diff --git a/.classpath b/.classpath
index bc494524a..22a9a7f23 100644
--- a/.classpath
+++ b/.classpath
@@ -18,7 +18,6 @@
 	<classpathentry kind="lib" path="lib/common-io-3.3.2.jar"/>
 	<classpathentry kind="lib" path="lib/common-lang-3.3.2.jar"/>
 	<classpathentry kind="lib" path="lib/commons-codec-1.14.jar"/>
-	<classpathentry kind="lib" path="lib/commons-collections-3.2.2.jar"/>
 	<classpathentry kind="lib" path="lib/commons-compress-1.20.jar"/>
 	<classpathentry kind="lib" path="lib/commons-fileupload-1.4.jar"/>
 	<classpathentry kind="lib" path="lib/commons-io-2.7.jar"/>
@@ -27,7 +26,6 @@
 	<classpathentry kind="lib" path="lib/commons-logging-1.2.jar"/>
 	<classpathentry kind="lib" path="lib/commons-math3-3.4.1.jar"/>
 	<classpathentry kind="lib" path="lib/fontbox-2.0.15.jar"/>
-	<classpathentry kind="lib" path="lib/guava-30.1-jre.jar"/>
 	<classpathentry kind="lib" path="lib/http2-client-9.4.34.v20201102.jar"/>
 	<classpathentry kind="lib" path="lib/http2-common-9.4.34.v20201102.jar"/>
 	<classpathentry kind="lib" path="lib/http2-http-client-transport-9.4.34.v20201102.jar"/>
@@ -109,6 +107,8 @@
 	<classpathentry kind="lib" path="libt/hamcrest-2.2.jar"/>
 	<classpathentry kind="lib" path="libt/hamcrest-core-2.2.jar"/>
 	<classpathentry kind="lib" path="libt/hamcrest-library-2.2.jar"/>
+	<classpathentry kind="lib" path="lib/commons-collections4-4.4.jar"/>
+	<classpathentry kind="lib" path="lib/guava-25.1-jre.jar"/>
 	<classpathentry kind="src" path="htroot/api/blacklists"/>
 	<classpathentry kind="src" path="htroot/api/bookmarks/posts"/>
 	<classpathentry kind="src" path="htroot/api/bookmarks/tags"/>
diff --git a/build.xml b/build.xml
index ee83dbe26..8e3d16306 100644
--- a/build.xml
+++ b/build.xml
@@ -184,7 +184,7 @@
         <pathelement location="${lib}/common-io-3.3.2.jar" />
         <pathelement location="${lib}/common-lang-3.3.2.jar" />
         <pathelement location="${lib}/commons-codec-1.14.jar" />
-        <pathelement location="${lib}/commons-collections-3.2.2.jar" />
+        <pathelement location="${lib}/commons-collections4-4.4.jar" />
         <pathelement location="${lib}/commons-compress-1.20.jar" />
         <pathelement location="${lib}/commons-fileupload-1.4.jar" />
         <pathelement location="${lib}/commons-io-2.7.jar" />
@@ -193,7 +193,7 @@
         <pathelement location="${lib}/commons-logging-1.2.jar" />
         <pathelement location="${lib}/commons-math3-3.4.1.jar" />
         <pathelement location="${lib}/fontbox-2.0.15.jar" />
-        <pathelement location="${lib}/guava-30.1-jre.jar" />
+        <pathelement location="${lib}/guava-25.1-jre.jar" />
         <pathelement location="${lib}/http2-client-9.4.34.v20201102.jar" />
         <pathelement location="${lib}/http2-common-9.4.34.v20201102.jar" />
         <pathelement location="${lib}/http2-http-client-transport-9.4.34.v20201102.jar" />
diff --git a/defaults/solr/schema.xml b/defaults/solr/schema.xml
index 546ac5c94..288cb1f50 100644
--- a/defaults/solr/schema.xml
+++ b/defaults/solr/schema.xml
@@ -2,18 +2,18 @@
 
