blocks|key|348676|text|另一种替代方案Proxool在this+article中提到。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|348677|您也许能够找出为什么Hibernate将c3p0捆绑在其默认连接池实现中？|348678|entityMap|0|LINK|mutability|MUTABLE|url|http://www.informit.com/articles/article.aspx?p=353736&seqNum=4^0|F|C|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@$A|O|B|P|1|Q]]|C|$]]|$1|D|3|E|5|6|7|R|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]]]

Another alternative, Proxool, is mentioned in <a href="http://www.informit.com/articles/article.aspx?p=353736&amp;seqNum=4" rel="noreferrer">this article</a>.

You might be able to find out why Hibernate bundles c3p0 for its default connection pool implementation?

blocks|key|353735|text|DBCP已过期且不是生产级。不久前，我们对这两者进行了内部分析，创建了一个测试夹具，针对这两个工具生成负载和并发性，以评估它们在现实生活条件下的适用性。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|353736|DBCP始终在我们的测试应用程序中生成异常，并努力达到C3P0在没有任何异常的情况下完全能够处理的性能级别。|353737|C3P0还健壮地处理了DB断开连接和恢复时的透明重新连接，而如果连接是从其下面移除的，则DBCP永远不会恢复连接。更糟糕的是，DBCP将连接对象返回到底层传输已中断的应用程序。|353738|从那时起，我们已经在4个主要的重载消费者web应用中使用了C3P0，并且再也没有回头看过。|353739|更新：事实证明，在搁置多年之后，Apache+Commons的人们已经采用了DBCP+out+of+dormancy，现在，它再次成为一个积极开发的项目。因此，我最初的帖子可能已经过时了。|offset|length|style|BOLD|353740|话虽如此，我还没有体验过这个新升级的库的性能，也没有听说过它在任何最近的应用程序框架中都是事实。|353741|entityMap|0|LINK|mutability|MUTABLE|url|http://commons.apache.org/dbcp/^0|0|0|0|0|0|3|12|K|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Y|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Z|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|10|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|11|8|@$J|12|K|13|L|M]]|9|@$J|14|K|15|1|16]]|A|$]]|$1|N|3|O|5|6|7|17|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|18|8|@]|9|@]|A|$]]]|Q|$R|$5|S|T|U|A|$V|W]]]]

DBCP is out of date and not production grade. Some time back we conducted an in-house analysis of the two, creating a test fixture which generated load and concurrency against the two to assess their suitability under real life conditions. 

DBCP consistently generated exceptions into our test application and struggled to reach levels of performance which C3P0 was more than capable of handling without any exceptions. 

C3P0 also robustly handled DB disconnects and transparent reconnects on resume whereas DBCP never recovered connections if the link was taken out from beneath it. Worse still DBCP was returning Connection objects to the application for which the underlying transport had broken. 

Since then we have used C3P0 in 4 major heavy-load consumer web apps and have never looked back.

UPDATE: It turns out that after many years of sitting on a shelf, the Apache Commons folk have taken <a href="http://commons.apache.org/dbcp/" rel="noreferrer">DBCP out of dormancy</a> and it is now, once again, an actively developed project. Thus my original post may be out of date. 

That being said, I haven't yet experienced this new upgraded library's performance, nor heard of it being de-facto in any recent app framework, yet.

blocks|key|3342872|text|对于DBCP的自动重新连接问题，是否有人尝试使用以下2个配置参数？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3342873|validationQuery="Some+Query"

testOnBorrow=true|code-block|syntax|javascript|3342874|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

For the auto-reconnect issue with DBCP, has any tried using the following 2 configuration parameters?

<pre><code>validationQuery="Some Query"

testOnBorrow=true
</code></pre>

blocks|key|3130031|text|不幸的是，它们都已经过时了。DBCP最近更新了一点，另外两个是2-3年前的，有很多突出的bug。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3130032|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Unfortunately they are all out of date. DBCP has been updated a bit recently, the other two are 2-3 years old, with many outstanding bugs.

