MongoDB : Document-Oriented NoSQL Database

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MongoDB: What does '[DataFileSync] flushing mmaps took … ms for … files' mean?

I am building an index in MongoDB for a large collections (~300GB) and the db terminal window keeps printing: [DataFileSync] flushing mmaps took 10920ms for 151 files The time that it takes to ...
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1answer
192 views

Books to start with big data [closed]

I would like to start learning about the big data technologies. I work in this area in the future. Does anyone know good books to start learning about it? Hadoop, HBase. Beginner - intermediate - ...
0
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1answer
317 views

RegEx bug in MongoDB

I run the following queries on a collection that have a lot of entries that contain [ and ]. db.test.find({word:/[\[]/}); // could not be run in console db.test.find({word:/\[/ }); ...
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603 views

Disk space recovery on Mongodb replicaset secondaries

Is it possible to recover disk space on replica set secondaries based on the results of a repairDatabase call performed on a primary? I can't seem to locate anything that would work short of bringing ...
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2answers
210 views

Sharded MongoDB backup solution

I am looking for a way that I can backup my 12 MongoDB shards into a single server. Disk space is not an issue but getting the backups to be on a single node would be the best. I am not sure if there ...
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2k views

Mongo replicated shard member not able to recover, stuck in STARTUP2 mode

I have following setup for a sharded replica set in Amazon VPC: mongo1: 8G RAM Duo core (Primary) mongo2: 8G RAM Duo core (Secondary) mongo3: 4G RAM (Arbiter) Mongo1 is the primary ...
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2answers
311 views

mongodb service not running after changing path

I have changed the dbpath of mongodb.conf. And after that trying to start mongodb service,when I run sudo service mongodb start I get back mongodb start/running, process 7320 After that I run: ...
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246 views

Choosing shard key and friendly URL Ids for my MongoDB

I have decided to use MongoDB as my Database for a web application. However, I have some difficulties to get started and I hope that you can help me out with a few questions. I am developing my ...
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153 views

Management tool for managing MongoDB sharded cluster

Is there a database management software for MongoDB that makes it easy to create a cluster, add shards, backup shards and all the complicated stuff. There are some many MongoDB clients but they are ...
2
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1answer
127 views

Preserving whitespace in MongoDB values

In a simple scenario of me inserting a key-value pair, when value contains some white space, how can I preserve it? Example: > > db.bar.insert({"name":"mike "}) > > db.bar.find() { ...
2
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1answer
530 views

MongoDB geospatial query with sort - performance issues

I have query (which is very slow ~2,5s): db.markers.find({ latlng: { '$within': { '$box': [ [ -16, -140 ], [ 75, 140 ] ] } } }).sort({_id: -1}).limit(1000) When I run explain for this query I get ...
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How to keep Mongodb log small via the conf file (or other persistent method)

This is related to my question in stackoverflow where vb.net simply hang on updating a mongodb query. http://stackoverflow.com/questions/12780258/insert-mongodb-using-vb-net/12796593#12796593 After ...
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1answer
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Can't start mongodb in ArchLinux

I have installed mongodb using sudo pacman -S mongodb in my 32-bit arch . At first I run this sudo mkdir -p /data/db to create /data/db ,and then run $ mongod ,then I got the following message : ...
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1answer
161 views

Moving a collection to a new database (v2.2)

To take advantage of the improved concurrency in Mongodb 2.2--namely database level locking--we would like to move a sharded collection to a new database. I have been unable to find any documentation ...
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1answer
129 views

Riak in SasS application

I am thinking about using Riak for a SasS application I started working on recently. I was originally thinking about MongoDB but after running into Riak it seems like it may be the better option. The ...
2
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1answer
2k views

Error “cannot connect to server” installing MongoDB on Ubuntu

I'm trying to install MongoDB on Ubuntu 10.04. I followed these installation instructions. I got the following error: Error: couldn't connect to server 127.0.0.1:27017 src/mongo/shell/mongo.js:91 ...
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1answer
87 views

Why searching with $all in Mongodb is FAR SLOWER than the EQUIVALENT search?

