Question

目标
我正在创建一个REST Web服务（使用RESTEasy），我认为如果我不管理连接池会很好，但我让Tomcat这样做。所以我在META-INF / context.xml中添加了一个资源

问题
我在MySQL服务器上看到了很多连接，但是我已经配置了只允许2个连接。我不知道为什么，但是我的设置没有得到关于nr连接等的信息。

context.xml中

<Context>
    <!-- DataSource management from tomcat (reference created in web.xml) -->
    <Resource name="jdbc/Taalmaatjes-db" auth="Container" type="javax.sql.DataSource"
              maxTotal="2" maxIdle="2"
              initialSize="1" maxWaitMillis="10000"
              username="root" password="rootie"
              driverClassName="com.mysql.jdbc.Driver" 
              url="jdbc:mysql://localhost:3306/taalmaatjes"
              removeAbandonedOnBorrow="true" 
              removeAbandonedOnMaintenance="true"
              removeAbandonedTimeout="5"
              singleton="false" defaultAutoCommit="false" rollbackOnReturn="true" />
</Context>

设置maxTotal，maxIdle，initialSize，maxWaitMillis似乎没有被提取。使用突击队'SHOW PROCESSLIST'并连接到我的应用程序39次，我得到：

3   root    localhost:56576 taalmaatjes Query   0   starting    /* ApplicationName=IntelliJ IDEA 2017.3.4 */ SHOW PROCESSLIST
231 root    localhost:57932 taalmaatjes Sleep   102     
232 root    localhost:57933 taalmaatjes Sleep   102     
233 root    localhost:57934 taalmaatjes Sleep   100     
234 root    localhost:57935 taalmaatjes Sleep   99      
235 root    localhost:57936 taalmaatjes Sleep   99      
236 root    localhost:57937 taalmaatjes Sleep   99      
237 root    localhost:57938 taalmaatjes Sleep   99      
238 root    localhost:57939 taalmaatjes Sleep   98      
239 root    localhost:57940 taalmaatjes Sleep   98      
240 root    localhost:57941 taalmaatjes Sleep   98      
241 root    localhost:57942 taalmaatjes Sleep   98      
242 root    localhost:57943 taalmaatjes Sleep   98      
243 root    localhost:57944 taalmaatjes Sleep   98      
244 root    localhost:57945 taalmaatjes Sleep   97      
245 root    localhost:57950 taalmaatjes Sleep   93      
246 root    localhost:57951 taalmaatjes Sleep   93      
247 root    localhost:57952 taalmaatjes Sleep   93      
248 root    localhost:57953 taalmaatjes Sleep   92      
249 root    localhost:57954 taalmaatjes Sleep   92      
250 root    localhost:57955 taalmaatjes Sleep   92      
251 root    localhost:57956 taalmaatjes Sleep   92      
252 root    localhost:57957 taalmaatjes Sleep   92      
253 root    localhost:57958 taalmaatjes Sleep   92      
254 root    localhost:57959 taalmaatjes Sleep   92      
255 root    localhost:57960 taalmaatjes Sleep   92      
256 root    localhost:57961 taalmaatjes Sleep   91      
257 root    localhost:57962 taalmaatjes Sleep   91      
258 root    localhost:57963 taalmaatjes Sleep   91      
259 root    localhost:57964 taalmaatjes Sleep   91      
260 root    localhost:57965 taalmaatjes Sleep   91      
261 root    localhost:57966 taalmaatjes Sleep   91      
262 root    localhost:57967 taalmaatjes Sleep   91      
263 root    localhost:57968 taalmaatjes Sleep   91      
264 root    localhost:57969 taalmaatjes Sleep   90      
265 root    localhost:57970 taalmaatjes Sleep   90      
266 root    localhost:57971 taalmaatjes Sleep   90      
267 root    localhost:57972 taalmaatjes Sleep   90      
268 root    localhost:57974 taalmaatjes Sleep   90      
269 root    localhost:57975 taalmaatjes Sleep   90

调用以获取代码中的DataSource

这里有一个放在我可以调用的方法中的例子：

@GET
public StringValueObject getVersion() throws NamingException, SQLException {
    DataSource dataSource1 = (DataSource) ((javax.naming.Context) new InitialContext()
            .lookup("java:comp/env"))
            .lookup("jdbc/Taalmaatjes-db");
    dataSource1.getConnection().close();
    return new StringValueObject("v0.1-unsecured");
}

请注意，在调用此getVersion 20次之后，我仍有20个连接显示SHOW PROCESSLIST。

也许有用的细节
我使用jOOQ作为我的ORM与MySQL数据库。它运行在一个tomcat上。我也尝试添加factory =“org.apache.tomcat.jdbc.pool.DataSourceFactory”，因为Why does my Tomcat only open 8 JDBC connections中提到了这一点。但是，它也没有用。

我的知识
我真的很喜欢这个JBNI，JDBC的东西。我知道的太少了，这就是我在这里学习的原因！我以为我使用的是Tomcat JBNI，但是当我使用设置removeAbandoned =“true”时，它给出了错误，即此设置不存在，我应该使用removeAbandonedOnBorrow。显然我正在使用Apache JBDC？真的不知道区别，因为我只是想让tomcat来处理我的连接池。看起来聪明，把它留给另一个图书馆。

Answer 1

问题是您已将数据源资源配置为非单例，此处：

<Resource name="jdbc/Taalmaatjes-db" auth="Container" type="javax.sql.DataSource"
    maxTotal="2" maxIdle="2"
    initialSize="1" maxWaitMillis="10000"
    username="root" password="rootie"
    driverClassName="com.mysql.jdbc.Driver" 
    url="jdbc:mysql://localhost:3306/taalmaatjes"
    removeAbandonedOnBorrow="true" 
    removeAbandonedOnMaintenance="true"
    removeAbandonedTimeout="5"
    <!-- here -->
    singleton="false" defaultAutoCommit="false" rollbackOnReturn="true" />

将其删除，然后重试。

上下文数据源设置无法获取

1 个答案: