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*
<
https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2FNSW-ATP-GRID.snl.7net.com.au%3A7799%2Fem%2Fredirect%3FpageType%3DTARGET_HOMEPAGE%26targetName%3DLISTENER_SCAN3_telstraexa1-000_1%26targetType%3Doracle_listener&data=01%7C01%7CJVanZanen%40Seven.com.au%7C5514208b3d2848d8fe9f08d774d613ee%7Cb359291241554399b790752c894d2935%7C0&sdata=Pww2ktObyuQu4vBRxuWvcmAGkXXJIozv%2F8nHJP1ABHE%3D&reserved=0>
Categories=*Availability*
Message=*The listener is down: TNS-12545: Connect failed because target host or object does not exist .*
<https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2FNSW-ATP-GRID.snl.7net.com.au%3A7799%2Fem%2Fredirect%3FpageType%3Dsdk-core-event-console-detailEvent%26issueID%3DE43696ECA26F42148CCCD6EC4862F4A9&data=01%7C01%7CJVanZanen%40Seven.com.au%7C5514208b3d2848d8fe9f08d774d613ee%7Cb359291241554399b790752c894d2935%7C0&sdata=z%2FQDPTS5qbEkx1MB8kdz3JKvyYGToJ4%2BUbcptqfRc7I%3D&reserved=0>

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

grid 24040 1 0 Nov23 ? 00:03:48 /u01/app/ 12.2.0.1/grid/bin/tnslsnr ASMNET1LSNR_ASM -no_crs_notify -inherit grid 24402 1 0 Nov23 ? 00:04:58 /u01/app/ 12.2.0.1/grid/bin/tnslsnr LISTENER -no_crs_notify -inherit grid 234773 1 0 Nov23 ? 00:02:16 /u01/app/ 12.2.0.1/grid/bin/tnslsnr LISTENER_SCAN2 -no_crs_notify -inherit grid 234791 1 0 Nov23 ? 00:02:13 /u01/app/ 12.2.0.1/grid/bin/tnslsnr 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



This e-mail and any attachments may contain confidential material for the sole use of the intended recipient. If you are not the intended recipient, please be aware that any disclosure, copying, distribution or use of this e-mail or any attachment is prohibited. If you have received this e-mail in error, please contact the sender and delete all copies. Thank you for your cooperation
--
http://www.freelists.org/webpage/oracle-l
Received on Mon Dec 02 2019 - 01:19:13 CET

Original text of this message