Configuring jdbc pool for high concurrency Tomcat. Expert posted by fhanik on April 1, 2. PM. In this article we will focus on configuration of the high concurrency connection pool. For ease of migration for Tomcat users, the configuration has been written to mimic that of Commons DBCP. The documentation of jdbc pool covers all the attributes. Please note that these attributes are also available as direct setters on the org. Java Spring MVC Hibernate MySQL integration example tutorial with CRUD operation and download example project, spring framework mvc tutorial. The first thing we notice is the factoryorg. DataSourceFactory attribute. When Tomcat reads the typejavax. DataSource it will. I am trying to connect to a database that I created using SQL Server 2012, but I keep getting an error. This is the code for the connection Driver d DriverClass. This controller lets you send an FTP retrieve file or upload file request to an FTP server. If you are going to send multiple requests to the same FTP server. Batch Insert in Java JDBC. To avoid SQL Injection as well as OutOfMemoryError. Batch Insert into Database using Java. Data. Source bean if youre using a dependency injection framework. So in this article we will focus on use cases, and different configurations for Tomcat. Simple Connection Pool for My. SQLlt Resource typejavax. Are you running this app on an application server If the server doesnt have the JDBC driver on its classpath try setting the scope to default compile for the. D0%A1%D0%B2%D0%BE%D0%B9%D1%81%D1%82%D0%B2%D0%B0-TCPIP-MS-SQL-12.png' alt='Microsoft Sql Server Jdbc Driver Maven 2' title='Microsoft Sql Server Jdbc Driver Maven 2' />Data. Source. namejdbcTest. DB. factoryorg. Data. Source. Factory. Class. Namecom. Driver. urljdbc mysql localhost 3. Triggers On Update Sql Server. The first thing we notice is the factoryorg. Data. Source. Factory attribute. When Tomcat reads the typejavax. Data. Source it will automatically configure its repackaged DBCP, unless you specify a different factory. The factory object is what creates and configures the connection pool itself. With this flexibility, Karaf is the perfect solution for microservices, systems integration, big data, and much more. There are two ways to configure Resource elements in Apache Tomcat. Configure a global connection pool. File confserver. Global. Naming. Resources. Resource typejavax. Data. Source. namejdbcTest. DB. factoryorg. Data. Source. Factory. Class. Namecom. Driver. urljdbc mysql localhost 3. Global. Naming. Resources. You then create a Resource. Link element to make the pool available to the web applications. If you want the pool available to all applications under the same name, the easiest way is to edit the File confcontext. Context. lt Resource. Link typejavax. Data. Source. namejdbcLocal. Test. DB. globaljdbcTest. DB. lt Context Note, that if you dont want a global pool, move the Resource element from server. And to retrieve a connection from this configuration, the simple Java code looks like. Context init. Context new. Initial. Context. Context env. Context Contextinit. Context. lookupjava compenv. Data. Source datasource Data. Sourceenv. Context. Local. Test. DB. Connection con datasource. Connection. Simple in Java. We can achieve the same configuration using just Java syntax. Data. Source ds new Data. Source. ds. set. Driver. Class. Namecom. Driver. Urljdbc mysql localhost 3. Usernameroot. Passwordpassword. Or to separate out the pool properties. Pool. Properties pp new Pool. Properties. pp. Driver. Class. Namecom. Driver. Urljdbc mysql localhost 3. Usernameroot. Passwordpassword. Data. Source ds new Data. Sourcepp. All properties that we make available in XML through the object factory are also available directly on the Pool. Properties or the Data. Source objects. Sizing the connection pool. We will work with the following attributes to size the connection poolinitial. Sizemax. Activemax. Idlemin. Idle. Its important to understand these attributes, as they do seem quite obvious but there are some secrets. Lets nail it down. Resource typejavax. Data. Source. namejdbcTest. DB. factoryorg. Data. Source. Factory. Class. Namecom. Driver. urljdbc mysql localhost 3. Size1. 0. max. Active1. Idle5. 0. min. Idle1. The initial. Size1. When defined in Global. Naming. Resources the pool is created upon Tomcat startup. When defined in Context the pool is created when its first looked up in JNDI. The max. Active1. This attribute is used to limit the number of connections a pool can have open so that capacity planning can be done on the database side. The min. Idle1. 0 is the minimum number of connections always established after the connection pool has reached this size. The pool can shrink to a smaller number of connections if the max. Age attribute is used and the connection that should have gone to the idle pool ends up being closed since it has been connected too long. However, typically we see that the number of open connections does not go below this value. The max. Idle attribute is a little bit trickier. It behaves differently depending on if the pool sweeper is enabled. The pool sweeper is a background thread that can test idle connections and resize the pool while the pool is active. The sweeper is also responsible for connection leak detection. The pool sweeper is defined bypublic boolean is. Pool. Sweeper. Enabled. Time. Between. Eviction. Runs. Millis 0. Remove. Abandoned get. Remove. Abandoned. Timeout 0. Suspect. Timeout 0. Test. While. Idle get. Validation. Querynull. The sweeper runs every time. Between. Eviction. Runs. Millis milliseconds. The max. Idle attribute is defined as follows. Pool sweeper disabled If the idle pool is larger than max. Idle, the connection will be closed when returned to the pool. Pool sweeper enabled Number of idle connections can grow beyond max. Idle but can shrink down to min. Idle if the connection has been idle for longer than min. Evictable. Idle. Time. Millis. This may sounds strange that the pool can will not close connections even if the idle pool is larger than max. Idle. It is actually optimal behavior. Imagine the following scenario. Each thread borrows a connection 3 times during a request. In this scenario, if we had max. Idle5. 0 then we could end up closing and opening 5. This taxes the database and slows down the application. During peak traffic spikes like this, we want to be able to utilize all the pooled connections. So we definitely want to have the pool sweeper enabled. We will get to that in the next section. There is an additional attribute we mentioned here, max. Age. max. Age defines the time in milliseconds that a connection can be openestablished. When a connection is returned to the pool, if the connection has been connected and the time it was first connected is longer than the max. Age value, it will be closed. As we saw by the is. Pool. Sweeper enabled algorithm, the sweeper is enabled when one of the following conditions is mettime. Between. Eviction. Runs. Millis 0 AND remove. Abandonedtrue AND remove. Abandoned. Timeout 0time. Between. Eviction. Runs. Millis 0 AND suspect. Timeout 0time. Between. Eviction. Runs. Millis 0 AND test. While. Idletrue AND validation. Querynull. As of version 1. Between. Eviction. Runs. Millis 0 AND min. Evictable. Idle. Time. Millis 0timer get. Min. Evictable. Idle. Time. Millis 0. So in order to get optimal pool sizing, wed like to modify our configuration to meet one of these conditionslt Resource typejavax. Data. Source. namejdbcTest. DB. factoryorg. Data. Source. Factory. Class. Namecom. Driver. urljdbc mysql localhost 3. Size1. 0. max. Active1. Idle5. 0. min. Idle1. Timeout6. 0. time. Between. Eviction. Runs. Millis3. 00. Evictable. Idle. Time. Millis6. 00. 00. Validating Connections. Pooling database connections presents a challenge, since pooled connections can become stale. Its often the case that either the database, or perhaps a device in between the pool and the database, timeout the connection. The only way to truly validate a connection is to make a round trip to the database, to ensure the session is still active. In Java 6, the JDBC API addressed this by supplying a is. Valid call on the java. Connection interface. Prior to that, pools had to resort to executing a query, such as SELECT 1 on My.