diff --git a/defaults/yacy.init b/defaults/yacy.init
index 98a786ec5..8aad8cd88 100644
--- a/defaults/yacy.init
+++ b/defaults/yacy.init
@@ -772,6 +772,14 @@ crawler.defaultAverageLatency = 500
 # The result is the minimum remote server access delay time
 crawler.latencyFactor = 0.5
 
+# The onDemandLimit is the maximum number of crawl queues that are concurrently opened
+# at the same time. If the number of hosts exceeds this number, onDemand queues are opened
+# which are opened each time a queue is accessed which creates high IO load. On the other
+# hand, having too many entries in onDemandLimit may exceed the maximum number of file
+# pointers. You can increase this number in /proc/sys/fs/file-max and adopt it to the number
+# defined here
+crawler.onDemandLimit = 1000
+
 # maximum size of indexing queue
 indexer.slots = 100
 
diff --git a/htroot/BlogComments.java b/htroot/BlogComments.java
index 7e21a1528..51849b73f 100644
--- a/htroot/BlogComments.java
+++ b/htroot/BlogComments.java
@@ -48,6 +48,7 @@ import net.yacy.data.BlogBoard.BlogEntry;
 import net.yacy.peers.Network;
 import net.yacy.peers.Seed;
 import net.yacy.search.Switchboard;
+import net.yacy.search.SwitchboardConstants;
 import net.yacy.server.serverObjects;
 import net.yacy.server.serverSwitch;
 
@@ -143,8 +144,8 @@ public class BlogComments {
                 messageForwardingViaEmail(sb, msgEntry);
 
                 // finally write notification
-                final File notifierSource = new File(sb.getAppPath(), sb.getConfig("htRootPath","htroot") + "/env/grafics/message.gif");
-                final File notifierDest   = new File(sb.getDataPath("htDocsPath", "DATA/HTDOCS"), "notifier.gif");
+                final File notifierSource = new File(sb.getAppPath(), sb.getConfig(SwitchboardConstants.HTROOT_PATH, SwitchboardConstants.HTROOT_PATH_DEFAULT) + "/env/grafics/message.gif");
+                final File notifierDest   = new File(sb.getDataPath(SwitchboardConstants.HTDOCS_PATH, SwitchboardConstants.HTDOCS_PATH_DEFAULT), "notifier.gif");
                 try {
                     Files.copy(notifierSource, notifierDest);
                 } catch (final IOException e) {
diff --git a/htroot/ConfigAppearance_p.java b/htroot/ConfigAppearance_p.java
index e7495bb6b..8635e90a3 100644
--- a/htroot/ConfigAppearance_p.java
+++ b/htroot/ConfigAppearance_p.java
@@ -162,7 +162,7 @@ public class ConfigAppearance_p {
     }
 
     private static boolean changeSkin(final Switchboard sb, final String skinPath, final String skin) {
-        final File htdocsDir = new File(sb.getDataPath("htDocsPath", "DATA/HTDOCS"), "env");
+        final File htdocsDir = new File(sb.getDataPath(SwitchboardConstants.HTDOCS_PATH, SwitchboardConstants.HTDOCS_PATH_DEFAULT), "env");
         final File styleFile = new File(htdocsDir, "style.css");
         final File skinFile = new File(skinPath, skin);
 
diff --git a/htroot/Messages_p.java b/htroot/Messages_p.java
index 80aeb46ef..45c59a749 100644
--- a/htroot/Messages_p.java
+++ b/htroot/Messages_p.java
@@ -38,6 +38,7 @@ import net.yacy.cora.protocol.RequestHeader;
 import net.yacy.data.MessageBoard;
 import net.yacy.peers.Seed;
 import net.yacy.search.Switchboard;
+import net.yacy.search.SwitchboardConstants;
 import net.yacy.server.serverObjects;
 import net.yacy.server.serverSwitch;
 
@@ -96,8 +97,8 @@ public class Messages_p {
         MessageBoard.entry message;
 
         // first reset notification
-        final File notifierSource = new File(sb.getAppPath(), sb.getConfig("htRootPath", "htroot") + "/env/grafics/empty.gif");
-        final File notifierDest = new File(sb.getDataPath("htDocsPath", "DATA/HTDOCS"), "notifier.gif");
+        final File notifierSource = new File(sb.getAppPath(), sb.getConfig(SwitchboardConstants.HTROOT_PATH, SwitchboardConstants.HTROOT_PATH_DEFAULT) + "/env/grafics/empty.gif");
+        final File notifierDest = new File(sb.getDataPath(SwitchboardConstants.HTDOCS_PATH, SwitchboardConstants.HTDOCS_PATH_DEFAULT), "notifier.gif");
         try {
             Files.copy(notifierSource, notifierDest);
         } catch (final IOException e) {
diff --git a/htroot/www/welcome.java b/htroot/www/welcome.java
index 86aed58b3..e131383df 100644
--- a/htroot/www/welcome.java
+++ b/htroot/www/welcome.java
@@ -35,6 +35,7 @@ import net.yacy.cora.protocol.HeaderFramework;
 import net.yacy.cora.protocol.RequestHeader;
 import net.yacy.peers.Seed;
 import net.yacy.search.Switchboard;
+import net.yacy.search.SwitchboardConstants;
 import net.yacy.server.serverObjects;
 import net.yacy.server.serverSwitch;
 
