OEM reporting listener down but listener not actually down

From: Jack van Zanen <jack_at_vanzanen.com>
Date: Mon, 2 Dec 2019 11:19:13 +1100
Message-ID: <CAFeFPA9g9J0uhYch0DR3Vb3jZLpA0mOnBUE9czWnjZsT8KAp-Q_at_mail.gmail.com>

intermittently we get some alert from OEM about listener being down.

Target name=*LISTENER_SCAN3_telstraexa1-000_1*
Message=*The listener is down: TNS-12545: Connect failed because target host or object does not exist .*

Checking the server we see no issue with the listener being down.

grid 24040 1 0 Nov23 ? 00:03:48 /u01/app/ ASMNET1LSNR_ASM -no_crs_notify -inherit grid 24402 1 0 Nov23 ? 00:04:58 /u01/app/ LISTENER -no_crs_notify -inherit grid 234773 1 0 Nov23 ? 00:02:16 /u01/app/ LISTENER_SCAN2 -no_crs_notify -inherit grid 234791 1 0 Nov23 ? 00:02:13 /u01/app/ LISTENER_SCAN3 -no_crs_notify -inherit

This is Oracle 12.2 on Exadata Cloud at Customer solution . Anyone else seen this behaviour before?

Oracle suggested to turn on client and server sql net tracing but I am a bit hesitant due to the sheer volume of tracing it will likely generate before I get the issue again.

To me it looks like a DNS issue, but Oracle looked at this and there is no issues there.

Jack van Zanen

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Received on Mon Dec 02 2019 - 01:19:13 CET

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