I have a spring boot application which I have configured most of the properties through the properties file. However, I was looking if there is a way to set the TRANSACTION_ISOLATION_LEVEL through the Spring boot properties. Could someone help me on this.
I'm initializing the data source bean in the following way:
#Bean
#ConfigurationProperties(prefix="spring.datasource")
public DataSource dataSource() {
return buildDataSource("spring.datasource");
}
private DataSource buildDataSource(String propPrefix) {
Stirng driverClassName = env.getProperty(propPrefix + ".driver-class-name");
return DataSourceBuilder.create()
.driverClassName(driverClassName)
.build();
}
Could someone please help me on how to specify the TRANSACTION_ISOLATION_LEVEL either through properties or during the data source initialization.
So, the javax.sql.DataSource does not provide a way to set default Transaction Isolation Level. Still, you can do it, but you must strict to particular implementation. Let me give you c couple of examples:
In case you use Apache BasicDataSource implementation of DataSource, then you can use this. This is for DBCP.
If you are using Apache BasicDataSource, but for DBCP2, you can do something like this.
But in most cases, if we are talking about Spring, we use Hikari Connection Pool. So, in case of HikariCP, you can use this method.
The same is applicable to Spring Boot. Let me explain - using Spring Boot properties file, you can set default transaction isolation level, but for specific DataSource, I mean this property:
spring.datasource.hikari.transaction-isolation
as you probably noticed, let you set default transaction isolation level for HikariCP (if you are using one) And this property:
spring.datasource.dbcp2.default-transaction-isolation
allow you to configure default isolation level for DBCP2.
Hope it helped, have a nice day! :)
Related
I am new at Hibernate.
Into my code, the connection to the DB is managed with the Hikari data source.
My code is right now multitenant, but it manages the same hibernate dialect for all tenants.
Is it possible to create a configuration where each tenant can use a different dialect?
The type of dialect can be provided as a tenant's property.
This is an example of the entityManagerFactory:
#Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
Map<String, Object> jpaProperties = new HashMap<>();
jpaProperties.put(..., ...);
jpaProperties.put(org.hibernate.cfg.Environment.DIALECT, "myDialect");
LocalContainerEntityManagerFactoryBean emfBean = new LocalContainerEntityManagerFactoryBean();
emfBean.setPackagesToScan(new String[] {MyEntity.class.getPackage().getName()});
emfBean.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
emfBean.setJpaPropertyMap(jpaProperties);
return emfBean;
}
Edit
I was looking to this solution: it suggests to create a duplicated LocalContainerEntityManagerFactoryBean for each dialect.
What I do not understand is how can I tell when using one EntityManager (MySQL) and when the other one (Postgres or MsSQL): the solution discriminates the entities (each entity has its own DB) but in my case, all entities are on all DBs. Is the tenant that discriminates.
For example: if I create a second instance of LocalContainerEntityManagerFactoryBean (i.e. msSQLEntityManagerFactory()) with setted the dialect for SQL Server, the application fails to start with:
Application failed to start due to an exceptionorg.springframework.beans.factory.NoUniqueBeanDefinitionException:
No qualifying bean of type 'javax.persistence.EntityManagerFactory' available:
expected single matching bean but found 2:
msSQLEntityManagerFactory,entityManagerFactory
That's not really possible as the dialect affects certain quoting rules etc. which you can't just "swap out" at runtime based on a tenant identifier. Just create two persistence units, each pointing to a different data source for every database type. You will have to somehow lookup the appropriate EntityManager/EntityManagerFactory based on your tenant identifier which makes it a bit harder when you want to use Spring Data JPA as that requires a compilation static name reference for the entity manager factory. Maybe you can create a custom EntityManagerFactory that delegates all method calls to the appropriate instance based on the tenant identifier. Overall, this is not so easy and you will probably have to do a lot of trial and error.
IMO it would be better to have a separate application deployment with separate configuration if possible per database type.
I finally managed to find a solution for this problem.
