special strategy for balancer: do not remove targets with zero wait time

from the queue

source/net/yacy/crawler/HostBalancer.java

@@ -257,14 +257,18 @@ public class HostBalancer implements Balancer {
                             while (i.hasNext()) {
                                 String s = i.next();
                                 HostQueue hq = this.queues.get(s);
-                                if (hq == null || hq.size() != 1) {i.remove();}
+                                if (hq == null) {i.remove(); continue;}
+                                int delta = Latency.waitingRemainingGuessed(hq.getHost(), s, robots, ClientIdentification.yacyInternetCrawlerAgent);
+                                if (hq.size() != 1 && delta > 10) {i.remove();}
                             }
                         } else if (smallStacksExist) {
                             Iterator<String> i = this.roundRobinHostHashes.iterator();
                             while (i.hasNext()) {
                                 String s = i.next();
                                 HostQueue hq = this.queues.get(s);
-                                if (hq == null || hq.size() > 10) {i.remove();}
+                                if (hq == null) {i.remove(); continue;}
+                                int delta = Latency.waitingRemainingGuessed(hq.getHost(), s, robots, ClientIdentification.yacyInternetCrawlerAgent);
+                                if (hq.size() > 10 && delta > 10) {i.remove();}
                             }
                         }
                     }
@@ -280,8 +284,8 @@ public class HostBalancer implements Balancer {
                         nhhi.remove();
                         continue nosleep;
                     }
-                    int delta = Latency.waitingRemainingGuessed(rhq.getHost(), DigestURL.hosthash(rhq.getHost(), rhq.getPort()), robots, ClientIdentification.yacyInternetCrawlerAgent);
-                    if (delta <= 10 || this.roundRobinHostHashes.size() == 1) {
+                    int delta = Latency.waitingRemainingGuessed(rhq.getHost(), rhh, robots, ClientIdentification.yacyInternetCrawlerAgent);
+                    if (delta <= 10 || this.roundRobinHostHashes.size() == 1 || rhq.size() == 1) {
                         nhhi.remove();
                         break nosleep;
                     }
@@ -289,6 +293,8 @@ public class HostBalancer implements Balancer {
                 
                 if (rhq == null) {
                     // second strategy: take from the largest stack and clean round robin cache
+                    // if we would not clear the round robin cache afterwards
+                    // then all targets would be accessed equally which makes this strategy useless
                     int largest = Integer.MIN_VALUE;
                     for (String h: this.roundRobinHostHashes) {
                         HostQueue hq = this.queues.get(h);

source/net/yacy/crawler/HostQueue.java

@@ -414,7 +414,7 @@ public class HostQueue implements Balancer {
                 // if not: return null. A calling method must handle the null value and try again
                 profileEntry = cs.get(UTF8.getBytes(crawlEntry.profileHandle()));
                 if (profileEntry == null) {
-                    ConcurrentLog.warn("Balancer", "no profile entry for handle " + crawlEntry.profileHandle());
+                    ConcurrentLog.fine("Balancer", "no profile entry for handle " + crawlEntry.profileHandle());
                     continue mainloop;
                 }
                 

source/net/yacy/crawler/LegacyBalancer.java

@@ -387,7 +387,7 @@ public class LegacyBalancer implements Balancer {
                 // if not: return null. A calling method must handle the null value and try again
                 profileEntry = cs.get(UTF8.getBytes(crawlEntry.profileHandle()));
                 if (profileEntry == null) {
-                    ConcurrentLog.warn("Balancer", "no profile entry for handle " + crawlEntry.profileHandle());
+                    ConcurrentLog.fine("Balancer", "no profile entry for handle " + crawlEntry.profileHandle());
                     continue;
                 }
                 // depending on the caching policy we need sleep time to avoid DoS-like situations