Value of variable updated with args.value when calling in multi threading

Hi Members
I am facing one problem.
I have an graphql application in nodejs and acting as api gateway. This graphql application is responsible for fetching data from a third party api. And output of one api is input of another api and return the api response. Another java application executing graphql api and java application is running in multihreading.

As it is running in multithreading, variable is getting updated with the latest value of args.
For example
index.js
const resolvers={
Query:{

customerData:(_, args)=> customer.customerData(_,args)

},
Customer:
{
	id:parent=>customer.id(parent),
	name:parent=>customer.name(parent),	
}

}

Utility.js

exports.typeDefs=gql`
type Query {

customer(traceId: String,offset: Int, limit: Int,customerId:String):[Customer]

}

Customer.js
var instructorEnrollments= async function(_, args){
var traceId=‘Ç’+args.traceId;
var customerId = args.const;
/////Business logic-----------------
}

In multithreading mode, java application used to call 100 request to the graphql server. Problem is value of customerId updated with the value of last call.

For example, I received customerId value as 100, when data fetching is in progress for 100, then new call for 101 arrive, at that time customerId updated with 101.

I want to what is wrong with me… How I solve this problem.
Any help is appreciated.