I managed to get around the problem with the dialects by having an entity manager factory for each dialect (in this case MySQL, Postgres and MS SQL Server).
Create a bean for EntityManagerFactory and return a proxy of that interface and in the handler, based on your logic, you can switch which emf to use to suit the used data source.
I have created a video for this because it seems like there is no documentation online.
Session Scoped Connection
It is pretty similar to what you're trying to achieve but in my case the users are providing the credentials, so it's even more complicated.
Goal
I want to introduce a transaction manage on my data source.
Looking for the correct way to use same instance of datasource for the transaction manager as well. My requirement is specify to Java Config way to pass the "Same instance" of DS to Transaction Manager. Correct me If there is a gap in my understanding.
In my case I have a datasource and of type autocommit false, and by using the Transaction Manager specified below, I want to commit/rollback a transaction (e.g. Update an operation/Revert an Update operation ---when there a error/no error in the transaction).
However, while debugging I have noticed that when I used java config specified below, I get two different instance of data source and trx.commit() does not work.
Programmatic transaction management
(https://docs.spring.io/spring/docs/3.0.0.M4/reference/html/ch10s06.html)
#Bean
public DataSource dataSource() {
return getMyDataSource(); //new instance of datasource.//this datasource is autocommit-false
}
#Bean
public DataSourceTransactionManage trxManager() {
return getTransationManage(dataSource()); // this creates another instance of dataSource
}
Any help in this regard is highly appreciated.
Edit :-
I was using Mybatis with Spring. Basically, I had to configure the DataSouce correctly. Below links were useful.
[Pass parameters dynamically to Spring beans ][1] [Mybatis Transaction
Management CTM and PTM ][2] [Spring Transaction Management Notes
][3] [Spring & JTA NOtes][4]
[1]: https://stackoverflow.com/a/21202458/5086633
[2]: http://www.mybatis.org/spring/transactions.html
[3]: https://docs.spring.io/spring/docs/3.0.0.M4/reference/html/ch10s06.html
[4]: https://docs.spring.io/spring/docs/current/spring-framework-reference/data-access.html#transaction
To use back the same instance of dataSource how about you do this:
#Bean
#Autowired
public DataSourceTransactionManage trxManager(DataSource dataSource) {
return getTransationManage(dataSource);
}
I have a simple Web MVC application using Spring Boot that communicates with a database; the DB is H2 and has been in memory until now. I want to change that, and thus use a jdbc:h2:file:... URL.
Up until now, I have not needed to add any XML to configure my application, and I'd prefer it to stay that way if possible. But I can't figure out how to specify a different JDBC URL. I obtained and inspected the data source by passing it to an #Bean method:
org.apache.tomcat.jdbc.pool.DataSource#745e6f01{ConnectionPool[
defaultAutoCommit=null;
defaultReadOnly=null;
defaultTransactionIsolation=-1;
defaultCatalog=null;
driverClassName=org.h2.Driver;
maxActive=100;
maxIdle=100;
minIdle=10;
initialSize=10;
maxWait=30000;
testOnBorrow=false;
testOnReturn=false;
timeBetweenEvictionRunsMillis=5000;
numTestsPerEvictionRun=0;
minEvictableIdleTimeMillis=60000;
testWhileIdle=false;
testOnConnect=false;
password=********;
url=jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE;
username=sa;
validationQuery=null;
validationQueryTimeout=-1;
validatorClassName=null;
validationInterval=30000;
accessToUnderlyingConnectionAllowed=true;
removeAbandoned=false;
removeAbandonedTimeout=60;
logAbandoned=false;
connectionProperties=null;
initSQL=null;
jdbcInterceptors=null;
jmxEnabled=true;
fairQueue=true;
useEquals=true;
abandonWhenPercentageFull=0;
maxAge=0;
useLock=false;
dataSource=null;
dataSourceJNDI=null;
suspectTimeout=0;
alternateUsernameAllowed=false;
commitOnReturn=false;
rollbackOnReturn=false;
useDisposableConnectionFacade=true;
logValidationErrors=false;
propagateInterruptState=false;
ignoreExceptionOnPreLoad=false;
}
(newlines mine)
The setup of that bean seems rather intricate, so I want to interfere with it as little as possible - just replace the default JDBC URL.
