Permisi agan / para suhu,

Mau nanya plus konsultasi nih,
beberapa waktu lalu saya install dan running nginx web server berjalan normal tanpa ada masalah dan tanpa ada notifikasi error. Baru beberapa hari ini muncul pesan error saat start nginx sebagai berikut :

root@bkd_apps:~ # service nginx restart
Performing sanity check on nginx configuration:
nginx: [emerg] gethostbyname() failed in /usr/local/etc/nginx/nginx.conf:228
nginx: the configuration file /usr/local/etc/nginx/nginx.conf syntax is ok
nginx: configuration file /usr/local/etc/nginx/nginx.conf test is successful
Stopping nginx.
Waiting for PIDS: 561.
Performing sanity check on nginx configuration:
nginx: [emerg] gethostbyname() failed in /usr/local/etc/nginx/nginx.conf:228
nginx: the configuration file /usr/local/etc/nginx/nginx.conf syntax is ok
nginx: configuration file /usr/local/etc/nginx/nginx.conf test is successful
Starting nginx.
nginx: [emerg] gethostbyname() failed in /usr/local/etc/nginx/nginx.conf:228

service running, tapi ada pesan error pada gethostbyname() failed, dan ini berimbas setelah service up beberapa lama, domain tidak bisa diakses sampai server di restart.

udah coba googling sana sini belum nemu solusinya.
mohon bantuan dan pencerahannya. terima kasih.