Questions tagged [mongodb]
All versions of MongoDB - a scalable, high-performance, open source, document-oriented database.
2,304
questions
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12
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How to increase writes (inserts) without reducing oplog window in MongoDB
I have a MongoDB cluster. The cluster is currently writing (mostly inserts) 4k/sec. When I increase the number of inserts from 4k to 5k, I can see oplog window slowly reducing, possibly to 0 if I do ...
-1
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0
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6
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best way to add/delete items in a mongoDB
I have an entity to which there are some children items. Now when i am editing the entity i can either new child or delete old child elements.
for eg: initially let's say there are children A, B, C. ...
-1
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0
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6
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Trying to find "magic combinations" in MongoDB
I have two MongoDB collections in a database named "records". Here's a sample document from the first collection:
course_completions
{
"_id" : NumberInt(12345),
"...
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0
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21
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how many databases can i make on a single mongodb replicaset cluster
I have a mongodb replicaset with 13000 tiny databases ( < 10 Mb )
This is now running on mongodb5.0
I restarted today to set the replicaset name
This is taking for ever
I get lines like
{"t&...
0
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1
answer
17
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how to convert mongodb db.currentOp() into json
I want to create an interface for all running processes in Mongodb
How can I convert mongodb db.currentOp() output into json so that I can access that
The output currently is a BSON string and I ...
0
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1
answer
14
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Increase security of mongodb-based flask/react applications?
this is the first time I use mongodb seriously, and I have a question about best practices when it comes to access.
Say you have a typical mongodb/flask application. The users use the browser (via ...
0
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0
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38
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Which database / search engine for filtering application
I've asked the question on here: https://stackoverflow.com/questions/71819288/mongodb-vs-elasticsearch-indexing-parallel-arrays
But, I didn't get any answer. I believe here it's the right place for ...
0
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1
answer
38
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Better way to store panel data in SQL or NoSQL
I have an Excel of raw panel data (cross sectional + time series) sent to me by customers (I cannot change this). For those not familiar, imagine the gdp time series for each country. I need to ...
-4
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1
answer
21
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MongoDB not logging to log file
mongodb at some point stops logging events in the mongodb.log. the mongod process results up.
version Mongodb 4.4 Replica Set ( PSA )
linux operating system CentOS Linux release 7.9.2009 (Core).
-rw--...
0
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2
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39
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how to get mongodb current featureCompatibilityVersion into a variable with only version
how to get mongodb current featureCompatibilityVersion into a variable with only version
instead of printing like this
db.adminCommand( { getParameter: 1, featureCompatibilityVersion: 1 } )
{ "...
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12
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Why do queries get stuck on single shard of mongodb cluster and disappear when i stepdown
I have a 15 shard mongodb PSS cluster with huge traffic approx 1TB per shard data
I have seen that the queries get piled up on some shards which I find using db.currentOp on the mongos server.
I do ...
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62
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Unable to start mongod service in 5.0 and connect to mongoshell
Unable to start mongod service in 5.0 and connect to mongo shell:
systemctl start mongod.service and tail the log, I see that process is getting killed.
Not sure what has changed in 5.0, I tried ...
0
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1
answer
41
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Do I need to split a 1.5 billion document database into several in a standalone MongoDB?
There will be total 1.5 billion documents in nearly 100 collections in one database. Need I to separate this database into several? Is there a performance limitation for a single database when the ...
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20
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Errors in mongos after changing config server
Replaced config server by https://www.mongodb.com/docs/v4.4/tutorial/replace-config-server/, now we are seeing problems from mongos
server. It can be seen from the log that the mongos server tries to ...
0
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0
answers
10
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Attempting to remove Object from a Array where an attribute matches the value passed through the query
I am attempting to write a query that removes the element from the array based on the messageId associated with said object in the array. This is submitted through curl hence the formatting, I've ...
0
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1
answer
39
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MongoDB: slow removeShard
I have a MongoDB cluster with 9 nodes (3 shards, 3 nodes each). I'm now removing one shard, but the process itself is running extremely slow. Each node of the shard being deleted stores ~400Gb of data,...
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21
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questions related to mongodb timestamp and mongodump with oplog
mongodb replica set is PSS:
d1node - SECONDARY
d2node - PRIMARY
d3node - RECOVERING
mongo ... --host=d3node --port =1234
mongo1234:RECOVERING> rs.printSlaveReplicationInfo()
source: d1node:...
