As i am going to configure EEM applet for TFTP backup on my cisco production device, I want to know weather there are any drawbacks of EEM applet like resources consumtion etc.
There will be some CPU cycles and memory resources used when the applet runs, but it will be negligible for what you want to do. It should be no more intense than doing a manual copy run tftp.
I am going to use below applet for Automatic TFTP backup.
action 1 cli command "enable"
action 2 cli command "configure terminal"
action 3 cli command "file prompt quiet"
action 4 cli command "end"
action 5 cli command "copy running-config tftp://tftp-server/router-confg"
action 6 cli command "configure terminal"
action 7 cli command "no file prompt quiet"
action 8 cli command "end"
Do I need to take any precautions during this applet configuration ?
Nothing from an EEM side. Just know that with TFTP, the file must typically exist on the server before you can copy it. You should also note that this capability is built into IOS with the config archive subsystem.
I haven't seen your event trigger, but assuming this is run infrequently, no, there will not be any more impact than running those commands manually.