/lib64/libc.so.6: version `GLIBC_2.14' not found. Why am I getting this error?

I am working in node js. I have installed hummus package. It installed properly. I am using this package for modifying the pdf files. While downloading the pdf I am calling hummus. Onclick of download I am getting this error.

Error: /lib64/libc.so.6: version `GLIBC_2.14' not found (required by /var/www/html/node_modules/hummus/binding/hummus.node)
    at Object.Module._extensions..node (module.js:681:18)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (/var/www/html/node_modules/hummus/hummus.js:5:31)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at /var/www/html/app/routes.js:2250:18
    at Layer.handle [as handle_request] (/var/www/html/node_modules/express/lib/router/layer.js:95:5)

With the help of this link I have updated glibc. But still I am getting the same error. Please help me to find out the issue. I am using CentOs 6.9

from /lib64/libc.so.6: version `GLIBC_2.14' not found. Why am I getting this error?