Why is mongodb atlas using 25 connections per 1 active client - mongodb

Question

I am currently connecting to mongodb atlas using the following code
exports.connectToMongoose = async() =>{
try{
const result = await mongoose.connect(process.env.mongodbURL,{
useNewUrlParser: true,
useUnifiedTopology: true,
useCreateIndex:true,
useFindAndModify:false
})
}
const connectionResult = await mongooseConnection.connectToMongoose();
Although I am the only one user logged In . I can see that mongodb atlas is using 25 connections from the 500 available. Why does each client uses 25 connections and does that mean the mongodb atlas can only handle 20 concurrent clients

Answer 1

db.serverStatus().connections This may be helpful to get the total connections from your clients to your server or primary node in your cluster

Answer 2

Are you sure thats from your one connection? Each Mongo server will have multiple connections from other servers in the cluster, such as Mongos, and Arbiters, as well as health checks and monitoring.
Found this a while back that gives a snapshot of the connections and the IPs they came from.. if this helps
db.currentOp(true).inprog.reduce((accumulator, connection) => {
ipaddress = connection.client ? connection.client.split(":")[0] : "Internal";
if(typeof accumulator[ipaddress] == "undefined"){
accumulator[ipaddress]= {"active":0, "inactive":0};
}
if(connection.active==true) {
accumulator[ipaddress]["active"] = (accumulator[ipaddress]["active"] || 0) + 1;
accumulator["ACTIVE"] = (accumulator["ACTIVE"] || 0 ) +1;
} else {
accumulator[ipaddress]["inactive"] = (accumulator[ipaddress]["inactive"] || 0) + 1;
accumulator["INACTIVE"] = (accumulator["INACTIVE"] || 0 ) +1;
}
accumulator["TOTAL_CONNECTION_COUNT"]++;
return accumulator;
},
{ TOTAL_CONNECTION_COUNT: 0 }
)