I'm trying to build a small cluster using mongodb sharding. I tried with everything in localhost and it works perfect. But when I try on my local network where there are two nodes, node1 and node2, it does not work. In both nodes, mongod are started to serve as shard. In node1, config server and mongos are started. All listening 0.0.0.0 with exclusively allocated ports.
I can connect and do things with both nodes. When I use mongo to login mongos in node1, I can add Node1 mongod as shard but when I try to add Node2, an error occurs:
mongos> sh.addShard("<ip of node2 in local network>")
{ "ok" : 0, "errmsg" : "No common protocol found.", "code" : 126 }
I did some searching but few documentation is about this error.
mongo addShard "No common protocol found" errmsg 126 shows the same error but it does not seem helpful.
Couple of things to check
a) Are you using the same version of Mongod on all machines.
b) Are you using same kind of storageEngine on all machines.
Our problem should have been obvious, but wasn't.
We simply forgot to configure ports here, so the :27000 was missing:
db.shards.updateOne({ "_id" : "shard0000" }, { $set : { "host" : "oururl.foo:27000" } })
db.shards.updateOne({ "_id" : "shard0001" }, { $set : { "host" : "oururl.foo:27000" } })
db.shards.updateOne({ "_id" : "shard0002" }, { $set : { "host" : "oururl.foo:27000" } })
db.shards.updateOne({ "_id" : "shard0003" }, { $set : { "host" : "oururl.foo:27000" } })
Related
In ref to mongo dba course trying to create replica set as asked shown by instructor in El Capitano (Single machine only), I get following error. I have three members:
(mongodb was installed using homebrew)
Step I: Setting up config
cfg ={ _id :"abc", members:[{_id:0, host:"localhost:27001"}, {_id:1, host:"localhost:27002"}, {_id:2, host:"localhost:27003"}] }
{
"_id" : "abc",
"members" : [
{
"_id" : 0,
"host" : "localhost:27001"
},
{
"_id" : 1,
"host" : "localhost:27002"
},
{
"_id" : 2,
"host" : "localhost:27003"
}
]
}
STEP II: Initialize the Config.
rs.reconfig(cfg)
2015-10-05T11:34:27.082-0400 E QUERY Error: Could not retrieve replica set config: { "ok" : 0, "errmsg" : "not running with --replSet", "code" : 76 }
at Function.rs.conf (src/mongo/shell/utils.js:1017:11)
at Function.rs.reconfig (src/mongo/shell/utils.js:969:22)
at (shell):1:4 at src/mongo/shell/utils.js:1017
Make sure you have the replSetName name configured in /etc/mongod.conf
replication:
replSetName: "somename"
Then restart your mongod.
sudo service mongod stop
sudo service mongod start
sudo service mongod restart
You are not running replica set with the repl set name.The solution is to set a replication set name in the mongod config file using the paramater --replSet.
eg) --replSet=test_replica
Once changes are done in config file restart the server.
I got sharded mongodb setup with two replica sets:
mongos> db.runCommand( { listShards : 1 } )
{
"shards" : [
{
"_id" : "rs01",
"host" : "rs01/10.133.250.140:27017,10.133.250.154:27017"
},
{
"_id" : "rs02",
"host" : "rs02/10.133.242.7:27017,10.133.242.8:27017"
}
],
"ok" : 1
}
Node 10.133.250.140 just went down, and I replaced it with another one (ip-address changed). Replica set reconfiguration was pretty easy, just rs.remove() and rs.add()
Now I have to update host config for shard rs01. What is proper way to do it?
Many times you would need to modify the host string for a shard. The simplest way to change host string is to run an update operation.
Connect to mongos and do this -
> use config
> db.shards.update({ "_id" : "rs01"},{$set : { "host" : "rs01/newip:27017,anothernewip:27017"} })
You might need to restart all mongos.
Hope this helps :-)
Well, removing problem shard and adding it again seems the only option.
I use play framework+morphia+mongodb. It works fine when mongodb is running wihout replset. However,when I set up mongodb replset with play framework, i got "com.mongodb.MongoException: not talking to master and retries used up" exception. How can i fix this so play framework can work with mongodb replset?
Play Framework
2.2.6
Mongodb Version
2.6.5
mongod.conf for all 3 mongodb instances
dbpath=/var/data/mongodb
logpath=/var/log/mongod.log
port=39068
nohttpinterface=false
fork=true
replSet=cluster
rs.conf from 192.168.1.1
{
"_id" : "cluster",
"version" : 2,
"members" : [
{
"_id" : 0,
"host" : "localhost.localdomain:39068"
},
{
"_id" : 1,
"host" : "192.168.1.2:39068"
}
,
{
"_id" : 2,
"host" : "192.168.1.3:39068",
"arbiterOnly" : true
}
]
}
It looks a bit strange to see localhost mentioned in a replica set configuration as it will resolve to 127.0.0.1 on all machines. I don't know for certain, but my guess is that your client is trying to connect to itself and not 192.168.1.1 (which I guess is the master).
MongoDB provides a tutorial on how to change the hostnames in a replica set. Try following it changing localhost.localdomain to 192.68.1.1.
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.
I have a mongodb replicaset on ubuntu.. In replica set, hosts are defined as localhost. You can see ;
{
"_id" : "myrep",
"version" : 4,
"members" : [
{
"_id" : 0,
"host" : "localhost:27017"
},
{
"_id" : 2,
"host" : "localhost:27018"
},
{
"_id" : 1,
"host" : "localhost:27019",
"priority" : 0
}
]
}
I want to change host adresses with real ip of server. But when i run rs.reconfig, I get error :
{
"assertion" : "hosts cannot switch between localhost and hostname",
"assertionCode" : 13645,
"errmsg" : "db assertion failure",
"ok" : 0
}
How can i solve it ?
Thank you.
There is a cleaner way to do this:
use local
cfg = db.system.replset.findOne({_id:"replicaSetName"})
cfg.members[0].host="newHost:27017"
db.system.replset.update({_id:"replicaSetName"},cfg)
then restart mongo
The only way I found to change host names is recreating replica set.. To make it right db directories need to be cleaned.. Then starting all servers with replication mode after that creating new repset with new host names fixed it.