I need to test the performance of application running on localhost as if it were in the online environment. I mean the performance test conducted by the network traffic simulation, limited bandwidth simulation, or other parameter as if it were online.
Could Apache Ab do the simulation?
We've used Charles and Firefox Throttle in the past to simulate slow networks.
Yes, but you will need to connect to your application by IP address, not "localhost" or 127.0.0.1. Typically for web applications (HTTP) I use Fiddler which can simulate limited bandwidth, but only if you connect as I have noted. Other bandwidth limiters for non-HTTP I'm not sure/aware of.
Ab won't simulate low level network errors. If you're on linux, you can simulate some networking with 'tc'. See http://www.kdedevelopers.org/node/1878 for a small example.
You can set up a local tunnel to expose your localhost to the world, using Ngrok. From there you can use any number of online performance tools
You can throttle bandwidth via Chrome Dev Tools
Why can't you connect to a different PC, or even use a virtual machine and rate limit the virtual network connection?