MongoDB is a scalable, high-performance, open source, document-oriented database. It supports a large number of languages and application development platforms. Questions about programming should be asked on http://stackoverflow.com.

learn more… | top users | synonyms

2
votes
1answer
111 views

Mongodb replica sets: why does my master server occupy more disk space than my slave?

I have two servers on my replica set. Let's call it the master and the slave, for the purpose of this discussion. The master was the original one, and the slave was replicated from that master. At ...
0
votes
0answers
19 views

Opinion on Database Design for Task [on hold]

Would like to know if this is a good database design. Once you see the picture it is pretty much self explanatory. But anyways I will keep it brief. Basically users signup to create a bet, users ...
0
votes
1answer
106 views

mongodb on-premise: will it work?

We are planning to package MongoDB-PostgreSQL hybrid solution in our application that will be deployed on customer site on-premise. It will be packaged as a software virtual appliance. Our reason for ...
0
votes
0answers
10 views

How to interpret Mongo MMS Stats?

The following image contains all of the charts from the Status tab in MMS. How does a noob looking at these charts navigate these waters, so to speak? The mongo box is a standalone installation ...
0
votes
0answers
3 views

Setting up MongoDB MMS on Sharded Cluster

I have followed these instructions to create a Sharded Cluster of MongoDB nodes. https://sebastianvoss.com/docker-mongodb-sharded-cluster.html I now want to setup MongoDB-MMS to monitor these 6 ...
0
votes
2answers
103 views

One of databases in MongoDB suddenly gets high lock %

I observe repeatable, sudden, short-time update queries slowdowns in MongoDB cluster for single database. That slowdowns lasts about 30 seconds and repeats few times a day. I found that lock % and ...
1
vote
1answer
215 views

Mongo replication lag slowly increasing

I am running a replica-set in production with slaveOk = false using mongo 2.0.7 in AWS The replication lag on one of the servers is close to 58 hours. This replication lag is sometimes decreasing ( at ...
0
votes
0answers
6 views

Expand a date range in mongodb

I have a document structure like { "startDate": ISODate("2015-01-01T00:00:00Z"), "endDate" : ISODate("2015-01-10T00:00:00Z"), "foo" : "bar" } Is it possible to expand the date range like ...
0
votes
1answer
255 views

MongoDB Replica Set Can't be connected To

I just set up a replica set for a standalone Mongo instance using the following changes to my config and rs.initiate(). # in master/slave replicated mongo databases, specify here whether # this is a ...
0
votes
0answers
7 views

Mongoose populate() and shard key

Our MongoDb setup has a number of sharded collections. When we use mongoose api populate(), it invokes a find() internally. For example: emailDAO.findOne(selector).populate({path: ...
0
votes
0answers
2 views

Service Busy Alarms on USSD GW due to MongoDB

We are getting service busy alarms on my machines which are using MongoDB. When the service busy alarm appears, we get the following errors on our Mongo router logs. The OS on these machines is ...
1
vote
1answer
48 views

MongoDB installation Ubuntu 12.04 LTS errors

I need some help with my MongoDB installation on a clean, fresh Ubuntu 12.04 LTS server with no nonsense installed. I thought it would be a piece of cake, but I got some errors and the Ubuntu-forums ...
0
votes
1answer
103 views

Mongo db sharded “the collection's metadata lock is taken” issue coming very frequently

I am seeing this warning in mongoS log consistently for one collection. [conn96] warning: splitChunk failed - cmd: { splitChunk: "ibeat20150105.dgrpCount", keyPattern: { articleId: 1, host: 1 }, min: ...
1
vote
1answer
259 views

MongoDB text index and text search

I have a mongodb collection db.articles,it has 2 keys ,"title" and "abstract".I want to do text search on these two keys.For example, the search text is "physics",and I want all the documents whose ...
1
vote
1answer
3k views

MongoVUE connect to mongodb with authencation failed!

I had a mongodb ,and a database named genbank ,genbank has a user whose role is "read" and "readAnyDatabase",it is very strange that I cannot connect genbank through this role by MongoVUE ,but I can ...
0
votes
1answer
164 views

Improve the insertion rate of mongo sharded cluster

I can't disable the write concern while i mongorestore with .bson file. It totally damages the insertion rate (insert/sec). This is my sharding status. mongos> sh.status() --- Sharding Status --- ...
1
vote
1answer
105 views

Selecting, filtering and aggregating in MongoDB

if we have two dataset 1-First dataset contains population data of cities in the United States of America. Each record in the dataset has the following format: { "city": "ACMAR", "loc": [ ...
0
votes
1answer
417 views

Can I copy a collection in mongoDB from one database to another by copying the db files directly?

