OC4J~OC4J_EM~default_island~1日志如下：

10/12/11 17:05:20 OVF Integration class
10/12/11 17:05:26 Oracle Application Server Containers for J2EE 10g (10.1.2.0.2) initialized
10/12/11 17:10:20 HealthMonitor : Executing diagnostic command for module omsThread. Dec 11, 2010 5:10:20 PM

--------
10/12/11 17:11:17 Start process
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Dec 11, 2010 5:11:20 PM org.apache.struts.util.PropertyMessageResources
INFO: Initializing, config='org.apache.struts.util.LocalStrings', returnNull=true
Dec 11, 2010 5:11:20 PM org.apache.struts.util.PropertyMessageResources
INFO: Initializing, config='org.apache.struts.action.ActionResources', returnNull=true
Dec 11, 2010 5:11:20 PM org.apache.struts.util.PropertyMessageResources
INFO: Initializing, config='view.ApplicationResources', returnNull=true
10/12/11 17:11:22 log4j:ERROR No appenders could be found for category (emSDK.conf).
10/12/11 17:11:22 log4j:ERROR Please initialize the log4j system properly.
10/12/11 17:11:32 java.lang.IllegalArgumentException: Service already exists: oracle.sysman.emSDK.tgt.svc.ServiceConfigManager
10/12/11 17:11:32       at oracle.sysman.emSDK.svc.ServiceUtil.setService(ServiceUtil.java:115)
10/12/11 17:11:32       at oracle.sysman.emSDK.svc.ServiceUtil.initService(ServiceUtil.java:94)
10/12/11 17:11:32       at oracle.sysman.ocs.svcsys.intg.OCSIntegration.init(OCSIntegration.java:121)
10/12/11 17:11:32       at oracle.sysman.eml.app.ContextInitializer.contextInitialized(ContextInitializer.java:461)
10/12/11 17:11:32       at com.evermind.server.http.HttpApplication.initDynamic(HttpApplication.java:1009)
10/12/11 17:11:32       at com.evermind.server.http.HttpApplication.(HttpApplication.java:549)
10/12/11 17:11:32       at com.evermind.server.Application.getHttpApplication(Application.java:890)
10/12/11 17:11:32       at com.evermind.server.http.HttpServer.getHttpApplication(HttpServer.java:707)
10/12/11 17:11:32       at com.evermind.server.http.HttpSite.initApplications(HttpSite.java:625)
10/12/11 17:11:32       at com.evermind.server.http.HttpSite.setConfig(HttpSite.java:278)
10/12/11 17:11:32       at com.evermind.server.http.HttpServer.setSites(HttpServer.java:278)
10/12/11 17:11:32       at com.evermind.server.http.HttpServer.setConfig(HttpServer.java:179)
10/12/11 17:11:32       at com.evermind.server.ApplicationServer.initializeHttp(ApplicationServer.java:2394)
10/12/11 17:11:32       at com.evermind.server.ApplicationServer.setConfig(ApplicationServer.java:1551)
10/12/11 17:11:32       at com.evermind.server.ApplicationServerLauncher.run(ApplicationServerLauncher.java:92)
10/12/11 17:11:32       at java.lang.Thread.run(Thread.java:534)
10/12/11 17:11:33 OVF Integration class
10/12/11 17:11:39 Oracle Application Server Containers for J2EE 10g (10.1.2.0.2) initialized

[oracle@gc2 bin]$ ./opmnctl status -l

Processes in Instance: EnterpriseManager0.gc2
-------------------+--------------------+---------+----------+------------+----------+-----------+------
ias-component      | process-type       |     pid | status   |        uid |  memused |    uptime | ports
-------------------+--------------------+---------+----------+------------+----------+-----------+------
DSA                | DSA                |    9047 | Alive    | 1099628636 |    44652 |  00:30:27 | N/A
HTTP_Server        | HTTP_Server        |    4643 | Alive    | 1099628629 |   158352 |  00:47:15 | http1:7778,http2:7200,https1:4444,https2:1159,http3:4889
LogLoader          | logloaderd         |    9068 | Alive    | 1099628637 |    62380 |  00:30:21 | LogLoaderAdmin:44000
dcm-daemon         | dcm-daemon         |    9128 | Alive    | 1099628638 |    48516 |  00:30:15 | N/A
OC4J               | home               |    4644 | Alive    | 1099628630 |    51040 |  00:47:39 | ajp:12501,rmi:12401,jms:12601
OC4J               | OC4J_EMPROV        |    4645 | Alive    | 1099628631 |    74484 |  00:47:39 | ajp:12502,rmi:12402,jms:12602
OC4J               | OC4J_EM            |   19326 | Init     | 1099628642 |    66436 |  00:00:15 | N/A
WebCache           | WebCache           |    4659 | Alive    | 1099628633 |    33400 |  00:47:39 | http:7777,invalidation:9401,statistics:9402
WebCache           | WebCacheAdmin      |    4648 | Alive    | 1099628634 |    12084 |  00:47:41 | administration:9400

可以看见OC4J_EM已经重启了，这会造成grid control连接断开，很头疼的一件事。

分析：数据库和gridcontrol都是10.2.0.1，怀疑是bug，可惜没找到对应的说明。

查资料后以为是jdk版本过低1.4.2，升级到1.6.结果情况依然，继续分析中。

这个问题始终未解决，最后通过重新安装grid control，问题未在出现，也许是安装的时候出了点什么问题