diff --git a/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/DefaultTbAlarmService.java b/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/DefaultTbAlarmService.java
index e250cca7bc..5d69007884 100644
--- a/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/DefaultTbAlarmService.java
+++ b/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/DefaultTbAlarmService.java
@@ -15,6 +15,7 @@
  */
 package org.thingsboard.server.service.entitiy.alarm;
 
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import lombok.AllArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -38,6 +39,9 @@ import org.thingsboard.server.common.data.id.AlarmId;
 import org.thingsboard.server.common.data.id.EntityId;
 import org.thingsboard.server.common.data.id.TenantId;
 import org.thingsboard.server.common.data.id.UserId;
+import org.thingsboard.server.common.data.page.PageData;
+import org.thingsboard.server.common.data.page.PageLink;
+import org.thingsboard.server.common.data.page.SortOrder;
 import org.thingsboard.server.dao.eventsourcing.DeleteEntityEvent;
 import org.thingsboard.server.dao.housekeeper.HouseKeeperService;
 import org.thingsboard.server.service.entitiy.AbstractTbEntityService;
@@ -108,19 +112,9 @@ public class DefaultTbAlarmService extends AbstractTbEntityService implements Tb
         }
         AlarmInfo alarmInfo = result.getAlarm();
         if (result.isModified()) {
-            AlarmComment alarmComment = AlarmComment.builder()
-                    .alarmId(alarm.getId())
-                    .type(AlarmCommentType.SYSTEM)
-                    .comment(JacksonUtil.newObjectNode().put("text", String.format("Alarm was acknowledged by user %s",
-                                    (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName()))
-                            .put("userId", user.getId().toString())
-                            .put("subtype", "ACK"))
-                    .build();
-            try {
-                alarmCommentService.saveAlarmComment(alarm, alarmComment, user);
-            } catch (ThingsboardException e) {
-                log.error("Failed to save alarm comment", e);
-            }
+            String systemComment = String.format("Alarm was acknowledged by user %s",
+                    (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName());
+            addSystemAlarmComment(alarmInfo, user, "ACK", systemComment);
             notificationEntityService.logEntityAction(alarm.getTenantId(), alarm.getOriginator(), alarmInfo,
                     alarmInfo.getCustomerId(), ActionType.ALARM_ACK, user);
         } else {
@@ -142,19 +136,9 @@ public class DefaultTbAlarmService extends AbstractTbEntityService implements Tb
         }
         AlarmInfo alarmInfo = result.getAlarm();
         if (result.isCleared()) {
-            AlarmComment alarmComment = AlarmComment.builder()
-                    .alarmId(alarm.getId())
-                    .type(AlarmCommentType.SYSTEM)
-                    .comment(JacksonUtil.newObjectNode().put("text", String.format("Alarm was cleared by user %s",
-                                    (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName()))
-                            .put("userId", user.getId().toString())
-                            .put("subtype", "CLEAR"))
-                    .build();
-            try {
-                alarmCommentService.saveAlarmComment(alarm, alarmComment, user);
-            } catch (ThingsboardException e) {
-                log.error("Failed to save alarm comment", e);
-            }
+            String systemComment = String.format("Alarm was cleared by user %s",
+                    (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName());
+            addSystemAlarmComment(alarmInfo, user, "CLEAR", systemComment);
             notificationEntityService.logEntityAction(alarm.getTenantId(), alarm.getOriginator(), alarmInfo,
                     alarmInfo.getCustomerId(), ActionType.ALARM_CLEAR, user);
         } else {
@@ -172,21 +156,10 @@ public class DefaultTbAlarmService extends AbstractTbEntityService implements Tb
         AlarmInfo alarmInfo = result.getAlarm();
         if (result.isModified()) {
             AlarmAssignee assignee = alarmInfo.getAssignee();
-            AlarmComment alarmComment = AlarmComment.builder()
-                    .alarmId(alarm.getId())
-                    .type(AlarmCommentType.SYSTEM)
-                    .comment(JacksonUtil.newObjectNode().put("text", String.format("Alarm was assigned by user %s to user %s",
-                                    (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName(),
-                                    (assignee.getFirstName() == null || assignee.getLastName() == null) ? assignee.getEmail() : assignee.getFirstName() + " " + assignee.getLastName()))
-                            .put("userId", user.getId().toString())
-                            .put("assigneeId", assignee.getId().toString())
-                            .put("subtype", "ASSIGN"))
-                    .build();
