3 ms·

Seems like a distributed stack unwind

lorendsr 3y ago
If I'm getting your point right, I agree! If you have the workflow / durable execution primitive to depend on (a durable function is guaranteed to complete executing), then there are a lot of pieces of distributed systems stacks that you no longer need to use. Your durable code is automatically backed by the event sourcing, timers, task queues, transfer queues, etc that Temporal internally uses to provide the guarantee, so that you don't need to build them yourself.
fortunaTemporal 3y ago
Author of the article here. Yeah, @agumonkey I like that analogy a lot! Generally, that's a good way of thinking about it. The one additional bit of nuance is it's like a "safe" stack unwind while other processes could be still modifying databases at the same time, so it's not a complete "rollback" of the whole world if that makes sense.
- agumonkey 3y ago
  Thanks, you're probably right, there's more to it. It's a thrilling topic, are there any other patterns, or abstractions into controlling "distributed state" (apologies if i'm twisting things too much again) between agents to keep things in a correct order ?
  - fortunaTemporal 3y ago
    One pattern is having a Workflow that runs as long as the lifetime of a domain object and holds a conceptual lock on that object—it receives requests to modify the object, and makes sure to only perform one operation at a time. (like the state pattern on a particular agent) Also related: Signals are events that you can send to Workflows and between Workflows, and they’re always delivered in the order they’re received. More generally, for a handy reference of Distributed Systems patterns, check out https://microservices.io/patterns/data/saga.html https://microservices.io/patterns/data/saga.html (though I personally find his diagrams a bit...overwhelming) and the MSN writeups: https://learn.microsoft.com/en-us/azure/architecture/patterns/ https://learn.microsoft.com/en-us/azure/architecture/pattern...
    - agumonkey 3y ago
      oh that's cool, thanks a lot

If I'm getting your point right, I agree! If you have the workflow / durable execution primitive to depend on (a durable function is guaranteed to complete executing), then there are a lot of pieces of distributed systems stacks that you no longer need to use. Your durable code is automatically backed by the event sourcing, timers, task queues, transfer queues, etc that Temporal internally uses to provide the guarantee, so that you don't need to build them yourself.

fortunaTemporal 3y ago

Author of the article here. Yeah, @agumonkey I like that analogy a lot! Generally, that's a good way of thinking about it. The one additional bit of nuance is it's like a "safe" stack unwind while other processes could be still modifying databases at the same time, so it's not a complete "rollback" of the whole world if that makes sense.

agumonkey 3y ago
Thanks, you're probably right, there's more to it. It's a thrilling topic, are there any other patterns, or abstractions into controlling "distributed state" (apologies if i'm twisting things too much again) between agents to keep things in a correct order ?
- fortunaTemporal 3y ago
  One pattern is having a Workflow that runs as long as the lifetime of a domain object and holds a conceptual lock on that object—it receives requests to modify the object, and makes sure to only perform one operation at a time. (like the state pattern on a particular agent) Also related: Signals are events that you can send to Workflows and between Workflows, and they’re always delivered in the order they’re received. More generally, for a handy reference of Distributed Systems patterns, check out https://microservices.io/patterns/data/saga.html https://microservices.io/patterns/data/saga.html (though I personally find his diagrams a bit...overwhelming) and the MSN writeups: https://learn.microsoft.com/en-us/azure/architecture/patterns/ https://learn.microsoft.com/en-us/azure/architecture/pattern...
  - agumonkey 3y ago
    oh that's cool, thanks a lot