blocks|key|350026|text|我邀请您尝试BoneCP+--它是免费的、开放源码的，并且比可用替代方案更快(请参阅基准测试小节)。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|350027|免责声明:我是作者，所以你可以说我有偏见:-)|350028|更新:截至2010年3月，仍然比新重写的Apache+DBCP+("tomcat+jdbc")池快35%25左右。请参阅基准测试部分中的动态基准测试链接。|350029|更新#2：(12月13日)在领先4年后，现在有了一个速度更快的竞争对手：https://github.com/brettwooldridge/HikariCP|350030|更新#3：(9月14日)在这一点上，请考虑将BoneCP作为不推荐使用的，建议切换到。|style|BOLD|350031|更新#4：(4月15日)+--我不再拥有域名jolbox.com|350032|entityMap|0|LINK|mutability|MUTABLE|url|http://www.jolbox.com/|1|https://github.com/brettwooldridge/HikariCP^0|6|6|0|0|0|0|10|17|1|0|U|6|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@$A|10|B|11|1|12]]|C|$]]|$1|D|3|E|5|6|7|13|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|14|8|@]|9|@]|C|$]]|$1|H|3|I|5|6|7|15|8|@]|9|@$A|16|B|17|1|18]]|C|$]]|$1|J|3|K|5|6|7|19|8|@$A|1A|B|1B|L|M]]|9|@]|C|$]]|$1|N|3|O|5|6|7|1C|8|@]|9|@]|C|$]]|$1|P|3|-4|5|6|7|1D|8|@]|9|@]|C|$]]]|Q|$R|$5|S|T|U|C|$V|W]]|X|$5|S|T|U|C|$V|Y]]]]

I invite you to try out <a href="http://www.jolbox.com/" rel="nofollow noreferrer">BoneCP</a> -- it's free, open source, and faster than the available alternatives (see benchmark section).

Disclaimer: I'm the author so you could say I'm biased :-)

UPDATE: As of March 2010, still around 35% faster than the new rewritten Apache DBCP ("tomcat jdbc") pool. See dynamic benchmark link in benchmark section.

Update #2: (Dec '13) After 4 years at the top, there's now a much faster competitor : <a href="https://github.com/brettwooldridge/HikariCP" rel="nofollow noreferrer">https://github.com/brettwooldridge/HikariCP</a>

Update #3: (Sep '14) Please consider BoneCP to be deprecated at this point, recommend switching to <a href="http://brettwooldridge.github.io/HikariCP/" rel="nofollow noreferrer">HikariCP</a>.

Update #4: (April '15) -- I no longer own the domain jolbox.com

blocks|key|3342975|text|刚刚在DBCP上浪费了一天半的时间。尽管我使用的是最新的DBCP版本，但我遇到了与j+pimmel完全相同的问题。我根本不推荐DBCP，特别是它在DB离开时将连接抛出池的诀窍，当DB返回时无法重新连接，以及它无法动态地将连接对象添加回池中(它永远挂起在post+JDBCconnect+I/O套接字读取上)。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3342976|我现在要切换到C3P0了。我曾在以前的项目中使用过它，它的工作和性能都非常出色。|3342977|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/520868/446591^0|15|8|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@$A|O|B|P|1|Q]]|C|$]]|$1|D|3|E|5|6|7|R|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]]]

Just got done wasting a day and a half with DBCP. Even though I'm using the latest DBCP release, I ran into exactly the same problems as <a href="https://stackoverflow.com/a/520868/446591">j pimmel</a> did. I would not recommend DBCP at all, especially it's knack of throwing connections out of the pool when the DB goes away, its inability to reconnect when the DB comes back and its inability to dynamically add connection objects back into the pool (it hangs forever on a post JDBCconnect I/O socket read)

I'm switching over to C3P0 now. I've used that in previous projects and it worked and performed like a charm.

blocks|key|3342987|text|DBPool是一个很好的选择，它很容易使用。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3342988|基于Java的数据库连接池应用工具，支持基于时间的到期、语句缓存、连接验证以及使用池管理器轻松配置。|3342989|http://www.snaq.net/java/DBPool/|3342990|entityMap|0|LINK|mutability|MUTABLE|url|1^0|0|6|0|0|0|0|W|1|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]]|C|$]]|$1|D|3|E|5|6|7|T|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|H|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|I|$J|$5|K|L|M|C|$N|G]]|O|$5|K|L|M|C|$N|G]]]]

A good alternative which is easy to use is <a href="http://www.snaq.net/java/DBPool/" rel="nofollow noreferrer">DBPool</a>. 

