Go to webAPI to understand the second type

haha @Dan Rammer (hamersaw) beat me to it

😄

i mean you could use it to call services and get instantaneous response

like a rest api caller

this can make it possible to write serverless workflows that run at high speed

goal is to do this with knative to provide lambda like services. But today its a little early

Can you elaborate more on Sync vs Async

sync should be like a webapi call that returns response. For example - lookup a value in a DB.

What do you mean by “no Async in terms of propeller”

Just want to make sure that for a Async task, the next task is stilled blocked by the termination of this task right

So propeller works as a k8s operator, periodically evaluating workflows in "rounds" where each round consists of checking the status' of tasks and scheduling new ones, retries, etc. These operations are all done synchronously within a round. For example, check status of node

n1

, if it's complete then write it's results to cache (given it's a cached node), then schedule downstream node

n2

, etc ... With the sync web API plugin checking the status of a node is a synchronous operation, so it requires a request RTT for each node check, these add up if there are many tasks making a single "round" of propeller large. Alternatively, the async web api plugin uses a background process in propeller to periodically check the task status, then in a propeller "round" each task status is stored in a cache and looked up in memory for extremely fast propeller "rounds".

This is extremely insightful thanks!