 <schema name="YaCy2Solr" version="1.4">
     <types>
-        <fieldType name="string"   class="solr.StrField"        omitNorms="true"  sortMissingLast="true" docValues="true" />
-        <fieldType name="boolean"  class="solr.BoolField"       omitNorms="true"  sortMissingLast="true" />
-        <fieldType name="int"      class="solr.TrieIntField"    omitNorms="true"  precisionStep="0" positionIncrementGap="0" docValues="true" />
-        <fieldType name="tint"     class="solr.TrieIntField"    precisionStep="8" positionIncrementGap="0" docValues="true" />
-        <fieldType name="long"     class="solr.TrieLongField"   precisionStep="0" positionIncrementGap="0" docValues="true" />
-        <fieldType name="tlong"    class="solr.TrieLongField"   precisionStep="8" positionIncrementGap="0" docValues="true" />
-        <fieldType name="double"   class="solr.TrieDoubleField" omitNorms="true"  precisionStep="0" positionIncrementGap="0" docValues="true" />
-        <fieldType name="tdouble"  class="solr.TrieDoubleField" omitNorms="true"  precisionStep="8" positionIncrementGap="0" docValues="true" />
-        <fieldType name="date"     class="solr.TrieDateField"   omitNorms="true"  precisionStep="0" positionIncrementGap="0" docValues="true" />
-        <fieldType name="float"    class="solr.TrieFloatField"  precisionStep="0" positionIncrementGap="0" docValues="true" />
-        <fieldType name="tfloat"   class="solr.TrieFloatField"  precisionStep="8" positionIncrementGap="0" docValues="true" />
-        <fieldType name="location" class="solr.LatLonType"      subFieldSuffix="_coordinate"/>
+        <fieldType name="string"   class="solr.StrField"         omitNorms="true" sortMissingLast="true" docValues="true" />
+        <fieldType name="boolean"  class="solr.BoolField"        omitNorms="true" sortMissingLast="true" />
+        <fieldType name="int"      class="solr.IntPointField"    docValues="true" omitNorms="true" />
+        <fieldType name="tint"     class="solr.IntPointField"    docValues="true" />
+        <fieldType name="long"     class="solr.LongPointField"   docValues="true" />
+        <fieldType name="tlong"    class="solr.LongPointField"   docValues="true" />
+        <fieldType name="double"   class="solr.DoublePointField" docValues="true" omitNorms="true" />
+        <fieldType name="tdouble"  class="solr.DoublePointField" docValues="true" omitNorms="true" />
+        <fieldType name="date"     class="solr.DatePointField"   docValues="true" omitNorms="true" />
+        <fieldType name="float"    class="solr.FloatPointField"  docValues="true" />
+        <fieldType name="tfloat"   class="solr.FloatPointField"  docValues="true" />
+        <fieldType name="location" class="solr.LatLonPointSpatialField" />
     
         <fieldType name="text" class="solr.TextField" positionIncrementGap="100" autoGeneratePhraseQueries="true">
             <analyzer type="index">
@@ -22,7 +22,7 @@
             </analyzer>
             <analyzer type="query">
                 <tokenizer class="solr.WhitespaceTokenizerFactory"/>
-                <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
+                <filter class="solr.SynonymGraphFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
                 <filter class="solr.LowerCaseFilterFactory"/>
             </analyzer>
         </fieldType>
@@ -36,7 +36,7 @@
             <analyzer type="query">
                 <tokenizer class="solr.StandardTokenizerFactory"/>
                 <filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt"/>
-                <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
+                <filter class="solr.SynonymGraphFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
                 <filter class="solr.LowerCaseFilterFactory"/>
             </analyzer>
         </fieldType>
@@ -44,9 +44,9 @@
         <fieldType name="text_en_splitting_tight" class="solr.TextField" positionIncrementGap="100" autoGeneratePhraseQueries="true">
             <analyzer>
                 <tokenizer class="solr.WhitespaceTokenizerFactory"/>
-                <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="false"/>
+                <filter class="solr.SynonymGraphFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="false"/>
                 <filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt"/>
-                <filter class="solr.WordDelimiterFilterFactory" generateWordParts="0" generateNumberParts="0" catenateWords="1" catenateNumbers="1" catenateAll="0"/>
+                <filter class="solr.WordDelimiterGraphFilterFactory" generateWordParts="0" generateNumberParts="0" catenateWords="1" catenateNumbers="1" catenateAll="0"/>
                 <filter class="solr.LowerCaseFilterFactory"/><filter class="solr.KeywordMarkerFilterFactory" protected="protwords.txt"/>
                 <filter class="solr.EnglishMinimalStemFilterFactory"/>
                 <filter class="solr.RemoveDuplicatesTokenFilterFactory"/>
diff --git a/defaults/solr/solrconfig.xml b/defaults/solr/solrconfig.xml
index 8d4b9a5ee..54b9afbca 100644
--- a/defaults/solr/solrconfig.xml
+++ b/defaults/solr/solrconfig.xml
@@ -35,7 +35,7 @@
        that you fully re-index after changing this setting as it can
        affect both how text is indexed and queried.
   -->
-  <luceneMatchVersion>6.6.0</luceneMatchVersion>
+  <luceneMatchVersion>8.8.1</luceneMatchVersion>
 
   <!-- <lib/> directives can be used to instruct Solr to load any Jars
        identified and use them to resolve any "plugins" specified in
diff --git a/lib/commons-collections-3.2.2.jar b/lib/commons-collections-3.2.2.jar
deleted file mode 100644
index fa5df82a6..000000000
Binary files a/lib/commons-collections-3.2.2.jar and /dev/null differ
diff --git a/lib/guava-25.1-jre.jar b/lib/guava-25.1-jre.jar
new file mode 100644
index 000000000..babc17553
Binary files /dev/null and b/lib/guava-25.1-jre.jar differ
diff --git a/lib/guava-30.1-jre.jar b/lib/guava-30.1-jre.jar
deleted file mode 100644
index dab80f395..000000000
Binary files a/lib/guava-30.1-jre.jar and /dev/null differ
diff --git a/source/net/yacy/cora/federate/solr/instance/EmbeddedInstance.java b/source/net/yacy/cora/federate/solr/instance/EmbeddedInstance.java
index a5f3e0bd9..45704e805 100644
--- a/source/net/yacy/cora/federate/solr/instance/EmbeddedInstance.java
+++ b/source/net/yacy/cora/federate/solr/instance/EmbeddedInstance.java
@@ -39,7 +39,7 @@ import org.apache.solr.core.SolrCore;
 import com.google.common.io.Files;
 
