我正在使用 R1Soft (5.8.1) 在一些服务器上进行文件备份，今晚我一直在尝试设置 MySQL 备份 - 我安装了驱动程序等，并正在设置策略，但出现了错误。
Failed to perform discovery on database instance '123'
Database instance discovery error
Error setting up proxy connection
Error could not connect to mysql instance
我的用户名等都是正确的，因此我可以正常进行身份验证（我知道这一点，因为我之前遇到了与主机名相关的不同错误，我必须使用“使用备用主机名/IP”来纠正）。
我搜索了错误，但没有找到任何有用的信息 - 我在http://wiki.r1soft.com/display/kb3/Known+Issues+affecting+upgrades+to+Server+Backup+Manager+5.6.x+(post+release)这是相同的消息，但它与升级有关，并且修复方法是确保代理和服务器运行相同的版本，并且它们在此实例中。
日志文件显示：
2014-11-26 21:52:17,533 INFO - AGENT(MYSQL_IP): Agent Version 5.8.1.38
2014-11-26 21:52:17,535 INFO - AGENT(MYSQL_IP): Connection authenticated; Waiting for command.
2014-11-26 21:52:17,576 INFO - AGENT(MYSQL_IP): Executing get device list request...
2014-11-26 21:52:17,576 INFO - AGENT(MYSQL_IP): Discovering devices available for replication ...
2014-11-26 21:52:17,972 INFO - TASK(NONE): Starting proxy to agent(MYSQL_IP) -> R1SOFT_IP:3306 on port 4306
2014-11-26 21:52:52,144 INFO - TASK(NONE): Shutting down proxy server on port 4306
2014-11-26 21:52:52,146 INFO - TASK(NONE): Proxy server on port 4306 stopped.
2014-11-26 21:52:52,972 ERROR - Failed to perform discovery on database instance '123'
com.r1soft.backup.server.facade.DatabaseException: Failed to perform discovery on database instance '123'
at com.r1soft.backup.server.facade.DatabaseFacade.discoverDatabaseInstance(DatabaseFacade.java:58)
at com.r1soft.backup.server.web.policy.AddDatabaseInstanceWindow.onValidateDataDirWillBeBackedUp(AddDatabaseInstanceWindow.java:865)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2726)
at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2654)
at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:136)
at org.zkoss.zk.ui.impl.EventProcessingThreadImpl.process0(EventProcessingThreadImpl.java:534)
at org.zkoss.zk.ui.impl.EventProcessingThreadImpl.run(EventProcessingThreadImpl.java:461)
Caused by: com.r1soft.backup.server.worker.WorkerException: Database instance discovery error
at com.r1soft.backup.server.worker.db.mysql.MySQLInstanceDiscoveryWorker.run(MySQLInstanceDiscoveryWorker.java:121)
at com.r1soft.backup.server.facade.DatabaseFacade.discoverDatabaseInstance(DatabaseFacade.java:51)
... 10 more
Caused by: com.r1soft.backup.server.worker.WorkerException: Error setting up proxy connection
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.acceptNewConnection(AgentProxyWorker.java:340)
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.run(AgentProxyWorker.java:405)
at java.lang.Thread.run(Unknown Source)
Caused by: com.r1soft.backup.server.worker.WorkerException: Error could not connect to mysql instance
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.getNewAutenticatedAgentSocket(AgentProxyWorker.java:305)
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.access$1100(AgentProxyWorker.java:123)
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer$AgentPipe.<init>(AgentProxyWorker.java:469)
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.acceptNewConnection(AgentProxyWorker.java:338)
... 2 more
2014-11-26 21:56:59,892 ERROR - GlobalUpdater failed to update properly
java.lang.NullPointerException
at com.r1soft.backup.server.web.GlobalUpdater$GlobalUpdaterThread.updateCharts(GlobalUpdater.java:1002)
at com.r1soft.backup.server.web.GlobalUpdater$GlobalUpdaterThread.doUpdates(GlobalUpdater.java:755)
at com.r1soft.backup.server.web.GlobalUpdater$GlobalUpdaterThread.run(GlobalUpdater.java:639)
2014-11-26 21:57:04,891 ERROR - GlobalUpdater failed to update properly
java.lang.NullPointerException
at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2654)
at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:136)
at org.zkoss.zk.ui.impl.EventProcessingThreadImpl.process0(EventProcessingThreadImpl.java:534)
at org.zkoss.zk.ui.impl.EventProcessingThreadImpl.run(EventProcessingThreadImpl.java:461)
Caused by: com.r1soft.backup.server.worker.WorkerException: Database instance discovery error
at com.r1soft.backup.server.worker.db.mysql.MySQLInstanceDiscoveryWorker.run(MySQLInstanceDiscoveryWorker.java:121)
at com.r1soft.backup.server.facade.DatabaseFacade.discoverDatabaseInstance(DatabaseFacade.java:51)
... 10 more
Caused by: com.r1soft.backup.server.worker.WorkerException: Error setting up proxy connection
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.acceptNewConnection(AgentProxyWorker.java:340)
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.run(AgentProxyWorker.java:405)
at java.lang.Thread.run(Unknown Source)
Caused by: com.r1soft.backup.server.worker.WorkerException: Error could not connect to mysql instance
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.getNewAutenticatedAgentSocket(AgentProxyWorker.java:305)
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.access$1100(AgentProxyWorker.java:123)
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer$AgentPipe.<init>(AgentProxyWorker.java:469)
at com.r1soft.backup.server.worker.AgentProxyWorker$AgentSocketProxyServer.acceptNewConnection(AgentProxyWorker.java:338)
... 2 more
谁知道可能是什么问题？