My application is using Websphere 6.1, Spring JDBC and oracle.I am using connection pooling to manage the connections.Is there any way to find out the number of connections active(alive) between the application and database at any point of time?.Can we have any indicator to let us know when a connection is/was dropped?
One option would be to manage your connection pool via JMX. Spring has excellent support for it. You just need to expose your connection pool bean via org.springframework.jmx.export.MBeanExporter. You can pick and choose the methods you want to expose. For example if you use DBCP you can use the method BasicDataSource#getNumActive().
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SpringBoot already is managing dataConnection then why is Hikari CP needed?
I have just started using SpringBoot so do not know much about SpringBoot and Hikari relation, although i read about Hikari but couldn't find any explicit explanation about its relationship with Springboot in presence of Spring data connection.
I read that Hikari is used when we need heavy db operations with lots of connections, if it is true then should we not use Hikari in follwoing scenario?
Scenario:
There is a small application, having maximum 8-10 REST calls once in a month or maximum fortnightly.That application needs to perform some probability and statistics related calculation.
Users login on that app at a time are of maximum 2-3 in numbers.
Do we still need to use Hikari?
There are two ways to communicate with the database from your application. You can either open a new DB connection any time you wish execute some query there, or you have a connection pool. Connection pool is a collection of reusable connections that application uses for DB communication. As establishing a new connection is relatively expensive operation, using connection pool gives you a significant performance improvement.
HikariCP is one of the connection pools libraries available in java and SpringBoot uses it as a default. As you don't need to do anything special to have it in your application, just enjoy your free lunch :)
HikariCP is used as the default connection pool in SpringBoot2, it was TomcatJDBC in SpringBoot 1. You must be using it as a default in your settings. You can overwrite it by setting another connection pool in your setting properties if you need. Please find more details about the connection pools and the default configurations of Spring Boot versions here.
Hikari is the default DataSource implementation with Spring Boot 2. This means we need not add explicit dependency in the pom.xml. The spring-boot-starter-JDBC and spring-boot-starter-data-JPA resolve it by default. To sum up, you require no other steps with Spring Boot 2.
Compared to other implementations, it promises to be lightweight and better performing.
Tuning Hikari Configuration Parameters:
spring.datasource.hikari.connection-timeout = 20000 #maximum number
of milliseconds that a client will wait for a connection
spring.datasource.hikari.minimum-idle= 10 #minimum number of idle
connections maintained by HikariCP in a connection pool
spring.datasource.hikari.maximum-pool-size= 10 #maximum pool size
spring.datasource.hikari.idle-timeout=10000 #maximum idle time for
connection
spring.datasource.hikari.max-lifetime= 1000 # maximum lifetime in
milliseconds of a connection in the pool after it is closed.
spring.datasource.hikari.auto-commit =true #default auto-commit
behavior.
HikariCP is a reliable, high-performance JDBC connection pool. It is much faster, lightweight, and has better performance as compared to other connection pool APIs. Because of all these compelling reasons, HikariCP is now the default pool implementation in Spring Boot 2. In this article, we will have a closer look to configure Hikari with Spring Boot.
I'd like to add XA connection pool to my Spring based application, specifically Oracle UCP. This pool works on XADataSource and XAConnection objects. Standard DataSource.getConnection(...) methods are not supported.
Trying working with that pool (that I am able to successfully set up in Spring) I am getting an error related to the fact that getConnection(...) methods invoked by JdbcTemplate are disabled and should not be used. I am just wondering whether any of Spring JDBC classes are able to work with XADataSource and XAConnections? Probably there are another ways to use Spring with XA connection pools? Will appreciate any advices on that topic.
Just for those who may experience similar problems - Spring doesn't support directly XA connection pools (through native XADataSource.getXAConnection(...) methods). You need to write a kind of wrapper utilizing DatSource.getConnection(...) methods.
What's the difference between MysqlConnectionPoolDataSource and C3p0, BoneCP or dbcp library for connection pooling? I don't understand why use a library if mysql connector give connection pooling.
A ConnectionPoolDataSource is not a connection pool (or at least: it shouldn't be), it is intended to be used by a DataSource that provides pooling (eg from an application server). A ConnectionPoolDataSource provides the physical connections that will be held in the connection pool. Besides creating those physical connections a ConnectionPoolDataSource shouldn't do anything else.
So if you are working in an application server, use the pooling provided by the DataSources of the application server. If you are in a standalone application or a server that doesn't provide datasources on its own, use third party connection pools like BoneCP, c3p0 or Apache DBCP. If MySQL also provides a normal DataSource that provides pooling, then you could use that.
I am using JPA together with the Tomcat 7 connection pool.
How is it possible to specify that the EntityManager injected (by Spring in this case) into a data access object should use a specific connection from the pool, not one taken at random?
In other words, the requirement is to initialize specific connections in the pool (so these connections see the database pre-configured in various states), to then 'label' these connections and to then get EntityManager / the transaction to use the connection with a specific label.
I know that Oracle UCP offers similar functionality, but we have had issues with that so we want to do the same thing with the Tomcat pool.
Thanks !
We are working on an IBM WebSphere MQ application, and we use JMS API to operate the message. But we have a problem that the connection takes too much time, and we want to pool the JMS connection, for it's a standalone application, we have no application container to provide JNDI or pooling service. So is there a solution to resolve this? For JDBC we can use DBCP or c3p0 to archive pooling datasource, in JMS, is there any similar project that can pool JMS connections?
It used to be that the JMS MQConnectionFactory had pooling built in, but it seems that in version 7, it has been removed.
Set the use of ConnectionPooling in earlier versions of the WebSphere
MQ classes for JMS. This method is retained for compatibility with
older MQJMS applications, but, because this Connection Pooling
functionality has been removed from version 7, setting this property
will have no effect.
In the absence of anything else, you can use Apache Commons Pool. Same idea as DBCP (which uses Pool) but for non JDBC objects.
Spring's CachingConnectionFactory works well for this use case.
This answer in https://stackoverflow.com/a/31119435/1765341 explains how to do this in Tomcat, but the code there can easily be adapted for Java standalone applications. This should be much easier (and less error prone) than writing an Apache Commons Pool implementation.