Questions tagged [mongodb]

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

Filter by
Sorted by
Tagged with
0
votes
1answer
473 views

how mongo db does locking for updates/inserts?

I have many data for each user that with write heavy and many for each separate users that there is not any relation between user's data; so there is two options for me to store them: 1. keep all user'...
2
votes
1answer
1k views

Merge 2 mongodb databases

Our team have hard time. Situation: API went down, all infrastructure (API + MongoDB) terminated. We restore API and mongodb (data restored from backup). After a while (let's say 1 day) we discovered ...
1
vote
1answer
698 views

Connection string for connecting mongo database with SSL enabled

Am facing some below problem in my mongodb replication environment I have 3 replica set environment with SSL enabled and ssl mode as preferSSL 3 servers has 3 different Key file with common CA file ...
1
vote
1answer
2k views

duplicate key error index MongoDB

I have rocket.chat server connected to LDAP. When one of users try logging to their account he get logged to someone other account, it's probably because indexes. My logs look like this: [...
0
votes
2answers
3k views

join two collections with group by and sum in Mongodb

i have this two collection and i want to join, after this I want to sum the value of TotalPrice each orderdate : some line of my two collections the first collection date : {"Id_Date":1,"...
1
vote
1answer
19 views

Efficient way to get data for each date range intervals using single query | MongoDB

I have collections about products and purchases. I need to get statistics for each time interval. I need following: Name quantity (date 1 range) quantity (date 2 range) Name One 500 400 Name Two ...
0
votes
1answer
681 views

mongodb crashed with the error or permission denied

Our mongodb server was running for the last two months without any error. Suddenly it crashed and below is the log. 2017-08-11T13:41:41.320+0100 E STORAGE [thread1] WiredTiger (13) [1502455301:...
1
vote
2answers
569 views

mongo primary is showing behind the primary?

mongo primary is showing behind the primary ?? Its increasing as time passes . Please suggest ? monRepl:PRIMARY> rs.printSlaveReplicationInfo() source: xxxxxx:27017 syncedTo: Mon Apr 27 2015 ...
5
votes
2answers
3k views

How do long string field names affect MongoDB database size?

I am using MongoDB and the names of my fields are strings with 10-20 characters. A typical document consists of 30.000 columns filled mostly with floats, like 1.2, 10.5, 2.55. It's size is 1MB. Do ...
1
vote
1answer
45 views

MongoDB + Compass exporting strings and numbers “columns” with value of 1 as “true”(boolean) and 2 or null as “false” to CSV

When I export my MongoDB collection to a CSV, the String and Number "column" data types values are converted to "true" for 1 and "false" for 2 and null - how do I retain ...
0
votes
0answers
21 views

Mongo Atlas connection error type=UNKNOWN, state=CONNECTING

Yesterday I've seen some strange behavior that my application can't connect to Atlas. This has never happened before for about 1 year, and there was no application deploying going on. The error that ...
3
votes
1answer
389 views

Mongo WriteConflictException in log file

I am experiencing ALOT of this WriteConflictException in my mongo log file, this does not seem to affect the application, because I am not seeing any special errors and everything seems to work fine. ...
0
votes
1answer
2k views

MongoDB 3.6 crashed due to invariant() failure

MongoDB crashed twice in 6 hours today due to invariant() failure. We have been using MongoDB 3.6.3 for more than a year now, but this is the first time that we saw this issue. The extract from the ...
2
votes
1answer
728 views

MongoDB: Mongoimport server selection error , connection refused, too many files open

Trying to insert several JSON files to MongoDB collections using shell script as following, #!/bin/bash NUM=50000 for ((i=o;i<NUM;i++)) do mongoimport --host localhost --port 27018 -u 'admin' -...
1
vote
1answer
677 views

MongoDB 3.6 create local Shard db without replica

This is what I want to do: Create a Config Server Create 2 Shard Create a Mongos Router I don't want to replicate my data using replica set, I want to simulate that each shard has only a part of ...
0
votes
0answers
27 views

MongoDB 3.6.21 crash and not reIndex

I try to reIndex() my collection but not working and It removed all indexes. I checked mongod.log and see: 2021-01-18T05:56:59.492-0600 E STORAGE [conn1] WiredTiger error (5) [1610971019:492802][...
1
vote
1answer
328 views

