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

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7
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0answers
2k views

Mongodb incremental backups

I was given the task to setup incremental backups for mongodb replicaset, as start point of course I googled about it and could not find anything on mongodb docs, I did find however this question ...
5
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0answers
214 views

Sudden Mongodb high connections/queues, db stops responding

The issue We have a strange issue on our mongodb setup. Sometimes we get peaks of high connections and high queues and the mongodb process stops responding if we let the queues and connections ...
3
votes
0answers
24 views

How to assign 'findandmodify' privilege to a mongo user?

I'm running a Mongo 2.6 replica instance where a node application needs to talk to. Basically nothing much was setup except these parameters: # where to write logging data. systemLog: destination: ...
3
votes
0answers
54 views

Read replica setting giving error “No candidate servers found”

I am running my website with Laravel 5 + MongoDB. I am using mongo cluster to speed up data read and write, and to lower CPU usage of the mongo server. I have set up the replica like this: ...
3
votes
0answers
39 views

AS/400 + DB2 to MongoDB?

I'm not seeing a whole lot of info on the subject, so I figured I'd ask people who might know more about it than I do: Is it possible to replicate data from an AS/400 + IBM DB2 instance to MongoDB? If ...
3
votes
0answers
92 views

Very slow MongoDB find query

I am having troubles with this simple query which takes a few minutes. db.data_items.find({'observation_target.observation_target_id': 2190}).limit(20000) The explain output shows that the query ...
3
votes
0answers
619 views

Mongo not using enough RAM, and is slow

Our Production Mongo appears to be behaving weirdly. As far as I have read, Mongo should eat up all the available RAM to cache Index and Data in memory but in our case it is not doing so. Our ...
3
votes
0answers
167 views

automated data sync after Primary node is down

I have this scenario, using version 2.2.2: Node A, Primary, Priority: 10, Wireless network Node B, Secondary, Priority: 9, VM Server1 Node C, Secondary, Priority: 8, VM Server1 Sequence: In Node ...
2
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0answers
32 views

mongod crashes with “Invariant failure getExtent( a )->xprev.isNull()” message

I am trying to start a mongodb server with the database, that is located on portable drive. I know barely nothing about the internals of this particular database. There are 647 database.N files, 2G ...
2
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0answers
709 views

Multiple IPs are not getting bind in mongodb conf file

I am trying to bind multiple IP to mongodb config file, one is 0.0.0.0 and other is 127.0.0.1. I did the following change in configuration file /etc/mongod.conf # network interfaces net: port: ...
2
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0answers
23 views

how to convert mongodb(2.4.10) startup2 to primary

I have standalone bitnami mongodb(2.4.10). The output of rs.status() command is below : rs.status() { "set" : "test", "date" : ISODate("2015-11-13T08:07:41Z"), "myState" : 5, ...
2
votes
0answers
29 views

Impact of adjusting Time of Mongodb server?

Using Ubuntu 14.04 and mongodb 2.6.10 I have time difference between a replica machine and primary , my secondary isn't configured with NTP what are the implications of adjusting time on the ...
2
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0answers
20 views

Should mongodb be run in a service, or a worker cluster?

I'm trying to implement an architecture that's similar to the coreos's production architecture (shown below) Should I run the database as a central service or one or more of the workers? I figured ...
2
votes
0answers
132 views

Why is our Non-Mapped Virtual memory usage high when running MongoDB (MMAP) on CENTOS

Our non-virtual virtual memory usage on our Linux MongoDb instances seems high, currently sitting just over 2GB. The instances are running a minimal installation of CENTOS (no GUI) and they acting as ...
2
votes
0answers
115 views

MongoDB C# driver fails to reconnect after stepDown

I have an Elastic Beanstalk environment in AWS that constantly verifies the DB is accessible by querying the mongos for one document. We only speak to the DB routers and not to specific instances. ...
2
votes
0answers
343 views

Error while creating an admin user in replica set

I have a relatively simple replica set test setup between two VMs and my host machine, with VM1 as primary, VM2 as secondary and the host as arbiter. I have mongodb 2.6.4 installed on all machines. So ...
2
votes
0answers
796 views

Positional Operator Matching Nested Arrays Workaround?

