Questions tagged [mongodb]
All versions of MongoDB - a scalable, high-performance, open source, document-oriented database.
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15 views
MongoDB: why does a DB with 0 connections still get “commands” and “getMores”?
I'm in the process of migrating an old mongoDB database.
Before shutting down the old one, I want to make sure nothing is still writing to it or reading from it. Looking at Compose's MongoDB classic ...
0
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0answers
20 views
Schema for workout history in MongoDb [on hold]
I am creating an application where there will be posted workouts and users can record scores to these workouts.
In the future, these workouts may be repeated, and I'd like to be able to compare ...
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0answers
22 views
How to delete a user in MongoDB 3.6
I was in trouble with deleting the users in mongodb3.6.
I created a user with:
db.createUser({ user: "username" , pwd: "password", roles: ["root"]})
And I deleted it with:
db.dropUser("username")
...
0
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1answer
14 views
Monitor mongodb replica sets [closed]
In my cluster environment i have two shard replica set and 1 config replica sets is configured ,When i ran the command db.stats(); why it always shows the shard replica sets data?
i need to collect ...
0
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1answer
23 views
What is a good practice for storing unstructured tables as a field in mongodb
Context:
I am developing an application that requires handling tables that do not necessarily have an uniform structure (eg. different/extra columns). Those unstructured files also need to be grouped ...
1
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1answer
42 views
MongoDB replica set quorum config (network partitioning behaviour)
I use mongodb 4.0.10. I want to establish a quorum for a cluster of one primary node and two secondary nodes as written here. When the number of nodes is less than the quorum, 3 nodes in my case, ...
1
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1answer
24 views
How to shutdown mongodb sharded cluster temporary
I have setup mongodb sharded cluster with following topology
3x3 shards (each have 2 replica sets)
1x3 config server replica cluster
2 mongos routers
I want to shutdown whole cluster temporary ...
0
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1answer
19 views
Slow performance of query with $and & $or operators
My query with $and, $or operators is performing poorly. Even though I've built a compound index on all three fields that are specified in my query criteria, the query does a complete collection scan. ...
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0answers
11 views
Coverting MongoDB timestamp to postgres [closed]
I have an export of MongoDB data that includes time stamp such as
lastRunEnd = 1549036780246
When I select this value as
select to_timestamp (('1549036780246'::double precision)) as lastRunEnd
I ...
0
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1answer
16 views
Spliting changes in separate collection/table or not?
I am using MongoDB to store products, user accounts and stuff on my server and so far it's going nice.
But now I'm stuck deciding how do I "split" things apart, like:
I have a database where ...
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0answers
25 views
Lots of CLOSE_WAIT and SYN_RECV Captured From ARBITERS With 'netstat'
I have a cluster with 7 nodes: 1 primary, 3 secondary and 3 arbiters.
I also have several more app servers which communicate with the cluster.
Recently, we've received lots of errors in the mongodb ...
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1answer
95 views
Can't solve MongoParseError: Invalid connection string
I'm not able to solve MongoParseError.
First my I tried this
mongoose.connect(`mongodb://${process.env.DB_USER}:${process.env.DB_PASSWORD}@db:27017/${process.env.DB_NAME}`, {useNewUrlParser: true});
...
-2
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1answer
15 views
Please guide me to change 1 node standlone to 2 node 1 arbiter Replicate Set [closed]
Please guide me to change 1 node standlone (have data) to 2 node 1 arbiter Replicate Set
1
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1answer
37 views
Is MongoDB secondary index size affected by primary key size?
If I understand correctly, secondary index leaf nodes in MySQL InnoDB engine hold the table primary key value (at least for a unique index).
Thus, looking up a value in the secondary index results ...
1
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0answers
19 views
MongoDB Fails due to permission error even though its setup
Attempting to start my MongoDB server using service mongod start fails for the reason: exception in initAndListen: IllegalOperation: Attempted to create a lock file on a read-only directory: /var/lib/...
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0answers
18 views
compund MongoDB index with _id
I have database with few fields:
_id, field0, field1, field2, field3, field4, field5..
I created index on as follows:
db.usertable.createIndex( { _id: 1, field1:1} )
The expected that a query ...
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0answers
15 views
MongoDB Atlas scaling with AWS regions [on hold]
I have 6 EC21) instances on different regions on AWS.
I have one MongoDB server on MongoDB Atlas (AWS)2).
I am having latency issue while updating data to the database.