I tried using cloneCollection http://docs.mongodb.org/manual/reference/command/cloneCollection/ , but clonecollection takes a lot of time in case of big collection because it starts indexing the data. ...
0
votes
1answer
20 views

MongoDB : How to estimate max number of connections supported?

We have a sharded cluster with 2 replica sets. Each replica set is a 3 member cluster with one primary and 2 secondaries. Each instance is a r3.large (aws-ec2) instance with 15G ram. mongos's are in ...
1
vote
2answers
46 views

How MongoDB allocate new data block when data block is full

I am using MongoDB in my project. And I have some questions about how Mongo storage allocated. For example, I have 16MB full data block, and I want to add new document into this data block. - How ...
0
votes
1answer
134 views

MongoDB can't add new replica set member

I have a replica set, and I added a new member to the set. The initialSync begins for the new member and rs.status (on primary) shows STARTUP2 as status. However, after a long enough time, there's a ...
1
vote
1answer
18 views

MongoDB document size for collection - impact on RAM and query performance

I have been advised on stackoverflow to ask this question on dba.stackexchange instead - We are using MongoDB version 3.0 with WiredTiger storage. As newbies to MongoDB, we may have designed our ...
1
vote
2answers
46 views

Mongos version 3.0.1 Split Chunk Error with Sharding

I have 3 config server and two shards. Each shard has a primary, secondary and an arbiter. This is running with the following mongod settings: storageEngine=wiredTiger ...
2
votes
1answer
959 views

verify that mongos server is connected to config servers

I've been writing a backup script for sharded replica-sets and it's almost done, except that I can't seem to get it to successfully start the balancer back up after everything's all said and done. ...
0
votes
1answer
126 views

Use index intersection feature in mongo 2.6 to compound shard key

I am having three indexes like name,age,salary. I can use them as compound index as per 2.6 (name and age together). But can i use the same indexes as compound shard key like name and age. i also have ...
0
votes
1answer
1k views

Storing multidimensional array in MongoDB

I am attempting to convert a large MySQL database of product information (dimensions, specifications, etc) to MongoDB for flexibility and to move away from the restriction of a column based table. I ...
15
votes
3answers
6k views

Difference between MongoDB's find and findone calls

I am working on a project and I am unsure if there is a difference between the way the find cursor works and the way the findOne cursor works. Is findOne just a wrapper for find().limit(1)? I was ...
1
vote
1answer
1k views

mongodb replication node stuck at “STARTUP2” with optimeDate as 1970

i have just setup replica sets with three nodes . the third node is stuck at stateStr STARTUP2 with "optimeDate" : ISODate("1970-01-01T00:00:00Z"). However its showing no error message. Is this ...
0
votes
1answer
24 views

Query MongoDB collection and find rows from 7 days ago

I have a MongoDB collection called messages and this is an example document for that collection: { "_id": { "$oid": "551943eee4c6acf40fe5a0f2" }, "sender_id": { "$oid": ...
0
votes
1answer
224 views

MongoDB - Insertion Speed

Suppose you have a collection of students of the following form: {"_id" : ObjectId("50c598f582094fb5f92efb96"), "first_name" : "John", "last_name" : "Doe", "date_of_admission" : ...
0
votes
1answer
118 views

Data Migration or Sharded Cluster to new Cluster

We have Sharded Mongo Cluster. However some documents are sharded and others are unsharded. We are planning to migrate these databases to new cluster. Please update if there is any process or steps ...
0
votes
1answer
212 views

Mongo Db server status with wired Tiger

I was testing my DB with Mongo 3.0 wiredTiger setup. After restoring my database with wiredTIger i ran db.serverStatus. I found following in console output. "bytes currently in the cache" : ...
3
votes
1answer
102 views

3 Node Replica Set all became SECONDARY

my 3 set replica set all became secondary and I'm not sure why. db1 2014-12-12T02:43:55.067+0000 [conn1413096] end connection 10.0.64.12:58483 (512 connections now open) 2014-12-12T02:43:55.067+0000 ...
2
votes
1answer
291 views

Best embed/reference/field strategy for many inserts (mongo)

