diff --git a/dnet-pace-core/src/main/java/eu/dnetlib/pace/config/PaceConfig.java b/dnet-pace-core/src/main/java/eu/dnetlib/pace/config/PaceConfig.java
index df66f53..4fde1de 100644
--- a/dnet-pace-core/src/main/java/eu/dnetlib/pace/config/PaceConfig.java
+++ b/dnet-pace-core/src/main/java/eu/dnetlib/pace/config/PaceConfig.java
@@ -23,9 +23,11 @@ public class PaceConfig implements Serializable {
 	private List<ClusteringDef> clustering;
 	private Map<String, List<String>> blacklists;
 
+	@JsonIgnore
 	private Map<String, FieldDef> modelMap;
 
-	//	public PaceResolver paceResolver;
+	@JsonIgnore
+	public static PaceResolver resolver = new PaceResolver();
 
 	public PaceConfig() {}
 
@@ -34,8 +36,6 @@ public class PaceConfig implements Serializable {
 		for(FieldDef fd : getModel()) {
 			modelMap.put(fd.getName(), fd);
 		}
-
-//		paceResolver = new PaceResolver();
 	}
 
 	public List<FieldDef> getModel() {
diff --git a/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/ClusteringDef.java b/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/ClusteringDef.java
index 3ee4be2..d2dab04 100644
--- a/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/ClusteringDef.java
+++ b/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/ClusteringDef.java
@@ -23,8 +23,6 @@ public class ClusteringDef implements Serializable {
 
 	private Map<String, Integer> params;
 
-	PaceResolver paceResolver = new PaceResolver();
-
 	public ClusteringDef() {}
 
 	public String getName() {
@@ -36,12 +34,7 @@ public class ClusteringDef implements Serializable {
 	}
 
 	public ClusteringFunction clusteringFunction() {
-		try {
-			return paceResolver.getClusteringFunction(getName(), params);
-		} catch (PaceException e) {
-			e.printStackTrace();
-			return null;
-		}
+		return PaceConfig.resolver.getClusteringFunction(getName(), params);
 	}
 
 	public List<String> getFields() {
diff --git a/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/CondDef.java b/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/CondDef.java
index b74a3cf..620984f 100644
--- a/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/CondDef.java
+++ b/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/CondDef.java
@@ -16,12 +16,10 @@ public class CondDef implements Serializable {
 
 	private List<String> fields;
 
-	PaceResolver paceResolver = new PaceResolver();
-
 	public CondDef() {}
 
-	public ConditionAlgo conditionAlgo(final List<FieldDef> fields){
-		return paceResolver.getConditionAlgo(getName(), fields);
+	public ConditionAlgo conditionAlgo(final List<FieldDef> fields) {
+		return PaceConfig.resolver.getConditionAlgo(getName(), fields);
 	}
 
 	public String getName() {
diff --git a/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/FieldDef.java b/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/FieldDef.java
index 56ca5a4..9964713 100644
--- a/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/FieldDef.java
+++ b/dnet-pace-core/src/main/java/eu/dnetlib/pace/model/FieldDef.java
@@ -34,8 +34,6 @@ public class FieldDef implements Serializable {
 
 	private double weight;
 
-	PaceResolver paceResolver = new PaceResolver();
-
 	/**
 	 * Sets maximum size for the repeatable fields in the model. -1 for unbounded size.
 	 */
@@ -82,13 +80,8 @@ public class FieldDef implements Serializable {
 			params = new HashMap<>();
 		}
 
-		//TODO verify that the init signatures for the distance algos are all the same!
-		/*
-		params.put("size", getSize());
-		params.put("length", getLength());
-		*/
 		params.put("weight", getWeight());
-		return paceResolver.getDistanceAlgo(getAlgo(), params);
+		return PaceConfig.resolver.getDistanceAlgo(getAlgo(), params);
 	}
 
 	public boolean isIgnoreMissing() {
diff --git a/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/PaceResolver.java b/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/PaceResolver.java
index f8ebb80..d9868b6 100644
--- a/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/PaceResolver.java
+++ b/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/PaceResolver.java
@@ -17,21 +17,25 @@ import java.util.stream.Collectors;
 
 public class PaceResolver implements Serializable {
 
+    public static final Reflections CLUSTERING_RESOLVER = new Reflections("eu.dnetlib.pace.clustering");
+    public static final Reflections CONDITION_RESOLVER = new Reflections("eu.dnetlib.pace.condition");
+    public static final Reflections DISTANCE_RESOLVER = new Reflections("eu.dnetlib.pace.distance.algo");
+
     private final Map<String, Class<ClusteringFunction>> clusteringFunctions;
     private final Map<String, Class<ConditionAlgo>> conditionAlgos;
     private final Map<String, Class<DistanceAlgo>> distanceAlgos;
 
     public PaceResolver() {
 
-        this.clusteringFunctions = new Reflections("eu.dnetlib").getTypesAnnotatedWith(ClusteringClass.class).stream()
+        this.clusteringFunctions = CLUSTERING_RESOLVER.getTypesAnnotatedWith(ClusteringClass.class).stream()
                 .filter(ClusteringFunction.class::isAssignableFrom)
                 .collect(Collectors.toMap(cl -> cl.getAnnotation(ClusteringClass.class).value(), cl -> (Class<ClusteringFunction>)cl));
 
-        this.conditionAlgos = new Reflections("eu.dnetlib").getTypesAnnotatedWith(ConditionClass.class).stream()
+        this.conditionAlgos = CONDITION_RESOLVER.getTypesAnnotatedWith(ConditionClass.class).stream()
                 .filter(ConditionAlgo.class::isAssignableFrom)
                 .collect(Collectors.toMap(cl -> cl.getAnnotation(ConditionClass.class).value(), cl -> (Class<ConditionAlgo>)cl));
 
-        this.distanceAlgos = new Reflections("eu.dnetlib").getTypesAnnotatedWith(DistanceClass.class).stream()
+        this.distanceAlgos = DISTANCE_RESOLVER.getTypesAnnotatedWith(DistanceClass.class).stream()
                 .filter(DistanceAlgo.class::isAssignableFrom)
                 .collect(Collectors.toMap(cl -> cl.getAnnotation(DistanceClass.class).value(), cl -> (Class<DistanceAlgo>)cl));
     }