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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3
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1answer
94 views

Mongodb restrict access on collections level

I'm building a backend system using MongoDB. Now I want to restrict access on certain numbers of database collections to this system. For example I have users, admin_users, pageviews and I want this ...
0
votes
1answer
70 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 ...
2
votes
1answer
395 views

How much free space do I need for mongoDB? and how to reclaim lost space?

I ran out of disk space on my mongo database. I saw it and dropped some collections (120 out of 1700 i had). And ran db.compact(...) thinking it would release free space. well, that was a stupid idea. ...
0
votes
0answers
91 views

How much free space do I need for mongoDB? and how to reclaim lost space?

I ran out of disk space on my mongo database. I saw it and dropped some collections (120 out of 1700 i had). And ran db.compact(...) thinking it would release free space. well, that was a stupid idea. ...
0
votes
1answer
168 views

Data Analysis with MongoDB or MySQL

I have a need for processing some data in order to come up with some statistic. This is the scenario: Each user can answer several questions from the question list. They pick their answers from a ...
1
vote
1answer
171 views

How to setup a MongoDB replica set for the connector

I want to keep MongoDB and Solr in sync. The mongodb-connector (python) is the tool I want to use to do that. Now a replica set in mongodb is required (see ReadMe), but I don't want (and can) setup a ...
0
votes
1answer
52 views

CRC checkup in MongoDB

I am new to MongoDB and currently working on a project. I read tutorials but I'm unable to find any information about Cyclic Redundancy Check (CRC) in MongoDB. Is there any way to check that the data ...
0
votes
2answers
271 views

How secure is mongodb with elastic beanstalk and EC2

I have a questions. I run MongoDB on one of instances of EC2 and application on Elastic BeansTalk. I restricted access to DB: only application can access it. DB instance has Elastic IP because it is ...
0
votes
3answers
949 views

Difference between Sharding And Replication on MongoDB

I am just confuse about the Sharding and Replication that how they works..According to Definition Replication: A replica set in MongoDB is a group of mongod processes that maintain the same data ...
0
votes
2answers
125 views

Running a simple logging program, how to diagnose spikes mongod's CPU activity?

I'm running mongodb 1.4.7 - I've a node server set up which logs incoming requests in a logs collection: {'u':'user123', 'l':'log data'} In addition, once the request happens, the server will check ...
0
votes
1answer
34 views

Replicating MongoDB server on windows

I have a main server(windows-27017) and on that i replicated my data on different port (37017) but same server. Now i am trying to add my notebook as a replicate server on mongodb and installed ...
0
votes
1answer
125 views

MongoDB Storage Architecture (MySQL innodb_file_per_table equivalent to MongoDB)

I am new to MongoDB.I looked inside dbpath I found users.0 - 16.8MB users.1 - 33.6MB users.ns - 16.8MB Further when I dig deeper I found, The .0, .1 files are datafiles. Each datafile is ...
3
votes
2answers
749 views

How to Determine Chunk Distribution (data and number of docs) in a Sharded MongoDB Cluster?

Having done all the right things - picked an appropriate shard key, scaled horizontally, distributed my data across several shards, I find I now have no real way to determine how well balanced the ...
0
votes
1answer
193 views

MongoDB shell version error (Server has startup warnings)

I installed MongoDB under Ubuntu server and when inter to MongoDB shell i got this error and warnings. MongoDB shell version: 2.4.7 connecting to: test Server has startup warnings: Sun Oct 27 ...
2
votes
1answer
119 views

Improving concurrency in MongoDB via sharding

Our current setup: Cluster of ~500 ec2 c1.xLarge worker nodes with 8 threads on each running scientific simulations Results temporarily stored at runtime on each worker node's local MongoDB, using ...
1
vote
1answer
442 views

“ERROR: could not read from config file” MongoDB

I'm trying to configure MongoDB in OS X Mountain Lion. I've installed with Homebrew; I have followed lots of tutorials, but I have got an issue which I haven't been able to solved. The issue is about ...
0
votes
1answer
223 views

