Wildfly并自动重新连接到数据库 [英] Wildfly and auto reconnect to the database

问题描述

我有一个客户端，一个服务器和一个数据库.客户端通过EJB远程接口与服务器通信.作为服务器-我使用Wildfly 8.2.0.作为数据库-我使用MySQL.服务器通过JPA/休眠与MySQL通信.当然，当我关闭MySQL服务器时，Wildfly会引发异常.但是，当我再次打开MySQL时-Wildfly仍然会抛出相同的错误.我必须关闭Wildfly，然后将其重新打开，以确保Wildfly重新连接到数据库.

如何在Wildfly中设置自动重新连接?

我试图在连接URL:jdbc:mysql://localhost/db?autoReconnect=true&useUnicode=yes&characterEncoding=UTF8中设置自动重新连接，并试图将其添加到我使用的standalone-full.xml文件中，这一行:<check-valid-connection-sql>select 1</check-valid-connection-sql>，但是两种解决方案均不起作用. /p>

standalone-full.xml:

<!-- ... -->
<datasource jta="true" jndi-name="java:jboss/datasources/MySQLDS" pool-name="MySQLDS" enabled="true" use-ccm="true">
    <connection-url>jdbc:mysql://localhost/db?autoReconnect=true&amp;amp;useUnicode=yes&amp;amp;characterEncoding=UTF8</connection-url>
    <driver-class>com.mysql.jdbc.Driver</driver-class>
    <driver>mysqlDriver</driver>
    <security>
        <user-name>user</user-name>
        <password>***</password>
    </security>
    <validation>
        <check-valid-connection-sql>select 1</check-valid-connection-sql>
        <validate-on-match>false</validate-on-match>
        <background-validation>false</background-validation>
    </validation>
    <timeout>
        <set-tx-query-timeout>false</set-tx-query-timeout>
        <blocking-timeout-millis>0</blocking-timeout-millis>
        <idle-timeout-minutes>0</idle-timeout-minutes>
        <query-timeout>0</query-timeout>
        <use-try-lock>0</use-try-lock>
        <allocation-retry>0</allocation-retry>
        <allocation-retry-wait-millis>0</allocation-retry-wait-millis>
    </timeout>
    <statement>
        <share-prepared-statements>false</share-prepared-statements>
    </statement>
</datasource>
<drivers>
    <driver name="mysqlDriver" module="com.mysql">
        <xa-datasource-class>com.mysql.jdbc.Driver</xa-datasource-class>
    </driver>
</drivers>
<!-- ... -->

解决方案

我通过将standalone-full.xml文件中的validate-on-match值更改为true解决了这个问题:

<validate-on-match>true</validate-on-match>

I've got a client, a server and a database. The client communicates with the server via a EJB remote interfaces. As the server - I use a Wildfly 8.2.0. As the database - I use a MySQL. The server communicates with the MySQL via a JPA/Hibernate. When I turn off the MySQL server - the Wildfly throws an exception, of course. But when I turn on the MySQL again - the Wildfly still throws the same ERROR. I've to turn off the Wildfly and turn it back that the Wildfly reconnect to the database.

How to set auto reconnect in the Wildfly?

I tried to set auto reconnect in a connection URL: jdbc:mysql://localhost/db?autoReconnect=true&useUnicode=yes&characterEncoding=UTF8 and i tried to add to the standalone-full.xml file which i use, this line: <check-valid-connection-sql>select 1</check-valid-connection-sql>, but both solutions don't work.

standalone-full.xml:

<!-- ... -->
<datasource jta="true" jndi-name="java:jboss/datasources/MySQLDS" pool-name="MySQLDS" enabled="true" use-ccm="true">
    <connection-url>jdbc:mysql://localhost/db?autoReconnect=true&amp;amp;useUnicode=yes&amp;amp;characterEncoding=UTF8</connection-url>
    <driver-class>com.mysql.jdbc.Driver</driver-class>
    <driver>mysqlDriver</driver>
    <security>
        <user-name>user</user-name>
        <password>***</password>
    </security>
    <validation>
        <check-valid-connection-sql>select 1</check-valid-connection-sql>
        <validate-on-match>false</validate-on-match>
        <background-validation>false</background-validation>
    </validation>
    <timeout>
        <set-tx-query-timeout>false</set-tx-query-timeout>
        <blocking-timeout-millis>0</blocking-timeout-millis>
        <idle-timeout-minutes>0</idle-timeout-minutes>
        <query-timeout>0</query-timeout>
        <use-try-lock>0</use-try-lock>
        <allocation-retry>0</allocation-retry>
        <allocation-retry-wait-millis>0</allocation-retry-wait-millis>
    </timeout>
    <statement>
        <share-prepared-statements>false</share-prepared-statements>
    </statement>
</datasource>
<drivers>
    <driver name="mysqlDriver" module="com.mysql">
        <xa-datasource-class>com.mysql.jdbc.Driver</xa-datasource-class>
    </driver>
</drivers>
<!-- ... -->

解决方案

I solved this problem by changing the validate-on-match value to true in my standalone-full.xml file:

<validate-on-match>true</validate-on-match>

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