The listener is a server process that listens to incoming client connection requests and manages traffic to the database. The Netlsnr agent brings the listener services online, monitors their status, and takes them offline.
The Netlsnr agent is IMF-aware.
See How the Oracle and Netlsnr agents support intelligent resource monitoring.
Table: Netlsnr agent functions lists the Netlsnr agent functions.
Table: Netlsnr agent functions
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Agent operation
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Description |
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Online
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Starts the listener process by using the following command:
lsnrctl start $LISTENER
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Offline
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Stops the listener process by using the following command:
lsnrctl stop $LISTENER
If the listener is configured with a password, the agent uses the password to stop the listener.
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Monitor
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Verifies the status of the listener process.
The Netlsnr agent provides two levels of monitoring, basic and detail:
In the basic monitoring mode, the agent scans the process table for the tnslsnr process to verify that the listener process is running. In the detail monitoring mode, the agent uses the lsnrctl status $LISTENER command to verify the status of the Listener process. (Default)
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netlsnr_imf_init
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Initializes the agent to interface with the AMF kernel driver, which is the IMF notification module for Netlsnr agent. This function runs when the agent starts up.
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netlsnr_imf_getnotification
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Gets notification about resource state change. This function runs after the agent registers with the AMF kernel module. This function continuously waits for notification and takes action on the resource upon notification.
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netlsnr_imf_register
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Registers or unregisters resource entities with the AMF kernel module. This function runs for each resource after the resource goes into steady state (online or offline).
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Clean
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Scans the process table for tnslsnr $LISTENER and kills it. |
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Action
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Performs the predefined actions on a resource.
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