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0
answers
27
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mongod replica set state change on secondary node when resyncing from healthy node in PSS architecture
In a PSS architecture ?
Question1 Are there a possibilities to get estimation of replication state change from ?
<STARTUP> To <RECOVERING>
<STARTUP> or <RECOVERING> To <...
0
votes
1
answer
35
views
mongodb rs.status to list status of the node
the moment I use sed to replace node and port the quotes are removed and hence syntax error.
Is there a different solution to this syntax error.
NODE=abcd
PORT=1234
mongo_cmd="mongo admin -u $...
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0
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40
views
What could cause "spikes" of slow queries in MongoDB?
I operate a fairly busy HTTP backend over a MongoDB cluster consisting of a primary instance and two secondary nodes. Most commands and queries are served by the primary DB node, and on the surface, ...
0
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24
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The amount of mongodb log is generated excessively
I’m using mongodb 3.6.8 for log collection.
I want to get only slow query and error level logs.
I set profilinglevel to (1, 5000), loglevel to 1 for queries only and 0 for everything else.
However, ...
0
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0
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13
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Older version of Mongo compass gives exact collection while new one does not
On version 1.29.4 of Mongo Compass I am presented with a document count of collections as soon as I click on a DB along with other overall stats. But on version 1.30.1 I only get a figure like 30 M or ...
0
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1
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19
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What is this mongo index with field._ref.$id_1
I have a document in a Mongo collection which has an index as follows:
field._ref.$id_1
This is tripping up a new database driver we're planning on using - it doesn't seem to understand this format, ...
1
vote
1
answer
64
views
MongoDB: specify a default sort order?
I'm using MongoDB v5.
Most of my collections have temporal data, so each document has at least one datetime. Naturally I'm generally most interested in the most recent data, but by default mongo ...
0
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0
answers
36
views
MongoDB vs PostGIS for geospatial data
My main concern is that I was I/O and bounding circle queries to be lightning fast. Does MongoDB spatial offer any advantages over POSTgis?
0
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1
answer
30
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Transition from MongoDB Time Series Collections to InfluxDB
With version 5.0 MongoDB's specialized Time Series Collections were introduced to deal with such data. As I already stored some sensor meta data (configuration, specification ...) in MongoDB, I ...
1
vote
1
answer
27
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Storing and Querying User Defined Data
I'm working on a system where each user defines a strongly typed definition of data they can store, consisting of classes with specified fields. Embedded classes are also supported. My first instinct ...
1
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0
answers
166
views
Using mongodump to dump all databases but exclude a collection
The mongodump tool seems not to support the option --excludeCollection=someCollection when not specifying the --db someDb option. We would like to dump just all databases without explicitly specifying ...
0
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0
answers
21
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Does time cost of insert depend on the collection's size in MongoDB?
I've noticed that the inserts on my MongoDB are getting slower as the collection grows. The collection doesn't have any indexes.
I wasn't able to find anything about this topic in the official ...
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0
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41
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Mongo db oplog size is much bigger than maxSize and filling up disk
Running Mongo 4.4.8 on Ubuntu Focal Docker with the following start up command:
mongod --keyFile /replica.key --replSet rs0 --oplogSize 991 --oplogMinRetentionHours 0.25 --wiredTigerCacheSizeGB 5 --...
1
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3
answers
75
views
SQL or/with Nosql
I am designing a mobile app with basic functionality such as sign-up, Auth, posts, real time messages etc. I think for this kind of work Nosql should work better. But over a long period of time I want ...
0
votes
1
answer
105
views
Can't restore `mongodump` archivegz file with `mongorestore`
I generated a MongoDB dump file with the archivegz format. When I try to restore it with the mongorestore command, it won't restore.
The command for restore
mongorestore --gzip --archive="./...
0
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0
answers
13
views
MongoDB datasize in replicaset dropped suddenly
We are using MongoDB 4.2 which has lot of collections and indexes. Yesterday we faced issue in which our mongodb started degraded performance where query which were taking few ms started taking ...
