initiate mongodb replica set - mongodb

I am running the following in a script to automate the initiation of a replica set:
var cfg = { _id: 'rs0',
members: [
{ _id: 0, host: '192.168.1.46:27017'},
{ _id: 1, host: '192.168.1.51:27017'},
{ _id: 2, host: '192.168.1.48:27017'}
]
};
var error = rs.initiate(cfg);
printjson(error);
However I am getting :
{ "ok" : 0, "errmsg" : "Missing expected field \"version\"", "code" : 93 }
After I run the script and am not sure why.
I have tried running the script locally as well using the following:
mongo 192.168.1.46:27017 /opt/scripts/initreplset.js
I am using mongodb v3.2.

I'm having the same problem now, probably is something quite new,
anyway it seems that the version field is now mandatory.
From the official documentation:
version
Type: int
An incrementing number used to distinguish revisions of the replica
set configuration object from previous iterations of the
configuration.
So probably you just need to add this number.
I.e.:
{
"_id" : "rs0",
"version" : 1,
"members" : [
{
"_id" : 1,
"host" : "mongodb0.example.net:27017"
}
]
}

Related

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

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?
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>
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" }
]
}
)
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.
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 --------

How to update _id in Mongodb Replica Set configuration?

I had 5 mongo members in Replica Set. After I deleted 3 from it.
How can I change "_id" in others members to values "0", "1" and "2"?
rs.conf()
{
"_id" : "rs0",
"version" : 151261,
"members" : [
{
"_id" : 3,
"host" : "mongodb3:27017"
},
{
"_id" : 4,
"host" : "mongodb4:27017"
},
{
"_id" : 5,
"host" : "ok:27017",
"arbiterOnly" : true
}
]
}
Directly editing the replica set configuration may not be an elegant way. Instead use the rs.remove(hostname) command to remove a member from replica set , this way you need not have to bring down the primary during reconfiguration which will automatically assign ascending order values to "_id" field.
Try dropping the slaves collection as described here: http://docs.mongodb.org/manual/tutorial/troubleshoot-replica-sets/#duplicate-key-error-on-local-slaves
The master will recreate the collection the next time it is required.
You could try this in the Mongo console:
conf = rs.conf()
conf.members[0]._id = 0
conf.members[1]._id = 1
conf.members[2]._id = 2
rs.reconfig(conf)

exception: hosts cannot switch between localhost and hostname

I created a replication set.
I added localhost in the set in the beginning, but when I try to edit the member with the actual hostname. I get error "exception: hosts cannot switch between localhost and hostname"
I need to get rid of localhost:27017 because, otherwise, it doesn't let me enter any other member as hostname (i.e. non-localhost address)
my-rs0:PRIMARY> cfg=rs.conf();
{
"_id" : "my-rs0",
"version" : 1,
"members" : [
{
"_id" : 0,
"host" : "localhost:27017"
}
]
}
my-rs0:PRIMARY> cfg.members[0].host="my-server04:27017"
my-rs0:PRIMARY> cfg
{
"_id" : "my-rs0",
"version" : 1,
"members" : [
{
"_id" : 0,
"host" : "my-server04:27017"
}
]
}
using rs.reconfig(cfg);
my-rs0:PRIMARY> rs.reconfig(cfg);
{
"errmsg" : "exception: hosts cannot switch between localhost and hostname",
"code" : 13645,
"ok" : 0
}
no luck with rs.add("my-server04:27017") or rs.remove("localhost:27017") as well.
my-rs0:PRIMARY> rs.add("my-server04:27017");
{
"errmsg" : "exception: can't use localhost in repl set member names except when using it for all members",
"code" : 13393,
"ok" : 0
}
I have tried all the reconfiguration methods mentioned here Replica Set Reconfig steps
But, none fixing above issue. Already spent hours, I am really frustrated.
I had the same problem and I fixed it without dropping any database. Just edited the host field of the member in the local.system.replset collection to match the local ip and then restarted mongod. Everything worked perfect.
It looks like you'll need to scrap your replicaset and start over.
I believe that when you initiated your Replica Set, you explicitly passed it a config document that references your MongoDB instance using localhost.
As I was investigating this, I brought up a replica set. When I initiated the replica set using rs.initiate() (without passing a config document) it used host name by default.
rs.initiate()
rs.conf()
{
"_id" : "stack1",
"version" : 1,
"members" : [
{
"_id" : 0,
"host" : "MY-HOSTNAME:28001"
}
]
}
This post describes the need to complete clear out your database files to create a fresh replica set.
Once I did this, I initiated a new replica set in the by passing a configuration document:
cfg = {
"_id" : "stack1",
"version" : 1,
"members" : [
{
"_id" : 0,
"host" : "localhost:28001"
}
]
}
rs.initiate(cfg)
rs.conf()
{
"_id" : "stack1",
"version" : 1,
"members" : [
{
"_id" : 0,
"host" : "localhost:28001"
}
]
}
Long story short, you'll need to delete all of the files in your --dbpath directory and re-create the replica set, without explicitly specifying "localhost" as your hostname.
I did according to the docs:
Restarted MongDB on another port (e.g. 37107) to prevent user connections to it.
Then started a shell on it:
$ mongo --port 37017
Then updated the configuration:
use local
cfg = db.system.replset.findOne( { "_id": "my-rs0" } )
cfg.members[0].host = "my-server04:27017"
db.system.replset.update( { "_id": "my-rs0" } , cfg )
Then restarted MongoDB on the original port.