What is the best way to ...
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0answers
13 views
Is it recommended to monthly planned restart MongoDB production server to clean non-mapped virtual memory?
We have a replica set of production mongoDB 3.6.10 , large volume of 5.5 TB , over 10,000 connections anytime , applications read both from primary and secondary servers , we see almost every month a ...
1
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1answer
36 views
Is it possible to move mongodb indexes to another file system?
Is it possible to separate MongoDB files location so the indexes are on another file system?
In the example below, I have database with 1.5TB of data + indexes of 330GB.
I have a very fast storage ...
0
votes
1answer
13 views
distinct values from multiple fields in array
I have a similar mongodb collection:
[{
"country": "France",
"exchange": {
export: [{
resource: 'MILK',
origin: ['Toulouse', 'Bordeaux']
}]
...
0
votes
1answer
17 views
Is mongodb upsert the right option for write intensive use case?
I'm designing a data model for a transactional use case which is write intensive. The write load would be 900 - 1,600 Transactions Per Second (TPS) which would account for 30 million Inserts/Updates ...
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2answers
22 views
mongodb schema design advice
I have a users index which has fields like id, email, password, etc. A user can see all other users except the ones who had blocked him. I want to design a database schema for this problem.
So I'm ...
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0answers
26 views
Mongodb Replica Set Collection Has Different Document Count
I've created a new 3 node replica set and rsync'ed data from an existing mongo database for initial population. The secondary nodes went into STARTUP2 mode and seemed to successfully sync from the ...
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0answers
15 views
is it possible to make multiple mongo routers connected to just one shard on a mongoDB shard cluster?
I'd like to make a mongo cluster with multiple mongo routers(mongos) with just one shard(mongod) like thses figures.
So I made two mongo routers named 'mongorouter-1', 'mongorouter-2',
and also ...
1
vote
1answer
18 views
MongoDB query choosing the wrong index in winning plan, Though in executionTimeMillisEstimate as lower for the other index?
MongoDB Query chooses the wrong index in the winning plan. I have two indexes for the same field, one is a single field index and a Compound index with another field.
Eg.
Field name: Field1, ...
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1answer
72 views
can't update user password on Mongodb 4.0.5 (Use of SCRAM-SHA-256 requires undigested passwords)
I'm trying to update a password from a user, using changeUserPassword(), and I just receive the following message:
Error: Updating user failed: Use of SCRAM-SHA-256 requires undigested passwords
&...
1
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0answers
15 views
Mongodb throwing an error when I run the query to record last position from oplog
I am getting an error when I run the query in the secondary member to record the last position from the oplog.
below is the query.
db.oplog.rs.find().sort({$natural:-1}).limit(1).next().ts
and the ...
0
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1answer
22 views
Why a query is not covered when using a range operator on documents?
I have created the following 1000 documents:
for(i=0;i<1000;i++){db.doc.insert({"doc":{"k1":"v_"+i,"k2":i},"scal":i})}
So a document looks like this:
var d1 = db.doc.findOne()
{
"_id" : ...
0
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0answers
43 views
Mongodb return Error : $cursor stage :: caused by :: operation was interrupted
In recently, i meet a problem with mongodb. After i surveyed on google, there is no good result unfortunately. So i really wish anyone could answer it.
As title, there is a kind of error message in ...
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0answers
22 views
Mongodb - Security weakness while using --authenticationDatabase admin? [duplicate]
I was trying to create a new Mongodb instance based on my old Mongo Database. In my current DB I have an user and password configured. So, I can access my database using:
$ mongo --host $MONGO_HOST -...
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0answers
15 views
MongoDB / PHP - How to change data type for every occurrence of field in a document
I'm trying to learn how to use MongoDB with PHP. I Have built a web application that loads data from database etc. The issue I am having is that when I import my data from a .CSV using MongoDB Compass,...
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0answers
12 views
MongoDB user password changed for already open connection
We're introducing this new password management infrastructure that changes passwords every X days, but there're these existing implementations in place that use singleton repositories, so once a ...
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0answers
13 views
mongodb after restoring replica-set from backup the primary is not master
after recovering replica-set from a snapshot (for testing)
when I run commands on the primary I got error
not master and slaveOk=false
does primary not equal to master?
I got this output for the ...
