I am developping a Spring MVC web application that use the dbcp database connection pool.
<bean id="datasourceAR_XXX" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close" scope="singleton">
<property name="driverClassName"><value>oracle.jdbc.driver.OracleDriver</value></property>
<property name="url"><value>jdbc:oracle:thin:#XXX.XXX.com:1500:SERVICE</value></property>
<property name="maxActive"><value>100</value></property>
<property name="maxIdle"><value>10</value></property>
<property name="username"><value>XXX</value></property>
<property name="password"><value>XXX</value></property>
</bean>
I recently moved the scope of those beans to singleton because the amount of connection per session started to be a bit too much.
The problem is :
Our database is shutting down every sunday and the spring application seems to act strangely by keeping the socket open and does not refresh the connection as I thought it would do.
Is there a way to refresh the beans scoped as singleton in a way that will refresh the connection everyday and not be obliged to relaunch the application every monday?
What you want to do is to configure validation for your connections. When a connection is borrowed from the pool you want to make sure that that connection is valid. For this you can specify the validationQuery property on your datasource.
<bean id="datasourceAR_XXX" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close" scope="singleton">
<property name="driverClassName"><value>oracle.jdbc.driver.OracleDriver</value></property>
<property name="url"><value>jdbc:oracle:thin:#XXX.XXX.com:1500:SERVICE</value></property>
<property name="maxActive"><value>100</value></property>
<property name="maxIdle"><value>10</value></property>
<property name="username"><value>XXX</value></property>
<property name="password"><value>XXX</value></property>
<property name="validationQuery" value="select 1 from dual" />
</bean>
See DBCP - validationQuery for different Databases for a list of possible validation queries for different databases.
There are some issues with Commons DBCP and it is pretty old (although there is a DBCP 2.x now). I would suggest moving to a different datasource like HikariCP this datasource is also a JDBC 4.x based datasource which allows for easier connection validation (it is part of the JDBC 4 spec).
<bean id="datasourceAR_XXX" class="com.zaxxer.hikari.HikariDataSource">
<property name="datasourceClassName" value="oracle.jdbc.pool.OracleDataSource"/>
<property name="maximumPoolSize" value="20" />
<property name="username" value="XXX" />
<property name="password" value="XXX" />
<property name="datasourceProperties">
<props>
<prop key="serverName">XXX.XXX.com</prop>
<prop key="port">1500</prop>
<prop key="databaseName">SERVICE</prop>
</props>
</property>
</bean>
If your oracle driver is new enough you don't need a validation query anymore as validation is provided by the driver instead of needing to be done with a query. Next to that you probably have better results with this pool.
Also you might have a bit of a large pool size, nice article/presentation about pool sizing can be found here.
Related
Can a HikariCP Datasource be started with a Lazy configuration?
For that, i'm using Spring LazyConnectionDataSourceProxy.
<bean id="hikariConfig" class="com.zaxxer.hikari.HikariConfig" lazy-init="true">
<property name="poolName" value="TargetHikariCP" />
<property name="dataSourceClassName" value="oracle.jdbc.pool.OracleDataSource" />
<property name="connectionInitSql" value="SELECT 1 FROM DUAL"/>
<property name="leakDetectionThreshold" value="300000"/>
<property name="minimumIdle" value="1"/>
<property name="maximumPoolSize" value="10"/>
<property name="autoCommit" value="false"/>
<property name="dataSourceProperties"> <props> ... </props> </property>
</bean>
<bean id="dataSourceLazy" class="com.zaxxer.hikari.HikariDataSource" destroy-method="close" lazy-init="true">
<constructor-arg ref="hikariConfig" />
</bean>
<bean id="dataSource"
class="org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy">
<property name="targetDataSource" ref="dataSourceLazy" />
</bean>
<bean id="txManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager" lazy-init="true">
<property name="dataSource" ref="dataSource" />
</bean>
Nevertheless, its not working, as the Datasource is started on project startup.
The same configuration, when using a org.springframework.jdbc.datasource.DriverManagerDataSource, works correctly.
In the version > 3 we can set setInitializationFailTimeout(-1);
According to docs:
Any value greater than zero will be treated as a timeout for pool initialization.The calling thread will be blocked from continuing until a successful connection
to the database, or until the timeout is reached. If the timeout is reached, then
a PoolInitializationException will be thrown.
A value of zero will not prevent the pool from starting in the
case that a connection cannot be obtained. However, upon start the pool will
attempt to obtain a connection and validate that the connectionTestQuery
and connectionInitSql are valid. If those validations fail, an exception
will be thrown. If a connection cannot be obtained, the validation is skipped
and the the pool will start and continue to try to obtain connections in the
background. This can mean that callers to DataSource#getConnection() may
encounter exceptions.
A value less than zero will bypass any connection attempt and validation during
startup, and therefore the pool will start immediately. The pool will continue to
try to obtain connections in the background. This can mean that callers to
DataSource#getConnection() may encounter exceptions.
