In my application we are using Toplink with Jpa.
Here the problem is we are using stored procedures in this application, we are taking the connection using Jndi connection for Stored Procedure calling, and we are using EntityManger for remaining queries. But here if we launching the application it is taking two connections from connection pool. After the application launching I am calling the Stored Procedure(sp)
one sp I am taking one connection but in websphere connection pool it is creating two connections?
can U plese help me how to overcome this problem.....
I won't using JTA, to get the JDBC connection I am using
EntityManager em = getJpaTemplate().getEntityManagerFactory().createEntityManager();
this way I am getting the JDBC Connection...and I configured the persitence.xml file following code...
<properties>
<property name="toplink.logging.level" value="OFF"/>
<property name="toplink.cache.type.default" value="NONE"/>
<property name="com.thoughtinc.runtime.persistence.sql.syntax" value="db2" />
</properties>
So, please kindly look into this and tell me any if I am doing any wrong here.
Are you using JTA or non-JTA? Are you releasing the connection back to the pool after using it?
Depending on your configuration (include your persistence.xml), if you have a non-JTA login configured TopLink may use this for non-transactional read queries. This is configurable in your persistence.xml.
To get the JDBC Connection from a TopLink (EclipseLink) EntityManager use em.unwrap(Connection.class)
Related
I intend to configure postgresql in my app, but I don't want to manage access to my db through WildFly. Is it possible to avoid this approach and to chose another way but with jndi?
If you want to connect a postgresql database without abstraction layer such as wildFly, you can use simply jdbc (https://jdbc.postgresql.org/about/about.html) :
PostgreSQL JDBC Driver (PgJDBC for short) allows Java programs to
connect to a PostgreSQL database using standard, database independent
Java code. Is an open source JDBC driver written in Pure Java (Type
4), and communicates in the PostgreSQL native network protocol.
If you prefer a lightweight ORM (Object Relational Mapping), I would advise activejdbc (http://javalite.io/activejdbc).
Here you can find the configuration of Wildfly Wildfly datasource configuration . The datasource can be access with jndi. You have to replace the example-jdbc-driver with postgres driver.
Bellow is my example of configuration of datasource for IBM-informix
<datasource jndi-name="java:jboss/datasources/mvpdb" pool-name="mvpdbpool">
<connection-url>jdbc:informix-sqli://mars.bza-intern.de:30020/demomvp:informixserver=tcpmars;DB_LOCALE=de_DE.8859-1;IFX_LOCK_MODE_WAIT=10;</connection-url>
<driver>informix</driver>
<transaction-isolation>TRANSACTION_READ_COMMITTED</transaction-isolation>
<pool>
<min-pool-size>1</min-pool-size>
<max-pool-size>3</max-pool-size>
<prefill>true</prefill>
</pool>
<security>
<user-name>abcd</user-name>
<password>efgh</password>
</security>
<statement>
<prepared-statement-cache-size>32</prepared-statement-cache-size>
<share-prepared-statements>true</share-prepared-statements>
</statement>
</datasource>
The datasource can be access ( Spring context ):
with Java Configuration
#Bean(name = "mvpds", autowire = Autowire.BY_NAME)
public DataSource Mvpds() {
logger.info("Mvpds-bean");
final JndiDataSourceLookup dsLookup = new JndiDataSourceLookup();
dsLookup.setResourceRef(true);
DataSource ds = dsLookup.getDataSource("java:jboss/datasources/mvpdb");
return ds;
}
or XML definition
<bean id="mvpds" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName"><value>java:jboss/datasources/mvpdb</value></property>
</bean>
The question was not correct because of lack of knowledge. The promblem is that no way to configure db without WildFly but with jndi. Jndi is an instrument WildFly uses to find a datasourse:)
I'm trying to use the Ignite Jdbc connection; with my goal to be able to call the cache from any client over Jdbc.
I've got a number of scenario's working; so have data loaded correctly; and can run sql queries 'directly' against the cache.
When I try to call from a separate client with
ResultSet rs = conn.createStatement().executeQuery("select * from my_table");
I hit an error:
class org.apache.ignite.IgniteCheckedException: Failed to find class with given class loader for unmarshalling (make sure same versions of all classes are available on all nodes or enable peer-class-loading) [clsLdr=URLClassLoader with NativeCopyLoader with RawResources(
Is there a way to prevent the Ignite jdbc connection from trying to do any unmarshalling?
I would like my client to be as agnostic as possible to the Ignite classes. For example; I would like to swap out calling mariaDb to Ignite - with as little code change as possible on the client side.
If I'm thinking about things the wrong way; then answer along the lines of No, that will never work because ... are more than welcome too.
Thanks
Brent
If you don't want copy libs to client's lib folder, you can turn on Peer Class Loading:
<bean class="org.apache.ignite.configuration.IgniteConfiguration">
...
<!-- Explicitly enable peer class loading. -->
<property name="peerClassLoadingEnabled" value="true"/>
...
