Aurora 故障转移使连接以只读状态打开

Question

我们在 Aurora 集群中使用 MySQL 我们有 2 个实例 - master 和 slave。我们正在 c3po 连接池之上处理 spring 个事务。我们正在使用 mariadb jdbc 驱动程序（版本 2.2.3）。

我们的 url 看起来像这样 - jdbc:mysql:aurora:myclaster-cluster.cluster-xxxxxx.us-east-1.rds.amazonaws.com:3306/db?rewriteBatchedStatements=true

测试故障转移时；每隔几次故障转移，我们就会进入使用只读连接的状态 -

Caused by: org.springframework.jdbc.UncategorizedSQLException: PreparedStatementCallback; uncategorized SQLException for SQL [INSERT INTO a (a1, a2, a3, a4) VALUES (?, ?, ?, ?) on duplicate key update ]; SQL state [HY000]; error code [1290]; (conn=7) The MySQL server is running with the --read-only option so it cannot execute this statement; nested exception is java.sql.SQLException: (conn=7) The MySQL server is running with the --read-only option so it cannot execute this statement
    at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:84)
    at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81)
    at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81)
    at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:645)
    at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:866)
    at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:927)
    at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:937)
    at com.persistence.impl.MyDao.insert(MyDao.java:52)
    at org.springframework.scheduling.quartz.QuartzJobBean.execute(QuartzJobBean.java:75)
    at org.quartz.core.JobRunShell.run(JobRunShell.java:213)
    ... 1 common frames omitted
Caused by: java.sql.SQLException: (conn=7) The MySQL server is running with the --read-only option so it cannot execute this statement
    at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.get(ExceptionMapper.java:198)
    at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.getException(ExceptionMapper.java:110)
    at org.mariadb.jdbc.MariaDbStatement.executeExceptionEpilogue(MariaDbStatement.java:228)
    at org.mariadb.jdbc.MariaDbPreparedStatementClient.executeInternal(MariaDbPreparedStatementClient.java:216)
    at org.mariadb.jdbc.MariaDbPreparedStatementClient.execute(MariaDbPreparedStatementClient.java:150)
    at org.mariadb.jdbc.MariaDbPreparedStatementClient.executeUpdate(MariaDbPreparedStatementClient.java:183)
    at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeUpdate(NewProxyPreparedStatement.java:410)
    at org.springframework.jdbc.core.JdbcTemplate.doInPreparedStatement(JdbcTemplate.java:873)
    at org.springframework.jdbc.core.JdbcTemplate.doInPreparedStatement(JdbcTemplate.java:866)
    at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:629)
    ... 9 common frames omitted

我们如何强制驱动程序return 仅连接到主实例？有没有办法强制 aurora 在故障转移时关闭所有打开的连接？

谢谢

Answer 1

我们通过实现一个异常拦截器解决了这个问题，在这个异常拦截器中我们关闭了连接，强制池创建一个新的连接。

此解决方案与 mysql-connector-java 5.1.47

有关

@Override
public SQLException interceptException(SQLException sqlEx, Connection conn) {
    if (sqlEx.getErrorCode() == READ_ONLY_ERROR_CODE) {
        log.warn("Got read only exception closing the connection {} ", sqlEx.getMessage());
        closeConnection(conn);
    }
    return sqlEx;
}

Aurora 故障转移使连接以只读状态打开

Aurora failover leaves connections open as read-only state

c3p0

mariadb

amazon-aurora