diff --git a/defaults/solr/solrconfig.xml b/defaults/solr/solrconfig.xml
index 9c536d3fa..b9d818a49 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>8.8.1</luceneMatchVersion>
+  <luceneMatchVersion>8.11.2</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/ivy.xml b/ivy.xml
index 73b4a7663..adbce9b57 100644
--- a/ivy.xml
+++ b/ivy.xml
@@ -13,6 +13,7 @@
       <dependency org="com.cybozu.labs" name="langdetect" rev="1.1-20120112" conf="compile->master"/>
       <dependency org="com.drewnoakes" name="metadata-extractor" rev="2.18.0"  />
       <dependency org="com.fasterxml.jackson.core" name="jackson-databind" rev="2.13.5"/>
+      <dependency org="com.github.ben-manes.caffeine" name="caffeine" rev="3.1.8"/>
       <dependency org="com.google.guava" name="guava" rev="28.0-jre" conf="compile->master"/>
       <dependency org="com.ibm.icu" name="icu4j" rev="73.2"/>
       <dependency org="com.jcraft" name="jsch" rev="0.1.55" />
@@ -41,24 +42,24 @@
       <dependency org="org.apache.httpcomponents" name="httpclient" rev="4.5.12"/>
       <dependency org="org.apache.httpcomponents" name="httpmime" rev="4.5.12"/>
       <dependency org="org.apache.james" name="apache-mime4j" rev="0.6"/>
-      <dependency org="org.apache.lucene" name="lucene-analyzers-phonetic" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-backward-codecs" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-classification" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-codecs" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-grouping" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-highlighter" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-join" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-memory" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-misc" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-queries" rev="8.9.0" />
-      <dependency org="org.apache.lucene" name="lucene-queryparser" rev="8.9.0" conf="compile->master"/>
-      <dependency org="org.apache.lucene" name="lucene-spatial-extras" rev="8.9.0" conf="compile->master"/>
-      <dependency org="org.apache.lucene" name="lucene-suggest" rev="8.9.0"/>
+      <dependency org="org.apache.lucene" name="lucene-analyzers-phonetic" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-backward-codecs" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-classification" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-codecs" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-grouping" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-highlighter" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-join" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-memory" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-misc" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-queries" rev="8.11.2" />
+      <dependency org="org.apache.lucene" name="lucene-queryparser" rev="8.11.2" conf="compile->master"/>
+      <dependency org="org.apache.lucene" name="lucene-spatial-extras" rev="8.11.2" conf="compile->master"/>
+      <dependency org="org.apache.lucene" name="lucene-suggest" rev="8.11.2"/>
       <dependency org="org.apache.pdfbox" name="pdfbox" rev="2.0.29"  />
       <dependency org="org.apache.poi" name="poi" rev="3.17"  />
       <dependency org="org.apache.poi" name="poi-scratchpad" rev="3.17"  />
-      <dependency org="org.apache.solr" name="solr-core" rev="8.9.0" conf="compile->master"/>
-      <dependency org="org.apache.solr" name="solr-solrj" rev="8.9.0" conf="compile->master" />
+      <dependency org="org.apache.solr" name="solr-core" rev="8.11.2" conf="compile->master"/>
+      <dependency org="org.apache.solr" name="solr-solrj" rev="8.11.2" conf="compile->master" />
       <dependency org="org.apache.zookeeper" name="zookeeper" rev="3.6.2" conf="compile->master" />
       <dependency org="org.bitlet" name="weupnp" rev="0.1.4"  />
       <dependency org="org.bouncycastle" name="bcmail-jdk15on" rev="1.70" />
diff --git a/source/net/yacy/search/index/Fulltext.java b/source/net/yacy/search/index/Fulltext.java
index 43fe1d740..718be0099 100644
--- a/source/net/yacy/search/index/Fulltext.java
+++ b/source/net/yacy/search/index/Fulltext.java
@@ -88,8 +88,10 @@ import net.yacy.search.schema.WebgraphSchema;
 
 public final class Fulltext {
 
-    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"};
+    private static final String SOLR_PATH = "solr_8_11_2"; // 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", "solr_8_8_1"};
 
     // class objects
     private final File                    segmentPath;
@@ -140,17 +142,15 @@ public final class Fulltext {
         final 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)) {
+                if (!oldLocation.renameTo(solrLocation)) {
                     ConcurrentLog.severe("Fulltext", "Failed renaming old Solr location ("
                             + oldLocation.getAbsolutePath() + ") to new location : " + solrLocation.getAbsolutePath());
                 }
             }
         }
-         */
 
         final 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});
         final SolrConfig config = localCollectionInstance.getDefaultCore().getSolrConfig();