Because of the size and complexity of the Enterprise Manager Cloud Control software, while browsing through the folders on OMS server, you may feel confused and think that everything is in complete disorder. In fact, the directory structure of EM13c is quite simple. During EM13c installation (“advanced mode”), the installer expects you to enter the folder names:

• Middleware home location (MW_HOME)
• OMS instance base location (EM_INSTANCE_BASE)
• Agent base location

Depending on your inputs, the installer will create a directory structure similar to the below one:

As you may notice, there are slight differences between directory structures of EM12c and EM13c. For example, in EM13c, there is no separate folder called “oms” in the middleware home. Therefore the binaries located in OMS folder (such as emctl) are now located in the “bin” folder in the Middleware home. Oracle_WT is also merged into the middleware home.

Knowing the directory structure helps you to access the important trace and log files of EM13c. Here’s the trace and log files you may use to diagnose problems about EM13c.

The Trace and Log Files of OMS:

The Oracle Management Service has two applications: OMS Console (emgc) and OMS Platform (empbs). The trace and log files of these applications are located in “sysman/log” directory in the EM Instance Home (for example: /u01/oracle/gc_inst/em/EMGC_OMS1/sysman/log ). These logs are very useful to diagnose OMS related problems.

• emoms.log The main log file for the OMS Console (emgc) application.
• emoms.trc The main trace file for the OMS Console (emgc) application.
• emoms_pbs.log The main log file for the OMS pbs (empbs) application.
• emoms_pbs.trc The main trace file for the OMS pbs (empbs) application.
• secure.log This log provides additional logs for “emctl secure oms” command.
• emctl.log This log contains OMS startup/shutdown details.
• emctl.msg This log is created by the OMS HealthMonitor thread, when it re-starts the OMS due to a critical error.

The Trace and Log Files of EM Managed Server:

EM Managed Server is the weblogic server hosting OMS applications. The logs are located in “logs” directory in EM Manager Server Home folder (for example: /u01/oracle/gc_inst/user_projects/domains/GCDomain/servers/EMGC_OMS1/logs):

• EMGC_OMS1.log: The EMGC_OMSn instance writes all messages from its subsystems and applications to this logfile.
• EMGC_OMS1.out: The messages written to sysout and syserr are saved in this file by the nodemanager. This log file is rotated by the nodemanager only at the time of Managed server start, and older files need to be manually purged.
• access.log: This log file contains details of HTTP requests processed by EM Managed Server.
• EMGC_OMS1-diagnostic.log: This log file contains application-related security errors.

The Trace and Log Files of Oracle HTTP Server (OHS)

Oracle HTTP Server (OHS) is the web server component of EM13c. It works as a reverse proxy for Oracle WebLogic Server and the framework for hosting static pages. It’s located in “logs” folder in the “OHS Home” (/u01/oracle/gc_inst/user_projects/domains/GCDomain/servers/ohs1/logs):

• access_log: Access logs stores all the client requests. The HTTP Response code is useful in identifying whether the client request was successful or not.
• ohs1.log: This is the error log for the OHS.
• admin_log: This log file keeps Oracle Dynamic Monitoring Service (DMS) requests.
• em_upload_http_access_log: The log file contains entries for Agent uploads in http mode.
• em_upload_https_access_log: The log file contains entries for Agent uploads in https mode.

The Trace and Log Files of EM Agents:

The agent log files are located in the “sysman/log” folder in the “Agent Instance Home” (for example: /u01/oracle/emagent/agent_inst/sysman/log).

• gcagent.log: This log file contains trace, debug, information, error, or warning messages from the Agent. It can be used for debugging Agent framework issues.
• gcagent_errors.log: It’s similar to the gcagent.log but it contains only the log messages of ERROR and FATAL levels. The log has no size limit.
• emagent.nohup: Nohup logs of the agent. This log contains startup and shutdown messages including JVM flags. It can be used to determine when the agent is down, and the errors generated on startup of shutdown can be examined with this log.
• gcagent_mdu.log: This log tracks the metadata updates (such as save or remove targets, blackouts, deployments of metric extensions) to the Agent.
• gcagent_sdk.trc: The gcagent_sdk.trc file contains log messages from each of the plugins and can be used for debugging plugin related issues.
• emctl.log: emctl.log provides logging for emctl commands.
• emdctlj.log: emdctlj.log contains logging for the entry point and the exit codes of the emctl commands.
• secure.log: This log provides additional logs for “emctl secure agent” command, and can be useful to diagnose failures during securing of the Agent.
• emagent_perl.trc: Trace file for the PERL scripts. EM uses perl scripts to gather some metrics and target discovery. The log level can be changed by modifying EMAGENT_PERL_TRACE_LEVEL variable in “sysman/config/emd.properties” file.