t0 = start action   ;t1= action find and merge entity; t2= start call to web service; t6= web service return; tend = end action  ;
t3= start second process ; t4= find and merge entity; t5=end second process

t0             t1        t2    t3    t4  t5            t6        tend

|---------------|--------|------------------------------|-------|

                               |-----|----|

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
  <persistence-unit name="ApplicationWeb_EJB" transaction-type="JTA">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <jta-data-source>java:/ds/VisiaIntegrazioneDS</jta-data-source>
    <class>.....entity.ApplicationServer</class>
    ....
    <class>.....entity.Devices</class>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
      <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLInnoDBDialect"/>
      <!-- Caching properties -->
      <property name="hibernate.cache.use_second_level_cache" value="true"/>
      <!--<property name="hibernate.cache.provider_class" value="net.sf.ehcache.hibernate.SingletonEhCacheProvider" />-->
      <property name="net.sf.ehcache.configurationResourceName" value="ehcache.xml"/>
      <!--<property name="hibernate.cache.provider_class" value="org.hibernate.cache.NoCacheProvider"/>-->
      <!--<property name="hibernate.cache.provider_class" value="org.hibernate.cache.EhCacheProvider" />-->
      <property name="hibernate.cache.use_query_cache" value="true"/>
      <property name="hibernate.cache.region.factory_class" value="net.sf.ehcache.hibernate.SingletonEhCacheRegionFactory"/>
      <property name="hibernate.transaction.manager_lookup_class" value="org.hibernate.transaction.JBossTransactionManagerLookup"/>
      <property name="hibernate.max_fetch_depth" value="4"/>
    <!-- hibernate.generate_statistics a true produce informazioni su hibernate da loggare -->
      <property name="hibernate.generate_statistics" value="true"/>

    </properties>
  </persistence-unit>
</persistence>

EntityManager em = EntityMan.getEMF().createEntityManager();

        try {

            em.find(Devices.class, device.getId());
            em.merge(device);
            em.flush();
        } catch (Exception e) {
            logger.debug(e.getMessage());
            e.printStackTrace();
        }