 public class EmbeddedInstance implements SolrInstance {
-    
+
     private final static String[] confFiles = {"solrconfig.xml", "schema.xml", "stopwords.txt", "synonyms.txt", "protwords.txt", "currency.xml", "elevate.xml", "xslt/example.xsl", "xslt/json.xsl", "lang/"};
                                               // additional a optional   solrcore.properties     (or solrcore.x86.properties for 32bit systems is copied
     private CoreContainer coreContainer;
@@ -54,16 +54,16 @@ public class EmbeddedInstance implements SolrInstance {
         super();
         // copy the solrconfig.xml to the storage path
         this.containerPath = containerPath;
-        
+
         // ensure that default core path exists
         File defaultCorePath = new File(containerPath, givenDefaultCoreName);
         if (!defaultCorePath.exists()) defaultCorePath.mkdirs();
-        
+
         // migrate old conf directory
         File oldConf = new File(containerPath, "conf");
         File confDir = new File(defaultCorePath, "conf");
         if (oldConf.exists()) oldConf.renameTo(confDir);
-        
+
         // migrate old data directory
         File oldData = new File(containerPath, "data");
         File dataDir = new File(defaultCorePath, "data");
@@ -72,12 +72,12 @@ public class EmbeddedInstance implements SolrInstance {
         // create index subdirectory in data if it does not exist
         File indexDir = new File(dataDir, "index");
         if (!indexDir.exists()) indexDir.mkdirs();
-        
+
         // initialize the cores' configuration
         for (String coreName: initializeCoreNames) {
             initializeCoreConf(solr_config, containerPath, coreName);
         }
-        
+
         // initialize the coreContainer
         File configFile = new File(solr_config, "solr.xml"); //  the configuration file for all cores
         this.coreContainer = CoreContainer.createAndLoad(containerPath.toPath(), configFile.toPath()); // this may take indefinitely long if solr files are broken
@@ -104,12 +104,12 @@ public class EmbeddedInstance implements SolrInstance {
     public int hashCode() {
         return this.containerPath.hashCode();
     }
-    
+
     @Override
     public boolean equals(Object o) {
         return o instanceof EmbeddedInstance && this.containerPath.equals(((EmbeddedInstance) o).containerPath);
     }
-    
+
     private static void initializeCoreConf(final File solr_config, final File containerPath, String coreName) {
 
         // ensure that default core path exists
@@ -121,7 +121,7 @@ public class EmbeddedInstance implements SolrInstance {
         if (!core_properties.exists()) {
             // create the file
             try (
-            	/* Automatically closed by this try-with-resources statement */
+                /* Automatically closed by this try-with-resources statement */
                 FileOutputStream fos = new FileOutputStream(core_properties);
             ) {
                 fos.write(ASCII.getBytes("name=" + coreName + "\n"));
@@ -140,7 +140,7 @@ public class EmbeddedInstance implements SolrInstance {
         conf.mkdirs();
         File data = new File(corePath, "data");
         data.mkdirs();
-        
+
         // (over-)write configuration into conf path
         File source, target;
         for (String cf: confFiles) {
@@ -158,14 +158,14 @@ public class EmbeddedInstance implements SolrInstance {
             } else {
                 target = new File(conf, cf);
                 target.getParentFile().mkdirs();
-                try {                                       
+                try {
                     Files.copy(source, target);
                 } catch (final IOException e) {
                     e.printStackTrace();
                 }
             }
         }
-        
+
         // copy the solrcore.properties
         // for 32bit systems (os.arch name not containing '64') take the solrcore.x86.properties as solrcore.properties if exists
         String os = System.getProperty("os.arch");            
@@ -188,17 +188,17 @@ public class EmbeddedInstance implements SolrInstance {
                 ex.printStackTrace();
             }
         }
-      
+
     }
-    
+
     public File getContainerPath() {
         return this.containerPath;
     }
-    
+
     public CoreContainer getCoreContainer() {
         return this.coreContainer;
     }
-    
+
     @Override
     public String getDefaultCoreName() {
         return this.defaultCoreName;
@@ -234,7 +234,7 @@ public class EmbeddedInstance implements SolrInstance {
         this.cores.put(name, c);
         return c;
     }
-    
+
     @Override
     protected void finalize() throws Throwable {
         this.close();
@@ -248,5 +248,5 @@ public class EmbeddedInstance implements SolrInstance {
             this.coreContainer = null;
         } catch (final Throwable e) {ConcurrentLog.logException(e);}
     }
-    
+
 }
diff --git a/source/net/yacy/search/index/Fulltext.java b/source/net/yacy/search/index/Fulltext.java
index 98cd37b64..f8499bee1 100644
--- a/source/net/yacy/search/index/Fulltext.java
+++ b/source/net/yacy/search/index/Fulltext.java
@@ -90,18 +90,18 @@ import org.apache.solr.schema.IndexSchema;
 