As was just pointed out to me on stackoverflow, Positional Operator Matching Nested Arrays has yet to be made available.. I need to display read.marked:true replies differently than read.marked:false ...
2
votes
0answers
392 views

MongoDB communication issues on Azure

I have a Python uWSGI app running behind Nginx using pymongo to communicate with a 4 machine replica set running Mongodb 2.6.3. The replica set is configured using domain names for each machine ...
2
votes
0answers
2k views

“Host has low open file limits” error in MMS

I am running Standalone MongoDB (v 2.6.0 64-bit) host on Centos (v 6.5). Centos is guest OS on Windows 7 host running under VirtualBox (4.3.10). MongoDB process runs under root account. And it is ...
2
votes
0answers
98 views

mysql vs mongodb cache/load balancing

I have a system where users can 'like' content. There will likely be many hundreds of these likes going on at once. I'd like it to be AJAX driven so you get an immediate response. At the moment I ...
2
votes
0answers
368 views

Store large hierarchy in NoSQL each day and compare

I'm in the process of creating a utility that stores a fairly large hierarchy into a NoSQL document. The data of this is similar to an Active Directory / LDAP structure which contains sub groupings, ...
1
vote
0answers
13 views

Too many open connections with MongoDB 2.6 + PyMongo 2.7.2

I was running MongoDB 2.4 with a replica set which contains 1 primary, 1 secondary and an arbiter. We were using PyMongo 2.6 and MongoEngine 0.8.2. Recently, we performed an upgrade to MongoDB 2.6, ...
1
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0answers
22 views

Is findOne() in mongoDB deprecated

Is findOne() in MongoDB deprecated? I am asking this because when I use findOne() in WebStorm the IDE puts a line through findOne() and gives a message saying findOne() is deprecated and to find ...
1
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0answers
20 views

Mongo is slow when the IOPS reaches 50%

We have an AWS-r3.large system. With 1.5TB data volume dedicated to Mongo. We are still using 2.6.3 (yes, upgrade pending for a while now). The data size is only 550GB. The volume that we have, has ...
1
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0answers
28 views

Why switch? [ReplicationExecutor] another primary seen with election time xxx:1 my election time is yyy:1

On 09-05-16 - 08:41:51 Replica Set elected a new primary. The question why? Here the logs from this time series and without login messages egrep -v 'NETWORK|ACCESS'. On the same OpenStack platform ...
1
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0answers
22 views

Solr with SQL Server or NoSQL

I am working on a POC of using Solr with SQL Server. I have a very complex data model with SQL server which required a bunch of joining and scalar functions to strip some mark up and other stuff. ...
1
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0answers
21 views

Running a query in Mongo Shell vs PyMongo (in Flask) results in extreme slowdown

When prototyping a query I've been using just the Mongo Shell to make sure my aggregation query is working fine: # Default query query = [{ # Supposedly forces MongoDB to initially use ...
1
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0answers
32 views

MongoDB with multi core instance

I have a "large" EC2 instance with 2 cores running MongoDB as part of a Replicaset. Does MongoDB use both cores in parallel by default or do I need to make some configuration change?
1
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0answers
28 views

Mongo indexes question

I have the following aggregation query: db.getCollection('usersongs').aggregate([ {$match: { room: 'someObjId', status: { $in: [ "ended", "skipped" ] } } }, {$group: { ...
1
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0answers
10 views

MongoDB Fails to get TGT

I've setup MongoDB enterprise on CentOS 7 with Kerberos support. Additionally I've setup a Kerberos service on CentOS 7 for the authentication. I know that Kerberos is setup correctly as I now have ...
1
vote
0answers
31 views

Would it be good practice to represent MongoDB ObjectId as a String or a Blob type in SQL Lite (RDMS world)?

All: We have a software application with 1) Web-based component 2) Mobile-based component Our 1) Web-based component uses a) MongoDB as the Database b) ASP.NET C# Our 2) Mobile-based component ...
1
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0answers
37 views

I can't see some databases with even though my user has the “root” role

I installed MongoDB 3.2 and I enabled authentication: security: authorization: enabled I created an admin user with the following command in the terminal: mongo admin --eval ...
1
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0answers
22 views

efficient way to store immutable numeric data

I'm trying to put a bunch of worldwide climate data into some kind of database structure so I can quickly access a collation of all 10 datasets simultaneously with fast indexing and hopefully ...
1
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0answers
16 views

ConfigServersInconsistent:How to correct the inconsistency?