0
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1answer
31 views
Exception during recovery in mongo
I tried to recover from a sudden shutdown of mongo, but I am experiencing some problems. Here is the log file
***** SERVER RESTARTED *****
Thu Apr 25 01:09:17 [initandlisten] MongoDB starting : pid=...
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1answer
11 views
mongoDB: Limit user to find documents only by ObjectId
I'm using mongoDB version 4.0.9 for various things. One of them is storing and retrieving files in mongoDB via GridFS. For that purpose, I have created a role/user in mongo with the privileges "...
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0answers
10 views
Mongo DB sharding concept of read/write [closed]
I am trying to set up mongodb sharding and almost done.
1. completed 1 config replicaSet
2. completed 1 shardsvr replicaSet
3. multiple mongos routers connected to config and shardsvr also done
I ...
-1
votes
1answer
43 views
What are the pros and cons of having more data-bearing members in a MongoDB replica set? [closed]
A 3 member replica set has the same fault tolerance if all 3 members contain a copy of the data or if one is an arbiter so why would I ever want all 3 members to have a copy of the data?
What is a ...
1
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1answer
13 views
Mongo DB multiple replicaset
I am trying to create multiple mongod instances on windows .
I run on 2 ports [27017,27020] with replSet ["ReplSet1","ReplSet2"].
first instance 27017#ReplSet1 is OK. But the second instance 27020 ...
0
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1answer
17 views
Is it possible to retrieve a history of the remote connections to the MongoDB including the IP addresses and the executed commands?
For some reasons I disabled the user access control and somehow all collections have been wiped out. So I want an activity log to find out how this happened
I need a list like this:
| Date/Time ...
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1answer
19 views
Why does a query on a sparse index perform much faster than a query on a partial index in MongoDB?
I created a sparse index in my MongoDB Atlas like so:
db.detection_events.createIndex({"emp_id": 1}, {sparse: true})
When I performed this operation:
db.detection_events.count({"emp_id": {$exists: ...
1
vote
1answer
35 views
Writing MongoDB logs to a remote logging server
I am trying to forward MongoDB logs from several remote servers to a central logging server. To do this, I changed my mongod.conf files to use syslog like so:
systemLog:
destination: syslog
...
0
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0answers
16 views
mongodb auto index future collections, big json size, correct structure?
We are going to index some data in mongodb (probbably), from some api calls sending json data ~10MB size, splited data in dates.
Since the data is large, I think it's better to split the result in ...
1
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1answer
26 views
My MongoDB Atlas Operations graph has doubled in the last few hours. How do I go about debugging this?
I noticed this graph in my MongoDB Atlas dashboard:
I'm not sure what is causing the increased Disk IOPS and Operations counts... Can I use the oplog to figure out what is causing this massive ...
0
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1answer
32 views
optimized query mongo find
I want to fetch all data from a collection. Since running just find({}) crashes the mongo container (the liveness probe seams to fail because k8s reboot the container), I ask myself if using skip/...
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0answers
41 views
How to choose database for scalable chat systems? [closed]
I have made a chat application where for now I am storing complete history of chat of all the users.
I am using django as backend and postgres as the database. I am nearing 100k daily active users ...
0
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1answer
23 views
MongoDB - Does WiredTiger benefit from virtual cpus cores the same way it does with physical cores?
According to https://docs.mongodb.com/manual/administration/production-notes/#id5 The WiredTiger storage engine is multithreaded and can take advantage of additional CPU cores.
We will be running ...
1
vote
1answer
27 views
Why $group is very slow in aggregation and how can faster it in MongoDB [closed]
My query is taking ~3 seconds to execute with the $group stage, How can I faster this?
My query is:
db.getCollection('employee_data').aggregate([
{ $match: //Filter
},
{
$group:
{
...
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0answers
44 views
Converting MySql Schema to MongoDB (Mongoose)
I am trying to convert MySql schema to MongoDB. I do understand how to make a reference to Users Table - UserId. My question is how to make a reference to Symbols Table - Symbol ? Here you will find ...
1
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2answers
49 views
Can sharding help in this scenario? [closed]
I will have around 600 GB of data in single table with multiple columns in MySQL. Basically this table will store user events from application.
Indexes are there on required columns.
Question: If I ...
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0answers
19 views
Error: No primary detected for replcaset
We have a Mongo cluster with 4 shards. Each shard with 3 nodes (Primary, Secondary, Arbiter). (rs1,rs2,rs3,rs4) - config server
rs1 shard completely down, so we rebuilt the rs1 with backup we have ...