 public final class Fulltext {
 
-    private static final String SOLR_PATH = "solr_6_6"; // the number should be identical to the number in the property luceneMatchVersion in solrconfig.xml
-    private static final String SOLR_OLD_PATH[] = new String[]{"solr_36", "solr_40", "solr_44", "solr_45", "solr_46", "solr_47", "solr_4_9", "solr_4_10", "solr_5_2", "solr_5_5"};
-    
+    private static final String SOLR_PATH = "solr_8_8_1"; // the number should be identical to the number in the property luceneMatchVersion in solrconfig.xml
+    private static final String SOLR_OLD_PATH[] = new String[]{"solr_36", "solr_40", "solr_44", "solr_45", "solr_46", "solr_47", "solr_4_9", "solr_4_10", "solr_5_2", "solr_5_5", "solr_6_6"};
+
     // class objects
     private final File                    segmentPath;
     private final File                    archivePath;
     private       Export                  exportthread; // will have a export thread assigned if exporter is running
     private       InstanceMirror          solrInstances;
-    
+
     /** Synchronization lock for solrInstances property */
     private ReentrantLock solrInstancesLock;
-    
+
     private final CollectionConfiguration collectionConfiguration;
     private final WebgraphConfiguration   webgraphConfiguration;
     private       boolean                 writeWebgraph;
@@ -117,11 +117,11 @@ public final class Fulltext {
         this.webgraphConfiguration = webgraphConfiguration;
         this.writeWebgraph = false;
     }
-    
+
     public void setUseWebgraph(boolean check) {
         this.writeWebgraph = check;
     }
-    
+
     public boolean useWebgraph() {
         return this.writeWebgraph;
     }
@@ -140,24 +140,28 @@ public final class Fulltext {
 
     public void connectLocalSolr() throws IOException {
         File solrLocation = new File(this.segmentPath, SOLR_PATH);
+
         // migrate old solr to new
+        /*
         for (String oldVersion: SOLR_OLD_PATH) {
             File oldLocation = new File(this.segmentPath, oldVersion);
             if (oldLocation.exists()) {
-            	if(!oldLocation.renameTo(solrLocation)) {
-					ConcurrentLog.severe("Fulltext", "Failed renaming old Solr location ("
-							+ oldLocation.getAbsolutePath() + ") to new location : " + solrLocation.getAbsolutePath());
-            	}
+                if(!oldLocation.renameTo(solrLocation)) {
+                    ConcurrentLog.severe("Fulltext", "Failed renaming old Solr location ("
+                            + oldLocation.getAbsolutePath() + ") to new location : " + solrLocation.getAbsolutePath());
+                }
             }
         }
-        
+        */
+
         EmbeddedInstance localCollectionInstance = new EmbeddedInstance(new File(new File(Switchboard.getSwitchboard().appPath, "defaults"), "solr"), solrLocation, CollectionSchema.CORE_NAME, new String[]{CollectionSchema.CORE_NAME, WebgraphSchema.CORE_NAME});
         SolrConfig config = localCollectionInstance.getDefaultCore().getSolrConfig();
         String versionValue = config.getVal(IndexSchema.LUCENE_MATCH_VERSION_PARAM, true);
         Version luceneVersion = SolrConfig.parseLuceneVersionString(versionValue);
-        String lvn = luceneVersion.major + "_" + luceneVersion.minor;
-        ConcurrentLog.info("Fulltext", "using lucene version " + lvn);
+        String lvn = luceneVersion.major + "_" + luceneVersion.minor + "_" + luceneVersion.bugfix;
         assert SOLR_PATH.endsWith(lvn) : "luceneVersion = " + lvn + ", solrPath = " + SOLR_PATH + ", check defaults/solr/solrconfig.xml";
+
+        ConcurrentLog.info("Fulltext", "using lucene version " + lvn);
         ConcurrentLog.info("Fulltext", "connected solr in " + solrLocation.toString() + ", lucene version " + lvn);
         this.solrInstances.connectEmbedded(localCollectionInstance);
     }
@@ -194,64 +198,64 @@ public final class Fulltext {
 
