I have got this issue while working on replica sets. Server is successfully turning on but after executing rs.initiate() and rs.status I am getting errors.
"info2" : "no configuration explicitly specified -- making one",
"errmsg" : "exception: bad --replSet config string format is: <setname>[host1>,<seedhost2>,...]",
"code" : 13093,
"ok" : 0
I ran into this problem as well. What happened was I configured the replica set in /etc/mongo.conf, went into the mongo client and executed rs.initiate(). What I forgot to do was restart mongo! A simple sudo service mongod restart fixed it.
Related
On mongo 3.2.17 I have the following output when running rs.initiate(). I need "ok" equal to 1. I don't know how to modified the configuration. Any suggestion?
{
"info2" : "no configuration specified. Using a default configuration for
the set",
"me" : "vpsxxxxxx:27017",
"info" : "try querying local.system.replset to see current
configuration",
"ok" : 0,
"errmsg" : "already initialized",
"code" : 23
}
You are getting this error because you have already initialized replication on your machine. This would work on a fresh instance. In your case try using reconfig instead of initiate
rs.reconfig(config, {force: true})
You can use force option when reconfiguring replica set. Make sure you have at least 3 nodes: 2 full nodes and 1 arbiter (minimum supported configuration) or 3 full nodes (minimum recommended configuration) so that primary node can be elected.
I want to set
mongoClient.setWriteConcern(WriteConcern.REPLICAS_SAFE);
only if replica set is present.
But in sharded environment when I do:
mongoClient.getReplicaSetStatus();
It returns null even though I have replica set.
To mongo client I am passing mongos IP.
Most MongoDB drivers, in particular Java driver which you are using will throw an exception if you try to set REPLICA_ACKNOWLEDGED writeConcern when it's not possible to get an acknowledgement from two or more nodes.
From the docs:
WriteConcern.REPLICA_ACKNOWLEDGED Tries to write to two separate nodes. [...] will
throw an exception if two writes are not possible.
See the following for more details:
http://docs.mongodb.org/manual/reference/write-concern/
http://docs.mongodb.org/ecosystem/drivers/java-replica-set-semantics/
In my testing with mongo shell, if you provide REPLICA_ACKNOWLEDGED (formerly called REPLICA_SAFE) concern to 'getlasterror' command, you will get an error when you are not communicating with a replica set. When talking to mongos process, the error will be:
{
"singleShard" : "localhost:30001",
"n" : 0,
"connectionId" : 3,
"wnote" : "no replication has been enabled, so w=2.0 won't work",
"err" : "norepl",
"ok" : 1
}
It is not the case that the client will hang forever without wtimeout being specified, that would only be the case if there is a replica set but two nodes are not available for writes indefinitely.
Note that using "majority" as w value for write concern will work correctly through mongos - note the difference in writeConcern responses:
mongos> db.coll.insert({}); db.runCommand({getlasterror:1,w:"majority"})
{
"singleShard" : "localhost:30001",
"n" : 0,
"connectionId" : 3,
"err" : null,
"ok" : 1
}
First verify that your replica set has a PRIMARY using the mongo shell command rs.status()
Then if that worked, verify that you are connecting to the database correctly:
MongoClient mongoClient = new MongoClient( "hostname" , 27017 );
If both of those are true then there should be no reason mongoClient.getReplicaSetStatus() should return NULL. It should be returning a ReplicaSetStatus object.
Consider, I have 4 replicate sets and the config is as follows:
{
"_id": "rs_0",
"version": 5,
"members" : [
{"_id": 1, "host": "127.0.0.1:27001"},
{"_id": 2, "host": "127.0.0.1:27002"},
{"_id": 3, "host": "127.0.0.1:27003"},
{"_id": 4, "host": "127.0.0.1:27004"}
]
}
I am able to connect to all sets using
mongo --port <port>
There are documents for getting information on Convert a Standalone to a Replica Set, but can anyone tell me how to convert back to standalone from replica set?
Remove all secondary hosts from replica set (rs.remove('host:port')), restart the mongo deamon without replSet parameter (editing /etc/mongo.conf) and the secondary hosts starts in standalone mode again.
The Primary host is tricky one, because you can't remove it from the replica set with rs.remove.
Once you have only the primary node in the replica set, you should exit mongo shell and stop mongo. Then you edit the /etc/mongo.conf and remove the replSet parameter and start mongo again.
Once you start mongo you are already in standalone mode, but the mongo shell will prompt a message like:
2015-07-31T12:02:51.112+0100 [initandlisten] ** WARNING: mongod started without --replSet yet 1 documents are present in local.system.replset
to remove the warning you can do 2 procedures:
1) Droping the local db and restarting mongo:
use local
db.dropDatabase();
/etc/init.d/mongod restart
2)Or if you don't want to be so radical, you can do:
use local
db.system.replset.find()
and it will prompt a message like:
{ "_id" : "replicaSetName", "version" : 1, "members" : [ { "_id" : 0, "host" : "hostprimary:mongoport" } ] }
then you will erase it using:
db.system.replset.remove({ "_id" : "replicaSetName", "version" : 1, "members" : [ { "_id" : 0, "host" : "hostprimary:mongoport" } ] })
and it will probably prompt:
WriteResult({ "nRemoved" : 1 })
Now, you can restart the mongo and the warning should be gone, and you will have your mongo in standalone mode without warnings
Just remove a host from replica set (rs.remove('host:port')), relaunch it without replSet parameter and it's standalone again.