Launchctl in MongoDB

I'm trying to configure MongoDB in OS X Mountain Lion. I've installed with Homebrew; I have followed lots of tutorials, but I have got an issue which I haven't been able to solved. The issue is ...
0
votes
0answers
400 views

Installing mongodb as service

I'm trying to install mongodb as service on a machine running Windows Server 2008R2. I'm getting this message in the command prompt: The service is not responding to the control function. More ...
0
votes
2answers
403 views

Diffrence between relational and unrelational database [closed]

What is the difference between relational(MySql) and unrelational database(MongoDb)
0
votes
1answer
119 views

Multiple system.replset collections in local

I have a replicaset that's showing multiple system.replset collection in the local db. replset1:PRIMARY> show collections; me oplog.rs replset.minvalid slaves system.indexes system.profile ...
0
votes
1answer
117 views

MongoDB cloneCollection between CentOS servers times out at 2 hours

I'm trying to clone a MongoDB collection from CentOS server A to CentOS server B. Both are running 2.4.6. The copy works great until exaxctly 2 hours, at which point I get a 9001 socket exception: ...
1
vote
2answers
104 views

MongoDB scaling when working with files

I have read through the MongoDB manual about sharding and replicasets. However, I would like to know if the following can be achieved with sufficient performance (read/write): Saving 10,000,000 ...
0
votes
1answer
67 views

What does maintenanceMode -7 mean on a mongo primary?

I've recently promoted a new member to primary of a mongo replicaset. Things seem to be running smoothly for several days and am not seeing any application symptoms of any problems. However peeking ...
2
votes
0answers
112 views

MongoDB advantages [closed]

I am actually can not understand the real advatage or killer feature of MongoDB storage. As I understand currently MongoDB implements exclusive per-database write lock that is even worse from the ...
1
vote
1answer
259 views

Need a solution to store cheaply a big MongoDB collection

We have the typical problem of Twitter's timeline tweets, or Facebook profile's news: we need to show the users only the new information (storing them in a fast db), and put all the old ones somewhere ...
1
vote
1answer
59 views

Based on what criteria voting take place in MongoDB?

Suppose a replication set R1 contains one primary, 2 secondary and one arbiter node. Voting will happen if the primery node goes down. Based on what criteria secondary members will vote to select the ...
1
vote
2answers
2k views

Write Locks in Mongo DB

I read somewhere that mongo db holds db level write lock, does this mean that when someone updates any collection others are not allowed to read other collection or how it works. Also when someone ...
1
vote
1answer
428 views

I found the normal ULimit setting for mongo db is as follows:

I found the normal ULimit setting for mongo db is as follows: -f (file size): unlimited -t (cpu time): unlimited -v (virtual memory): unlimited [1] -n (open files): 64000 -m ...
2
votes
1answer
82 views

Accessing unsharded database in a MongoDB shard cluster without going through mongos?

As far as I can understand, not all databases in a MongoDB shard cluster have to be sharded; I can keep some databases unsharded, on only one of the shards. So suppose I have a shard cluster, with ...
2
votes
1answer
895 views

Can I disable journalling to improve performance

We have a 16 shard MongoDB 2.4 installation running in AWS that is eating money. The data is volatile, it only gets used within 15 minutes of creation If the cluster goes down we wipe it out and ...
0
votes
0answers
117 views

Import only selected column from tsv into mongodb

Edit I am uploading very big tsv file thats why i dont want to import unnecessary column in mongodb, I know how to upload file into mongodb(just as attachment) as:- mongoimport --db xyztsv--c ...
1
vote
2answers
132 views

Does mongodb support non readable file?