     public RemoteSolrConnector getDefaultRemoteSolrConnector() {
         try {
-    		boolean useBinaryResponseWriter = SwitchboardConstants.REMOTE_SOLR_BINARY_RESPONSE_ENABLED_DEFAULT;
-    		if (Switchboard.getSwitchboard() != null) {
-    			useBinaryResponseWriter = Switchboard.getSwitchboard().getConfigBool(
-    					SwitchboardConstants.REMOTE_SOLR_BINARY_RESPONSE_ENABLED,
-    					SwitchboardConstants.REMOTE_SOLR_BINARY_RESPONSE_ENABLED_DEFAULT);
-    		}
+            boolean useBinaryResponseWriter = SwitchboardConstants.REMOTE_SOLR_BINARY_RESPONSE_ENABLED_DEFAULT;
+            if (Switchboard.getSwitchboard() != null) {
+                useBinaryResponseWriter = Switchboard.getSwitchboard().getConfigBool(
+                        SwitchboardConstants.REMOTE_SOLR_BINARY_RESPONSE_ENABLED,
+                        SwitchboardConstants.REMOTE_SOLR_BINARY_RESPONSE_ENABLED_DEFAULT);
+            }
             return this.solrInstances.getDefaultRemoteConnector(useBinaryResponseWriter);
         } catch (IOException e) {
             return null;
         }
     }
-    
+
     public EmbeddedInstance getEmbeddedInstance() {
-    	this.solrInstancesLock.lock();
+        this.solrInstancesLock.lock();
         try {
             if (this.solrInstances.isConnectedEmbedded()) {
-            	return this.solrInstances.getEmbedded();
+                return this.solrInstances.getEmbedded();
             }
             return null;
         } finally {
-        	this.solrInstancesLock.unlock();	
+            this.solrInstancesLock.unlock();    
         }
     }
-    
+
     public SolrConnector getDefaultConnector() {
-    	this.solrInstancesLock.lock();
+        this.solrInstancesLock.lock();
         try {
             return this.solrInstances.getDefaultMirrorConnector();
         } finally {
-        	this.solrInstancesLock.unlock();	
+            this.solrInstancesLock.unlock();    
         }
     }
-    
+
     public SolrConnector getWebgraphConnector() {
         if (!this.writeWebgraph) {
-        	return null;
+            return null;
         }
-    	this.solrInstancesLock.lock();
+        this.solrInstancesLock.lock();
         try {
             return this.solrInstances.getGenericMirrorConnector(WebgraphSchema.CORE_NAME);
         } finally {
-        	this.solrInstancesLock.unlock();
+            this.solrInstancesLock.unlock();
         }
     }
-    
+
     public int bufferSize() {
         return this.solrInstances.bufferSize();
     }
-    
+
     public void clearCaches() {
         this.solrInstances.clearCaches();
     }
 
     public void clearLocalSolr() throws IOException {
         if (this.exportthread != null) {
-        	this.exportthread.interrupt();
+            this.exportthread.interrupt();
         }
-    	this.solrInstancesLock.lock();
+        this.solrInstancesLock.lock();
         try {
             EmbeddedInstance instance = this.solrInstances.getEmbedded();
             if (instance != null) {
@@ -262,12 +266,12 @@ public final class Fulltext {
             }
             this.solrInstances.clearCaches();
         } finally {
-        	this.solrInstancesLock.unlock();
+            this.solrInstancesLock.unlock();
         }
     }
 
     public void clearRemoteSolr() throws IOException {
-    	this.solrInstancesLock.lock();
+        this.solrInstancesLock.lock();
         try {
             ShardInstance instance = this.solrInstances.getRemote();
             if (instance != null) {
@@ -277,7 +281,7 @@ public final class Fulltext {
             }
             this.solrInstances.clearCaches();
         } finally {
-        	this.solrInstancesLock.unlock();
+            this.solrInstancesLock.unlock();
         }
     }
 
@@ -297,7 +301,7 @@ public final class Fulltext {
         this.collectionSizeLastValue = size;
         return size;
     }
-    
+
     /**
      * @return the size of the webgraph index
      */
@@ -309,10 +313,10 @@ public final class Fulltext {
         try {
             this.solrInstances.close();
         } catch (Throwable e) {
-        	ConcurrentLog.logException(e);
+            ConcurrentLog.logException(e);
         }
     }
-    
+
     private long lastCommit = 0;
     public void commit(boolean softCommit) {
         long t = System.currentTimeMillis();
@@ -346,15 +350,15 @@ public final class Fulltext {
         if (urlHash == null) return null;
         return getMetadata(urlHash, null, 0L);
     }
-    
+
     private URIMetadataNode getMetadata(final byte[] urlHash, final WordReferenceVars wre, final long score) {
         String u = ASCII.String(urlHash);
-        
+
         // get the metadata from Solr
         try {
             SolrDocument doc = this.getDefaultConnector().getDocumentById(u);
             if (doc != null) {
-            	return new URIMetadataNode(doc, wre, score);
+                return new URIMetadataNode(doc, wre, score);
             }
         } catch (final IOException e) {
             ConcurrentLog.logException(e);
@@ -411,7 +415,7 @@ public final class Fulltext {
                         Collection<Object> collections = doc.getFieldValues(CollectionSchema.collection_sxt.getSolrFieldName());
                         // collection dht is used to identify metadata from full crawled documents (if "dht" exists don't overwrite rich crawldata with metadata
                         if (!collections.contains("dht")) return;
-                        
+
                         // passed all checks, overwrite document
                         putDocument(getDefaultConfiguration().metadata2solr(entry));
                     }
@@ -451,7 +455,7 @@ public final class Fulltext {
                 (freshdate == null || freshdate.after(now)) ? null :
                 (WebgraphSchema.load_date_dt.getSolrFieldName() + ":[* TO " + ISO8601Formatter.FORMATTER.format(freshdate) + "]"));
     }
-    
+
     /**
      * delete all documents within a domain that are registered as error document
      * @param hosthashes
@@ -459,7 +463,7 @@ public final class Fulltext {
     public void deleteDomainErrors(final Set<String> hosthashes) {
         deleteDomainWithConstraint(this.getDefaultConnector(), CollectionSchema.host_id_s.getSolrFieldName(), hosthashes, CollectionSchema.failreason_s.getSolrFieldName() + AbstractSolrConnector.CATCHALL_DTERM);
     }
-    
+
     private static void deleteDomainWithConstraint(SolrConnector connector, String fieldname, final Set<String> hosthashes, String constraintQuery) {
         if (hosthashes == null || hosthashes.size() == 0) return;
         int subsetscount = 1 + (hosthashes.size() / 255); // if the list is too large, we get a "too many boolean clauses" exception
@@ -492,8 +496,7 @@ public final class Fulltext {
         } catch (final IOException e) {
         }
     }
-    
-    
+
     /**
      * remove a full subpath from the index
      * @param basepath the left path of the url; at least until the end of the host
@@ -522,7 +525,7 @@ public final class Fulltext {
         } catch (final InterruptedException e) {}
         return count.get();
     }
-    
+
     /**
      * remove a list of id's from the index (matching fulltext.id and webgraph.source_id_s
      * @param deleteIDs a list of urlhashes; each denoting a document
@@ -533,7 +536,7 @@ public final class Fulltext {
             this.getDefaultConnector().deleteByIds(deleteIDs);
             if (this.writeWebgraph) { // Webgraph.id is combination of sourceHash+targetHash+hexCounter, to be successful use source_id_s and/or target_id_s
                 for (String id : deleteIDs) {
-                	/* Add quotes around the url hash to prevent Solr logging a ParseException stack trace when the hash start with a '-' character */
+                    /* Add quotes around the url hash to prevent Solr logging a ParseException stack trace when the hash start with a '-' character */
                     this.getWebgraphConnector().deleteByQuery(WebgraphSchema.source_id_s.name() + ":\"" + id  + "\"");
                 }
             }
@@ -554,7 +557,7 @@ public final class Fulltext {
             String id = ASCII.String(urlHash);
             this.getDefaultConnector().deleteById(id);
             if (this.writeWebgraph) { // Webgraph.id is combination of sourceHash+targetHash+hexCounter, to be successful use source_id_s and/or target_id_s
-            	/* Add quotes around the url hash to prevent Solr logging a ParseException stack trace when the hash start with a '-' character */
+                /* Add quotes around the url hash to prevent Solr logging a ParseException stack trace when the hash start with a '-' character */
                 this.getWebgraphConnector().deleteByQuery(WebgraphSchema.source_id_s + ":\"" + id + "\"");
             }
         } catch (final Throwable e) {
@@ -565,12 +568,12 @@ public final class Fulltext {
 