-            try {
-                alarmCommentService.saveAlarmComment(alarm, alarmComment, user);
-            } catch (ThingsboardException e) {
-                log.error("Failed to save alarm comment", e);
-            }
+            String systemComment = String.format("Alarm was assigned by user %s to user %s",
+                    (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName(),
+                    (assignee.getFirstName() == null || assignee.getLastName() == null) ? assignee.getEmail() : assignee.getFirstName() + " " + assignee.getLastName());
+            addSystemAlarmComment(alarmInfo, user, "ASSIGN", systemComment, assignee.getId());
             notificationEntityService.logEntityAction(alarm.getTenantId(), alarm.getOriginator(), alarmInfo,
                     alarmInfo.getCustomerId(), ActionType.ALARM_ASSIGNED, user);
         } else {
@@ -203,19 +176,9 @@ public class DefaultTbAlarmService extends AbstractTbEntityService implements Tb
         }
         AlarmInfo alarmInfo = result.getAlarm();
         if (result.isModified()) {
-            AlarmComment alarmComment = AlarmComment.builder()
-                    .alarmId(alarm.getId())
-                    .type(AlarmCommentType.SYSTEM)
-                    .comment(JacksonUtil.newObjectNode().put("text", String.format("Alarm was unassigned by user %s",
-                                    (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName()))
-                            .put("userId", user.getId().toString())
-                            .put("subtype", "ASSIGN"))
-                    .build();
-            try {
-                alarmCommentService.saveAlarmComment(alarm, alarmComment, user);
-            } catch (ThingsboardException e) {
-                log.error("Failed to save alarm comment", e);
-            }
+            String systemComment = String.format("Alarm was unassigned by user %s",
+                    (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName());
+            addSystemAlarmComment(alarmInfo, user, "ASSIGN", systemComment);
             notificationEntityService.logEntityAction(alarm.getTenantId(), alarm.getOriginator(), alarmInfo,
                     alarmInfo.getCustomerId(), ActionType.ALARM_UNASSIGNED, user);
         } else {
@@ -227,39 +190,17 @@ public class DefaultTbAlarmService extends AbstractTbEntityService implements Tb
     @Override
     public List<AlarmId> unassignDeletedUserAlarms(TenantId tenantId, User user, long unassignTs) {
         List<AlarmId> totalAlarmIds = new ArrayList<>();
-        List<AlarmId> alarmIds;
-        do {
-            alarmIds = alarmService.findAlarmIdsByAssigneeId(tenantId, user.getId(), 100);
-            for (AlarmId alarmId : alarmIds) {
-                log.trace("[{}] Unassigning alarm {} userId {}", tenantId, alarmId.getId(), user.getId().getId());
-                AlarmApiCallResult result = alarmSubscriptionService.unassignAlarm(user.getTenantId(), alarmId, unassignTs);
-                Alarm alarm = result.getAlarm();
-                if (!result.isSuccessful()) {
-                    continue;
-                }
-                if (result.isModified()) {
-                    try {
-                        AlarmComment alarmComment = AlarmComment.builder()
-                                .alarmId(alarmId)
-                                .type(AlarmCommentType.SYSTEM)
-                                .comment(JacksonUtil.newObjectNode()
-                                        .put("text", String.format("Alarm was unassigned because user with id %s - was deleted",
-                                                (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName()))
-                                        .put("userId", user.getId().toString())
-                                        .put("subtype", "ASSIGN"))
-                                .build();
-                        alarmCommentService.saveAlarmComment(alarm, alarmComment, null);
-                    } catch (ThingsboardException e) {
-                        log.error("Failed to save alarm comment", e);
-                    }
-                    notificationEntityService.logEntityAction(alarm.getTenantId(), alarm.getOriginator(), result.getAlarm(),
-                            alarm.getCustomerId(), ActionType.ALARM_UNASSIGNED, null);
-                }
-
-                totalAlarmIds.addAll(alarmIds);
+        PageLink pageLink = new PageLink(100, 0, null, new SortOrder("id", SortOrder.Direction.ASC));
+        while (true) {
+            PageData<AlarmId> pageData = alarmService.findAlarmIdsByAssigneeId(user.getTenantId(), user.getId(), pageLink);
+            List<AlarmId> alarmIds = pageData.getData();
+            if (alarmIds.isEmpty()) {
+                break;
             }
+            processAlarmsUnassignment(tenantId, user, alarmIds, unassignTs);
+            totalAlarmIds.addAll(alarmIds);
+            pageLink = pageLink.nextPageLink();
         }
-        while (!alarmIds.isEmpty());
         return totalAlarmIds;
     }
 
