[hibernate-issues] [Hibernate-JIRA] Closed: (HHH-2640) Clob management and deadlock

[Steve Ebersole (JIRA)]

     [ http://opensource.atlassian.com/projects/hibernate/browse/HHH-2640?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Steve Ebersole closed HHH-2640.
-------------------------------

    Resolution: Rejected

This is not a help forum.

> Clob management and deadlock
> ----------------------------
>
>                 Key: HHH-2640
>                 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-2640
>             Project: Hibernate Core
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 3.2.0.ga
>         Environment: JDK 1.5, Oracle 10g v2
>            Reporter: Samuel Emangard
>            Priority: Trivial
>         Attachments: Samuel.rar
>
>
> Mapping documents:
> <?xml version="1.0"?>
> <!DOCTYPE hibernate-mapping PUBLIC
> '-//Hibernate/Hibernate Mapping DTD 3.0//EN'
> 'http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd'>
> <hibernate-mapping package="com.toluna.samuel.hibernate.emailtemplate">
> <class name="EmailTemplate" table="EmailTemplate">
> <id name="id" type="long">
> <column name="template_id" not-null="true"/>
> <generator class="native"/>
> </id>
> <property name="name">
> <column name="email_name" not-null="false"/>
> </property>
> <property name="htmlTextClob" type="clob">
> <column name="html_Text" not-null="false"/>
> </property>
> <property name="plainTextClob" type="clob">
> <column name="plain_Text" not-null="false"/>
> </property>
> </class>
> </hibernate-mapping>
> Extract also of my Java bean:
> ublic class EmailTemplate {
> private long id;
> private String name;
> private String plainText = " ";
> private String htmlText = " ";
> private Clob plainTextClob;
> private Clob htmlTextClob;
> ...
> Code of the test case:
> Session ss = HibernateUtil.getSessionFactory().getCurrentSession();
> //S_LOGGER.debug("Number of current Hibernate sessions: "+ HibernateUtil.getSessionFactory().getStatistics().getSessionOpenCount());
> ss.getTransaction().begin();
> EmailTemplate et = (EmailTemplate) ss.load(EmailTemplate.class, new Long("299941536982302"));
> S_LOGGER.debug(et.getName());
> Thread.sleep(5000);
> S_LOGGER.debug("BEFORE FLUSH");
> ss.flush();
> S_LOGGER.debug("AFTER FLUSH");
> ss.getTransaction().commit();
> The generated SQL :
> The load statement is always generated:
> /* load com.toluna.samuel.hibernate.emailtemplate.EmailTemplate */ select
> emailtempl0_.template_id as template1_0_0_,
> emailtempl0_.email_name as email2_0_0_,
> emailtempl0_.html_Text as html3_0_0_,
> emailtempl0_.plain_Text as plain4_0_0_
> from
> EmailTemplate emailtempl0_
> where
> emailtempl0_.template_id=?
> ....
> Depending on the implementation of the getter, the following update statement is generated:
> /* update
> com.toluna.samuel.hibernate.emailtemplate.EmailTemplate */ update
> EmailTemplate
> set
> email_name=?,
> html_Text=?,
> plain_Text=?
> where
> template_id=?
> Here is the getter:
> Clob getHtmlTextClob() {
> //1-
> //return Hibernate.createClob(htmlText != null ? htmlText : " ");
> //2-
> return htmlTextClob;
> }
> With 1- the update statement is generated
> With 2- the update statement is not generated
> Why?
> Extract of the setter:
> void setHtmlTextClob(Clob htmlTextClob) {
> this.htmlTextClob = htmlTextClob;
> try {
> if (htmlTextClob != null) {
> htmlText = HibernateUtil.getStringFromClob(htmlTextClob);
> //htmlText = "samuel";
> } else
> htmlText = "";
> } catch (SQLException e) {
> throw new RuntimeException(e);
> } catch (IOException e) {
> throw new RuntimeException(e);
> }
> }
> I have also another more critical issue which seems tied to the previous:
> If I write the following piece of test code instead of the one shown above:
> Session ss = HibernateUtil.getSessionFactory().openSession();
> //S_LOGGER.debug("Number of current Hibernate sessions: "+ HibernateUtil.getSessionFactory().getStatistics().getSessionOpenCount());
> EmailTemplate et = (EmailTemplate) ss.load(EmailTemplate.class, new Long("299941536982302"));
> S_LOGGER.debug(et.getName());
> Thread.sleep(5000);
> S_LOGGER.debug("BEFORE FLUSH");
> ss.flush();
> S_LOGGER.debug("AFTER FLUSH");
> As you can see in this piece of code i do not manage transactions explicitly and in that case my 2 java threads generated update statements which never ended: there was a deadlock on the DB.
> During the last test, If I still did not manage transactions explicitly but I modified the getter like that:
> Clob getHtmlTextClob() {
> return htmlTextClob;
> }
> Then neither update statements nor deadlock were generated.
> I wrote this piece of test code to reproduce deadlock I was facing on my Jonas server.
> Could you please help me to understand this behaviour?
> Here is anextract of my hibernate.cfg.xml:
> <property name="connection.url">jdbc:oracle:thin:@192.168.2.7:1521:tlorcl1</property>
> <property name="connection.username">samuel</property>
> <property name="connection.password">toluna</property>
> <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
> <property name="dialect">org.hibernate.dialect.Oracle9Dialect</property>
> <property name="hibernate.show_sql">true</property>
> <property name="hibernate.format_sql">true</property>
> <property name="hibernate.use_sql_comments">true</property>
> <property name="myeclipse.connection.profile">QA</property>
> <property name="current_session_context_class">thread</property>
> Thanks in advance
> Regards
> Samuel

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