I'm building a gaming backend with Mongo, and have some issues on how to best design the schema to maximize performance and database size. My models: User Match -ReferenceMany (User) ...
2
votes
1answer
329 views

MongoDB Replica Set: Can't Add Member/Connect

I'm building a MongoDB replicaset w/ three Ubuntu 14 servers. I'm connected to the primary server and authenticated w/ userAdminAnyDatabase and clusterAdmin privileges. When I run ...
0
votes
1answer
41 views

Size of data in secondary exceeded primary after its initial resync from primary in MongoDB

I step down the primary node, deleted its data and performed the initial resync from new primary. But when i checked the size of data after the completion of initial resync, I found that the size of ...
0
votes
1answer
125 views

Failing to automatically re-connect to New PRIMARY after a replica set failover , from Mongoose (MongoDB, NodeJS Driver)

I made a simple NodeJS App, with Mongoose as MongoDB Driver. And connected to a mongodb replica set. The App is working fine until I shut down the current primary, When the PRIMARY is down, the ...
1
vote
1answer
38 views

check storage engine from shell

I'm upgrading to 3.0 and ran into some issues with the upgrade. Specifically, I got an error when trying to start up mongod via ssh, it tried to use the default dbpath instead of the one i specified ...
0
votes
0answers
16 views

Replica Set In Mongo Are All Primary

So I saw a thread on here for when all the replica sets are Primary. The fix was to do rs.Add(hostportStr) on the master server before you do rs.initiate() on the server you want to become a ...
2
votes
1answer
92 views

'mongod wiredTiger' on Ubuntu?

I cannot use wiredTiger as a service for MongoDB. Then, I progresses step by step according to the following guide; http://docs.mongodb.org/manual/release-notes/3.0-upgrade/ Step-1: Start 3.0 ...
0
votes
1answer
19 views

mongodb wont read config file using upstart

The problem started where mongo wouldn't start because of low disk space. So I enabled the small files directive in the config file. Now it starts if I run: /usr/bin/mongod --config /etc/mongod.conf ...
0
votes
0answers
10 views

how to set the permissions for the mongodb packages to run mongo cluster and keep *least privilege principle*?

I followed the instructions of mongodb doc to install the mongodb package on my ubuntu. As a result, the owner of all files in mongodb package is root, and the group is root. I have some questions. ...
0
votes
0answers
32 views

what is the password to user mongodb when mongodb is installed in ubuntu?

When I installed mongodb in ubuntu, user mongodb and group mongodb are created in /etc/passwd and /etc/group. But I have no idea of the password to these user and group. I have to run mongod as root ...
0
votes
1answer
133 views

MongoDB syncingTo change

I have a 3 members replica set version 2.6.1 with following configuration "_id" : 0, "host" : "10.125.16.22:30000", "priority" : 2 ...
0
votes
2answers
325 views

Mongodb ubuntu - config server and shard together

I have the following services on a single shard server: sudo mongod --dbpath /data/db/ --port 31001 sudo mongod --configsvr --dbpath /data/configdb/ --port 21001 The same server is using for shard ...
0
votes
0answers
48 views

Mongodb 3.0.1 in ubuntu starts but status, stop or restart show 'mongo stop/waiting'

I am relatively new to Mongo and have installed 3.0.1 on a Digital Ocean droplet (Ubuntu 14.04 LTS). The database starts without problems but I am unable to 'sudo service mongod [stop/restart/status]' ...
2
votes
1answer
337 views

Best design of mongo replica set for DB read/write speed

I'm building a Node app that uses MongoDB. Whilst it would probably be fine to have node and mongo sitting on the same VPS, I want to ensure that the MongoDB is backed up and maintain high ...
-2
votes
0answers
21 views

Simple Mongo DB replication

I need to get things done, quick and fast and now. Later on, down the road, say in a month or less, or more, I will want to have my database replicated in few more machines. I wonder, if I can ...
0
votes
1answer
418 views

Issue while restarting - mongdb

I had tried to start the mongodb service using the following command in linux machine. service mongod restart I am getting the following error Stopping mongod: ...
1
vote
1answer
50 views

Shoud I uninstall mongodb 2.6 before upgrade to 3.0?

I installed mongodb 2.6 in my machine. This week, I followed the instructions in the subsection of Install MongoDB on http://docs.mongodb.org/manual/tutorial/install-mongodb-on-ubuntu/. I installed ...