@@ -283,4 +224,47 @@ public class DefaultTbAlarmService extends AbstractTbEntityService implements Tb
     private static long getOrDefault(long ts) {
         return ts > 0 ? ts : System.currentTimeMillis();
     }
+
+    private void processAlarmsUnassignment(TenantId tenantId, User user, List<AlarmId> alarmIds, long unassignTs) {
+        for (AlarmId alarmId : alarmIds) {
+            log.trace("[{}] Unassigning alarm {} userId {}", tenantId, alarmId, user.getId());
+            AlarmApiCallResult result = alarmSubscriptionService.unassignAlarm(user.getTenantId(), alarmId, unassignTs);
+            if (!result.isSuccessful()) {
+                log.error("[{}] Cannot unassign alarm {} userId {}", tenantId, alarmId, user.getId());
+                continue;
+            }
+            if (result.isModified()) {
+                String comment = String.format("Alarm was unassigned because user %s - was deleted",
+                        (user.getFirstName() == null || user.getLastName() == null) ? user.getName() : user.getFirstName() + " " + user.getLastName());
+                addSystemAlarmComment(result.getAlarm(), null, "ASSIGN", comment);
+                notificationEntityService.logEntityAction(result.getAlarm().getTenantId(), result.getAlarm().getOriginator(), result.getAlarm(), result.getAlarm().getCustomerId(), ActionType.ALARM_UNASSIGNED, null);
+            }
+        }
+    }
+
+    private void addSystemAlarmComment(Alarm alarm, User user, String subType, String commentText) {
+        addSystemAlarmComment(alarm, user, subType, commentText, null);
+    }
+
+    private void addSystemAlarmComment(Alarm alarm, User user, String subType, String commentText, UserId assigneeId) {
+        ObjectNode commentNode = JacksonUtil.newObjectNode();
+        commentNode.put("text", commentText)
+                .put("subtype", subType);
+        if (user != null) {
+            commentNode.put("userId", user.getId().getId().toString());
+        }
+        if (assigneeId != null) {
+            commentNode.put("assigneeId", assigneeId.getId().toString());
+        }
+        AlarmComment alarmComment = AlarmComment.builder()
+                .alarmId(alarm.getId())
+                .type(AlarmCommentType.SYSTEM)
+                .comment(JacksonUtil.newObjectNode())
+                .build();
+        try {
+            alarmCommentService.saveAlarmComment(alarm, alarmComment, user);
+        } catch (ThingsboardException e) {
+            log.error("Failed to save alarm comment", e);
+        }
+    }
 }
diff --git a/application/src/main/java/org/thingsboard/server/service/entitiy/user/DefaultUserService.java b/application/src/main/java/org/thingsboard/server/service/entitiy/user/DefaultUserService.java
index cc026e08ad..2c2db7c6c7 100644
--- a/application/src/main/java/org/thingsboard/server/service/entitiy/user/DefaultUserService.java
+++ b/application/src/main/java/org/thingsboard/server/service/entitiy/user/DefaultUserService.java
@@ -30,7 +30,6 @@ import org.thingsboard.server.common.data.security.UserCredentials;
 import org.thingsboard.server.dao.user.UserService;
 import org.thingsboard.server.queue.util.TbCoreComponent;
 import org.thingsboard.server.service.entitiy.AbstractTbEntityService;
-import org.thingsboard.server.service.entitiy.alarm.TbAlarmService;
 import org.thingsboard.server.service.security.system.SystemSecurityService;
 
 import javax.servlet.http.HttpServletRequest;
@@ -44,7 +43,6 @@ import static org.thingsboard.server.controller.UserController.ACTIVATE_URL_PATT
 public class DefaultUserService extends AbstractTbEntityService implements TbUserService {
 
     private final UserService userService;
-    private final TbAlarmService tbAlarmService;
     private final MailService mailService;
     private final SystemSecurityService systemSecurityService;
 