</bean>
Also, you can work with BinaryObject, instead of your classes. Here is some example of using sql with BinaryObjects. More information on the binary format is provided here.
I'm using jboss 5.0.1 with multiple data sources configured.
It seems that on startup, if one of those is configured incorrectly, jboss throws an exception and refuses to start.
I would like to know if it's possible to configure jboss to be resilient to these kind of problems.
You can configure the connections in the xml file which holds the connection parameters/mapping. In my case, i am using a microsoft sql server as the datasource, so i have to use the mssql-ds.xml file (inside the server/deploy directory) to specify:
<?xml version="1.0" encoding="UTF-8"?>
<datasources>
<local-tx-datasource>
<jndi-name>myTestServer</jndi-name>
<connection-url>jdbc:sqlserver://xxx.xxx.xxx.xxx:1433;databaseName=MyDB</connection-url>
<driver-class>com.microsoft.sqlserver.jdbc.SQLServerDriver</driver-class>
<user-name>test</user-name>
<password>abc123</password>
<min-pool-size>10</min-pool-size>
<max-pool-size>25</max-pool-size>
<!-- sql to call when connection is created -->
<new-connection-sql>select getdate()</new-connection-sql>
<!-- -->
<!-- sql to call on an existing pooled connection when it is obtained from pool
This will be run before a managed connection is removed from the pool
for use by a client -->
<check-valid-connection-sql>select getdate()</check-valid-connection-sql>
</local-tx-datasource>
</datasources>
This helps control the connections in the pool, and should stop dodgy deadlocks. I'm not entirely sure whether this will test the current transaction level on the connection in question, so if you want to make absolutely sure, you can try: <check-valid-connection-sql>IF ##TRANCOUNT > 0 raiserror ('%s',18,1,'Open Transactions Discovered')</check-valid-connection-sql> This will give you an explicit SQLException to handle.
But if you are getting an error on startup, it would be very useful to see what those errors are.
I have a code that works perfectly on WAS 7 but fail when i run it in WAS 8.0.0.5. I am using JPA 2.0 with openJPA as my provider. Calling persist on my em throws a nested exception. Has anyone ever managed to write a JPA program in WAS 8.0.0.5
here is the Exception
WTRN0074E: Exception caught from before_completion synchronization operation: org.apache.openjpa.persistence.PersistenceException: DB2 SQL Error: SQLCODE=-204, SQLSTATE=42704, SQLERRMC=.OPENJPA_SEQUENCE_TABLE, DRIVER=3.58.81 {prepstmnt -1559269434 SELECT SEQUENCE_VALUE FROM .OPENJPA_SEQUENCE_TABLE WHERE ID = ? FOR READ ONLY WITH RS USE AND KEEP UPDATE LOCKS [params=?]}
The SQLCODE=-204 points that something is missing. The log keeps printing THAKHANI.OPENJPA_SEQUENCE_TABLE which makes think that maybe the table is missing. You could also check to make sure the DB2 user that JPA is using has permissions to create tables and run SELECT statements on them.
I manage to resolve the problem by selecting Identity as my primary key generation mechanism when generating entities from tables. I also add the following in my persistence.xml.
<properties>
<!-- OpenJPA specific properties -->
<property name="openjpa.TransactionMode" value="managed"/>
<property name="openjpa.ConnectionFactoryMode" value="managed"/>
<property name="openjpa.jdbc.DBDictionary" value="db2"/>
<property name="openjpa.jdbc.Schema" value=<SchemaName>/>
</properties>
I am having problems connecting to 2 persistence units from within the same transaction using following tech stack,
WLS 10.3.x, Eclipselink 2.1, Oracle 11g JDBC driver, Informix 10 JDBC driver
Using inputs from this SO post I made the oracle datasource XA compliant and the Informix ds "Emulate 2-phase commit" and things started to work. However, now I am getting a strange problem.
I am using standalone java client to invoke my ejb 3 SLSB which in turn invokes the JPA entities. The problem I am facing is it works the first time, the second time it does not throw any exception but does not update the data in either databases and the 3rd time it throws an exception stating "Transaction has already been committed" as if the application server JTA transaction manager is holding on to the original transaction context. Please note these 3 invocations are separate and sequential wherein every invocations completes with the client exiting the client process. The problem is very consistent and happens in the exact same sequence every time I restart the app server.
Appreciate any input!
<persistence-unit name="TopLinkDB" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>jdbc/oracleDS</jta-data-source>
<class>com.home.domain.Property</class>
<properties>
<property name="eclipselink.target-server" value="WebLogic_10" />
</properties>
</persistence-unit>
<persistence-unit name="TopLinkINFO" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>jdbc/infoDS</jta-data-source>
<class>com.home.domain.GlobalNumber</class>
<properties>
<property name="eclipselink.target-server" value="WebLogic_10" />
</properties>
</persistence-unit>