Using multiply aggregation with MongoDB

I have several documents that looks like this:
{
"hostname" : "server1.example.com",
"virtual" : true,
"processors" : {
"cores" : 1,
"sockets" : 4
}
}
{
"hostname" : "server2.example.com",
"virtual" : false,
"processors" : {
"cores" : 2,
"sockets" : 2
}
}
I am trying to output the hostname, virtual and total number of cores for each document. I keep getting a syntax error that has me stumped. Here is my query and the syntax error.
c.aggregate( {
$project: {
hostname: 1,
total-cores: {$multiply: ["$processors.sockets", "$processors.cores"]},
virtual: 1,
_id: 0
}
});
Thu Apr 25 14:12:18 SyntaxError: missing : after property id (shell):1
Judging from the documentation, this should work. What am I missing? I am running MongoDB 2.2.2.
http://docs.mongodb.org/manual/reference/aggregation/project/
Quote the total-cores key so that it's parsed correctly with the embedded hyphen:
c.aggregate({
$project: {
hostname: 1,
"total-cores": {$multiply: ["$processors.sockets","$processors.cores"]},
virtual: 1,
_id: 0
}
});

Replication set for MongoDB

I am trying to follow the instructions for setting up a replication set for a MongoDB database with Azure. The original instructions are at http://www.mongodb.org/display/DOCS/MongoDB+on+Azure+VM+-+Linux+Tutorial. I connect the script interpreter with 'mongo --host bsicentos.cloudapp.net --port 27018' (somehting the instructions didn't tell me). The final step instructions me to enter:
> conf = {
id = “mongors”,
members : [
\{id:0, host:”mongodbrs.cloudapp.net:27018\},
\{id:0, host:”mongodbrs.cloudapp.net:27019\},
\{id:0, host:”mongodbrs.cloudapp.net:27020\}]}
>rs.initiate(conf)
If I don't type this exactly as specified and I modify it slightly to fit my host (missing closing quotes, not escapes, and id numbers all zero) I finally get an accepted command:
mongors:PRIMARY> conf = {
... _id:"mongors",
... members:[
... {_id:0,host:"bsicentos.cloudapp.net:27018"},
... {_id:1,host:"bsicentos.cloudapp.net:27019"},
... {_id:2,host:"bsicentos.cloudapp.net:27020"}]}
{
"_id" : "mongors",
"members" : [
{
"_id" : 0,
"host" : "bsicentos.cloudapp.net:27018"
},
{
"_id" : 1,
"host" : "bsicentos.cloudapp.net:27019"
},
{
"_id" : 2,
"host" : "bsicentos.cloudapp.net:27020"
}
]
}
But I get and error:
mongors:PRIMARY> rs.initiate(conf)
{
"info" : "try querying local.system.replset to see current configuration",
"errmsg" : "already initialized",
"ok" : 0
}
Ideas?