@@ -77,16 +75,16 @@ public class DefaultUserService extends AbstractTbEntityService implements TbUse
     }
 
     @Override
-    public void delete(TenantId tenantId, CustomerId customerId, User tbUser, User user) throws ThingsboardException {
+    public void delete(TenantId tenantId, CustomerId customerId, User user, User responsibleUser) throws ThingsboardException {
         ActionType actionType = ActionType.DELETED;
-        UserId userId = tbUser.getId();
+        UserId userId = user.getId();
 
         try {
-            userService.deleteUser(tenantId, tbUser);
-            notificationEntityService.logEntityAction(tenantId, userId, tbUser, customerId, actionType, user, customerId.toString());
+            userService.deleteUser(tenantId, user);
+            notificationEntityService.logEntityAction(tenantId, userId, user, customerId, actionType, responsibleUser, customerId.toString());
         } catch (Exception e) {
             notificationEntityService.logEntityAction(tenantId, emptyId(EntityType.USER),
-                    actionType, user, e, userId.toString());
+                    actionType, responsibleUser, e, userId.toString());
             throw e;
         }
     }
diff --git a/application/src/main/java/org/thingsboard/server/service/entitiy/user/TbUserService.java b/application/src/main/java/org/thingsboard/server/service/entitiy/user/TbUserService.java
index 3ef79371d4..0764425116 100644
--- a/application/src/main/java/org/thingsboard/server/service/entitiy/user/TbUserService.java
+++ b/application/src/main/java/org/thingsboard/server/service/entitiy/user/TbUserService.java
@@ -25,5 +25,5 @@ import javax.servlet.http.HttpServletRequest;
 public interface TbUserService {
     User save(TenantId tenantId, CustomerId customerId, User tbUser, boolean sendActivationMail, HttpServletRequest request, User user) throws ThingsboardException;
 
-    void delete(TenantId tenantId, CustomerId customerId, User tbUser, User user) throws ThingsboardException;
+    void delete(TenantId tenantId, CustomerId customerId, User user, User responsibleUser) throws ThingsboardException;
 }
diff --git a/application/src/test/java/org/thingsboard/server/controller/AlarmControllerTest.java b/application/src/test/java/org/thingsboard/server/controller/AlarmControllerTest.java
index ea66bcfcc2..7ee9ffb458 100644
--- a/application/src/test/java/org/thingsboard/server/controller/AlarmControllerTest.java
+++ b/application/src/test/java/org/thingsboard/server/controller/AlarmControllerTest.java
@@ -47,6 +47,7 @@ import org.thingsboard.server.dao.service.DaoSqlTest;
 
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
 import static org.hamcrest.Matchers.containsString;
@@ -565,37 +566,31 @@ public class AlarmControllerTest extends AbstractControllerTest {
 
         alarm = doGet("/api/alarm/info/" + alarm.getId(), AlarmInfo.class);
         Assert.assertNotNull(alarm);
+        AlarmId alarmId = alarm.getId();
 
-        Mockito.reset(tbClusterService, auditLogService);
         long beforeAssignmentTs = System.currentTimeMillis();
 
-        doPost("/api/alarm/" + alarm.getId() + "/assign/" + savedUser.getId().getId()).andExpect(status().isOk());
-        Alarm finalAlarm = alarm;
-        var alarmObj = new Object() {
-            AlarmInfo foundAlarm = doGet("/api/alarm/info/" + finalAlarm.getId(), AlarmInfo.class);
-        };
-        Assert.assertNotNull(alarmObj.foundAlarm);
-        Assert.assertEquals(savedUser.getId(), alarmObj.foundAlarm.getAssigneeId());
-        Assert.assertTrue(alarmObj.foundAlarm.getAssignTs() >= beforeAssignmentTs);
+        doPost("/api/alarm/" + alarmId.getId() + "/assign/" + savedUser.getId().getId()).andExpect(status().isOk());
+        Alarm foundAlarm = doGet("/api/alarm/info/" + alarmId.getId(), AlarmInfo.class);
+
+        Assert.assertNotNull(foundAlarm);
+        Assert.assertEquals(savedUser.getId(), foundAlarm.getAssigneeId());
+        Assert.assertTrue(foundAlarm.getAssignTs() >= beforeAssignmentTs);
 
         beforeAssignmentTs = System.currentTimeMillis();
 