MongoDB specifying shard key and sharding strategy

What is the syntax to state that a collection is to be sharded as location based, while using the range based sharding strategy. I know you have to use the the sh.shardCollection() command, but what ...
0
votes
1answer
134 views

UserNotFound mongodb error

I know there are lot of articles with the same issue and I explored every other article trying everything and still this error persists. Here are the steps I followed: use admin. created an admin ...
1
vote
2answers
1k views

Copy Specific Columns from DB 1 To DB 2 on MongoDB

I have Two Instance of Node JS server which is handled By NGINX. First server is connect with MongoDB First Server i.e mongoose.connect('mongodb://127.0.0.1/db_primary', { useMongoClient: true }); ...
1
vote
1answer
1k views

Mongodb: Determining shard key strategy on compound index

I have a collection with 170 millions+ documents and it is only going to increase. The size of the collection is not that huge, currently around 70 GB. The collection has two fields indexed on: {...
0
votes
0answers
6 views

Rotating MongoDB Replica Set Internal Auth Certificate Authority

I noticed that for replica set internal authentication all MongoDB instances must have certificates signed by the same CA. (Source) Rotating individual certificates is sensible, but if I wanted to ...
5
votes
1answer
2k views

Mongodb crash after WiredTiger Cannot allocate memory error

I am using MongoDB (3.2.6) as storage for my application and since a couple of weeks MongoDB started to crash usually every 1 or 2 weeks. The crash seems to come from an issue during WiredTiger memory ...
0
votes
1answer
1k views

Could not add Replica Set to MongoDB Shard

I want to deploy a MongoDB Cluster for testing on 3 Virtual Machines using Docker. On the first Virtual Machine I have the Router Instance and a Replica Set of the 3 Config Servers. The second ...
6
votes
1answer
7k views

Restore mongoDB by --repair and WiredTiger

We accidentally deleted the directory rm -rf /data/db which was our MongoDB path, and thanks to extundelete, we recovered it and got the directory /data/db. Here are our files in the directory, and ...
0
votes
1answer
1k views

Mongo DB sharded cluster fails when one shard is down

I am using Mongo Sharded cluster with two shards. There was an issue on my one shard and and it was down for around 30 minutes. It stopped my writes to other shards also. Logically if one shard is ...
7
votes
4answers
24k views

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. https://stackoverflow.com/questions/12780258/insert-mongodb-using-vb-net/12796593#12796593 After ...
0
votes
0answers
5 views

MongoDB numerous slow query logs with zero keysExamined

using a MongoDB version 3.6 Replica Set, I am wondering why a query that resulted in no key examination and document examination would result in being slow. For example, I have numerous slow query ...
0
votes
1answer
13k views

MongoDB - Mongoose query findOneAndUpdate() doesn't update/duplicates the DB

I am trying to save and update (upsert: true - creates the object if it doesn't exist) the result of the Web Api which contains multiple arrays of data to populate the stock chart. Each time I enter a ...
1
vote
0answers
11 views

Want to add more options on User database schema to premade users

So I have this User MongoDB Schema, and I want to add other options to it. but if I do then the current users have to create a NEW Account to see the new changes. is there a way to update all the ...
0
votes
1answer
27 views

show users doesn't show anything, although it has users

So I'm using MongoDB, and this is my first time dealing with a VPS on my own, I'm trying to view the users i have on the website. I know for a fact that there are signed up users, because I can signup ...
2
votes
1answer
169 views

MONGOS uselessly scanning indexed documents when counting on shards

I have a simple collection with 40M documents distributed over 2 shards. The documents contain a field named COUNTRY with a sparse index on it. db.contacts.count({ "COUNTRY": "US" }) I am trying to ...
1
vote
1answer
5k views

Aggregation vs Cursor For Reshaping MongoDB Documents

I'm looking to reshape the Documents in one of my collections, and have found two ways to do it, but need guidance. For simplicity, say I have a collection, "myColl", and I need to reshape Documents ...
0
votes
1answer
1k views

Clean up orphaned documents in MongoDB

Currently we have a 4 shard cluster Can you give me the procedure to check the orphaned documents in our cluster And can you provide me the procedure to delete the orphaned documents in the cluster ...
4
votes
3answers
9k views

Close MongoDB dead connections

I have a script that connects to my local mongos and do some processing. However, during the process, I encountered many cursor timeout exceptions, which (I suspected) left many dead connections on my ...
2
votes
1answer
3k views

Read concern level of majority error while upgrading Sharded Cluster from 3.2 to 3.4

I have upgraded MongodDB sharded cluster having two replica sets from 3.2 to 3.4. Current storage engine is MMAPv1. After successfully upgrading all the secondary, primary, config server and mongos to ...
0
votes
0answers
12 views

Why is my mongodb setup not reaching EBS IOPS limit?