HikariCP has a property, initializationFailFast, that controls whether the pool will "fail fast" if the pool cannot be seeded with initial connections successfully:
This property controls whether the pool will "fail fast" if the pool cannot be seeded with initial connections successfully. If you want your application to start even when the database is down/unavailable, set this property to false. Default: true
This property was documented in their site, but per version 2.6.2 its not, but it seems its still supported.
In my use case, the use of this property should be enough to solve my problem.
In spring I have a datasource defined in this way:
<bean id="dataSource" class="oracle.jdbc.pool.OracleDataSource" destroy-method="close">
<property name="URL" value="${jdbc.url}" />
<property name="user" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
<property name="connectionCachingEnabled" value="true"/>
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
This datasource is used by my REST service and everything works fine...anyway first REST call is very slow (about ~5 secs), after that EVERY other call is fast.
I think this is an initialization related problem, in the sense that initialization is made when first DB call is received.
Is there a way to tell spring to initialize this datasource on server startup?
I think this is an initialization related problem, in the sense that
initialization is made when first DB call is received.
With your current config I think that's what's happening.
Is there a way to tell spring to initialize this datasource on server
startup?
It's the behavior of the connection pool, not Spring. Spring is creating the bean when your app starts (you aren't using lazy-init="true" on the bean). However, the connection pool isn't creating connections to the database when Spring instantiates it. From the Oracle docs:
The initial pool size property specifies the number of available
connections that are created when the connection pool is initially
created or re-initialized. This property is typically used to reduce
the ramp-up time incurred by priming the pool to its optimal size.
A value of 0 indicates that no connections are pre-created. The
default value is 0.
Try setting a non-zero value for initialPoolSize.
Edit: Try setting ConnectionCacheProperties instead:
<property name="connectionCacheProperties">
<props merge="default">
<prop key="InitialLimit">5</prop>
</props>
</property>
I am using Spring MVC 3 and Hibernate 3.6, I use xml configured transaction management,
my code works greate but my JDBC are not being released although it says it does.
I checked it with JProfiler and it says the connection is open.
this is my spring-config code
<bean id="ds" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/parse_web?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8"/>
<property name="username" value="root" />
<property name="password" value="miles106" />
<property name="initialSize" value="5"/>
<property name="maxActive" value="50000"/>
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource" ref="ds" />
<property name="mappingResources">
<list>
<value>com/mubasher/parsewebpage/entities/Changes.hbm.xml</value>
<value>com/mubasher/parsewebpage/entities/Owners.hbm.xml</value>
<value>com/mubasher/parsewebpage/entities/Ownerships.hbm.xml</value>
<value>com/mubasher/parsewebpage/entities/TargetCompanies.hbm.xml</value>
<value>com/mubasher/parsewebpage/entities/TempData.hbm.xml</value>
<value>com/mubasher/parsewebpage/entities/Exceptions.hbm.xml</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="dialect">org.hibernate.dialect.MySQL5Dialect</prop>
<prop key="hibernate.connection.useUnicode">true</prop>
<prop key="hibernate.connection.characterEncoding">UTF-8</prop>
<prop key="hibernate.connection.charSet">UTF-8</prop>
<prop key="hibernate.connection.release_mode">after_statement</prop>
</props>
</property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
and this is my debug code
DEBUG [myExec-2] (JDBCTransaction.java:223) - re-enabling autocommit
DEBUG [myExec-2] (JDBCTransaction.java:143) - committed JDBC Connection
DEBUG [myExec-2] (ConnectionManager.java:427) - aggressively releasing JDBC connection
DEBUG [myExec-2] (ConnectionManager.java:464) - releasing JDBC connection [ (open PreparedStatements: 0, globally: 0) (open ResultSets: 0, globally: 0)]
DEBUG [myExec-2] (HibernateTransactionManager.java:734) - Closing Hibernate Session [org.hibernate.impl.SessionImpl#52ab7af2] after transaction
DEBUG [myExec-2] (SessionFactoryUtils.java:789) - Closing Hibernate Session
but in JProfiler i can see that the connection is still open as you see
this is realy causing me problems, my application is doing massive database work, so I need the connection to close as soon as the work is done, should I use maxIdle ?
Connections are not closed, they are reused. This is the whole purpose of commons-dbcp, which stands for Database Connection Pool.
Establishing a new connection is usually an expensive operation. So what DBCP is doing is that instead of closing connection, it leaves it open and returns it to the connection pool for another use.
If you want your database connections to get closed and re-opened with each request, then you need to use a different data source (e.g. org.springframework.jdbc.datasource.SimpleDriverDataSource).
UPDATE 1: Also note, that in your example you are setting maximum number of parallel connections (maxActive) to be 50000. That is some extreme number (default is 8!!!), which IMO can cause a lot of problems.