@@ -61,8 +62,8 @@ public class welcome {
         final boolean senior = (peertype.equals(Seed.PEERTYPE_SENIOR)) || (peertype.equals(Seed.PEERTYPE_PRINCIPAL));
         if (senior) { prop.put("couldcan", "can"); } else { prop.put("couldcan", "could"); }
         if (senior) { prop.put("seniorinfo", "This peer runs in senior mode which means that your peer can be accessed using the addresses shown above."); } else { prop.putHTML("seniorinfo", "<b>Nobody can access your peer from the outside of your intranet. You must open your firewall and/or set a 'virtual server' in the settings of your router to enable access to the addresses as shown below.</b>"); }
-        final File wwwpath = env.getDataPath("htDocsPath", "DATA/HTDOCS");
-        prop.putHTML("wwwpath", wwwpath.isAbsolute() ? wwwpath.getAbsolutePath() : "<application_root_path>/" + env.getConfig("htDocsPath", "DATA/HTDOCS"));
+        final File wwwpath = env.getDataPath(SwitchboardConstants.HTDOCS_PATH, SwitchboardConstants.HTDOCS_PATH_DEFAULT);
+        prop.putHTML("wwwpath", wwwpath.isAbsolute() ? wwwpath.getAbsolutePath() : "<application_root_path>/" + env.getConfig(SwitchboardConstants.HTDOCS_PATH, SwitchboardConstants.HTDOCS_PATH_DEFAULT));
 
         // return rewrite properties
         return prop;
diff --git a/htroot/yacy/message.java b/htroot/yacy/message.java
index 3544c4186..41bb6dde4 100644
--- a/htroot/yacy/message.java
+++ b/htroot/yacy/message.java
@@ -45,6 +45,7 @@ import net.yacy.peers.Network;
 import net.yacy.peers.Protocol;
 import net.yacy.peers.Seed;
 import net.yacy.search.Switchboard;
+import net.yacy.search.SwitchboardConstants;
 import net.yacy.server.serverObjects;
 import net.yacy.server.serverSwitch;
 import net.yacy.utils.crypt;
@@ -148,8 +149,8 @@ public final class message {
             messageForwardingViaEmail(sb, msgEntry);
 
             // finally write notification
-            final File notifierSource = new File(sb.getAppPath(), sb.getConfig("htRootPath","htroot") + "/env/grafics/message.gif");
-            final File notifierDest   = new File(sb.getDataPath("htDocsPath", "DATA/HTDOCS"), "notifier.gif");
+            final File notifierSource = new File(sb.getAppPath(), sb.getConfig(SwitchboardConstants.HTROOT_PATH,SwitchboardConstants.HTROOT_PATH_DEFAULT) + "/env/grafics/message.gif");
+            final File notifierDest   = new File(sb.getDataPath(SwitchboardConstants.HTDOCS_PATH, SwitchboardConstants.HTDOCS_PATH_DEFAULT), "notifier.gif");
             try {
                 Files.copy(notifierSource, notifierDest);
             } catch (final IOException e) {
diff --git a/source/net/yacy/crawler/HostBalancer.java b/source/net/yacy/crawler/HostBalancer.java
index 9a48f7396..1404ddec4 100644
--- a/source/net/yacy/crawler/HostBalancer.java
+++ b/source/net/yacy/crawler/HostBalancer.java
@@ -68,11 +68,14 @@ public class HostBalancer implements Balancer {
     private final boolean exceed134217727;
     private final Map<String, HostQueue> queues;
     private final Set<String> roundRobinHostHashes;
+    private final int onDemandLimit;
 
     public HostBalancer(
             final File hostsPath,
+            final int onDemandLimit,
             final boolean exceed134217727) {
         this.hostsPath = hostsPath;
+        this.onDemandLimit = onDemandLimit;
         this.exceed134217727 = exceed134217727;
         