1
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0
answers
17
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Match, group and get percent of documents by a specific date in MongoDb
An exemple fo my data
{
"_id" : ObjectId("61cda8dabc3c3e648af34775"),
"icone" : [
"pomme",
"mangue"
],
"is_good&...
0
votes
3
answers
79
views
Should I use SQL vs NoSQL for files catalog? [closed]
I will be implementing a system which will be storing 250 Million files/user. I want to perform list operations from the client side, where the client application will be fetching 100 records at a ...
1
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0
answers
22
views
How to structure MongoDB for multi-field query?
Right now, we have a Post collection that the users query based on their locale. The collection looks like this:
Post {
userId: String
text: String
locale: String
...
...
}
And a User ...
0
votes
1
answer
164
views
Chat schema for PostgreSQL and MongoDB
I'm designing a schema for a very large chat app. I had problems with NoSQL databases such as MongoDB and Cassandra. Some part of the schema is relational i decided to use both PostgreSQL and MongoDB ...
0
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0
answers
44
views
MongoDB Stock Data Schema design advice
I am thinking of two structures, I don't know which is better or is there are better structure? Im seeking your advise
Normal structure with code as id and time as string
{
"_id": &...
-1
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1
answer
29
views
Creating a database with authentication enabled on mongodb
I can create a database using a specific role for my "user1".
I have tested and a user "test1" can not create a database in the mode authorization enabled.
How works the creation ...
0
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0
answers
14
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MongoDB : How to set persisent mongos and shard configuration
I have a test environment running on Windows 10 as follows :
A replica set "rs0" with 3 nodes : MONGO2, MONGO3, MONGOARB1 each running on port 27017.
A config server in a replicaSet "...
-1
votes
1
answer
109
views
Joining in NoSQL to get chat messages for a user
In my chat app i have private / group chats and I need to get messages for a user.
Let me first explain the whole system.
Messages:
// group message
{
id: 1,
text: 'hello',
chat_id: 'AjK954_e5iP'...
1
vote
1
answer
164
views
How to count number of occurrences of each key in a MongoDB collection efficiently (one pass?)?
I'm a MongoDB noob and I have a MongoDB collection with millions of documents, each with tens of keys (average ~ 60, large variance) from a set of around 100. I'd like to get a count of each key ...
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0
answers
25
views
Mongodb search and sort
My scenario is to search and then sort according to date for this I have made my schema like this
{
section:String,
name:String,(always lowercase)
updated_at:Date.now
...many more fields
}
...
0
votes
1
answer
47
views
Update data type from integer to decimal128 for all document having nest array in mongo db
Had a JSON structure which is having nested array and need to update all data type for that json structure
[
{
student: [
{
name: {
firstName: "Rahul",
...
0
votes
0
answers
20
views
How to enable Mongodb data encryption at rest with kubernetes operator
There is documentation for how to secure deployment using TLS with Kubernetes operator in MongoDB. But no such docs there for data encryption at rest. is it enabled by default or how to enable via ...
1
vote
1
answer
27
views
Cannot connect to MongoDB router in sharded cluster
I followed this guide on how to setup a sharded MongoDB cluster with Docker containers.
It all seemed to work as it should because there were no error messages in the logs and the sh.status() command ...
0
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0
answers
315
views
Add an arbiter to mongodb ReplicaSet failed
I am new to mongodb and this is my second post in order to build a test cluster and gain knowledge at the same time. I have a 3 nodes cluster holding server MONGO2, MONGO3 and MONGOARB1. MONGO2 and ...
0
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1
answer
56
views
update datatype field int to decimal128 in mongo db in nested json structure
Hi have tried to updated nested field datatype
db.test.find().forEach(function(data){
data.age = NumberDecimal(data.age);
data.phone.$.mob = NumberDecimal(data.phone.$.mob);
db.test.updateOne({_id:...
0
votes
1
answer
42
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What could be the better Database to make a book reader one or more books? [closed]
I am thinking about a personal book reading mobile app project. I have a total of 13 different books. Each book has 10 chapters and each chapter has its own content. It should have the feature of ...
1
vote
4
answers
1k
views
MongoDB : How to Convert a Standalone to a Replica Set
I am new to MongoDB and searching for several hours how to promote my mongo standalone instance into a replicaset. My actual environnement is one ubuntu server
root@UMONGO1:/home/msc# lsb_release -a
...