I have uploaded PDF/PST file in mongodb by mongofiles but by retrieving them in R(BSON) and converting it to "Character" type i didnt find the PDF/PST file,so is it possible to upload PDF file or PST ...
6
votes
1answer
3k views

mongodb config servers not in sync

I have setup with 2 shards, with 2 replica servers and 3 config servers, and 2 mongos. I have following problems: 1) mongo config servers out of sync: Aug 14 09:46:48 server mongos.27017[10143]: Sun ...
0
votes
2answers
278 views

mongo replication not happening

I setup master/slave replication of mongodb on EC2. But I see not replication happening. When I do "show dbs" on master, it shows all dbs expected. But when I do the same on replica, it does not show ...
2
votes
1answer
145 views

Memory management scenario with MongoDB

I'm implementing a medium scale marketing e-commerce affiliation site, which has following estimates, Total Size of Data: 5 - 10 GB Indexes on Data: 1 GB approx (which I wanted to be in memory) Disk ...
2
votes
1answer
2k views

Creating mongo 3 node replica set on ec2 problems

I'm trying to create a 3 node cluster of mongo replicas on ec2 instances, with internal ips 10.168.xxx.xxx, 10.166.xxx.xxx and 10.188.xxx.xxx, my config file is: dbpath = /home/ubuntu/mongo-data/ ...
0
votes
1answer
496 views

mongodb user for ubuntu EC2 instance

I am trying to install mongodb on Ubuntu EC2 instance. However, I am confused about what user the DB would run as: If I follow: http://docs.mongodb.org/manual/tutorial/install-mongodb-on-ubuntu/ ...
2
votes
1answer
56 views

How to handle “or” possibilities in MongoDB

I'm new to MongoDB and by no means an expert in DB design in general. This feels like a really basic question that's probably been answered a million times, but I'm having a surprisingly hard time ...
1
vote
1answer
295 views

Mongo repair database “ERROR: error: exception cloning object in local.system.replset ”

I'm trying to repair a mongo database and am running into the following error early on: Wed Jul 24 16:55:21 [initandlisten] ERROR: error: exception cloning object in local.system.replset E11000 ...
0
votes
0answers
67 views

MongoDB RAM requirements doubt

I have a data file with 100 million documents. The number of documents is expected to always remain between 100 million and 200 million for atleast a year. I have 15 GB Ram. Currently the update ...
1
vote
0answers
198 views

MongoDB performance limits of mongo

There are 100 data files, each with 60 fields and over 4 million records. There is a perl program that inserts the records or updates them based on an userdefined _id field. There is also a History ...
1
vote
1answer
37 views

Check and remove iteratively without an index

Without sync priority or performance requirements on the task, I need to check all documents once per day and removing some of them. The find filter is not static but can be defined within a db ...
0
votes
1answer
205 views

Preventing mongodb crashes

I am using mongodb with the web server. Recently, I observed that mongodb server crashed after "no space left" for journalling. So, after some online help I could repair and restart the DB. But, ...
1
vote
2answers
1k views

Mongo DB Cant Start

Evening we have had a mongodb running fine for a few weeks and all of sudden it has gone down. We are unable to start it back up as it is complaining that the "dbpath (/data/db/) does not exist" I've ...
3
votes
1answer
600 views

mongostat causing CPU 100%

On a 64Bit Debian 6 OS with 4 CPU cores and 8GB RAM, I can reproduce an issue with mongostat. Whenever I create an index, reIndex or even index in background, according to top, the CPU load is 40-60% ...
1
vote
0answers
99 views

MongoDB secondary heartbeat hangs

We have got the same issue in two replica sets in AWS cloud. According to rs.status() on primary secondary jumping between SECONDARY and unhealthy states. With period of 10-20 seconds. In logs I see ...
8
votes
1answer
4k views

What happens if there are too many inserts in MongoDB? How to ensure all data is stored?

I use MongoDB to store periodically measured values. Every ~100 ms a bunch of values is inserted as document. It works fine, but I'm worried about performance issues. (I use safe inserts, it seems as ...
0
votes
0answers
85 views

Locking and Faulting on import

My collection with a _id and a single field index is run on a single node/on localhost, has 48GB RAM and 16 core CPU available. The hdd is in RAID1, without SSD cache. Mongo version 2.4. I run a ...
1
vote
1answer
288 views

optimizing MySQL for traffic analytics system

background : I've developed a URL shortener system like Bitly with same features , so the system also tracks clickers info and represent as graphs to the person who has shorten the link as ...
3
votes
2answers
179 views

Scalability: Desiging a message table

This question might be deadly simple but I wanted to make sure I am going through the correct path and not making any simple and irrevertible mistakes. My project will be based on messaging and it ...