set politeness policies accordingly. Also, always identify your crawl with contact information in the User-Agent so sites that may be adversely affected by your crawl can contact you or adapt their server behavior accordingly.
† The newer wildcard extension to robots.txt is not yet supported.
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