Detected that the one of the config servers is inconsistent with rest two, in a 3 config-server environment. But not sure how to set this right. I have gone through mongodb config servers not in sync ...
1
vote
0answers
58 views

Adding a Mongo Shard decreases the insert performance

For a mobile application which will hold quite some documents, we've chosen Mongo as a database. Let me explain the situation first: Every day, I have a set of documents that needs to be inserted, ...
1
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0answers
17 views

Syncing writes and not deletes - mongoDB

Is it possible to have a secondary instance of mongoDB which syncs all the write operations to the database and not the delete operation? I'm looking for this solution so that I have a backup even if ...
1
vote
0answers
42 views

How to Shard a Mongodb Collection based on String and Date Time Shard Key using Range Based Sharding

I am new to Mongodb,I have to Shard a Collection Based on Integer, String and Date time shard key, I am able to shard a collection using integer shard key. below is the command,I am using for Range ...
1
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0answers
24 views

Security: direct remote access vs webinterface

I need to remotely connect to my (mongoDB) database and I currently allow direct access to the DB server port with user/pw login. I often read that this is generally a bad idea and that one should ...
1
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0answers
75 views

MongoDB replicaSet keep 'syncing to' and only can be connect with shell

Hi I am new with MongoDB 2.6 Replica Set I have three DB service in Docker and DB work in Replica Set It works great I can connect to DB Read,Write in C#,MongoVUE but I didn't know why my db will ...
1
vote
0answers
21 views

MongoDB replCallbackWithGlobalLock-0. What does it mean?

I have a production replica set with 3 members (primary, secondary, arbiter). Almost every day, there's a short downtime where the primary is demoted to secondary for no apparent reason. The replica ...
1
vote
0answers
73 views

mongodump monitoring (with exit codes)

This is how we monitor backups with mongodump. Exit code and mail if not 0. Mailing is reliable in our environment. mongodump -h $RANDOM_SECONDARY -u $BACKUP_USER -p $BACKUP_PASSWD --out ...
1
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0answers
33 views

Performance issue when querying items inside circles

I need to query 300 items among 100,000+ and all of these 300 must be contained inside a set of many circles (hundreds). I am using a MongoDB database and here is a part of my logs: "command": "{ ...
1
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0answers
76 views

admin user creation is giving error in mongodb 3.0

I am trying to create admin user in mongoDB and it's giving me following error. MongoDB 3.0 version is being used. Error : 2015-12-10T15:23:47.065+0000 E QUERY Error: couldn't add user: Could not ...
1
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0answers
36 views

How to use DBRefs to fetch records from multiple collections in MongoDB

I am working on a database for library system. I have a collection called 'books' and another collection called 'publishers'. This is my documents structure in collection 'book'. { "_id" : ...
1
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0answers
32 views

How does defining a MongoDB shard key influence the connectivity between my mongo(s/d)s?

I am trying to test mongoDB sharding, but when following the basic steps in common tutorials, I am facing a CONNECT_ERROR issue that really doesn't make sense to me. I use four machines for this test ...
1
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0answers
179 views

Mongodb Huge Number of Open Connections and Write Locks

We are seeing around 800 open connections to our Mongodb. To clarify our issue: We have 5 different clients who write the data into Mongodb. Each of these clients - write four different type of ...
1
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0answers
45 views

Is there a way of implementing a composite primary key with varying fields in MongoDB?

Here is the information about my development environment: -Mongodb 3.0.0 -Microsoft Visual Studio Professional 2013 -.NET Framework 4.5 We are trying to design some MongoDB collections at work ...
1
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0answers
106 views

MongoDB very poor query performance vs Oracle

I'm a MongoDB noob and trying to import data from an Oracle table. My Oracle table has 1 unique index on a single column, which is an id (a number - primary key). I successfuly imported data to ...
1
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0answers
27 views

what is getmore / cursor batch

In MongoDB world you see often getmore. For example in mongostat. What is that exactly? What would be the analogous term for MySQL/MariaDB or Oracle RDBMS?
1
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0answers
42 views

Identify a blocking process in MongoDB

I have a single MongoDB instance is performing quite badly. I noticed that db.currentOP().inprog.length quite often becomes quite big, sometimes even goes up to 100. When I drill down to the actual ...