     public DigestURL getURL(final String urlHash) throws IOException {
         if (urlHash == null || this.getDefaultConnector() == null) return null;
-        
+
         SolrConnector.LoadTimeURL md = this.getDefaultConnector().getLoadTimeURL(urlHash);
         if (md == null) return null;
         return new DigestURL(md.url, ASCII.getBytes(urlHash));
     }
-    
+
     /**
      * get the load time of a resource.
      * @param urlHash
@@ -582,7 +585,7 @@ public final class Fulltext {
         if (md == null) return -1l;
         return md.date;
     }
-    
+
     public List<File> dumpFiles() {
         EmbeddedInstance esc = this.solrInstances.getEmbedded();
         ArrayList<File> zips = new ArrayList<File>();
@@ -604,7 +607,7 @@ public final class Fulltext {
         }
         return zips;
     }
-    
+
     /**
      * Create a dump file from the current embedded solr directory
      * @return file reference to the dump
@@ -613,11 +616,11 @@ public final class Fulltext {
     public File dumpEmbeddedSolr() throws SolrException {
         final EmbeddedInstance esc = this.solrInstances.getEmbedded();
         if(esc == null) {
-        	throw new SolrException(ErrorCode.SERVICE_UNAVAILABLE, "No embedded Solr available.");
+            throw new SolrException(ErrorCode.SERVICE_UNAVAILABLE, "No embedded Solr available.");
         }
         final File storagePath = esc.getContainerPath();
         final File zipOut = new File(this.archivePath, storagePath.getName() + "_" + GenericFormatter.SHORT_DAY_FORMATTER.format() + ".zip");
-    	this.solrInstancesLock.lock();
+        this.solrInstancesLock.lock();
         try {
             this.disconnectLocalSolr();
             try {
@@ -632,11 +635,11 @@ public final class Fulltext {
                 }
             }
         } finally {
-        	this.solrInstancesLock.unlock();
+            this.solrInstancesLock.unlock();
         }
         return zipOut;
     }
-    
+
     /**
      * Restore a solr dump to the current embedded solr directory
      * @param solrDumpZipFile the dump file to use
@@ -645,10 +648,10 @@ public final class Fulltext {
     public void restoreEmbeddedSolr(final File solrDumpZipFile) {
         final EmbeddedInstance esc = this.solrInstances.getEmbedded();
         if(esc == null) {
-        	throw new SolrException(ErrorCode.SERVICE_UNAVAILABLE, "No embedded Solr available.");
+            throw new SolrException(ErrorCode.SERVICE_UNAVAILABLE, "No embedded Solr available.");
         }
         final File storagePath = esc.getContainerPath();
-    	this.solrInstancesLock.lock();
+        this.solrInstancesLock.lock();
         try {
             // this.disconnectLocalSolr(); // moved to (InstanceMirror) sorlInstances.close()
             this.solrInstances.close();
@@ -665,7 +668,7 @@ public final class Fulltext {
                 }
             }
         } finally {
-        	this.solrInstancesLock.unlock();
+            this.solrInstancesLock.unlock();
         }
     }
 
