All versions of MongoDB - a scalable, high-performance, open source, document-oriented database.

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5
votes
7answers
9k views

MongoDB doesn't start 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 well. Then I changed the data directory and log path in the ...
2
votes
2answers
504 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
250 views

While installing Mongodb, getting “enabling http interface” message and stopped

I am getting following error while installing mongodb, $ mongod --directoryperdb --dbpath C:/mongodb/data/db --logpath c:/mongodb/log/ >mongodb.log --logappend --rest 2015-03-17T17:32:55.359+0530 ...
2
votes
1answer
2k views

When upgrading config servers to use WireTiger, the running config server with wiredtiger does not authenticate the existing pass and user?

In order to upgrade mongodb to 3.0.0, I am upgrading my config servers to use WireTiger. I followed the subsection of Change Config Server to Use WiredTiger. There are 18 steps. I run mongodump --port ...
1
vote
1answer
2k views

Why do I have to run mongod as root?

When I run "/usr/bin/mongod --config /var/data/rs1/rs1db0v3.conf". It failes. The error is: warning: bind_ip of 0.0.0.0 is unnecessary; listens on all ips by default about to fork child process, ...
2
votes
1answer
3k views

MongoDB Insufficient free space for journal files

I have installed a standalone mongo 2.6 in amazon ec2. The instance has reach the limit of disk space and it doesnt run now. I have set before the smallfiles=true in mongod.conf file, but for some ...
3
votes
2answers
3k views

Upgrade mongodb from 2.4 to 3.0

I have mongodb 2.4 database with some indexing. Now I want to upgrade that version to 3.0. I searched on google but did not find any firm answer. I tried installing 3.0 but then it gives me error of ...
1
vote
1answer
355 views

In mongodb cluster, Can I shut down one config server and one data server in the shard at the same time

I have one mongodb cluster, including 3 config servers, and one shard (3 data servers in this shard). One data server and one config server are on the same machine. Can I shut both of them down to ...
1
vote
1answer
270 views

When upgrading to mongodb 3.0, should I upgrade authentication schema after upgrading the storage engine to WiredTiger? [closed]

I know that, I need to upgrade the storage engine after upgrading the binaries. But I am not very sure whether I should upgrade the authentication after upgrading the storage engine. Or it does not ...
2
votes
1answer
4k views

how to upgrade the config servers to use WiredTiger in mongodb 3.0.0

I am reading the document upgrade config servers to use WiredTiger. In the section of "change config server to use WiredTiger", the second step is "stop the last config server listed in the mongos' ...
0
votes
1answer
662 views

can we use a mongodb 3.0 and mongodb 2.6 in same replica set?

i know that replicas using different storage engines can coexist in a replica set on MongoDB 3.0 but can we add a MongoDB 3.0 replica to a replica set that consists of MongoDB 2.6 instances ? That ...
0
votes
0answers
1k views

Mongo db replication issue with 3.0.0

I updated my mongo instance to 3.0.0. Now i am seeing this error continuously in the replica set log 2015-03-12T15:24:23.141+0530 W NETWORK [ReplExecNetThread-74] Failed to connect to ...
1
vote
1answer
178 views

Mongodb: Couldn't find mech GSSAPI

I am trying to understand how mongodb works with kerberos. To do that I have configured a kerberos server, just only for local. This is the configuration of my realm: this is the content of krb5.conf ...
0
votes
0answers
51 views

MongoDB shard not working

I have a mongoDB cluster of 3 replication sets Getting this error: id_ObjectId('54f9ed416aad853b66d0c21f')", configdb: "172.31.12.107:27019,172.31.12.93:27019,172.31.12.43:27019" } result: { ...
1
vote
0answers
134 views

MongoDB with WireTiger Extract Data from Collection FIles

Is there a way to get data from a wiretige (*.wt) collection file ? I've a corrupted database and need the data of a single collection. I tried mongod --repair but didn't help i got various ...
0
votes
1answer
667 views

Mongodb update conditional set operator ($set only when it is insert )

Is there anything in Mongo update where $set when will work only when an insert is done. example is I have a collection which has these fields: Username FirstOccurrence Count What i want that i ...
0
votes
0answers
189 views

MongoDB replica set with arbiter

I'm trying to configure a replica set in MongoDB 3.0 with two replicas and one arbiter, but it's not working as expected. As you can see in the following pictures each instance tells a different ...
2
votes
1answer
176 views

MongoDB on RAID0?

