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Monitoring Apache Tomcat Server Fails With Metric Collection Error when Tomcat is Down (Doc ID 889675.1)

Last updated on APRIL 01, 2022

Applies to:

Enterprise Manager for Miscellaneous Plug-ins - Version 1.0 to 1.0
Information in this document applies to any platform.
Applies to version (release 6) of the Tomcat plug-in



Let us consider the case of Grid Control monitoring Apache Tomcat using the Apache Tomcat plugin.

When Tomcat is up, Grid Control reports the availability of the Tomcat target as up.
However, when Tomcat is down, Grid Control reports a Metric Collection Error for the Tomcat target, instead of showing it down.

Here's an example of that collection error:

Target: MatTomcat
Type: Apache Tomcat
Metric: Response
Collection Timestamp: Sep 18, 2009 4:18:16 PM
Error Type: Collection Failure
Message: oracle.sysman.emSDK.emd.fetchlet.FetchletException: oracle.sysman.emSDK.emd.fetchlet.FetchletException: Failed to retrieve RMIServer stub: javax.naming.ServiceUnavailableException [Root exception is java.rmi.ConnectException: Connection refused to host: <hostname.domain>; nested exception is: Connection refused]

The $AGENT_HOME/sysman/log/emagent.trc has the following entries:

<Timestamp> Thread-2872040352 ERROR engine:
[tomcat,MatTomcat,Response] : nmeegd_GetMetricData failed :
Failed to retrieve RMIServer stub: javax.naming.ServiceUnavailableException
[Root exception is java.rmi.ConnectException: Connection refused to host:
<hostname.domain>; nested exception is:
Connection refused]

The $AGENT_HOME/sysman/log/emagentfetchlet.trc has the following entries:

<Timestamp> [nmefmgr_getJNIFetchlet] ERROR JMX.generic logp.251 - Error: cannot communication with Target Failed to retrieve RMIServer stub: javax.naming.ServiceUnavailableException
[Root exception is java.rmi.ConnectException: Connection refused to host: <hostname.domain>; nested exception is: Connection refused]
at oracle.sysman.emd.fetchlets.JMX.generic.JMXContext.connectJVM(
at oracle.sysman.emd.fetchlets.JMX.generic.JMXContext.connect(
at oracle.sysman.emd.fetchlets.JMX.generic.JMXFetchlet.getMetric(
at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(
at java.lang.reflect.Method.invoke(
at oracle.sysman.emd.fetchlets.JMX.JMXFetchletWrapperBase.getMetric(
at oracle.sysman.emd.fetchlets.FetchletWrapper.getMetric(


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