Question

突然间，我为选择查询连续收到以下错误。

Unable to enlist connection in transaction: enlistResource returns 'false'

这似乎是从DBCP（https://commons.apache.org/proper/commons-dbcp/jacoco/org.apache.commons.dbcp2.managed/TransactionContext.java.html）

引发的

本质上，此代码调用javax.transaction.Transaction.enlistResource

查看API，它说“使用与目标Transaction对象关联的事务指定资源。如果资源成功登记，则为true;否则为false。”

我仍然不清楚为什么抛出这个异常。

什么是将资源登记到交易？
当enlist资源返回false时？我的意思是什么时候交易无法登记资源？
如何避免这个问题？

Tech Stack：

TomEE 7.0.4
JPA
MariaDB的

数据源配置：

<Resource id="jdbc/myDS" type="javax.sql.DataSource">
    dataSourceCreator = tomcat
    jtaManaged        = true
    driverClassName   = ${jdbc.driver}
    url               = ${jdbc.url}
    username          = ${jdbc.username}
    password          = ${jdbc.password}
    initialSize       = 5
    maxActive         = 100
    maxIdle           = 10
    minIdle           = 5
    maxWait           = 30000
    validationQuery   = SELECT 1
    testOnBorrow      = false
    testOnReturn      = false
    testWhileIdle     = true
    timeBetweenEvictionRunsMillis = 1800000
    numTestsPerEvictionRun = 2
    minEvictableIdleTimeMillis = 1800000
    accessToUnderlyingConnectionAllowed = false
</Resource>

堆栈追踪：

Caused by: org.apache.openjpa.lib.jdbc.ReportingSQLException: Unable to enlist connection in transaction: enlistResource returns 'false'. 
    at org.apache.openjpa.lib.jdbc.LoggingConnectionDecorator.wrap(LoggingConnectionDecorator.java:218) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.lib.jdbc.LoggingConnectionDecorator.wrap(LoggingConnectionDecorator.java:198) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.lib.jdbc.LoggingConnectionDecorator.access$000(LoggingConnectionDecorator.java:58) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.lib.jdbc.LoggingConnectionDecorator$LoggingConnection.prepareStatement(LoggingConnectionDecorator.java:250) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.lib.jdbc.DelegatingConnection.prepareStatement(DelegatingConnection.java:133) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.lib.jdbc.ConfiguringConnectionDecorator$ConfiguringConnection.prepareStatement(ConfiguringConnectionDecorator.java:139) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.lib.jdbc.DelegatingConnection.prepareStatement(DelegatingConnection.java:133) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.kernel.JDBCStoreManager$RefCountConnection.prepareStatement(JDBCStoreManager.java:1642) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.lib.jdbc.DelegatingConnection.prepareStatement(DelegatingConnection.java:122) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.sql.SQLBuffer.prepareStatement(SQLBuffer.java:513) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.sql.SQLBuffer.prepareStatement(SQLBuffer.java:493) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.sql.SelectImpl.prepareStatement(SelectImpl.java:480) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.sql.SelectImpl.execute(SelectImpl.java:421) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.sql.SelectImpl.execute(SelectImpl.java:392) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.sql.LogicalUnion$UnionSelect.execute(LogicalUnion.java:427) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.sql.LogicalUnion.execute(LogicalUnion.java:230) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.sql.LogicalUnion.execute(LogicalUnion.java:220) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.jdbc.kernel.SelectResultObjectProvider.open(SelectResultObjectProvider.java:93) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.kernel.QueryImpl$PackingResultObjectProvider.open(QueryImpl.java:2075) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.lib.rop.EagerResultList.<init>(EagerResultList.java:33) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.kernel.QueryImpl.toResult(QueryImpl.java:1257) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:1013) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:869) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:800) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.kernel.DelegatingQuery.execute(DelegatingQuery.java:541) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.persistence.QueryImpl.execute(QueryImpl.java:274) ~[openjpa-2.4.2.jar:2.4.2]
    at org.apache.openjpa.persistence.QueryImpl.getResultList(QueryImpl.java:290) ~[openjpa-2.4.2.jar:2.4.2]

Answer 1

刚刚遇到同样的问题，并在我的日志文件中挖掘了一些。就在第一次出现之前

enlistResource returns 'false'

我找到了

Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

进一步检查并找到了

WARNING [https-jsse-nio-8443-exec-1] org.apache.geronimo.transaction.manager.TransactionImpl.enlistResource Unable to enlist XAResource org.apache.openejb.resource.jdbc.managed.local.LocalXAResource@2ce72e5a, errorCode: 0
    javax.transaction.xa.XAException: Count not turn off auto commit for a XA transaction

这一切都让我从tomee-openejb邮件列表中找到old post。所以我最近的tomee.xml配置看起来像这样：

<Resource id="[Resourcename]" type="javax.sql.DataSource">
    jdbcDriver = com.mysql.jdbc.Driver
    jdbcUrl = jdbc:mysql://localhost:3306/[Databasename]
    userName = [Username]
    password = [Password]
</Resource>

现在我将其更改为以下配置：

<Resource id=[Name] type="javax.sql.DataSource">
    jdbcDriver = com.mysql.jdbc.Driver
    jdbcUrl = jdbc:mysql://localhost:3306/[Databasename]
    jtaManaged = true
    username = [Username]
    password = [Password]
    defaultAutoCommit = false
    testOnReturn = true
    testWhileIdle = true
    timeBetweenEvictionRunsMillis = 60
    initialSize = 2
    minIdle = 2
    validationQuery = "select 1" 
</Resource>

手指交叉，它将无任何进一步的问题。如果我不再在这里更新它将会正常工作。

更多信息：

Tomee DataSource Configuration

无法在事务中登记连接：enlistResource返回'false'

1 个答案: