openai-aspnet-core/references/realtime-grpc-and-background-work.md

Realtime, gRPC, And Background Work

Primary docs: - https://learn.microsoft.com/aspnet/core/signalr/introduction - https://learn.microsoft.com/aspnet/core/grpc/ - https://learn.microsoft.com/aspnet/core/fundamentals/host/hosted-services

SignalR

Use SignalR when the server must push updates to connected clients in near real time.

Good fits:

• chat
• dashboards
• notifications
• collaborative editing
• live status streams

Guidance:

• model the hub as a communication boundary, not the home of business logic
• use groups and user targeting deliberately
• authenticate connections when data is user-specific
• plan for scale-out if the app may run on multiple instances

Remember that Blazor interactive server rendering already relies on a real-time connection. Do not add a second realtime channel unless the feature truly needs one.

gRPC

Use gRPC for efficient service-to-service communication, strongly typed contracts, and streaming over HTTP/2.

Prefer gRPC when:

• both ends are under your control
• performance and contract fidelity matter
• streaming is a first-class requirement

Guidance:

• keep .proto contracts versioned and stable
• generate client and server types from contracts
• keep auth, logging, and DI integrated with the host
• account for browser interoperability differences before choosing gRPC for public browser clients

Background Work

Use IHostedService or BackgroundService for in-process background tasks tied to the application host.

Defaults:

• keep background services small and observable
• create scopes for scoped dependencies
• do not capture scoped services directly in singleton hosted services
• respect cancellation tokens
• avoid long blocking startup paths

If the work is durable, high-volume, or business-critical, consider whether it belongs in an out-of-process queue or worker instead of only inside the web host.