On an Ubuntu Machine
Stop your mongo server
open /etc/mongod.conf
Comment the replication and replSetName line
#replication:
#replSetName: rs0
Start your mongo server and go to mongo shell
drop local database
use local
db.dropDatabase()
Restart mongo
The MongoDB Documentation suggests the following to perform maintenance on a replica set member, which brings the the replica set member into standalone mode for further operations. With little modification it can be made standalone:
If node in concern is the only node in a shard, drain the chunks to other shards as per MongoDB documentation here, or else the sharded database will break, i.e.
Make sure balancer is enabled by connecting to mongos and run sh.startBalancer(timeout, interval)
For the shard in concern, go to admin database and db.adminCommand( { removeShard: "mongodb0" } )
Check draining status by repeating above removeShard command, wait for draining to complete
If node in concern is primary, do rs.stepDown(300)
Stop the node by running db.shutdownServer()
Change the yaml config by:
commenting out replication.replSetName (--replSetName in command line)
commenting out sharding.clusterRole for shard or config server (--shardsvc and --configsvr in command line)
commenting out net.port, then change it to a different port (--port in command line)
Start the mongod instance
If change is permanent, go to other mongod instance and run rs.remove("host:port")
After this, the node in concern should be up and running in standalone mode.
Follow below steps :
Go to mongo shell on Secondary servers
Stop the secondary servers by using below command :
use admin
db.shutdownServer()
Go to Linux shell- on secondary servers and type below command :
sudo service mongod stop
Starting the MongoDB replication -
Go to Linux shell - on secondary servers and type below command :
sudo service mongod start
Starting the MongoDB replication -
Go to primary and type below commands to start the replication :
a] rs.initiate()
b] rs.add("Secondar -1:port no")
c] rs.add("Secondary-2:port no")
d] rs.add({ "_id" : 3, "host" : "Hidden_member:port no", "priority" : 0,
"hidden" : true })
e] rs.status()
I am using the MongoDB 2.4.3, and following the wizard:
http://docs.mongodb.org/manual/tutorial/deploy-replica-set/
But when adding the other members into replica-set, get the following error:
root#vm3:~# mongo
MongoDB shell version: 2.4.3
connecting to: test
rs1:PRIMARY> rs.add("vm1")
{
"errmsg" : "exception: set name does not match the set name host vm1:27017 expects",
"code" : 13145,
"ok" : 0
}
rs1:PRIMARY> rs.add("vm4")
{
"errmsg" : "exception: set name does not match the set name host vm4:27017 expects",
"code" : 13145,
"ok" : 0
}
vm1, vm3 and vm4 know each other because I configured their /etc/hosts files correctly.
Any idea? I don't understand what does this error message mean!
After restarting all vms, it works now.
root#vm3:~# mongo
MongoDB shell version: 2.4.3
connecting to: test
rs1:PRIMARY> rs.add("vm4")
{ "ok" : 1 }
rs1:PRIMARY> rs.add("vm1")
{ "ok" : 1 }
In my case, just restart virtual machines, every thing is fine.
If you are re-installing a MongoDB instance, the replSet may be living in your data file on the drive. I had the same problem setting up a new replica set. The problem was from changing the replica set name after bringing up instances with an older replSet name. I deleted the data files, ran my install scripts again and it worked just fine.
I did a mistake when configuring replica sets in mongodb. I think that what I did wrong is that I did a rs.initialize() on both nodes, which made them confused in some way. I'm not sure.
Now all I want to do is start over, but I couldn't find a way to de-initialize a node. So I followed the advice to delete the local* db files, thus resetting the configurations. I did that, and now nothing works.
> rs.initiate()
{
"info2" : "no configuration explicitly specified -- making one",
"me" : "0.0.0.0:27017",
"errmsg" : "couldn't initiate : can't find self in the replset config",
"ok" : 0
}
> rs.conf()
null
I tried to remove and reinstall the package (I'm doing this on Ubuntu servers) which just meant that my mongodb.conf disappeared and my init script stopped working. This is of course easy enough to solve.
So how do I start over?
Note: I did look at this answer, but since rs.conf() doesn't work this doesn't work either.
You'll also get this error if your machine's hostname doesn't map back to 127.0.0.1. Update your /etc/hosts and/or your /etc/hostname, and rs.initiate() with no config should work.
If you force a reconfig with a config that you have generated, does it resolve the issue?
You could do this similar to the follow from the {{mongo}} shell:
> cfg = {
... "_id" : "rs0",
... "version" : 1,
... "members" : [
... {
... "_id" : 0,
... "host" : "0.0.0.0:27017"
... }
... ]
... }
>rs.reconfig(cfg, {force:true})
You may need to tune the cfg variable to have your hostname and portname, as the can't find self in new replset config error will be returned to the shell if the repl set can't find the node it is running from in the config.
If you just comment out bind_ip in /etc/mongod.conf this will achieve the correct result so that you can reissue a rs.initiate() command to set-up or reconfig the replica.