As I'm reading production notes of mongodb I found that RAID0 is not recommended: Most MongoDB deployments should use disks backed by RAID-10. Avoid RAID-0 with MongoDB deployments. While RAID-0 ...
0
votes
1answer
195 views

Mongo repairDatabase procedure

I need to run a repairDatabase in mongo in order to reclaim some os disk space. Can anyone provide feedback on the following procedure: let me know if its correct, if I'm missing anything, if the ...
1
vote
1answer
84 views

MongoDB failover reasons

I have a replica set on MongoDB with 3 members - primary, secondary and arbiter. One day I came and saw that primary and secondary have switched. I'd like to find a reason for the failover that caused ...
1
vote
0answers
443 views

Mongo range query became extremely slow on large collection

I have a collection which has 50 million records in it. After using wired Tiger its size became only 3 GB (2 GB data 700 MB index). I have created index on this collection. But when i do a range query ...
1
vote
0answers
120 views

Mongo 3 Intermitted Crashes

Currently running two VMs with fresh installs of Ubuntu 14.04 x64 and Mongo 3 Stable. Each VM has the same specs with 8 cores and 56GBs of RAM. Our processing VM is doing great under heavy loads, ...
0
votes
1answer
58 views

Multiple databases through a single connection MongoDB, GridFS

I want to use GridFS in your project. As the main database using mongodb. My application can do only one connection to the database (such conditions). Can I make calls to other databases using the ...
1
vote
1answer
920 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" : ...
1
vote
2answers
1k views

Does MongoDB support two 2-way synchronization

We are looking at moving our data from IBM Domino to another backend. One of the things Domino does really well is replicate (or synchronize as they call it) between a Server and Clients. That means ...
0
votes
0answers
239 views

Mongo DB accessesNotInMemory issue with RAM size

I am using Mongo Replica set and it seems to be working fine but when i check db.serverStatus i saw that there are lots of accessesNotInMemory for all The DBs in my mongo instance. I checked MY RAM ...
0
votes
1answer
61 views

Mongo 3.0 release for Cent OS

Can any one tell me When Mongo team will release 3.0 production release. Also will it be available for cent OS as we are shifting g our production boxes from RHEL 6 to cent OS and on Mongo Download ...
0
votes
1answer
107 views

Error while doing in replicaset in windows (mongodb)

I tried doing the replicatset in windows, but im getting the below error. I checked the mongo process and killed the existing process. Even though the error exists. help me on this pls Thx ...
0
votes
1answer
52 views

How the statement based replication works internal on secondary node of mongodb?

Mongodb supports statement-based-replication. Would like to know, how the statement based replication converts the code internally on secondary node of mongodb. Is that working related to the ...
0
votes
1answer
39 views

Sorting on compound Indexes

This may be a novice question but could it be possible query here. If I have a compound Index as { a: 1, b: 1, c: 1, d: 1 } Is this query possible? db.data.find( { a: {$gte:1,$lt:2}, b: { $gt: 3} ...
1
vote
0answers
55 views

Mongodb schema design validation

I am building an app which allows users to do some "tasks" to earn points. The "tasks" are part of a "campaign" which themselves are a part of "brands". I am confused about the schema for storing the ...
0
votes
0answers
16 views

Can we resize a already capped collection in mongo db [duplicate]

I have a capped collection whose initial size i gave 3 GB. Can I modify its size again i mean reducing or increasing both way as per need? is there any command to do it. ...
1
vote
2answers
1k views

MongoDB: co-locate the mongos process on application servers

I would like to ask a question about a best practice described in this document: http://info.mongodb.com/rs/mongodb/images/MongoDB-Performance-Best-Practices.pdf Use multiple query routers. Use ...
1
vote
0answers
101 views

