Database Connection Pool, database connection pool java
I. Why should I use the database connection pool?
Database Connection resources are very expensive, especially when accessing the database through the network. A simple physical connection causes low performance.
Therefore, the concept of database connection pool
参考数据库链接串:
查看应用程序池占用数量:select*fromsysprocesseswheredbid=db_id(‘数据库名‘)
Max Pool Size:如果未设置则默认为100,理论最大值为32767。最大连接数是连接池能申请的最大连接数,如果数据库连接请求超过此数,后面的数据库连接请求将被加入到等待队列中,这会影响之后的数据库操作。在等待队列中,默认等待与服务器的连接的时间为15秒。
中文错误:
超时时间已到。超时时间已到,但是尚未从池中获取连接。出现这种情况可能是因为所有池连接均在使用,并且达到了最大池大小。
英文错误:
Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled c
Because applications in an application pool are separated from other applications by the worker process boundaries, applications in one application pool are not affected by problems with applications in other application pools.
Windows 2003 supports both operating modes, and the default is the ISS 6.0 worker process isolation mode. Worker process isolation mode prevents one application or site from stoppin
Label:In the last mention of an analysis of Emysql pool (http://www.cnblogs.com/--00/p/4281938.html)
Now the Emysql_conn_mgr gen_server process is a single point, that is, all pool management scheduling is done by a process.
If you manage a large number of pool in the same Erlang node, there is a bottleneck. For a hotspot process, improving its proc
Java Virtual Machine: runtime volume pool, Java Virtual Machine volume pool1. Introduction to the runtime frequent pool
Runtime Constant Pool, which is part of the method area. In addition to the description of the version, field, method, and interface of the Class, the Class file also contains the Constant Pool Table
Implementation Principle
When the database connection pool is initialized, a certain number of database connections are created into the connection pool, which is restricted by the minimum number of database connections. Regardless of whether or not these database connections are used, the connection pool will always ensure that there are at least as many connec
Introduction The Python Standard Library provides the threading and multiprocessing modules for us to write the corresponding multi-threaded multi-process code. However, when the project reaches a certain scale, frequent creation and destruction of processes or threads consume a lot of resources, at this time, we need to write our own thread pool process pool to change the space for time. However, from Pyth
JDK5 new features thread pool (1), jdk5 new features Thread Pool
1. Concept of thread pool:
In fact, we have been familiar with many concepts about the pool so far: string pool and connection pool. The purpose of this
The relationship between queue and pool size in the Java thread poolJava threads write their own understanding of the relationship between queue, pool size, and core threads in the thread pool (threadpoolexecutor):1: Core thread: Simply the number of threads in the thread pool that can allow concurrent runs concurrentl
Tags: competition thread pool Enterprise database ERP load Lin ASE creationthread pool and connection pool Connection pooling is typically implemented on the client side, meaning that the application (client) creates a pre-created connection that leverages these connections to serve all DB requests from the client. If, at some point, the number of idle connection
Many DBAs are confused about how to use nonpage pool and paged pool. Find a document and translate it.
From: http://blogs.technet.com/ B /markrussinovich/archive/2009/03/26/3211216.aspx
Nonpaged pool(Non-Paging pool)
The kernel and device drivers use nonpaged pool to store d
There are many benefits of using the thread pool, such as saving system resources, saving time for creating and destroying threads, and so on, when we need to deal with more tasks, we can use the thread pool, and many users may not know how to use the Java thread pool? Here is a small series to share the Java four thread pool
Servlet thread pool and EJB object pool
2008/11/13 p.m. go to http://hi.baidu.com/%D3%C0%CA%C0%CF%E9%BA%CD/blog/item/ca83e8876c55142dc65cc31a.html
Currently, all B/S system applications can be classified into statefull and stateless. Stateful means that some information should be retained throughout the processing of the system, while stateless means that, on the contrary, each request is an independent
This chapter describes the life cycle of the thread pool.Threads have 5 states: New state, ready state, running state, blocking state, dead state. The thread pool also has 5 states; However, threads are different than threads, and the 5 states of the line pool are: Running, SHUTDOWN, STOP, tidying, TERMINATED.The thread pool status definition code is as follows:/
ObjectiveThreads are scarce resources, if created without restriction, will not only consume system resources, but also reduce the stability of the system, reasonable use of thread pool to uniform distribution, tuning and monitoring, there are the following benefits1. Reduce resource consumption2. Improve response speed3, improve the manageability of threadsThe executor framework, introduced in java1.5, decouples the submission and execution of tasks
Java multi-thread (4) thread pool and java multi-thread pool
A good software does not randomly create and destroy threads, because it takes a lot of CPU time and requires a lot of interaction with the memory. Therefore, JDK 5 proposes to use the thread pool so that programmers can focus more on the business logic and weaken the thread open/closed management.
JDK
Introduction The Python Standard Library provides the threading and multiprocessing modules for us to write the corresponding multi-threaded multi-process code. However, when the project reaches a certain scale, frequent creation and destruction of processes or threads consume a lot of resources, at this time, we need to write our own thread pool process pool to change the space for time. However, from Pyth
Simple IntroductionThe string Chang in Java is a pool of strings stored in the Java heap memory . We know that string is a special class in Java, and we can create a string object using the new operator, or you can create a string object with double quotation marks ("").string constant pool in Java, which clearly explains how to maintain a string constant pool in
Thread Pool task execution process
We started from an API to learn how Executor processes task queues.
Java.util.concurrent.Executor.exe cute (Runnable)
Executes the given task sometime in the future. the task may execute in a new thread or in an existing pooled thread. if the task cannot be submitted for execution, either because this executor has been shutdown or because its capacity has been reached, the task is handled by the current RejectedExecu
JDBC: database connection pool, jdbc database connection pool
Required tools
Commons-pool2-2.3.jar: dependency library implemented by connection pool
Commons-dbcp2-2.0.1.jar: Implementation of Connection Pool
C3p0-0.9.2.1.jar
If Method 'initializationerror' not found occurs when c3p0 is used, opening the test class, an
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