$all with only one item is equivalent with normal search right? Here is the log without $all (I used 4700 test cases with 30 thread): Thu Sep 20 17:27:05 [conn11] query newisikotagte15.tablebusiness ...
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646 views

Storing dictionaries in mongo

Is there any reliable and fast database architecture that allows to store a dictionary(containing up to hundred thousand words) using mongodb?
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162 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) ...
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1answer
55 views

Why $in is much faster then $all

I am well aware of what those 2 do. $in take .3 seconds. And $all take 26 seconds. Huge different. If anything $in should take longer because it returns more data. Also if the limit is removed, $in ...
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536 views

$nearSphere returns too many data. What am I missing? Am I wrong? Is it a bug? Does other see the same thing?

I noticed that $near and $nearSphere returns completely different data and I got suspicious. After all, when latitude is near equator it sphere distance shouldn't differ a lot from euclidean distance. ...
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What does reslen and other means in mongodb log?

database.tablebusiness query: { LongitudeLatitude: { $nearSphere: [ 106.772835, -6.186753 ], $maxDistance: 0.04498373205078301 }, Prominent: { $gte: 15 }, indexContents: { $all: [ /^aru/, /^op/ ] } } ...
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83 views

Is Index Used for This Query

If so, which one? How do we know? I have 3 indexes in a query. Actually only the first 2 should be useful { "v": NumberInt(1), "key": { "LongitudeLatitude": "2d", "Prominent"▼: ...
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500 views

How to interpret this “db.explain()” for this mongodb query

db.tablebusiness.find({ "LongitudeLatitude" : { "$within" : { "$centerSphere" : [[106.772835, -6.186753], 0.0089967464101566] } }, "indexContents" : { "$all" : ["warung"] }, "Prominent" : { "$gte" : ...
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2answers
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Error: couldn't connect to server 127.0.0.1:27017 src/mongo/shell/mongo.js:91 when changing mongodb data directory

I already change the owner of the directory I want to use root@ip-10-138-30-205:/media/newdrive# ls -l ...
3
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1answer
752 views

Mongo connection failing with 'Transport endpoint is not connected'

I have a 2 server installation. A web server with Apache and a DB server with MongoDB. I am load testing it, and on ~300 RPS I am getting this error: PHP Fatal error: Uncaught exception ...
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206 views

Compare MongoDB and MySQL

Can anyone help me to make right decision for choosing scalable and reliable database? I have to create 3-4 tables with around 200 columns each and these tables will have around 5000 data records. As ...
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139 views

What's the fastest way to replicate data?

I have a mongodb database data on my computer. I want to upload that into amazon.com server. The bottle neck is the internet connection. One way is to zip the file and then upload it to the server. ...
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213 views

Does MongoDB auto compacting

I copy a collection to another collection. Data is 14GB. I deleted the copied collection. Yet the size of the directory is still 14 GB. I chose repair but it seems to take forever. Actually inserting ...
4
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3k views

Mongodb - Returning the points nearest to a location, with distance

What is the MongoDB's equivalent to this query: SELECT 111151.29341326 * SQRT( pow(-6.186753-`Latitude`, 2) + pow(106.772835-`Longitude`, 2) ...
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431 views

Where can I find manual and tutorial for rockmongo? [closed]

I tried to find it in google and couldn't find it. Most just tell how to install. None tell how to use execute, for example.
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619 views

Where can I get this nice phpMyadmin features for mongodb

In phpmyadmin Say I browse a table, or do anything. I will be told the actual sql command that I should run to execute the query. Say I want to do a query and then I want to do something else ...
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2answers
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How to display query result in rockmongo by using execute method

