CODEWITHSUNDEEP
node.jsexpressworker
Abrar Hossain
Abrar Hossain

Reputation: 2702

Handling Response on a Worker Process in NodeJs

I am trying to design a service following the Command Query Responsibility Segregation Pattern (CQRS) in NodeJs. To handle segregation, I am taking the following approach:

  1. Create separate workers for querying and executing commands
  2. Expose them using a REST API

The REST API has been designed with ExpressJs. All endpoints starting with 'update', 'create' and 'delete' keywords are treated as commands; all endpoints with 'get' or 'find' are treated as queries.

When a request reaches its designated handler, one of the following occurs:

  1. If its a command, a response is sent immediately after delegating the task to worker process; other services are notified by generating appropriate events when the master process receives a completion message from the worker.

  2. If its a query, the response is handled by a designated worker that can use a reference of the database connection passed on as arguments to fetch and send the query result.

For (2) above, I am trying to create a mechanism that somehow "passes" the response object to the worker which, can then complete the request. Can this be done by "cloning" the response object and passing it as plain arguments? If not, what is the preferred way of achieving this?

Upvotes: 1

Views: 626

Answers (1)

nbwoodward
nbwoodward

Reputation: 3156

I think you are better off in (2) to pass the query off onto a worker process, which returns to the master process, which then sends back the request.

First of all, you don't really want to give the worker processes "access" to the outside. They should be all internal workers, managed by the master process.

Second, the Express server's job is to receive requests, do something with them, then return a result. It seems like over-complicating to try to pass the communication off to a worker.

If you are really worried about your Express server getting overwhelmed with requests, you should consider something like Docker to create a "swarm" of express instances.

Upvotes: 2

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