Monitor per object (node/pool member)

[philippegrouber]

Hi all

i have searched F5 web site and other resources on the internet for something bothering me which is how to find out which monitor can be associated to a node and which one can be associated to a pool member.

is there any document which describe classification of monitors per type of objects (node/pool member) ??

thanks all

[Daniel_Wolf]

Hi ,

quoting from AskF5 Home >> Knowledge Centers >> BIG-IP LTM BIG-IP Local Traffic Manager: Monitors Reference >> Mo...:

Simple monitoring determines whether the status of a resource is up or down. Simple monitors do not monitor pool members (and therefore, individual protocols, services, or applications on a node), but only the node itself. The system contains three simple monitors, Gateway ICMP, ICMP, and TCP_ECHO.

I think this manual chapter will also answer all possible other questions regarding monitors.

KR

Daniel

[philippegrouber]

Thank you Daniel for the answer.

i probably wasn't clear enough in my question , i will try to clarify.

in the BIG-IP you can create a lot of kind of monitors, some of them can be associated to a node and others not.

when we are creating a new nodes/pools on the BIG-IP i through web interface or TMSH the TMOS list the supported monitors depending if we are creating nodes or creating pools.

for a deep understanding of monitors and BIG-IP how this selection is done?

hope i have been clearer this time and thank you again

[Daniel_Wolf]

A node does not have a service port assigned, therefore you can assign only simple monitors like ICMP.

A pool member is always node + port, therefore it has a service port. Means you can assign monitors of the kind Active or Passive. For example http oder https.

[philippegrouber]

This what i was thinking too

but .....

 

[Daniel_Wolf]

In this case the port is determined by the monitor, not by the node. Hence you can assign it to a node.

Compare the following monitors:

tcp - has no port assigned, cannot be assigned to a node

tcp_777 - has a port assigned, can be assigned to a node

https - has no port assigned, cannot be assigned to a node

https_443 - has a port assigned, can be assigned to a node

[philippegrouber]

thans a lot Daniel

i understand that but it is more like an assumption based on experience , i cannot find any document explaining precisely this classification

[Daniel_Wolf]

See the section Monitor association with pools and nodes >> Monitor-to-node association

"...

Node-only monitors specify a destination address in the format of an IP address with no service port (for example, 10.10.10.2). Conversely, monitors that you can associate with nodes, pools, and pool members specify a destination address in the format of an IP address and service port (for example, 10.10.10.2:80). Therefore, when you use the BIG-IP Configuration utility to associate a monitor with a pool, pool member, or node, the utility displays only those pre-configured monitors that are designed for association with that server.

...''

Yes, you can say that you will learn this only with experience. But it is also written in the manual.

[philippegrouber]

Hi Daniel

i have suumrized my tests on the folowing table, my be it can help in the future