9:08 a.m.
Hi Raymond,
since you show just one piece of code and your issue is a deadlock one
cannot really give much advice. It's even unclear whether the code
you showed participated in the deadlock.
I suggest to either trace or debug to find deadlocked threads. Since
there is a DB involved your deadlock might actually consist of Java
and DB locks. If it were a DB only deadlock, chances are that your DB
detects it and kills one of the two transactions (MS SQL Server does
for example).
Kind regards
robert
2007/3/14, Raymond Auge <rauge(a)liferay.com>:
Hello All,
I'm in need of some insight on a hibernate problem.
A little about the environment
- hibernate 3.2 CR2
- Spring 1.2.8
some background...
We have some logic which performs several operations on the db in a fairly
random sequence... one of the operations is an SQL insert via hibernate
try {
session = openSession();
if (draftAction.isNew()) {
session.save(draftAction);
}
session.flush();
draftAction.setNew(false);
return draftAction;
} catch (HibernateException he) {
throw new SystemException(he);
} finally {
}
Now, since the sequence is random, we are expecting an exception to be
thrown, because due to the behaviour of our business logic, the object we're
trying ti insert may already exist in the db. So we are
anticipating it.
Here is the info log in the catch block wrapping the dao insert call:
22:19:41,634 INFO [DraftUtil:581] com.sc.ScApplicationException:
com.liferay.portal.SystemException:
org.hibernate.exception.ConstraintViolationException: Could not execute JDBC
batch update
com.liferay.portal.SystemException: com.sc.ScApplicationException:
com.liferay.portal.SystemException:
org.hibernate.exception.ConstraintViolationException: Could not execute JDBC
batch update
at
com.sc.portlet.draft.service.spring.DraftActionLocalServiceUtil.addDraftAction(DraftActionLocalServiceUtil.java:14)
at com.sc.portlet.draft.util.DraftUtil.doAutoDraft(DraftUtil.java:570)
at com.sc.portlet.draft.util.DraftUtil.autoDraftRound(DraftUtil.java:495)
at
com.sc.portlet.fantasyteam.mlb.draft.action.JSONDraftedDataAction.getJSON
So, at a high level, imagine that there are 1000 choices to pick from, only
one choice can be made, choices are made randomly, everyone's choice must be
unique among the 1000, and there are 12 people making a choice in a random
order, one after another. in a loop...
So the insert is both the selection action and the determination of whether
the choice is already used up (when the exception is thrown, try again)...
The problem: randomly during execution (but very frequently) we are getting
threads which become deadlocked while performing this operation and never
return, and eventually all thread in the system are used up and the server
become unresponsive.
Here is the hbm for one object:
<class name="com.sc.portlet.draft.model.DraftAction"
table="DraftAction">
<cache usage="read-write" />
<composite-id name="primaryKey"
class="com.sc.portlet.draft.service.persistence.DraftActionPK">
<key-property name="draftId" />
<key-property name="fantasyTeamId" />
<key-property name="round" />
</composite-id>
<property name="action"
type="com.liferay.util.dao.hibernate.StringType" />
<property name="range"
type="com.liferay.util.dao.hibernate.StringType" />
<property name="playerId"
type="com.liferay.util.dao.hibernate.StringType"
/>
<property name="createDate" />
</class>
Here is the Spring config for the dao:
<bean
id="com.sc.portlet.draft.service.spring.DraftActionLocalService.professional"
class="com.sc.portlet.draft.service.impl.DraftActionLocalServiceImpl"
lazy-init="true" />
<bean
id="com.sc.portlet.draft.service.spring.DraftActionLocalService.transaction"
class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean"
lazy-init="true">
<property name="transactionManager">
<ref bean="liferayTransactionManager" />
</property>
<property name="target">
<ref
bean="com.sc.portlet.draft.service.spring.DraftActionLocalService.professional"
/>
</property>
<property name="transactionAttributes">
<props>
<prop key="*">PROPAGATION_REQUIRED</prop>
</props>
</property>
</bean>
<bean
id="com.sc.portlet.draft.service.spring.DraftActionLocalServiceFactory"
class="com.sc.portlet.draft.service.spring.DraftActionLocalServiceFactory"
lazy-init="true">
<property name="service">
<ref
bean="com.sc.portlet.draft.service.spring.DraftActionLocalService.transaction"
/>
</property>
</bean>
If anyone has any insight on why this might occur I would be very greatful.
Thank you,
Raymond Auge
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