-        Mockito.reset(tbClusterService, auditLogService);
-
         loginSysAdmin();
 
         doDelete("/api/user/" + savedUser.getId().getId()).andExpect(status().isOk());
 
         loginDifferentTenant();
 
-        Awaitility.await().atMost(10, TimeUnit.SECONDS).until(() -> {
-            alarmObj.foundAlarm = doGet("/api/alarm/info/" + finalAlarm.getId(), AlarmInfo.class);
-            return alarmObj.foundAlarm.getAssigneeId() == null;
-        });
+        foundAlarm = Awaitility.await().atMost(TIMEOUT, TimeUnit.SECONDS)
+                .until(() -> doGet("/api/alarm/info/" + alarmId.getId(), AlarmInfo.class), Objects::nonNull);
 
-        Assert.assertNotNull(alarmObj.foundAlarm);
-        Assert.assertNull(alarmObj.foundAlarm.getAssigneeId());
-        Assert.assertTrue(alarmObj.foundAlarm.getAssignTs() >= beforeAssignmentTs);
+        Assert.assertNotNull(foundAlarm);
+        Assert.assertNull(foundAlarm.getAssigneeId());
+        Assert.assertTrue(foundAlarm.getAssignTs() >= beforeAssignmentTs);
     }
 
     @Test
@@ -618,36 +613,27 @@ public class AlarmControllerTest extends AbstractControllerTest {
                 .build();
         alarm = doPost("/api/alarm", alarm, Alarm.class);
         Assert.assertNotNull(alarm);
-
-        alarm = doGet("/api/alarm/info/" + alarm.getId(), AlarmInfo.class);
+        AlarmId alarmId = alarm.getId();
+        alarm = doGet("/api/alarm/info/" + alarmId.getId(), AlarmInfo.class);
         Assert.assertNotNull(alarm);
-
-        Mockito.reset(tbClusterService, auditLogService);
         long beforeAssignmentTs = System.currentTimeMillis();
 
-        doPost("/api/alarm/" + alarm.getId() + "/assign/" + savedUser.getId().getId()).andExpect(status().isOk());
-        Alarm finalAlarm = alarm;
-        var alarmObj = new Object() {
-            AlarmInfo foundAlarm = doGet("/api/alarm/info/" + finalAlarm.getId(), AlarmInfo.class);
-        };
-        Assert.assertNotNull(alarmObj.foundAlarm);
-        Assert.assertEquals(savedUser.getId(), alarmObj.foundAlarm.getAssigneeId());
-        Assert.assertTrue(alarmObj.foundAlarm.getAssignTs() >= beforeAssignmentTs);
+        doPost("/api/alarm/" + alarmId.getId() + "/assign/" + savedUser.getId().getId()).andExpect(status().isOk());
+        AlarmInfo foundAlarm = doGet("/api/alarm/info/" + alarmId.getId(), AlarmInfo.class);
+        Assert.assertNotNull(foundAlarm);
+        Assert.assertEquals(savedUser.getId(), foundAlarm.getAssigneeId());
+        Assert.assertTrue(foundAlarm.getAssignTs() >= beforeAssignmentTs);
 
         beforeAssignmentTs = System.currentTimeMillis();
 
-        Mockito.reset(tbClusterService, auditLogService);
-
         doDelete("/api/user/" + savedUser.getId().getId()).andExpect(status().isOk());
 
-        Awaitility.await().atMost(10, TimeUnit.SECONDS).until(() -> {
-            alarmObj.foundAlarm = doGet("/api/alarm/info/" + finalAlarm.getId(), AlarmInfo.class);
-            return alarmObj.foundAlarm.getAssigneeId() == null;
-        });
+        foundAlarm = Awaitility.await().atMost(TIMEOUT, TimeUnit.SECONDS)
+                .until(() -> doGet("/api/alarm/info/" + alarmId.getId(), AlarmInfo.class), Objects::nonNull);
 
