NSCD sometimes die itself and DNS resolving doesn't happen properly. How can we avoid NSCD for DNS and there is a disadvantage to bypass it

nscd is a daemon that provides a cache for the most common name service requests. When resolving a user, group, host, service..., the process will first try to connect to the nscd socket (something like /var/run/nscd/socket).
If nscd has died, the connect will fail, and so nscd won't be used and that should not be a problem.
If it's in a hung state, then the connect may hang or succeed. If it succeeds the client will send its request (give IP address for www.google.com, passwd entries...). Now, you can configure nscd to disable caching for any type of database (for instance by having enable-cache hosts no in /etc/nscd.conf for the hosts database).
However, if nscd is in a hung state, it may not be able to even give that simple won't do answer, so that won't necessarily help. nscd is a caching daemon, it's meant to improve performance. Disabling it would potentially make those lookups slower. However, that's only true for some kind of databases. For instance, if user/service/group databases are only in small files (/etc/passwd, /etc/group, /etc/services), then using nscd for those will probably bring little benefit if any. nscd will be useful for the hosts database.