do not run dht ditribution if system load is over 2.5

defaults/yacy.init

@@ -837,6 +837,7 @@ indexControl.gzipBody = true
 indexControl.timeout = 60000
 indexDistribution.timeout = 60000
 indexTransfer.timeout = 120000
+indexTransfer.maxload = 2.5
 
 # defining max. allowed amount of open files during index- transfer/distribution
 indexDistribution.maxOpenFiles = 800

source/net/yacy/search/Switchboard.java

@@ -3283,6 +3283,12 @@ public final class Switchboard extends serverSwitch {
                 + ", sbQueue.size() = "
                 + getIndexingProcessorsQueueSize();
         }
+        
+        double load = Memory.load();
+        float maxload = getConfigFloat(SwitchboardConstants.INDEX_TRANSFER_MAXLOAD, 1.5f);
+        if (load > maxload) {
+            return "no DHT distribution: system has too high load = " + load + ", maxload = " + maxload;
+        }
         return null; // this means; yes, please do dht transfer
     }
 

source/net/yacy/search/SwitchboardConstants.java

@@ -254,6 +254,7 @@ public final class SwitchboardConstants {
     public static final String INDEX_DIST_ALLOW_WHILE_CRAWLING  = "allowDistributeIndexWhileCrawling";
     public static final String INDEX_DIST_ALLOW_WHILE_INDEXING  = "allowDistributeIndexWhileIndexing";
     public static final String INDEX_TRANSFER_TIMEOUT           = "indexTransfer.timeout";
+    public static final String INDEX_TRANSFER_MAXLOAD           = "indexTransfer.maxload";
     public static final String INDEX_TRANSFER_GZIP_BODY         = "indexTransfer.gzipBody";
     public static final String PARSER_MIME_DENY                 = "parser.mime.deny";
     public static final String PARSER_EXTENSIONS_DENY           = "parser.extensions.deny";