Single Instance Mongodb Replica Set - cannot perform query/insert operations - mongodb

Question

After installing mongodb, I ran mongod with
mongod --dbpath <pathtodb> --logpath <pathtolog> --replSet rs0
I then connected with the mongo shell and ran
rs.initiate()
I then tried to insert a document into a collection, but received an error:
> db.blah.insert({a:1})
WriteResult({ "writeError" : { "code" : undefined, "errmsg" : "not master" } })
Looking at rs.status(), I see the status is REMOVED:
> rs.status()
{
"state" : 10,
"stateStr" : "REMOVED",
"uptime" : 1041,
"optime" : Timestamp(1429037007, 1),
"optimeDate" : ISODate("2015-04-14T18:43:27Z"),
"ok" : 0,
"errmsg" : "Our replica set config is invalid or we are not a member of it",
"code" : 93
}
I have no idea what I could have done to mess this up. This should have worked I think. How do I get past this?

Answer 1

As above answers said, the config is not set correctly.
I tried to re-init the replica, but got the error msg:
singleNodeRepl:OTHER> rs.initiate({ _id: "rs0", members: [ { _id: 0, host : "localhost:27017" } ] } )
{
"info" : "try querying local.system.replset to see current configuration",
"ok" : 0,
"errmsg" : "already initialized",
"code" : 23,
"codeName" : "AlreadyInitialized"
}
The solution is to reconf the mongo:
singleNodeRepl:OTHER> rsconf = rs.conf()
singleNodeRepl:OTHER> rsconf.members = [{_id: 0, host: "localhost:27017"}]
[ { "_id" : 0, "host" : "localhost:27017" } ]
singleNodeRepl:OTHER> rs.reconfig(rsconf, {force: true})
{ "ok" : 1 }
singleNodeRepl:OTHER>
singleNodeRepl:SECONDARY>
singleNodeRepl:PRIMARY>

Answer 2

Problem here is that you ran rs.initiate().. As EMPTY! You didn't tell what machines belongs to that replica set.
So..
rs.initiate({
_id: "rs0",
version: 1,
members: [
{ _id: 0, host : "address.to.this.machine:27017" }
]
}
)

Answer 3

Short Answer:
I needed to do:
rs.initiate({_id:'rs0', version: 1, members: [{_id: 0, host:'localhost:27017'}]}
rather than rs.initiate().
Long Answer:
I am almost the same as #Madbreaks and #Yihe 's comment, but I was in the different background so that I'm adding my comment here.
Background
I used docker container of mongoDB and initiated the replicaset by rs.initiate(). (The data volume is mounted to the host, but it is out-of-topic here).
What Happend
When I restart the mongoDB container, the error "MongoError: not master and slaveOk=false" happened. Yes, the error message was different from #d0c_s4vage 's, but the workaround is the same as #Yihe 's.
Root Cause
The root cause was dynamically assigned hostname as follows:
rs0:PRIMARY> rs.conf()
{
"_id" : "rs0",
...
"members" : [
{
...
"host" : "ee4ed99b555e:27017", # <----- !!!!
Where, the host "ee4..." above comes from docker container's internal hostname; this is set by my first rs.initiate(). This would be changed when recreate container. In my case, localhost is fine because of single server and single replicaset for 'rocketchat' app evaluation purpose.

Answer 4

I'm also facing same issue, I tried below steps,
NOTE: If you have already cluster setup follow my steps
I stopped particular server (host : "address.to.this.machine:27017")
Remove mongod.lock file
create one more data directory
- (deafult: /data/db, new Data directory: /data/db_rs0)
update the **configuration ** file
-change dbpath ( "/data/db_rs0" ),
- check bindIP (default: 127.0.0.0 to 0.0.0.0)
Check Hostname & Hosts
hostname
sudo vi /etc/hosts
add to hosts
127.0.0.0 hostname
127.0.1.1 hostname
(add your Public/Private IP) hostname
Start the MONGODB server in
sudo /usr/bin/mongod -f /etc/mongod.conf &
rs.initiate({ _id: "rs0", members: [ { _id: 0, host : "hostname:27017" } ] } )
rs.status()
{
....
"members": [
{
"_id": 0,
"name": "hostname:27017",
"health": 1,
"state": 1,
"stateStr": "PRIMARY",
"uptime": 98231,
"optime": {
"ts": Timestamp(1474963880, 46),
"t": NumberLong(339)
},
"optimeDate": ISODate("2016-09-27T08:11:20Z"),
"electionTime": Timestamp(1474956813, 1),
"electionDate": ISODate("2016-09-27T06:13:33Z"),
"configVersion": 12,
"self": true
},
...........
]
"ok": 1
}
-------- THANK YOU --------