Index: MyWork/wildfly/ejb3/src/main/java/org/jboss/as/ejb3/timerservice/persistence/database/DatabaseTimerPersistence.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- MyWork/wildfly/ejb3/src/main/java/org/jboss/as/ejb3/timerservice/persistence/database/DatabaseTimerPersistence.java	(date 1508813748000)
+++ MyWork/wildfly/ejb3/src/main/java/org/jboss/as/ejb3/timerservice/persistence/database/DatabaseTimerPersistence.java	(date 1522993721787)
@@ -393,6 +393,7 @@
         Connection connection = null;
         PreparedStatement statement = null;
         try {
+            tm.begin();
             try {
                 connection = dataSource.getConnection();
                 statement = connection.prepareStatement(loadTimer);
@@ -408,9 +409,14 @@
                 }
             } catch (SQLException e) {
                 // something wrong with the preparation
+                try {
+                    tm.rollback();
+                } catch (Exception ee){
+                    EjbLogger.EJB3_TIMER_LOGGER.timerUpdateFailedAndRollbackNotPossible(ee);
+                }
                 throw new RuntimeException(e);
             }
-            tm.begin();
+
             int affected = statement.executeUpdate();
             tm.commit();
             return affected == 1;
Index: MyWork/wildfly/ejb3/src/main/java/org/jboss/as/ejb3/timerservice/TimerServiceImpl.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- MyWork/wildfly/ejb3/src/main/java/org/jboss/as/ejb3/timerservice/TimerServiceImpl.java	(date 1508813748000)
+++ MyWork/wildfly/ejb3/src/main/java/org/jboss/as/ejb3/timerservice/TimerServiceImpl.java	(date 1522993721756)
@@ -604,10 +604,47 @@
                     EJB3_TIMER_LOGGER.timerPersistenceNotEnable();
                     return;
                 }
+
+                Transaction clientTX = transactionManager.getTransaction();
                 if (newTimer) {
-                    timerPersistence.getValue().addTimer(timer);
+                    if( clientTX == null ){
+                        transactionManager.begin();
+                    }
+                    try {
+                        timerPersistence.getValue().addTimer(timer);
+                        if(clientTX == null) transactionManager.commit();
+                    } catch (Exception e){
+                        if(clientTX == null) {
+                            try {
+                                transactionManager.rollback();
+                            } catch (Exception ee){
+                                EjbLogger.EJB3_TIMER_LOGGER.timerUpdateFailedAndRollbackNotPossible(ee);
+                            }
+                        }
+                        throw e;
+                    }
                 } else {
-                    timerPersistence.getValue().persistTimer(timer);
+                    if( clientTX != null ) transactionManager.suspend();
+                    for (int count = 3; count > 0; count--) {
+                        try {
+                            transactionManager.begin();
+                            timerPersistence.getValue().persistTimer(timer);
+                            transactionManager.commit();
+                            break;
+                        } catch (RuntimeException e) {
+                            try {
+                                transactionManager.rollback();
+                            } catch (Exception ee) {
+                                // omit;
+                            }
+                            if (count > 1) {
+                                EJB3_TIMER_LOGGER.debug("Failed to persist timer " + timer + " due to " + e.getCause());
+                            } else {
+                                throw e;
+                            }
+                        }
+                    }
+                    if( clientTX != null ) transactionManager.resume(clientTX);
                 }
 
             } catch (Throwable t) {