"A Java-based database connection pooling utility, supporting time-based expiry, statement caching, connection validation, and easy configuration using a pool manager."

<a href="http://www.snaq.net/java/DBPool/" rel="nofollow noreferrer">http://www.snaq.net/java/DBPool/</a>

blocks|key|3343005|text|当连接超时时，我遇到了DBCP的问题，所以我试用了c3p0。我本打算将其发布到生产环境中，但后来开始了性能测试。我发现c3p0的表现很糟糕。我根本无法对其进行配置以获得良好的性能。我发现它的速度是DBCP的两倍。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3343006|然后我尝试了Tomcat+connection+pooling。|offset|length|3343007|这比c3p0快了一倍，并解决了我在使用DBCP时遇到的其他问题。我花了很多时间调查和测试这3个池。如果要部署到Tomcat，我的建议是使用新的Tomcat+JDBC池。|3343008|entityMap|0|LINK|mutability|MUTABLE|url|http://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html^0|0|6|P|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@]|9|@$D|R|E|S|1|T]]|A|$]]|$1|F|3|G|5|6|7|U|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|O]]]]

I was having trouble with DBCP when the connections times out so I trialled c3p0. I was going to release this to production but then started performance testing. I found that c3p0 performed terribly. I couldn't configure it to perform well at all. I found it twice as slow as DBCP.

I then tried the <a href="http://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html" rel="noreferrer">Tomcat connection pooling</a>.

This was twice as fast as c3p0 and fixed other issues I was having with DBCP. I spent a lot of time investigating and testing the 3 pools. My advice if you are deploying to Tomcat is to use the new Tomcat JDBC pool.

blocks|key|353837|text|如果配置正确，Dbcp就可以投入生产了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|353838|例如，它被用于一个每天有350000访问者和200个连接池的商业网站上。|353839|如果配置正确，它可以很好地处理超时。|353840|版本2正在开发中，它的背景使其变得可靠，因为许多生产问题已经解决。|353841|我们将它用于我们的批处理服务器解决方案，它已经运行了数百个批处理，这些批处理在数据库中的数百万行上工作。|353842|tomcat+jdbc+pool运行的性能测试表明，它比cp30具有更好的性能。|353843|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|P|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|Q|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|R|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|S|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|M|$]]

Dbcp is production ready if configured properly.

It is for example used on a commerce Website of 350000 visitors/ day and with pools of 200 connections.

It handles very well timeouts provided you configure it correctly.

Version 2 is on progress and it has a background which makes it reliable since Many
Production problems have been tackled.

We use it for our batch server solution and it has been running hundreds of batches That work on millions of lines in database.

Performance tests run by tomcat jdbc pool show it has better performance than cp30.

blocks|key|3343089|text|当我们使用多线程项目时，c3p0是很好的。在我们的项目中，我们通过使用DBCP同时使用多个线程执行，如果我们使用更多的线程执行，那么我们就会得到连接超时。因此，我们采用了c3p0配置。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3343090|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

c3p0 is good when we are using mutithreading projects. In our projects we used simultaneously multiple thread executions by using DBCP, then we got connection timeout if we used more thread executions. So we went with c3p0 configuration.

blocks|key|353874|text|已经在生产中使用DBCP几年了。它是稳定的，在DB服务器重启后仍能存活。只需正确配置即可。它只需要指定少量的参数，所以不要偷懒。以下是我们的系统生产代码中的一段代码，其中列出了我们显式设置以使其工作的参数：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|353875|DriverAdapterCPDS+driverAdapterCPDS+=+new+DriverAdapterCPDS();
driverAdapterCPDS.setUrl(dataSourceProperties.getProperty("url"));
driverAdapterCPDS.setUser(dataSourceProperties.getProperty("username"));
driverAdapterCPDS.setPassword(dataSourceProperties.getProperty("password"));
driverAdapterCPDS.setDriver(dataSourceProperties.getProperty("driverClass"));

driverAdapterCPDS.setMaxActive(Integer.valueOf(dataSourceProperties.getProperty("maxActive")));
driverAdapterCPDS.setMaxIdle(Integer.valueOf(dataSourceProperties.getProperty("maxIdle")));
driverAdapterCPDS.setPoolPreparedStatements(Boolean.valueOf(dataSourceProperties.getProperty("poolPreparedStatements")));

