The clock get unsynchronized between clusters after like 4/5 days. I'm not using ntp because of no internet connection on all clusters. and using ssh to make zookeeper synchronized with the namenode. Currently i'm doing this sudo date --set="$(ssh admin@si-vm-198 date)". How to make an permanent fix? Cluster is kerberosed.
If you have a couple of servers with connection to NTP servers, then configure them to synchronize their clocks. And configure all other servers to use these two servers as NTP source.
If no NTP server is available for any server, just pick two of your nodes and configure them as ntp servers to all other nodes.