Forum Discussion
efleis_26345
Nimbostratus
NimbostratusQuestions re: polling an F5 for updates
Hi all,
Long time balanced user, first time balancer.
I am writing some control against iControl 9.x (can get more specific version info if you'd like) and have a question about how to best find out "what's going on" on the F5.
My app will need to know essentially the latest configuration of the F5 (what virtual IPs are on there, members behind them, member status) on a quazi-regular basis. In the best case, I'd hope that i could register for a callback of some sort and you'd let me know if something changes. Since I don't see this, I'm assuming that I need to poll for updates...is that correct?
If so, are there any perf concerns in doing this? Eg: If I were to poll every minute and dump the state of the F5, is this a perf concern?
Does this sort of a poll have perf implications on traffic being routed on the unit?
Is a poll an expensive operation?
Thx.
~Eric
- There actually is a way, via iControl, to monitor for change notifications that the BIG-IP will push to you.
To do this you'll want to read about the Event API: Click here
You'll also want to set up an API listener Click here and subscription client Click here.
Hopefully this will get you started.
Colin 
efleis_26345Cool, thanks! I'll push on going in this direction instead.
If I am forced to go down the polling route in the short term, do you have any perf guidance?- As far as performance impact, I would think this would be pretty negligible. With only a few polls per minute, and those being sent over the management interface, most likely, I can't think you'd see any effect on traffic at all.
Colin - I'm with Colin - near zero if not zero impact from polling because the management interface is separate (physically) from the VIP/Node interfaces.
As to getting the information you need, if you have a list of exactly what you'd like we can help point you in the right direction.
Another option is to FTP or SCP the config file and parse it locally - that will have all of the information about current configuration in it, it just won't have information about the current firmware levels and such bigpipe is running.
Don. - efleis_26345Thx! I'm actually not interested in pushing hard to get most data. I'm particularly interested in member status, but sans that, I'll just re-read the config from time to time as a correctness / convergence protocol sort of thing.
So really, I'm interested in finding out about VIP member state aggressively.
THe other thing I'll look at from time to time is general load stats. Things like CPU load, throughput, and all that. General operational stats so I get a sense of how the unit is doing. - Arrrgghhh. I hate that ;-). thats LocalLB.PoolMember and LocalLB.Pool.
Sorry about that, I know of that smiley insertion, and forgot to use periods.
Don.
