From 9f60c276127c94b2e136cd83d171aa98c229932c Mon Sep 17 00:00:00 2001
From: Pablo Hoffman <pablo@pablohoffman.com>
Date: Fri, 5 Aug 2011 20:41:59 -0300
Subject: [PATCH] added setting to support disabling DNS cache:
 DNSCACHE_ENABLED

---
 docs/topics/settings.rst            | 9 +++++++++
 scrapy/crawler.py                   | 3 ++-
 scrapy/settings/default_settings.py | 2 ++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/docs/topics/settings.rst b/docs/topics/settings.rst
index 4743d9b40..24da5c2e6 100644
--- a/docs/topics/settings.rst
+++ b/docs/topics/settings.rst
@@ -366,6 +366,15 @@ Default: ``False``
 Whether to collect verbose depth stats. If this is enabled, the number of
 requests for each depth is collected in the stats.
 
+.. setting:: DNSCACHE_ENABLED
+
+DNSCACHE_ENABLED
+----------------
+
+Default: ``True``
+
+Whether to enable DNS in-memory cache.
+
 .. setting:: DOWNLOADER_DEBUG
 
 DOWNLOADER_DEBUG
diff --git a/scrapy/crawler.py b/scrapy/crawler.py
index ceeae57d6..b5ac99620 100644
--- a/scrapy/crawler.py
+++ b/scrapy/crawler.py
@@ -70,7 +70,8 @@ class CrawlerProcess(Crawler):
 
     def start(self):
         super(CrawlerProcess, self).start()
-        reactor.installResolver(CachingThreadedResolver(reactor))
+        if self.settings.getbool('DNSCACHE_ENABLED'):
+            reactor.installResolver(CachingThreadedResolver(reactor))
         reactor.addSystemEventTrigger('before', 'shutdown', self.stop)
         reactor.run(installSignalHandlers=False) # blocking call
 
diff --git a/scrapy/settings/default_settings.py b/scrapy/settings/default_settings.py
index c2438e60b..9f38c2010 100644
--- a/scrapy/settings/default_settings.py
+++ b/scrapy/settings/default_settings.py
@@ -49,6 +49,8 @@ DEPTH_LIMIT = 0
 DEPTH_STATS = True
 DEPTH_PRIORITY = 1
 
+DNSCACHE_ENABLED = True
+
 DOWNLOAD_DELAY = 0
 
 DOWNLOAD_HANDLERS = {}