@@ -678,13 +681,13 @@ public final class Fulltext {
         getDefaultConnector().optimize(size);
         if (this.writeWebgraph) getWebgraphConnector().optimize(size);
     }
-    
+
     /**
      * Reboot the local embedded Solr (experimental to check resource management).
      * Please check before that the local embedded Solr is enabled and no external remote Solr is attached.
      */
     public void rebootEmbeddedLocalSolr() {
-    	this.solrInstancesLock.lock();
+        this.solrInstancesLock.lock();
         try {
             this.disconnectLocalSolr();
             // this.solrInstances.close(); // moved to (InstanceMirror) sorlInstances.close()
@@ -695,7 +698,7 @@ public final class Fulltext {
                 ConcurrentLog.logException(e);
             }
         } finally {
-        	this.solrInstancesLock.unlock();
+            this.solrInstancesLock.unlock();
         }
     }
 
@@ -705,10 +708,10 @@ public final class Fulltext {
         private ExportFormat(String ext) {this.ext = ext;}
         public String getExt() {return this.ext;}
     }
-    
+
     public final static String yacy_dump_prefix = "yacy_dump_";
     public Export export(Fulltext.ExportFormat format, String filter, String query, final int maxseconds, File path, boolean dom, boolean text) throws IOException {
-        
+
         // modify query according to maxseconds
         long now = System.currentTimeMillis();
         if (maxseconds > 0) {
@@ -720,7 +723,7 @@ public final class Fulltext {
         } else {
             query = query == null? AbstractSolrConnector.CATCHALL_QUERY : query;
         }
-        
+
         // check the oldest and latest entry in the index for this query
         SolrDocumentList firstdoclist, lastdoclist;
         Object firstdateobject, lastdateobject;
@@ -732,61 +735,60 @@ public final class Fulltext {
         final long doccount;
         final Date firstdate, lastdate;
         if (firstdoclist.size() == 0 || lastdoclist.size() == 0) {
-        	/* Now check again the number of documents without sorting, for compatibility with old fields indexed without DocValues fields (prior to YaCy 1.90)
-        	 * When the local Solr index contains such old documents, requests with sort query return nothing and trace in logs 
-        	 * "java.lang.IllegalStateException: unexpected docvalues type NONE for field..." */
-        	doccount = this.getDefaultConnector().getCountByQuery(query);
-        	if(doccount == 0) {
-        		/* Finally no document to export was found */
-        		throw new IOException("number of exported documents == 0");
-        	}
-       		/* we use default date values just to generate a proper dump file path */
-       		firstdate = new Date(0);
-       		lastdate = new Date(0);
-        		
+            /* Now check again the number of documents without sorting, for compatibility with old fields indexed without DocValues fields (prior to YaCy 1.90)
+             * When the local Solr index contains such old documents, requests with sort query return nothing and trace in logs 
+             * "java.lang.IllegalStateException: unexpected docvalues type NONE for field..." */
+            doccount = this.getDefaultConnector().getCountByQuery(query);
+            if(doccount == 0) {
+                /* Finally no document to export was found */
+                throw new IOException("number of exported documents == 0");
+            }
+               /* we use default date values just to generate a proper dump file path */
+               firstdate = new Date(0);
+               lastdate = new Date(0);
+
         } else {
-        	doccount = firstdoclist.getNumFound();
-        
-        	// create the export name
-        	SolrDocument firstdoc = firstdoclist.get(0);
-        	SolrDocument lastdoc = lastdoclist.get(0);
-        	firstdateobject = firstdoc.getFieldValue(CollectionSchema.load_date_dt.getSolrFieldName());
-        	lastdateobject = lastdoc.getFieldValue(CollectionSchema.load_date_dt.getSolrFieldName());
-        	
-        	/* When firstdate or lastdate is null, we use a default one just to generate a proper dump file path 
-        	 * This should not happen because load_date_dt field is mandatory in the main Solr schema, 
-        	 * but for some reason some documents might end up here with an empty load_date_dt field value */
+            doccount = firstdoclist.getNumFound();
+
+            // create the export name
+            SolrDocument firstdoc = firstdoclist.get(0);
+            SolrDocument lastdoc = lastdoclist.get(0);
+            firstdateobject = firstdoc.getFieldValue(CollectionSchema.load_date_dt.getSolrFieldName());
+            lastdateobject = lastdoc.getFieldValue(CollectionSchema.load_date_dt.getSolrFieldName());
+
+            /* When firstdate or lastdate is null, we use a default one just to generate a proper dump file path 
+             * This should not happen because load_date_dt field is mandatory in the main Solr schema, 
+             * but for some reason some documents might end up here with an empty load_date_dt field value */
             if(firstdateobject instanceof Date) {
-            	firstdate = (Date) firstdateobject;
+                firstdate = (Date) firstdateobject;
             } else {
-    			ConcurrentLog.warn("Fulltext", "The required field " + CollectionSchema.load_date_dt.getSolrFieldName() + " is empty on document with id : "
-    					+ firstdoc.getFieldValue(CollectionSchema.id.getSolrFieldName()));
-            	firstdate = new Date(0);
+                ConcurrentLog.warn("Fulltext", "The required field " + CollectionSchema.load_date_dt.getSolrFieldName() + " is empty on document with id : "
+                        + firstdoc.getFieldValue(CollectionSchema.id.getSolrFieldName()));
+                firstdate = new Date(0);
             }
             if(lastdateobject instanceof Date) {
-            	lastdate = (Date) lastdateobject;
+                lastdate = (Date) lastdateobject;
             } else {
-    			ConcurrentLog.warn("Fulltext", "The required field " + CollectionSchema.load_date_dt.getSolrFieldName() + " is empty on document with id : "
-    					+ lastdoc.getFieldValue(CollectionSchema.id.getSolrFieldName()));
-            	lastdate = new Date(0);
+                ConcurrentLog.warn("Fulltext", "The required field " + CollectionSchema.load_date_dt.getSolrFieldName() + " is empty on document with id : "
+                        + lastdoc.getFieldValue(CollectionSchema.id.getSolrFieldName()));
+                lastdate = new Date(0);
             }
         }
-        
 
