If MongoDB rs.status() displays the following error:
> rs.status()
{
"startupStatus" : 4,
"errmsg" : "all members and seeds must be reachable to initiate set",
"ok" : 0
}
The first course of action is to look at the MongoDB logs. In my Amazon Linux installation, these are at /var/log/mongo/mongod.log.
$ tail -n 100 /var/log/mongo/mongod.log
You might find an entry like this:
(date) [rsStart] getaddrinfo("ip-10-0-1-94") failed: Name or service not known
Under certain configurations, your machine’s hostname might not actually be reachable. An easy solution is to make it so by adding the an entry to /etc/hosts:
127.0.0.1 ip-10-0-1-94
After restarting mongo, you’ll be able to run rs.config without problems with any IPs you want as members of the replica set.
