diff --git a/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStore.java b/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStore.java
index 345500737..db200cd6a 100644
--- a/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStore.java
+++ b/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStore.java
@@ -3,6 +3,7 @@ package eu.dnetlib.data.mdstore.manager.common.model;
 
 import java.io.Serializable;
 import java.util.Date;
+import java.util.Objects;
 import java.util.UUID;
 
 import javax.persistence.Column;
@@ -153,4 +154,23 @@ public class MDStore implements Serializable {
 		return md;
 	}
 
+	@Override
+	public String toString() {
+		return String
+			.format("MDStore [id=%s, format=%s, layout=%s, interpretation=%s, datasourceName=%s, datasourceId=%s, apiId=%s, hdfsPath=%s, creationDate=%s]", id, format, layout, interpretation, datasourceName, datasourceId, apiId, hdfsPath, creationDate);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(id);
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (this == obj) { return true; }
+		if (!(obj instanceof MDStore)) { return false; }
+		final MDStore other = (MDStore) obj;
+		return Objects.equals(id, other.id);
+	}
+
 }
diff --git a/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreCurrentVersion.java b/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreCurrentVersion.java
index f74ab39be..e25e7dc2a 100644
--- a/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreCurrentVersion.java
+++ b/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreCurrentVersion.java
@@ -2,6 +2,7 @@
 package eu.dnetlib.data.mdstore.manager.common.model;
 
 import java.io.Serializable;
+import java.util.Objects;
 
 import javax.persistence.Column;
 import javax.persistence.Entity;
@@ -48,4 +49,22 @@ public class MDStoreCurrentVersion implements Serializable {
 	public static MDStoreCurrentVersion newInstance(final MDStoreVersion v) {
 		return newInstance(v.getMdstore(), v.getId());
 	}
+
+	@Override
+	public String toString() {
+		return String.format("MDStoreCurrentVersion [mdstore=%s, currentVersion=%s]", mdstore, currentVersion);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(currentVersion, mdstore);
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (this == obj) { return true; }
+		if (!(obj instanceof MDStoreCurrentVersion)) { return false; }
+		final MDStoreCurrentVersion other = (MDStoreCurrentVersion) obj;
+		return Objects.equals(currentVersion, other.currentVersion) && Objects.equals(mdstore, other.mdstore);
+	}
 }
diff --git a/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreVersion.java b/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreVersion.java
index 62370c0f5..26c34fcad 100644
--- a/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreVersion.java
+++ b/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreVersion.java
@@ -3,6 +3,7 @@ package eu.dnetlib.data.mdstore.manager.common.model;
 
 import java.io.Serializable;
 import java.util.Date;
+import java.util.Objects;
 
 import javax.persistence.Column;
 import javax.persistence.Entity;
@@ -111,4 +112,23 @@ public class MDStoreVersion implements Serializable {
 	public void setHdfsPath(final String hdfsPath) {
 		this.hdfsPath = hdfsPath;
 	}
+
+	@Override
+	public String toString() {
+		return String
+			.format("MDStoreVersion [id=%s, mdstore=%s, writing=%s, readCount=%s, lastUpdate=%s, size=%s, hdfsPath=%s]", id, mdstore, writing, readCount, lastUpdate, size, hdfsPath);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(id);
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (this == obj) { return true; }
+		if (!(obj instanceof MDStoreVersion)) { return false; }
+		final MDStoreVersion other = (MDStoreVersion) obj;
+		return Objects.equals(id, other.id);
+	}
 }
diff --git a/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreWithInfo.java b/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreWithInfo.java
index 72915a9c8..e34e4c000 100644
--- a/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreWithInfo.java
+++ b/dhp-common/src/main/java/eu/dnetlib/data/mdstore/manager/common/model/MDStoreWithInfo.java
@@ -3,6 +3,7 @@ package eu.dnetlib.data.mdstore.manager.common.model;
 
 import java.io.Serializable;
 import java.util.Date;
+import java.util.Objects;
 
 import javax.persistence.Column;
 import javax.persistence.Entity;
@@ -163,4 +164,24 @@ public class MDStoreWithInfo implements Serializable {
 	public void setHdfsPath(final String hdfsPath) {
 		this.hdfsPath = hdfsPath;
 	}
+
+	@Override
+	public String toString() {
+		return String
+			.format("MDStoreWithInfo [id=%s, format=%s, layout=%s, interpretation=%s, datasourceName=%s, datasourceId=%s, apiId=%s, currentVersion=%s, creationDate=%s, lastUpdate=%s, size=%s, numberOfVersions=%s, hdfsPath=%s]", id, format, layout, interpretation, datasourceName, datasourceId, apiId, currentVersion, creationDate, lastUpdate, size, numberOfVersions, hdfsPath);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(id);
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (this == obj) { return true; }
+		if (!(obj instanceof MDStoreWithInfo)) { return false; }
+		final MDStoreWithInfo other = (MDStoreWithInfo) obj;
+		return Objects.equals(id, other.id);
+	}
+
 }