How can I configure individual properties for Spring to create the datasource? Preferably in Java, but if there is a concise XML way I'm happy as well. I just want to avoid adding 100 lines of boilerplate for something equivalent to url=...
A DataSource is auto configured by Spring Boot for you. To influence how and what there are several properties you can set. Those are prefixed with spring.datasource, for a list take a look at the Spring Boot Reference Guide for a full list.
In your case simply add the following to the application.properties file
spring.datasource.url=jdbc:h2:file:...
This will tell Spring Boot to use this URL instead of the default.
As H2 is considered an in-memory database and not a regular database, when using JPA this will lead to your database to be dropped when the application is stopped. To fix this simply add the following
spring.jpa.hibernate.ddl-auto=update
To specify a dialect simply add the following
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
or even simpler
spring.jpa.database=H2
I am trying to enable my web application to use one (MySQL) schema per user.
I am using Spring with JPA along with Hibernate.
Is the Hibernate Multi-tenancy concept relevant?
The way I am trying to do it is
(a) have a EntityManagerFactory per HTTPSession and
(b) set the schema in it at login.
I have figured out how to do (b), but I still have issues doing (a).
I tried putting #Scope(WebApplicationContext.SCOPE_SESSION), but what about the global EntityManagerFactory?
Any help?
You can implement your own ConnectionProvider and there make extra settings.
But I think that you have large problems with the architecture your application if you want to do one schema per user.
UPD1
If you use spring. You can try to declare a bean with own impl of ConnectionProvider in Session scope.
But there is a big problem. Hibernate make the ConnectionProvider. It means that you have to impl own ServiceRegistry (with working through Spring) and override StandardServiceRegistryBuilder, and impl EntityManagerFactoryBuilder (based on EntityManagerFactoryBuilderImpl but with your StandardServiceRegistryBuilder).
When new session have been created it'll use ConnectionProvider to create the connection (Probably you'll have to override some classes).
This is really not suggested.. This will harm you later, you can't do differnt schema for diffrent user. You can always create you own properties to the connection..
Configuration cfg = new Configuration();
cfg.configure();
System.setProperty("hibernate.connection.password",pass);
System.setProperty("hibernate.connection.username",usr);
System.setProperty("hibernate.connection.driver_class", driver_class);
System.setProperty("hibernate.connection.url", driver_url);
System.setProperty("hibernate.dialect", dialect);
// etc, etc, for all properties
cfg.setProperties(System.getProperties());
sessionFactory = cfg.buildSessionFactory();
It can be something like that.. But this is WRONG!
I'm just starting to learn Jboss AP6 and I have a few questions:
I created Local Tx Datasource (MySql Database)and can access it in my code using JNDI.
Now I would like to create kind of Transaction Management resource inside of my Jboss AP.
1) Is there any JTA feature built in Jboss AP6?
2) Can I apply it to my local DataSource which I created?
3) Can you please point me to any documentation which explains how to configure it and use it in my code, ot is there any article which coversthese topics in depth?
I googled it for some period of time, but haven't found any useful documentation. I don't want to use Spring/Hibernate out of the box solution just Mysql and plain JTA.
JBoss AP6 support JTA 1.1
Yes you can
If you declareLocalTxDatasource, this is mean, than whenever you get
connection from this datasource this connection will participate in "current" transaction.
If you want to manupulate transaction yourself, without EJB for example, you must enject TransactionManager from JNDI.
Example
TransactionManager tm = (TransactionManager)context.lookup("java:/TransactionManager");
tm.begin();
try{
DataSource ds = context.lookup("java:/testDS");
connection = ds.getConnection()
//do useful work
connection.close();
tm.commit();
}catch(Exception e){
tm.rollback()
}