SharedPoolDataSource+poolDataSource+=+new+SharedPoolDataSource();
poolDataSource.setConnectionPoolDataSource(driverAdapterCPDS);
poolDataSource.setMaxWait(Integer.valueOf(dataSourceProperties.getProperty("maxWait")));
poolDataSource.setDefaultTransactionIsolation(Integer.valueOf(dataSourceProperties.getProperty("defaultTransactionIsolation")));
poolDataSource.setDefaultReadOnly(Boolean.valueOf(dataSourceProperties.getProperty("defaultReadOnly")));
poolDataSource.setTestOnBorrow(Boolean.valueOf(dataSourceProperties.getProperty("testOnBorrow")));
poolDataSource.setValidationQuery("SELECT+0");|code-block|syntax|javascript|353876|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Have been using DBCP for a couple of years now in production. It is stable, survives DB server reboot. Just configure it properly. It only requires a handful of parameters to be specified so don't be lazy. Here is a snippet from our system production code which lists parameters that we explicitly set to make it work:

<pre><code>DriverAdapterCPDS driverAdapterCPDS = new DriverAdapterCPDS();
driverAdapterCPDS.setUrl(dataSourceProperties.getProperty("url"));
driverAdapterCPDS.setUser(dataSourceProperties.getProperty("username"));
driverAdapterCPDS.setPassword(dataSourceProperties.getProperty("password"));
driverAdapterCPDS.setDriver(dataSourceProperties.getProperty("driverClass"));

driverAdapterCPDS.setMaxActive(Integer.valueOf(dataSourceProperties.getProperty("maxActive")));
driverAdapterCPDS.setMaxIdle(Integer.valueOf(dataSourceProperties.getProperty("maxIdle")));
driverAdapterCPDS.setPoolPreparedStatements(Boolean.valueOf(dataSourceProperties.getProperty("poolPreparedStatements")));

SharedPoolDataSource poolDataSource = new SharedPoolDataSource();
poolDataSource.setConnectionPoolDataSource(driverAdapterCPDS);
poolDataSource.setMaxWait(Integer.valueOf(dataSourceProperties.getProperty("maxWait")));
poolDataSource.setDefaultTransactionIsolation(Integer.valueOf(dataSourceProperties.getProperty("defaultTransactionIsolation")));
poolDataSource.setDefaultReadOnly(Boolean.valueOf(dataSourceProperties.getProperty("defaultReadOnly")));
poolDataSource.setTestOnBorrow(Boolean.valueOf(dataSourceProperties.getProperty("testOnBorrow")));
poolDataSource.setValidationQuery("SELECT 0");
</code></pre>

blocks|key|350107|text|另一种选择是HikariCP。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|350108|下面是比较benchmark|350109|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/brettwooldridge/HikariCP|1|https://github.com/brettwooldridge/HikariCP-benchmark^0|6|8|0|0|5|9|1|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]]|C|$]]|$1|D|3|E|5|6|7|T|8|@]|9|@$A|U|B|V|1|W]]|C|$]]|$1|F|3|-4|5|6|7|X|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]|N|$5|I|J|K|C|$L|O]]]]

Another alternative is <a href="https://github.com/brettwooldridge/HikariCP" rel="noreferrer">HikariCP</a>.

Here is the comparison <a href="https://github.com/brettwooldridge/HikariCP-benchmark" rel="noreferrer">benchmark</a>

blocks|key|3130312|text|我们遇到了一种情况，我们需要引入连接池，而我们面前有4个选择。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3130313|3130314|DBCP2|unordered-list-item|3130315|C3P0|3130316|Tomcat+JDBC|3130317|HikariCP|3130318|3130319|我们根据我们的标准进行了一些测试和比较，并决定使用HikariCP。请阅读this+article，它解释了我们为什么选择HikariCP。|offset|length|3130320|entityMap|0|LINK|mutability|MUTABLE|url|https://beansroasted.wordpress.com/2017/07/29/connection-pool-analysis/^0|0|0|0|0|0|0|0|11|C|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|10|8|@]|9|@]|A|$]]|$1|F|3|G|5|E|7|11|8|@]|9|@]|A|$]]|$1|H|3|I|5|E|7|12|8|@]|9|@]|A|$]]|$1|J|3|K|5|E|7|13|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|14|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|15|8|@]|9|@$O|16|P|17|1|18]]|A|$]]|$1|Q|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

We came across a situation where we needed to introduce connection pool and we had 4 options in front of us.