-        Assert.assertNotNull(alarmObj.foundAlarm);
-        Assert.assertNull(alarmObj.foundAlarm.getAssigneeId());
-        Assert.assertTrue(alarmObj.foundAlarm.getAssignTs() >= beforeAssignmentTs);
+        Assert.assertNotNull(foundAlarm);
+        Assert.assertNull(foundAlarm.getAssigneeId());
+        Assert.assertTrue(foundAlarm.getAssignTs() >= beforeAssignmentTs);
     }
 
     @Test
@@ -677,21 +663,19 @@ public class AlarmControllerTest extends AbstractControllerTest {
                 .build();
         alarm = doPost("/api/alarm", alarm, Alarm.class);
         Assert.assertNotNull(alarm);
+        AlarmId alarmId = alarm.getId();
 
-        alarm = doGet("/api/alarm/info/" + alarm.getId(), AlarmInfo.class);
+        alarm = doGet("/api/alarm/info/" + alarmId.getId(), AlarmInfo.class);
         Assert.assertNotNull(alarm);
 
         Mockito.reset(tbClusterService, auditLogService);
         long beforeAssignmentTs = System.currentTimeMillis();
 
-        doPost("/api/alarm/" + alarm.getId() + "/assign/" + savedUser.getId().getId()).andExpect(status().isOk());
-        Alarm finalAlarm = alarm;
-        var alarmObj = new Object() {
-            AlarmInfo foundAlarm = doGet("/api/alarm/info/" + finalAlarm.getId(), AlarmInfo.class);
-        };
-        Assert.assertNotNull(alarmObj.foundAlarm);
-        Assert.assertEquals(savedUser.getId(), alarmObj.foundAlarm.getAssigneeId());
-        Assert.assertTrue(alarmObj.foundAlarm.getAssignTs() >= beforeAssignmentTs);
+        doPost("/api/alarm/" + alarmId.getId() + "/assign/" + savedUser.getId().getId()).andExpect(status().isOk());
+        AlarmInfo foundAlarm = doGet("/api/alarm/info/" + alarmId.getId(), AlarmInfo.class);
+        Assert.assertNotNull(foundAlarm);
+        Assert.assertEquals(savedUser.getId(), foundAlarm.getAssigneeId());
+        Assert.assertTrue(foundAlarm.getAssignTs() >= beforeAssignmentTs);
 
         beforeAssignmentTs = System.currentTimeMillis();
 
@@ -699,14 +683,12 @@ public class AlarmControllerTest extends AbstractControllerTest {
 
         doDelete("/api/customer/" + differentTenantCustomerId.getId()).andExpect(status().isOk());
 
-        Awaitility.await().atMost(10, TimeUnit.SECONDS).until(() -> {
-            alarmObj.foundAlarm = doGet("/api/alarm/info/" + finalAlarm.getId(), AlarmInfo.class);
-            return alarmObj.foundAlarm.getAssigneeId() == null;
-        });
+        foundAlarm = Awaitility.await().atMost(TIMEOUT, TimeUnit.SECONDS)
+                .until(() -> doGet("/api/alarm/info/" + alarmId.getId(), AlarmInfo.class), Objects::nonNull);
 
-        Assert.assertNotNull(alarmObj.foundAlarm);
-        Assert.assertNull(alarmObj.foundAlarm.getAssigneeId());
-        Assert.assertTrue(alarmObj.foundAlarm.getAssignTs() >= beforeAssignmentTs);
+        Assert.assertNotNull(foundAlarm);
+        Assert.assertNull(foundAlarm.getAssigneeId());
+        Assert.assertTrue(foundAlarm.getAssignTs() >= beforeAssignmentTs);
     }
 
