我们正在使用GAE和JDO2.3，有这样的代码。

public void submit_job (HttpSession session, BlobKey blobKey) throws Exception {
  // START TRANSACTION
  PersistenceManager pm = PMF.get().getPersistenceManager();
  Transaction tx = pm.currentTransaction();
  tx.begin();
  // GET JOB AND MEMBER FROM DATASTORE
  Key jobKey = (Key)session.getAttribute("jobkey");
  String userName = session.getAttribute("username").toString();
  Job job = pm.getObjectById(Job.class, jobKey);
  Member m = pm.getObjectById(Member.class, username);
  // STORE JOB INFORMATION IN DATASTORE
  Date now = new Date();
  job.caricature = blobKey;
  job.whenSubmitted = now;
  job.whenFinished = now;
  pm.makePersistent(job);
  pm.flush();
  log.warning("submit_job: updating job " + job.key);
  // UPDATE MEMBER INFORMATION
  m.numSubmittedJobs++;
  pm.makePersistent(m);
  pm.flush();    
  log.warning("submit_job: updating user " + username);
  // COMPLETE TRANSACTION
  tx.commit();
  pm.close();
  log.warning("transaction completed? " + !tx.isActive());
没有抛出异常，一切运行正常
在最后，交易被正确地完成（"交易完成？）
下面的查询可以从成员和工作对象中读取更新的数据
该信息没有显示在数据存储管理器中
重启实例后，JDO对象仍有其旧值。所有的变化都丢失了。
这里是我们的jdoconfig.xml。
<?xml version="1.0" encoding="utf-8"?>
<jdoconfig xmlns="http://java.sun.com/xml/ns/jdo/jdoconfig"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:noNamespaceSchemaLocation="http://java.sun.com/xml/ns/jdo/jdoconfig">
   <persistence-manager-factory name="transactions-optional">
       <property name="javax.jdo.PersistenceManagerFactoryClass"
           value="org.datanucleus.api.jdo.JDOPersistenceManagerFactory"/>
       <property name="javax.jdo.option.ConnectionURL" value="appengine"/>
       <property name="javax.jdo.option.NontransactionalRead" value="true"/>
       <property name="javax.jdo.option.NontransactionalWrite" value="true"/>
       <property name="javax.jdo.option.RetainValues" value="true"/>
       <property name="datanucleus.appengine.autoCreateDatastoreTxns" value="true"/>
       <property name="datanucleus.appengine.singletonPMFForName" value="true"/>
       <property name="datanucleus.appengine.datastoreEnableXGTransactions" value="true"/>
   </persistence-manager-factory>
</jdoconfig>
和persistence.xml。
<?xml version="1.0" encoding="UTF-8" ?>
<persistence
    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"
    version="1.0">
    <persistence-unit name="transactions-optional">
        <provider>org.datanucleus.api.jpa.PersistenceProviderImpl</provider>
        <properties>
            <property name="datanucleus.NontransactionalRead" value="true"/>
            <property name="datanucleus.NontransactionalWrite" value="true"/>
            <property name="datanucleus.ConnectionURL" value="appengine"/>
        </properties>
    </persistence-unit>
</persistence>
希望得到任何帮助，我们已经在这个问题上花了很多精力，但是还不能解决这个问题。