<ul>
<li>DBCP2</li>
<li>C3P0</li>
<li>Tomcat JDBC</li>
<li>HikariCP</li>
</ul>

We carried out some tests and comparison based on our criteria and decided to go for HikariCP.
Read <a href="https://beansroasted.wordpress.com/2017/07/29/connection-pool-analysis/" rel="nofollow noreferrer">this article</a> which explains why we chose HikariCP.

blocks|key|3343243|text|要以最好的方式实现C3P0，请使用check+this+answer|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3343244|C3P0|style|BOLD|3343245|对于企业级应用来说，C3P0是最好的方法。C3P0是一个易于使用的库，用于使用可绑定DataSources+(包括实现连接和语句池的DataSources，如jdbc3规范和JNDI标准扩展所描述的)增强传统的(基于DriverManager的)+jdbc2驱动程序。C3P0还健壮地处理了DB断开连接和恢复时的透明重新连接，而如果连接是从其下面移除的，则DBCP永远不会恢复连接。|3343246|这就是为什么c3p0和其他连接池也有准备好的语句缓存-它允许应用程序代码避免处理所有这些问题。这些语句通常保存在一些有限的LRU池中，因此常见的语句重用一个PreparedStatement实例。|3343247|更糟糕的是，DBCP将连接对象返回到底层传输已中断的应用程序。c3p0的一个常见用例是替换Apache+Tomcat中包含的标准DBCP连接池。程序员经常会遇到这样的情况:在DBCP连接池中没有正确地回收连接，在这种情况下，c3p0是一个有价值的替代方案。|3343248|在当前的更新中，C3P0有一些出色的特性。下面给出以下几点：|3343249|ComboPooledDataSource+dataSource+=+new+ComboPooledDataSource();
dataSource.setMinPoolSize();
dataSource.setMaxPoolSize();
dataSource.setMaxIdleTime();
dataSource.setMaxStatements();
dataSource.setMaxStatementsPerConnection();
dataSource.setMaxIdleTimeExcessConnections();|code-block|syntax|javascript|3343250|这里，最大和最小池大小定义了连接的界限，这意味着该应用程序将采用的最小和最大连接数。MaxIdleTime()定义何时释放空闲连接。|CODE|3343251|DBCP|3343252|这种方法也很好，但也有一些缺点，比如连接超时和连接重新释放。当我们使用多线程项目时，C3P0是很好的。在我们的项目中，我们通过使用DBCP同时使用多个线程执行，如果我们使用更多的线程执行，那么我们就会得到连接超时。因此，我们采用了c3p0配置。我根本不推荐DBCP，特别是它在DB离开时将连接抛出池的诀窍，当DB返回时无法重新连接，以及它无法动态地将连接对象添加回池中(它永远挂起在post+JDBCconnect+I/O套接字读取上)。|3343253|谢谢:)|3343254|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/51838455/3073945^0|H|H|0|0|0|4|0|0|0|0|0|0|8|3|16|D|0|0|4|0|0|0^^$0|@$1|2|3|4|5|6|7|1B|8|@]|9|@$A|1C|B|1D|1|1E]]|C|$]]|$1|D|3|E|5|6|7|1F|8|@$A|1G|B|1H|F|G]]|9|@]|C|$]]|$1|H|3|I|5|6|7|1I|8|@]|9|@]|C|$]]|$1|J|3|K|5|6|7|1J|8|@]|9|@]|C|$]]|$1|L|3|M|5|6|7|1K|8|@]|9|@]|C|$]]|$1|N|3|O|5|6|7|1L|8|@]|9|@]|C|$]]|$1|P|3|Q|5|R|7|1M|8|@]|9|@]|C|$S|T]]|$1|U|3|V|5|6|7|1N|8|@$A|1O|B|1P|F|G]|$A|1Q|B|1R|F|W]]|9|@]|C|$]]|$1|X|3|Y|5|6|7|1S|8|@$A|1T|B|1U|F|G]]|9|@]|C|$]]|$1|Z|3|10|5|6|7|1V|8|@]|9|@]|C|$]]|$1|11|3|12|5|6|7|1W|8|@]|9|@]|C|$]]|$1|13|3|-4|5|6|7|1X|8|@]|9|@]|C|$]]]|14|$15|$5|16|17|18|C|$19|1A]]]]