         // create a stack for newly entered entries
@@ -81,7 +84,7 @@ public class HostBalancer implements Balancer {
         String[] list = this.hostsPath.list();
         for (String address: list) try {
             File queuePath = new File(this.hostsPath, address);
-            HostQueue queue = new HostQueue(queuePath, this.queues.size() > 100, this.exceed134217727);
+            HostQueue queue = new HostQueue(queuePath, this.queues.size() > this.onDemandLimit, this.exceed134217727);
             if (queue.size() == 0) {
                 queue.close();
                 queuePath.delete();
@@ -210,7 +213,7 @@ public class HostBalancer implements Balancer {
         synchronized (this) {
             HostQueue queue = this.queues.get(hosthash);
             if (queue == null) {
-                queue = new HostQueue(this.hostsPath, entry.url().getHost(), entry.url().getPort(), this.queues.size() > 100, this.exceed134217727);
+                queue = new HostQueue(this.hostsPath, entry.url().getHost(), entry.url().getPort(), this.queues.size() > this.onDemandLimit, this.exceed134217727);
                 this.queues.put(hosthash, queue);
                 // profile might be null when continue crawls after YaCy restart
                 robots.ensureExist(entry.url(), profile == null ? ClientIdentification.yacyInternetCrawlerAgent : profile.getAgent(), true); // concurrently load all robots.txt
diff --git a/source/net/yacy/crawler/data/CrawlQueues.java b/source/net/yacy/crawler/data/CrawlQueues.java
index 34dcf0521..3430bdfc9 100644
--- a/source/net/yacy/crawler/data/CrawlQueues.java
+++ b/source/net/yacy/crawler/data/CrawlQueues.java
@@ -87,7 +87,7 @@ public class CrawlQueues {
 
         // start crawling management
         log.config("Starting Crawling Management");
-        this.noticeURL = new NoticedURL(queuePath, sb.useTailCache, sb.exceed134217727);
+        this.noticeURL = new NoticedURL(queuePath, sb.getConfigInt("crawler.onDemandLimit", 1000), sb.exceed134217727);
         this.errorURL = new ErrorCache(sb.index.fulltext());
         this.delegatedURL = new ConcurrentHashMap<String, DigestURL>();
     }
@@ -104,7 +104,7 @@ public class CrawlQueues {
         this.errorURL.clearCache();
         this.remoteCrawlProviderHashes.clear();
         this.noticeURL.close();
-        this.noticeURL = new NoticedURL(newQueuePath, this.sb.useTailCache, this.sb.exceed134217727);
+        this.noticeURL = new NoticedURL(newQueuePath, sb.getConfigInt("crawler.onDemandLimit", 1000), this.sb.exceed134217727);
         this.delegatedURL.clear();
     }
 
diff --git a/source/net/yacy/crawler/data/NoticedURL.java b/source/net/yacy/crawler/data/NoticedURL.java
index 5754e902d..c49f6aa85 100644
--- a/source/net/yacy/crawler/data/NoticedURL.java
+++ b/source/net/yacy/crawler/data/NoticedURL.java
@@ -60,13 +60,13 @@ public class NoticedURL {
 
     protected NoticedURL(
             final File cachePath,
-            @SuppressWarnings("unused") final boolean useTailCache,
+            final int onDemandLimit,
             final boolean exceed134217727) {
         ConcurrentLog.info("NoticedURL", "CREATING STACKS at " + cachePath.toString());
-        this.coreStack = new HostBalancer(new File(cachePath, "CrawlerCoreStacks"), exceed134217727);
-        this.limitStack = new HostBalancer(new File(cachePath, "CrawlerLimitStacks"), exceed134217727);
-        this.remoteStack = new HostBalancer(new File(cachePath, "CrawlerRemoteStacks"), exceed134217727);
-        this.noloadStack = new HostBalancer(new File(cachePath, "CrawlerNoLoadStacks"), exceed134217727);
+        this.coreStack = new HostBalancer(new File(cachePath, "CrawlerCoreStacks"), onDemandLimit, exceed134217727);
+        this.limitStack = new HostBalancer(new File(cachePath, "CrawlerLimitStacks"), onDemandLimit, exceed134217727);
+        this.remoteStack = new HostBalancer(new File(cachePath, "CrawlerRemoteStacks"), onDemandLimit, exceed134217727);
+        this.noloadStack = new HostBalancer(new File(cachePath, "CrawlerNoLoadStacks"), onDemandLimit, exceed134217727);
     }
 
     public void clear() {
diff --git a/source/net/yacy/http/servlets/YaCyDefaultServlet.java b/source/net/yacy/http/servlets/YaCyDefaultServlet.java
index 6ad91b7a1..dd8098a5b 100644
--- a/source/net/yacy/http/servlets/YaCyDefaultServlet.java
+++ b/source/net/yacy/http/servlets/YaCyDefaultServlet.java
@@ -356,7 +356,7 @@ public class YaCyDefaultServlet extends HttpServlet  {
             }
         } finally {
             if (resource != null) {
-                resource.release();
+                resource.close();
             }
         }
     }