Erro monitors F5 Big IP APM

[matharau]

Hey guys.

I'm experiencing a problem with the Monitors in my environment.

I'm on Version 16.1.3 using APM.

The Monitors settings seem OK but when we have some fluctuation in the network, the monitors go down and do not go up automatically.
It requires me to manually make a change to its configuration (such as switching from HTTP to icmp)

This brings a very big impact because we have hundreds of POOL and NODES in the Environment.

If anyone has gone through something similar and can share the solution we will be grateful.

[whisperer]

Read this carefully:

https://techdocs.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-monitors-reference-12-0-0/2...

Check time until up, manual resume, ramp up time, etc. Also, be sure to check the timeout and monitor check settings.

Finally, you are making a very very BAD assumption. Ping is not a good monitor. If a web server reboots, and even the BIG-IP has a web server, the device will respond to Ping way before it responds to HTTP. Why? Device is rebooting and the HTTP service has not yet started!!! So even if you have manually marked the server as up immediately via Ping, it doesn't mean the backend server is ready to accept HTTP connection and indeed the client may be experiencing an outage at that point.

Nothing in life is quick, have patience 🙂

[matharau]

Many thanks for the reply.

I think I wasn't very clear on the issue.

So I'll give as an example
I have an application that is with the MONITOR (TCP) when there is an oscillation in the network, this monitor drops and does not come back when the application returns (I have to manually) make any change in the Monitor to force it to respond with status ok

[whisperer]

You need to provide some more information my friend!

- Can you post a screenshot and/or configuration snippet of the monitor?

- Can you search /var/log/ltm and grep out the log entries for this particular monitor?

[matharau]

The issue is that when the network presents instability and the monitor points as offline status, however the network works again and the Monitor status does not change automatically. like this was a bug or something.
because I have to go manually (change any parameter) inside the monitor for it to reprocess

[boneyard]

please add the configuration of the monitor itself, we need to see if you want changes to the defaults.

[matharau]

Thanks for the feedback

I doubt if you can understand the problem I'm going through.

I am sending the Print of the configuration, we are using the Default and we created one, in both the problem happens.

[boneyard]

Ok, yeah then you are right. What you see shouldn't happen.

As also requested before, what does the /var/log/ltm show about this monitor. Do you see it go up there or also not?

If not then it might be an issue between the BIG-IP and the server. Perhaps after the issue on the server the traffic gets lost. You would have to do a packetcapture on the server to determine that.

All in all it might be easier to create a support ticket, F5 support can help with this things on your actual system.