pool monitor issue

[Michaelyang]

Hello,

I encountered a problem here...
I set up the oracle external monitor will suddenly fail, manually build a similar test but normal again.
Here is monitor setting

Today, I changed back to the original monitor and it is normal again...

Any help is appreciated.
Thanks.

[CA_Valli]

Your external monitor will check for output being returned to stdout in order to mark a pool member available.
If no data was returned, it will mark pool member down. 

To manually run external monitor and check for output, you can move to  /config/filestore/files_d/Common_d/external_monitor_d/ where all of your external monitor scripts are stored, check for script name (I noticed BIG-IP appends some sort of versioning to the files) and then run it as as script, passing it the required parameters (I  believe defaults are server ip, L4 port and timeout)  

[root@f5:Active:Standalone] common # cd /config/filestore/files_d/Common_d/external_monitor_d/
[root@f5:Active:Standalone] external_monitor_d # ./\:Common\:myexternalmonitor_320535_2 <server ip ex 10.10.10.10> <server port ex. 1813> <timeout ex. 16>

This will immediately let you know if output is seen or not, or if there are other errors -- for example I noteiced PERL interpreter changing directory when moving to BIG-IPv15 

[Michaelyang]

Hi CA_Valli,

Thanks for your aply.

But I find it odd that a node with the original state of down actually UP after switching to another monitor with the same settings...

And it also happened three times...

[CA_Valli]

As long as your script retrieves anything an answer (so that there is some data in stdout output), external monitor will mark node up... let's say it returns a "KO" message or "connession issue" messege -- those are both non-null strings so monitor will be green.