         String s = new File(path, yacy_dump_prefix +
                 "f" + GenericFormatter.SHORT_MINUTE_FORMATTER.format(firstdate) + "_" +
                 "l" + GenericFormatter.SHORT_MINUTE_FORMATTER.format(lastdate) + "_" +
                 "n" + GenericFormatter.SHORT_MINUTE_FORMATTER.format(new Date(now)) + "_" +
                 "c" + String.format("%1$012d", doccount)).getAbsolutePath() + "_tc"; // the name ends with the transaction token ('c' = 'created')
-        
+
         // create export file name
         if (s.indexOf('.',0) < 0) s += "." + format.getExt();
         final File f = new File(s);
         f.getParentFile().mkdirs();
-        
+
         return export(f, filter, query, format, dom, text);
     }
-    
+
     // export methods
     public Export export(final File f, final String filter, final String query, final ExportFormat format, final boolean dom, final boolean text) {
         if ((this.exportthread != null) && (this.exportthread.isAlive())) {
@@ -797,10 +799,10 @@ public final class Fulltext {
         this.exportthread.start();
         return this.exportthread;
     }
-    
+
     public static void main(String args[]) {
-    	Date firstdate = null;
-    	System.out.println(GenericFormatter.SHORT_MINUTE_FORMATTER.format(firstdate));
+        Date firstdate = null;
+        System.out.println(GenericFormatter.SHORT_MINUTE_FORMATTER.format(firstdate));
     }
 
     public Export export() {
@@ -816,7 +818,7 @@ public final class Fulltext {
         private final boolean dom, text;
 
         private Export(final File f, final String filter, final String query, final ExportFormat format, final boolean dom, final boolean text) {
-        	super("Fulltext.Export");
+            super("Fulltext.Export");
             // format: 0=text, 1=html, 2=rss/xml
             this.f = f;
             this.pattern = filter == null ? null : Pattern.compile(filter);
@@ -831,20 +833,20 @@ public final class Fulltext {
 
         @Override
         public void run() {
-        	try {
+            try {
                 final File parentf = this.f.getParentFile();
                 if (parentf != null) {
-                	parentf.mkdirs();
+                    parentf.mkdirs();
                 }
-        	} catch(Exception e) {
+            } catch(Exception e) {
                 ConcurrentLog.logException(e);
                 this.failure = e.getMessage();
                 return;
-        	}
-        	
+            }
+
             try (/* Resources automatically closed by this try-with-resources statement */
                 final OutputStream os = new FileOutputStream(this.format == ExportFormat.solr ? new File(this.f.getAbsolutePath() + ".gz") : this.f);
-            	final OutputStream wrappedStream = ((this.format == ExportFormat.solr)) ? new GZIPOutputStream(os, 65536){{def.setLevel(Deflater.BEST_COMPRESSION);}} : os;
+                final OutputStream wrappedStream = ((this.format == ExportFormat.solr)) ? new GZIPOutputStream(os, 65536){{def.setLevel(Deflater.BEST_COMPRESSION);}} : os;
                 final PrintWriter pw =  new PrintWriter(new BufferedOutputStream(wrappedStream));
             ) {
                 if (this.format == ExportFormat.html) {
@@ -946,7 +948,7 @@ public final class Fulltext {
                     pw.println("</response>");
                 }
             } catch (final Exception e) {
-            	/* Catch but log any IO exception that can occur on copy, automatic closing or streams creation */
+                /* Catch but log any IO exception that can occur on copy, automatic closing or streams creation */
                 ConcurrentLog.logException(e);
                 this.failure = e.getMessage();
             }
@@ -964,12 +966,12 @@ public final class Fulltext {
         public int count() {
             return this.count;
         }
-        
+
         @SuppressWarnings("unchecked")
-		private String getStringFrom(final Object o) {
-        	if (o == null) return "";
-        	if (o instanceof ArrayList) return ((ArrayList<String>) o).get(0);
-        	return (String) o;
+        private String getStringFrom(final Object o) {
+            if (o == null) return "";
+            if (o instanceof ArrayList) return ((ArrayList<String>) o).get(0);
+            return (String) o;
         }
 
     }