UPDATE 2: Using maxIdle is a good idea if you don't wan't to get rid of the pool. But that will not save you from "having non-closed connections". If you are thinking about setting maxIdle=0, then drop the pool completely.
UPDAET 3: I just need to stress out this one again - If you need 50000 parallel connections, then there is really something wrong with your code.
As it is mentioned in blogs/books (e.g. Java Transactions Design Strategies by Mark Richards), read operations must have the Propagation.SUPPORTS attribute.
In a simple Spring 3.1 MVC project with Hibernate 4.1 the scenario is:
Declarative transaction management using #Transactional
sessionFactory of org.springframework.orm.hibernate4.LocalSessionFactoryBean
Transaction manager of org.springframework.orm.hibernate4.HibernateTransactionManager
Service class with #Transactional(propagation=Propagation.REQUIRED)
Function of that Service class that only retrieves a resultset (performs read operation) with #Transactional(propagation=Propagation.SUPPORTS)
Function of read operation retieves the resultset using sessionFactory.getCurrentSession().get()
Of course, when a Controller executes the function of read operation, the exception "No Session found for current thread" is raised because a transaction is not started and a session is not obtained.
Based on the above configuration (while it is best e.g. non-invasive, less code etc) the Propagation.SUPPORTS attribute cannot be used unless a transaction is started before with Propagation.REQUIRED or Propagation.REQUIRES_NEW.
How do we use use Propagation.SUPPORTS for read operations without having to start a transaction e.g. with Propagation.REQUIRED before but still taking advantage the benefits of declarative transaction management?
Thank you in advance.
Coder, here is the configuration:
<tx:annotation-driven transaction-manager="txManager"/>
<context:component-scan base-package="com.myapps.service.impl" />
<bean id="txManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${db.driverClassName}" />
<property name="url" value="${db.url}" />
<property name="username" value="${db.username}" />
<property name="password" value="${db.password}" />
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="mappingResources">
<list>
<value>.....</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${db.dialect}</prop>
<prop key="hibernate.format_sql">true</prop>
</props>
</property>
</bean>
I disagree with using SUPPORTS for read operations. Use REQUIRED.
A transaction is needed anyway to perform every database operation
Doing several small transactions to read several things at once won't benefit from the first-level cache
There won't be any isolation between all the subsequent reads, meaning that something not visible to the first read might become visible for the second one
you'll get lazy loading exceptions when traversing associations
Transaction is not always required for Propagation.SUPPORTS.
Propagation.SUPPORTS: Support a current transaction, execute non-transactionally if none exists.
I have a complex situation where I have to use 2 different databases, there for I use 2 different transaction managers. Is there a way in Spring to link these transaction managers to work in a single transaction ? In case of an exception on the second dataSource changes on the first should be rolled-back.
<bean id="baseTransactionProxy" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean"
abstract="true">
<property name="transactionManager" ref="transactionManager" />
<property name="transactionAttributes">
<props>
<prop key="insert*">PROPAGATION_REQUIRED</prop>
<prop key="update*">PROPAGATION_REQUIRED</prop>
<prop key="save*">PROPAGATION_REQUIRED</prop>
<prop key="remove*">PROPAGATION_REQUIRED</prop>
<prop key="*">PROPAGATION_REQUIRED,readOnly</prop>
</props>
</property>
</bean>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="oracle.jdbc.OracleDriver" />
<property name="url" value="jdbc:oracle:thin:#dummyHost:1521:dummySID" />
<property name="username" value="owner" />
<property name="password" value="password" />
</bean>
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<bean id="dataSource2" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="oracle.jdbc.OracleDriver" />
<property name="url" value="jdbc:oracle:thin:#dummyHost2:1521:dummySID2" />
<property name="username" value="owner" />
<property name="password" value="password" />
</bean>
<bean id="transactionManager2" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource2" />
</bean>
You can use Spring's JtaTransactionManager to make sure both DBs are transacted with a single transaction manager.
Note, you would have to choose an underlying implementation which can either be a container's one: e.g. WebLogic, WebSphere and OC4J, etc.. or a stand alone, even an open source one: e.g. Atomikos.
HOWEVER
XA transaction management complicates things (configuration / performance / problem resolution / maintenance / etc.). And in a lot of cases, it can be avoided by clever patterns.
To get a solid understanding on whether you need to use XA ( e.g. distributed ) transaction manager, take a look at this fantastic article by Spring's own Dave Syer: Distributed transactions in Spring, with and without XA
You need a global transaction manager which supports 2-phase-commit (XA). Several independent and free ones are available. I've used Bitronix in a Spring-based project, but there is also Atomikos, and probably others. See http://en.wikipedia.org/wiki/Java_Transaction_API#Opensource_JTA_implementations
For routing through multiple datasource, You could use abstractRoutingDataSource but if you have requirements like one rollbackack affecting another you would need a JtaTransactionManager for distributed txn management .