To Implement the C3P0 in best way then <a href="https://stackoverflow.com/a/51838455/3073945">check this answer</a>

C3P0:

For enterprise application, C3P0 is best approach. 
C3P0 is an easy-to-use library for augmenting traditional (DriverManager-based) JDBC drivers with JNDI-bindable DataSources, including DataSources that implement Connection and Statement Pooling, as described by the jdbc3 spec and jdbc2 std extension.
C3P0 also robustly handled DB disconnects and transparent reconnects on resume whereas DBCP never recovered connections if the link was taken out from beneath it. 

So this is why c3p0 and other connection pools also have prepared statement caches- it allows application code to avoid dealing with all this. The statements are usually kept in some limited LRU pool, so common statements reuse a PreparedStatement instance.

Worse still DBCP was returning Connection objects to the application for which the underlying transport had broken.
A common use case for c3p0 is to replace the standard DBCP connection pooling included with Apache Tomcat. Often times, a programmer will run into a situation where connections are not correctly recycled in the DBCP connection pool and c3p0 is a valuable replacement in this case.

In current updates C3P0 has some brilliant features. those are given bellow:

<pre><code>ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setMinPoolSize();
dataSource.setMaxPoolSize();
dataSource.setMaxIdleTime();
dataSource.setMaxStatements();
dataSource.setMaxStatementsPerConnection();
dataSource.setMaxIdleTimeExcessConnections();
</code></pre>

Here, max and min poolsize define bounds of connection that means how minimum and maximum connection this application will take. <code>MaxIdleTime()</code> define when it will release the idle connection.

DBCP:

This approach is also good but have some drawbacks like connection timeout and connection realeasing.
C3P0 is good when we are using mutithreading projects. In our projects we used simultaneously multiple thread executions by using DBCP, then we got connection timeout if we used more thread executions. So we went with c3p0 configuration.
I would not recommend DBCP at all, especially it's knack of throwing connections out of the pool when the DB goes away, its inability to reconnect when the DB comes back and its inability to dynamically add connection objects back into the pool (it hangs forever on a post JDBCconnect I/O socket read)

Thanks :)

blocks|key|3343277|text|我的建议是|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3343278|hikari+>德鲁伊>+UCP+>+c3p0+>+DBCP|offset|length|style|BOLD|3343279|它是基于我已经测试过的--+20190202，在我的本地测试环境(+docker/pool+minSize=1，maxSize=8中的4+4GB/mysql)中，hikari可以服务1024线程x1024次来获得连接，每个线程完成的平均时间是100万或200万秒，而c3p0只能服务256个线程x1024次，每个线程的平均时间已经是2100万秒。(512个线程失败)。|3343280|entityMap^0|0|0|U|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@$D|N|E|O|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|P|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

my recommendation is

hikari > druid > UCP > c3p0 > DBCP

It's based on what I have tested - 20190202, in my local test environment(4GB mac/mysql in docker/pool minSize=1, maxSize=8), hikari can serve 1024 threads x 1024 times to get connections, average time for each thread to finish is 1 or 2 million seconds, while c3p0 can only serve 256 threads x 1024 times and average time for each thread is already 21 million seconds. (512 threads failed).

What is the best connection pooling library available for Java/JDBC?

I'm considering the 2 main candidates (free / open-source): 

<ul>
<li>Apache DBCP - <a href="http://commons.apache.org/dbcp/" rel="noreferrer">http://commons.apache.org/dbcp/</a></li>
<li>C3P0 - <a href="http://sourceforge.net/projects/c3p0" rel="noreferrer">http://sourceforge.net/projects/c3p0</a></li>
</ul>

I've read a lot about them in blogs and other forums but could not reach a decision.

Are there any relevant alternatives to these two?

Connection pooling options with JDBC: DBCP vs C3P0

数据库连接池

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可用于Java/JDBC的最好的连接池是什么？我正在考虑两个主要的候选者(免费/开源)：Apache DBCP - C3P0 -  我在博客和其他论坛上读到了很多关于它们的信息，但无法做出决定。除了这两个之外，还有其他相关的选择吗？

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