I executed a command in mongo.exe > db.tablebusiness.find({"_id": "the-simmons-paradise__41.85_-87.88"}); I got results: Now I try similar command in rockmongo. If I execute ...
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2answers
732 views

mongoDB rs.initiate hangs

I am having trouble setting up replication on a new mongoDB installation. Everything works fine when I run without replication but when I run mongod with the --replSet option, and run rs.initiate(), ...
5
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1answer
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Mongo cannot find my collection

My mongodb server has a database named villageContents It has a collection named tablebusiness If I run mongo I saw MongoDB shell version: 2.0.7 connecting to: test > I wonder what "test" is. ...
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448 views

How to add spatial indexes through rockmongo

In rockmongo we got fields for the field name and whether we should sort by ascending or descending. How to add spatial indexes then?
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How can I time-stamp data in MongoDB?

I'm responsible for writing an app to juggle a huge amount of client and business intelligence information. This information involves records for various businesses and metrics like revenue, their web ...
4
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1answer
288 views

Ideal environment and cost for running a medium size MongoDb server

I know some people will say this question does not belong here but i didnt find a better place on the internet to ask this. Please migrate to an appropriate place if you think it should be. I am using ...
4
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1answer
532 views

MongoDB optimization on high data

I have a mongoDB collection with 42M registers with 1M new registers every day. We found a low performance on mongoDB querying. showing in mongostat the fields: qr|qw ar|aw with values of 300-500. ...
3
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1answer
836 views

MongoDB - handling embedded documents and relations

I am researching MongoDB for a web app that I am bulding. Coming from a MySQL background, the concept of embedded documents is not so easy to fully understand. Let's say I have a document called ...
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1answer
73 views

MongoDB: Can I perform a second query if the first doesn't match

When querying MongoDB is it possible to perform a query and if it isn't matched perform a second query. I could perform an $or which will do booth queries and return the results for booth but I only ...
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348 views

mongodb: replica-set processing reads on the primary

Running a replica-set with 1 primary and 2 secondaries, I wonder why the READs are also done on the primary. Shouldn't the primary mainly do the WRITEs and the secondary can share the READ-load?! I ...
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1answer
74 views

How can I automate sharding in the presence of continuous reads

I am using a pymongo in a sharded mongo environment. I have some fairly write-intensive systems, so I split the data up by time, with one database per hour, so the heavy-lifting of index-updates can ...
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1answer
2k views

mongodb: drop all collections

How to remove existing content before entering a replicaset the first time? mongodb worries about: ... has data already, cannot initiate set. All members except initiator must be empty.
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1answer
159 views

Does mongodb automatically move small non-partitoned databases to spread read load?

I have a few hundred small databases, each between 0.2GB and 4.0GB in size. These are sitting on a sharded mongodb environment with 10 or so shards. At any one time, only a very small subset of these ...
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mongodb: replica-set with load balancer

Is there an option for load balancing with mongodb replica sets? I am not asking for a HAProxy or similar, but for a built-in feature from mongodb. Could not find tips for this in the docs.
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111 views

Storing all data in a single db versus multiple dbs in Mongodb

We have an app that is basically an ERP. Some of the resources in the ERP are satellite tracked. So the information related to the resource itself is minimal, but the satellite tracker produces data ...
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1answer
165 views

What database do most mobile start ups use? [closed]

mongodb? MySQL? PostgreSQL? If someone would add pluses and minus, let me know. Why I ask: I am a mobile startup. I need a database that supports spatial indexes. The spatial index must be able to ...
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2answers
620 views

MongoDB: Replica Set - master vs. slave

We think about moving from a master-slaves to mongodb with replica-set. Now I wonder if mongodb replicas are also set up like read-only slaves or if each mongos is able to write and sync the others ...
5
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1answer
297 views

MongoDB deployment best practices

I had a few questions around deployment best practices and how folks are using mongodb today. Feel free to add any other comments you can think off. No of databases per mongod instance. Is the ...