Good way to store daily train data in MongoDB

I am preparing to collect large amounts of information about trains in my country. Each train in my country has a number. I've already collected all of these numbers. There are about 4000 of them. ...
1
vote
0answers
211 views

MongoDB auto-failover: election doesn't happen

I have the following working replica set: { "_id" : "repl1", "version" : 6, "members" : [ { "_id" : 0, "host" : "hostA", ...
0
votes
0answers
90 views

MongoDB stops responding after 2 days of working

I've written small application in Python (I used Twisted). Program receives data and writes it to MongoDB. Every 2 days MongoDB stops responding: 2015-02-11T10:47:20.918+0100 [initandlisten] can't ...
0
votes
1answer
460 views

Extremely long startup time for MongoDB server

I have a MongoDB Server with just over 2 million documents in one collection. Individual documents can contain large amounts of data (some are several megabytes each) but none of that data is in ...
1
vote
1answer
23 views

What “fromRouter” option means on MongoDB aggregations?

Recently i notice that a parameter fromRouter" : true exists on mongoDB aggregations. I search the MongoDB documentation and google for it, but i didn't found anything about it. Can anyone explain ...
3
votes
2answers
555 views

Why does mongodb require three config servers

The official mongodb documentation states to use three config servers. They say its for redudancy, because 1 server would be a point of failure.... but why not 2? in a production sharded cluster, if I ...
0
votes
0answers
271 views

Saving String as unique number in Mongo

I have a field in my collection which is a String in nature. When i run aggregation for this field in data it takes considerable time in aggregation. Total 6 million records are in collection which ...
0
votes
1answer
137 views

MongoDB Hashed Shard Keys Selection

I have a DB which holds very simple documents called "Item": {_id:<ObjectId>, playerId:int, isRead:bool, content:string} containing about 80M documents. Each Item belongs to a certain player, ...
0
votes
0answers
45 views

Data containing list of all the domain names. MongoDB or MySQL?

Data containing list of all the domain names (currently present in the Internet world), along with few attributes (5-6 or maybe 10, each attribute being a column) will be considered as Big Data? ...
1
vote
2answers
218 views

MongoDB Disk Usage with Capped Collections

I am using MongoDB using C#. I am currently using only a single server. Since I have to create Table events for MongoDB collections I have created a single replica set(primary). And using ...
0
votes
1answer
20 views

what is default balancing window in MongoDB

I have read about balancing window in MongoDB document. I see mongo tell about how to modify balancing window but I don't see the default of balancing window. I see only one document about chunk size ...
1
vote
0answers
55 views

why my data is not being sharded?

I am using mongo 2.6.7 I deploy a sharding cluster follow the guide: http://docs.mongodb.org/manual/tutorial/deploy-shard-cluster/ My sharding cluster include: - two replica sets (one primary + one ...
0
votes
1answer
145 views

How to get all documents from a particular chunks in MongoDB?

From mongos log, I got the following message balancer move failed: { chunkTooBig: true, estimatedChunkSize: 408839903, ok: 0.0, errmsg: "chunk too big to move" } from: shard4 to: shard1 I know ...
0
votes
0answers
82 views

MongoDB GridFS delete operation too slow while mongod process takes up 100% CPU

I'm using Python (CPython 2.7.3 on Debian 7.8 amd64) with pymongo driver (version 2.7.2) to connect to a MongoDB (db version v2.4.12) database which has solely been used to store files in a GridFS ...
1
vote
1answer
74 views

Setup MongoDB replica servers with different power?

Is it a good practice to setup replicas with the same machine size (wrt. CPUs, RAM, Bandwidth, etc.) or can replicas be based on smaller machines? One usecase might be to have a small non-voting ...
0
votes
1answer
145 views

Converting sql into mongodb nosql

I am trying to convert oracle sql into its mongodb equivalent version. create table my_hll as select mod(ora_hash(n), 1024) bucket, max(num_zeroes(trunc(ora_hash(n)/1024)))+1 val from previous_data ...
0
votes
0answers
56 views

What exactly should I backup in MongoDB when using replica sets?

I have several instances of MongoDB replica set servers with a primary and a failover machine for each replica set. The primary machine makes daily backups by creating an LVM snapshot and copying all ...