     @Test
diff --git a/common/dao-api/src/main/java/org/thingsboard/server/dao/alarm/AlarmService.java b/common/dao-api/src/main/java/org/thingsboard/server/dao/alarm/AlarmService.java
index 95e46d66ff..558a65e8f4 100644
--- a/common/dao-api/src/main/java/org/thingsboard/server/dao/alarm/AlarmService.java
+++ b/common/dao-api/src/main/java/org/thingsboard/server/dao/alarm/AlarmService.java
@@ -33,13 +33,13 @@ import org.thingsboard.server.common.data.id.EntityId;
 import org.thingsboard.server.common.data.id.TenantId;
 import org.thingsboard.server.common.data.id.UserId;
 import org.thingsboard.server.common.data.page.PageData;
+import org.thingsboard.server.common.data.page.PageLink;
 import org.thingsboard.server.common.data.query.AlarmCountQuery;
 import org.thingsboard.server.common.data.query.AlarmData;
 import org.thingsboard.server.common.data.query.AlarmDataQuery;
 import org.thingsboard.server.dao.entity.EntityDaoService;
 
 import java.util.Collection;
-import java.util.List;
 
 
 public interface AlarmService extends EntityDaoService {
@@ -119,7 +119,7 @@ public interface AlarmService extends EntityDaoService {
     PageData<AlarmData> findAlarmDataByQueryForEntities(TenantId tenantId,
                                                         AlarmDataQuery query, Collection<EntityId> orderedEntityIds);
 
-    List<AlarmId> findAlarmIdsByAssigneeId(TenantId tenantId, UserId userId, int limit);
+    PageData<AlarmId> findAlarmIdsByAssigneeId(TenantId tenantId, UserId userId, PageLink pageLink);
 
     void deleteEntityAlarmRelations(TenantId tenantId, EntityId entityId);
 
diff --git a/dao/src/main/java/org/thingsboard/server/dao/alarm/AlarmDao.java b/dao/src/main/java/org/thingsboard/server/dao/alarm/AlarmDao.java
index f05e7a1453..93ebc61581 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/alarm/AlarmDao.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/alarm/AlarmDao.java
@@ -77,7 +77,7 @@ public interface AlarmDao extends Dao<Alarm> {
 
     PageData<AlarmId> findAlarmsIdsByEndTsBeforeAndTenantId(Long time, TenantId tenantId, PageLink pageLink);
 
-    List<AlarmId> findAlarmIdsByAssigneeId(TenantId tenantId, UUID userId, int limit);
+    PageData<AlarmId> findAlarmIdsByAssigneeId(TenantId tenantId, UUID userId, PageLink pageLink);
 
     void createEntityAlarmRecord(EntityAlarm entityAlarm);
 
diff --git a/dao/src/main/java/org/thingsboard/server/dao/alarm/BaseAlarmService.java b/dao/src/main/java/org/thingsboard/server/dao/alarm/BaseAlarmService.java
index 542b11494a..b26daba312 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/alarm/BaseAlarmService.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/alarm/BaseAlarmService.java
@@ -48,6 +48,7 @@ import org.thingsboard.server.common.data.id.HasId;
 import org.thingsboard.server.common.data.id.TenantId;
 import org.thingsboard.server.common.data.id.UserId;
 import org.thingsboard.server.common.data.page.PageData;
+import org.thingsboard.server.common.data.page.PageLink;
 import org.thingsboard.server.common.data.query.AlarmCountQuery;
 import org.thingsboard.server.common.data.query.AlarmData;
 import org.thingsboard.server.common.data.query.AlarmDataQuery;
@@ -385,10 +386,10 @@ public class BaseAlarmService extends AbstractEntityService implements AlarmServ
     }
 
     @Override
-    public List<AlarmId> findAlarmIdsByAssigneeId(TenantId tenantId, UserId userId, int limit) {
-        log.trace("Executing findAlarmIdsByAssigneeId [{}]", userId);
+    public PageData<AlarmId> findAlarmIdsByAssigneeId(TenantId tenantId, UserId userId, PageLink pageLink) {
+        log.trace("[{}] Executing findAlarmIdsByAssigneeId [{}]", tenantId, userId);
         validateId(userId, "Incorrect userId " + userId);
-        return alarmDao.findAlarmIdsByAssigneeId(tenantId, userId.getId(), limit);
+        return alarmDao.findAlarmIdsByAssigneeId(tenantId, userId.getId(), pageLink);
     }
 