I have an application that is constantly pumping data to MongoDB. MongoDB instance is running with 2-replicas, each with 3TB gp2 EBS volume. As you can see on the following graph of irate(...
0
votes
1answer
352 views

MongoDB 4.2 using change streams with read concern majority disabled in a PSA deployment

I currently run a PSA (Primary, Secondary, Arbiter) deployment and thous only have two databearing nodes. In case of a databearing node going down, read concern majority prevented the change stream to ...
1
vote
1answer
728 views

Replication priority

I have two MongoDB instances running on two servers (instance1 and instance2) and they are configured as a replica set. Instance1 is the primary and instance2 is the secondary. When instance1 was ...
1
vote
1answer
53 views

Not able to connect to Mongodb vie mongo shell

I am no able to connect to mongodb via mongo shell. command: sudo mongo --tls --tlsCertificateKeyFile server.pem --tlsCAFile CA_INTERMEDIATE --host "mongodb://xxx:xxx@some-url:27020/data_base?ssl=...
0
votes
1answer
3k views

Insert on duplicate key update using MongoDB

Can somebody tell me how I should build MongoDB "updateOne" query to get analog of the following SQL query: INSERT INTO `collection` (`hash`, `total`, `base_fare`) VALUES ('aaa', 200, 150) ON ...
3
votes
1answer
3k views

How to improve performance of this aggregate query? [closed]

I have the following tables in MongoDB: Users table (count 200+ users): { "_id" : ObjectId("56dd6204ce47a3c44d8b4567"), "u_role" : "1", "u_fname" : "dsfsd", "u_lname" : "dsfdsf", "u_email" : "dsfds@...
0
votes
1answer
511 views

High CPU usage on fresh new install of MongoDB

I read a lot of post about high CPU usage of Mongo but almost all relates to queries. I just did a fresh install of MongoDB 4. I have no other databases than the default one. As soon as I start the ...
3
votes
2answers
8k 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 ...
1
vote
1answer
770 views

Service Discovery for MongoDB

What is the best way of implement a Service Discovery like ETCD for use in a mongodb cluster? I wish have, 1 master for HA and two nodes, in my master i have a static ip, but nodes maybe can changes ...
0
votes
2answers
405 views

Mongodb shard balancing failed

Data balancing fails on Mongo cluster with 1 mongos and 3 mongod instances. All the data for the collection fs.chunks stays in the same shard with the following error. Env: Ubuntu- AWS m3.large, ...
0
votes
1answer
117 views

Mongoimport monitoring successfully entered row/data

How to monitor mongoimport hass successfully saved data into our database? Let's say I have 20,000 rows of CSV data. When I press the button to start mongoimport, the user will see the progress. Is ...
2
votes
1answer
194 views

MongoDB stale replication, odd timestamp after data flush

Right before my secondary goes stale, it first has this written in the log: 2017-04-25T06:48:02.991+0000 I STORAGE [DataFileSync] flushing mmaps took 13530ms for 3150 files Then it gives me a odd ...
2
votes
2answers
3k views

How do i copy my mongodb data-files to mongodb server

I actually copied above two files in MongoDB's data folder which is default in windows machine (C:\data\db ). But when I start mongo shell and type show dbs, it will not show my database. Steps I ...
0
votes
2answers
50 views

MongoDB covered query needs to fetch and examine documents when exists operator is used

I need to execute following query on mongo db: db.testCollection.find({ dataType: { $exists: true } }, { _id: 0, date: 1 }) .sort({ date: -1 }) .limit(1) so basically only I need to do is to ...
0
votes
1answer
41 views

Read Concern Majority when majority nodes are down

I have a 6 node replica set (all of them data bearing) with 5 voting members. If I lose 3 voting members, I will not have a majority voting members and my replica set will become read-only. In this ...

1 2
3
4 5
44