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.

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1answer
136 views

mongoexport not exporting all possible data

I have a collection with documents similar to the following: { _id: 'p_123456', id: 123456, kind: 'person' data: [...] } id field can contain either positive or negative integers. This ...
0
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2answers
354 views

MongoDB/MySQL - auto increment vs object ID

I am in the process of evaluating MongoDB and writing some basic PHP applications around it. Typically in my PHP/MySQL applications, I would create an ID field and set it to auto-increment on each row ...
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9 views

MongoDB denying API access, while console shell works

I am a MongoDB newbie, with a MongoDB instance running on a Ubuntu machine. If I login onto the machine's console and run mongo -u username -p password databasename I have permissions for the ...
0
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1answer
15 views

Restart failed mongodb replica set instance under docker

I am trying to simulate when the master mongod instance shuts down for some reason in mongo replica set. So I took I docker file from here: ...
2
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1answer
179 views

Chunk Size is shown as 1 KB in mongo db logs even it is set to 300 MB

I am running a mongo cluster. Chunk size set is 300 MB but for today morning it is showing me in logs taht chunk size is 1024 Byte. I checked in current op there also it is showing chunks of 1024 ...
2
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1answer
125 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
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1answer
322 views

How to update a field in sharded environment in mongodb using C# driver

I have successfully done loading in sharded environment. It is working fine. But when I do update in sharded environment, I am getting the error as : WriteConcern detected an error 'update { q: { ...
1
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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 ...
1
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1answer
102 views

Limit the RAM memory usage in MongoDB

I am using MongoDB-2.6.1. The question from me is that- "Is there any way to limit the RAM memory usage??" Fr example: Out of 4 GB RAM, let MongoDB use till 3 GB (<= 3 GB). Please help me out.. ...
1
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1answer
20 views

MongoLab: Does hardware effect performance of a find() query [on hold]

I asked a pervious question on StackOverflow about if document size affected the performance of fetching that document (the document is 3MB in size) ...
1
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2answers
109 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 ...
0
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1answer
139 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: ...
0
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1answer
325 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
1answer
111 views

mongodb on-premise: will it work? [on hold]

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
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2answers
81 views

Standalone MongoDB to MongoDB Shard Setup

I'm learning MongoDB currently so maybe the title of this question is worded poorly, but I'm looking to understand the scaling of Mongo better. I did some research on what DB would be best for my ...
1
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1answer
222 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
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0answers
14 views

MongoDB Backup & purge [duplicate]

I'm exploring solutions for a basic dbadmin need : periodically backing up and purging data in MongoDB. Basically, I need a logrotate for mongodb. I have a backend program filling a collection. I ...
0
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1answer
590 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. ...
1
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1answer
212 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
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1answer
107 views

MongoDB Insert Performance

I have some data which are aggregated in chunks and later pushed into another collection. The problem is that aggregated data pushing to another collection is very slow and takes from few hours and i ...
1
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1answer
140 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 ...
1
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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 ...
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0answers
31 views

When performing an UPSERT, how to keep track of which rows were inserted vs updated? [closed]

This question is not necessarily specific to one particular database platform, but I'm looking for an answer for any of one of the following databases: MySQL PostgreSQL SQL Server Oracle MongoDB ...
1
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1answer
277 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
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1answer
112 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": [ ...
2
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1answer
1k 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. ...
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0answers
18 views

cannot log in to mongo from command line - using MongoDB 3.0 and WiredTiger - I've followed all instructions

NOTE: I have tried not setting bind_ip and also setting it to 0.0.0.0 -- neither one fixed my issue. This is my mongod.conf file: systemLog: destination: file path: "/root/mongodb.log" ...
0
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1answer
168 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
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1answer
148 views

MongoDB does'nt starts after changing the data directory

I have installed a mongodb instance using yum..Now everything works fine.I started the service using service mongod start,it works good.Then i changed the data directory and log path in the ...
0
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1answer
133 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 ...
3
votes
1answer
110 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 ...
0
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1answer
172 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
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0answers
16 views

Docker Mongodb replication on different hosts is not working

I am trying to setup a mongodb replication in Docker containers running on different hosts. Please find the steps below: In a VM1 running ubuntu 14.04, installed docker, then created container C1. ...
0
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1answer
2k 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 ...
0
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1answer
138 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
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1answer
13 views

Running Aggregation logic on multiple shards of MongoDB

Suppose we have 5 shards in MongoDB having collection of data, and I have to write an Aggregation logic which should work on each of 5 shards in my cluster and collect data from these shards. Should ...
0
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1answer
300 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" : ...
0
votes
1answer
12 views

MongoDB 3.0 - how do I check which storage engine is being used? [duplicate]

I have MongoDB 3.0.0 running on a Digital Ocean droplet. How can I tell which storage engine it is using?
0
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1answer
26 views

Understanding MongoDB Aggregation

Pretend that our collection has 1M document Now if i do aggregation like this: db.users.aggregate({ $group: { _id : "$gender", avgAge : { $avg : "$age" } } }) then how it ...
0
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2answers
47 views

In mongodb, is “sh.getBalancerState() is false” the same as “sh.isBanlancerRunning is false”?

During upgrading config servers to use WiredTIger, I stopped balancer using sh.setBalancerState(false), and then I run sh.getBalancerState(). The output is false. Does this mean the balancer is not ...
0
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0answers
30 views

Best way to run an ETL on a production MongoDB database

We have the following environment: 3 servers + 3 replica set servers Each server has 3 shards Our main collection has around 40,000,000 documents that average at around 6kb Our shard key is ...
2
votes
1answer
203 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 ...
2
votes
1answer
388 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
38 views

Who can explain mongodb with ssl?

I created certificates according to the instructions on the official website of MongoDB, but it doesn't work properly. I have a replica set and self-signed certificates. I need a full encryption ...
3
votes
0answers
21 views

Remove a shard in MongoDB

I have a MongoDB cluster, I accidentally hosed a shard, I don't have a backup. It's pretty easy to recover the data, but after issuing the removeShard command, it says it's draining. However, the ...
2
votes
1answer
301 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) ...
0
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1answer
115 views

MongoDB service not working after upgrade to Ubuntu 15.04

I have recently upgraded my Ubuntu from 14.10 to 15.04. All features seems to be working fine except MongoDB. It is not controllable from service as we do normally in Ubuntu. sudo service mongodb ...
0
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2answers
369 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
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1answer
31 views

MongoDb replica set: How do I verify data replication on other servers?

I have a 3 member replica set running. It's geo-located on 3 separate VPSs. On primary I can do rs.status() and see it's working. I can't execute any mongo shell commands on the secondaries. How do I ...
0
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1answer
22 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 ...