Two application comunication

Question

Dear All,

Looking for event/request to Sent from One Windows service to desktop application on same server/machine.
I have tried Some of the technology e.g.  MSMQ, Selfhosted service, Web API etc.

Above all thing is working fine when the volume of the data is less or in fifty thousands records in a day.

When volume is huge like 1/5 crore records in day. then perfomnace of the application and server goes down and take more time process the data.

I have one application which is received the data from various source and saved data in db.

My question is the which is the best way to get data from various app.