$ sudo apt-get update
$ sudo apt-get install gearman-job-server 

gearman-job-server is installed in your system.

Make ensure the gearman-job-server package were installed using the commands given below,

$ sudo dpkg-query -l | grep gearman-job-server *

You will get with gearman-job-server package name, version, architecture and description in a table

gearman-job-server package basic information: