How to performe command in multiple servers through ssh?

Question

I'm trying to execute command on multiple servers through ssh, that's what I'm trying to do:

for i in {1..3}; do `ssh nginx_$i ps aux | grep logstash`; done

But it tells me to install some package:

The program 'root' is currently not installed. You can install it by typing:
sudo apt-get install root-system-bin

I'm not convinced that I need to install it, because if I do

ssh nginx_1 ps aux | grep logstash

It works, and gives me the correct result.

PS Assuming that I have configured .ssh/config file to connect to nginx_1 , nginx_2 and nginx_3 .

Answer 1

 for i in {1..3}; do `ssh nginx_$i ps aux | grep logstash`; done ^ ^ 

Drop the backquotes. If you include them, the shell will try to execute the output of the command.

Answer 2

而不是for循环，应该使用pssh 。