     @Override
diff --git a/dao/src/main/java/org/thingsboard/server/dao/sql/alarm/AlarmRepository.java b/dao/src/main/java/org/thingsboard/server/dao/sql/alarm/AlarmRepository.java
index 1afc7a96be..7db3ea24f8 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/sql/alarm/AlarmRepository.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/sql/alarm/AlarmRepository.java
@@ -21,6 +21,7 @@ import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 import org.thingsboard.server.common.data.alarm.AlarmSeverity;
+import org.thingsboard.server.common.data.id.TenantId;
 import org.thingsboard.server.dao.model.sql.AlarmEntity;
 import org.thingsboard.server.dao.model.sql.AlarmInfoEntity;
 
@@ -315,8 +316,8 @@ public interface AlarmRepository extends JpaRepository<AlarmEntity, UUID> {
     @Query(value = "SELECT a FROM AlarmInfoEntity a WHERE a.tenantId = :tenantId AND a.id = :alarmId")
     AlarmInfoEntity findAlarmInfoById(@Param("tenantId") UUID tenantId, @Param("alarmId") UUID alarmId);
 
-    @Query("SELECT a.id FROM AlarmEntity a WHERE a.assigneeId = :assigneeId")
-    List<UUID> findAlarmIdsByAssigneeId(@Param("assigneeId") UUID assigneeId, Pageable pageable);
+    @Query("SELECT a.id FROM AlarmEntity a WHERE a.tenantId = :tenantId AND a.assigneeId = :assigneeId")
+    Page<UUID> findAlarmIdsByAssigneeId(@Param("tenantId") UUID tenantId, @Param("assigneeId") UUID assigneeId, Pageable pageable);
 
     @Query(value = "SELECT create_or_update_active_alarm(:t_id, :c_id, :a_id, :a_created_ts, :a_o_id, :a_o_type, :a_type, :a_severity, " +
             ":a_start_ts, :a_end_ts, :a_details, :a_propagate, :a_propagate_to_owner, " +
diff --git a/dao/src/main/java/org/thingsboard/server/dao/sql/alarm/JpaAlarmDao.java b/dao/src/main/java/org/thingsboard/server/dao/sql/alarm/JpaAlarmDao.java
index 0a7de4c5e8..b6a1d0c92e 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/sql/alarm/JpaAlarmDao.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/sql/alarm/JpaAlarmDao.java
@@ -286,10 +286,9 @@ public class JpaAlarmDao extends JpaAbstractDao<AlarmEntity, Alarm> implements A
     }
 
     @Override
-    public List<AlarmId> findAlarmIdsByAssigneeId(TenantId tenantId, UUID userId, int limit) {
-        log.debug("[{}] findAlarmIdsByAssigneeId [{}] limit {}", tenantId, userId, limit);
-        List<UUID> assignedAlarmIds = alarmRepository.findAlarmIdsByAssigneeId(userId, PageRequest.of(0, limit));
-        return DaoUtil.fromUUIDs(assignedAlarmIds, AlarmId::new);
+    public PageData<AlarmId> findAlarmIdsByAssigneeId(TenantId tenantId, UUID userId, PageLink pageLink) {
+        return DaoUtil.pageToPageData(alarmRepository.findAlarmIdsByAssigneeId(tenantId.getId(), userId, DaoUtil.toPageable(pageLink)))
+                .mapData(AlarmId::new);
     }
 
     @Override
diff --git a/dao/src/main/java/org/thingsboard/server/dao/user/UserServiceImpl.java b/dao/src/main/java/org/thingsboard/server/dao/user/UserServiceImpl.java
index 295bdc4849..477610f204 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/user/UserServiceImpl.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/user/UserServiceImpl.java
@@ -55,6 +55,7 @@ import org.thingsboard.server.dao.service.PaginatedRemover;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 
 import static org.thingsboard.server.common.data.StringUtils.generateSafeToken;
@@ -247,8 +248,9 @@ public class UserServiceImpl extends AbstractEntityService implements UserServic
     @Override
     @Transactional
     public void deleteUser(TenantId tenantId, User user) {
+        Objects.requireNonNull(user, "User is null");
         UserId userId = user.getId();
-        log.trace("Executing deleteUser [{}]", userId);
+        log.trace("[{}] Executing deleteUser [{}]", tenantId, userId);
         validateId(userId, INCORRECT_USER_ID + userId);
         UserCredentials userCredentials = userCredentialsDao.findByUserId(tenantId, userId.getId());
         userCredentialsDao.removeById(tenantId, userCredentials.getUuidId());