connection-pooling

问题 I am working on a project in which I need to make a HTTP URL call to my server which is running Restful Service which returns back the response as a JSON String. Below is my main code which is using the future and callables - public class TimeoutThreadExample { private ExecutorService executor = Executors.newFixedThreadPool(10); public String getData() { Future<String> future = executor.submit(new Task()); String response = null; try { response = future.get(100, TimeUnit.MILLISECONDS); }

问题 Can anybody provide examples or links on how to establish a JDBC connection pool? From searching google I see many different ways of doing this and it is rather confusing. Ultimately I need the code to return a java.sql.Connection object, but I am having trouble getting started..any suggestions welcome. Update: Doesn't javax.sql or java.sql have pooled connection implementations? Why wouldn't it be best to use these? 回答1: If you need a standalone connection pool, my preference goes to C3P0

问题 Can anybody provide examples or links on how to establish a JDBC connection pool? From searching google I see many different ways of doing this and it is rather confusing. Ultimately I need the code to return a java.sql.Connection object, but I am having trouble getting started..any suggestions welcome. Update: Doesn't javax.sql or java.sql have pooled connection implementations? Why wouldn't it be best to use these? 回答1: If you need a standalone connection pool, my preference goes to C3P0

问题 I have Created an Java Swing Application with MySQL as the database, Now i am hosting my MySQL database online and Swing Application will be stored locally, Now in order to experiment i have hosted my database i.e MySQL database on https://www.freemysqlhosting.net/ account as it allows free hosting for certain period, Also Connection is successfull and works but the application works too slow suppose if i have to search any entry from the swing aplication from the oline hosted database it

问题 I am developing an application with spring and hibernate entityManager The oracle database is outside the DMZ, running on tomcat 7 . the connection will be interrupted after a period of inactivity by the firewall. I added the ValidationQuery select 1 from dual in context.xml but it does not solve the problem. 2014-12-10 10:04:27 WARN SqlExceptionHelper:143 - SQL Error: 17008, SQLState: null 2014-12-10 10:04:27 ERROR SqlExceptionHelper:144 - Connexion interrompue org.springframework.security

问题 I am developing an application with spring and hibernate entityManager The oracle database is outside the DMZ, running on tomcat 7 . the connection will be interrupted after a period of inactivity by the firewall. I added the ValidationQuery select 1 from dual in context.xml but it does not solve the problem. 2014-12-10 10:04:27 WARN SqlExceptionHelper:143 - SQL Error: 17008, SQLState: null 2014-12-10 10:04:27 ERROR SqlExceptionHelper:144 - Connexion interrompue org.springframework.security

问题 We are trying to implement connection pooling using c3p0. The issue is when there are no transactions on our server for long time, the very first next transaction have connection timeout issue. Exception stacktrace: Could not open JPA EntityManager for transaction; nested exception is javax.persistence.Pers istenceException: org.hibernate.TransactionException: JDBC begin transaction failed: org.springframework.transaction.CannotCreateTransactionException: Could not open JPA EntityManager for

问题 I develop an web application using Spring MVC + MySQL. To manage JDBC connection I used c3p0 for connection pooling. If I am using c3p0, What I suppose if, 5 connections are open in pool and all 5 connections are in sleep mode and if I request getConnection() from java then one of them should be returned as Connection . Am I correct? If Yes Then consider following load testing scenario where I am getting Exception Connections could not be acquired from the underlying database! . Using Jmeter

问题 I have just installed the MS SQL Server 2005 Express and, of course, I am trying to connect it with my test app but the thing is ... for some reason I cannot connect it I have already checked its port with the CP "netstat -an" but the outcoming list does not contain any 1433 port at all :( The SQL service is running I could check it with the OS Services but its port is unavailable :( I have installed MS SQL Server 2005 Express Management Studio but for some reason it connected the MS SQL

问题 I am rebuilding a system that has developed over the past five years, initially started with Classic ASP I am now moving the whole thing to ASP.NET (using VB.NET) The system has been plagued by a persistent problem of having too many data connections open, resulting in periodic "max_connections is exceeeded" errors. Having asked my server hosts many times about this, I am still having troubles so thought I'd open it up to SO. I am currently opening connections as follows: Dim sql = "SQL