5 ms·
While I'm not disputing the limit numbers or whatever hardship they might cause, it's worth noting that this is a basic limitation of the original Lambda model
by sudhirj 7y ago
While I'm not disputing the limit numbers or whatever hardship they might cause, it's worth noting that this is a basic limitation of the original Lambda model and maybe FaaS in general. The capability comes from running a giant pseudo-infinite mesh of isolated execution environments that load your code and execute on demand, while having to buffer both the request and response to make sure clients are protected from the details. This buffering means that size of the buffer will always be limited - the team managing might make the buffers bigger based on experience, but it's not a solved problem.
ALB to containers or servers is a different beast - here the entire request and response need not be buffered at all (there might still be a very small buffer, mostly negligible), so streaming responses, websockets etc become possible.
We use lambda to resize images, so we do push against these limits a bit, but it's a fair tradeoff for the advantages - no worries about CPU throttling from too many requests, no waiting for servers to start for spiky loads etc.
- inopinatus 7y agoLambda was not designed for request/response. It’s an event driven service. Wrapping API gateway around it is an architectural blunder, and leads to folks like the GP wondering why their use case is a shitty fit.
- fulafel 7y agoWhy is request/response not a fit for an event driven service in your view? A lot of request/response server apps are written using the event model.
- inopinatus 7y agoTrying to build synchronous out of asynchronous requires state machines, buffering, and overallocation of resources. It’s the enemy of scale. The two styles are an impedance mismatch.
- toomuchtodo 7y agoI would read a deep dive blog post about this.
- fulafel 7y agoLambda is natively http based, no? Like all aws apis. It's just that it only speaks it's own json protocol, not generic web. Also request/response is not inherently synchronous or asynchronous. It's just a protocol design pattern. Buffering, overcommit, etc are also kust normal facts of life in both sync and async messaging.
- inopinatus 7y agoNo, it it natively event driven. Don’t confuse the control plane for the operational. Request/response is fundamentally synchronous. If you want to nitpick about other layers not blocking, that’s missing the wood for the trees.
- markonen 7y agoThere is nothing inherently asynchronous about the Lambda product, unless you’re talking about the Node.js runtime and even then that’s more about Node than about Lambda. Each Lambda invocation gets a dedicated VM for the duration of the request. It is a great match for synchronous code.
- inopinatus 7y agoThat is a mis-statement. Lambda executes functions in response to events. It is totally asynchronous with regards to its execution triggers. Lambda does reuse VMs, so I hope you aren’t relying on containers being discarded for any integrity or security outcomes. All the responses in this thread illustrate to me that AWS needs to put more effort into socialising how the product works. Since I was physically in the room for Lambda’s AWS internal launch this is twice disappoint because the technical messaging then was very clear and compelling.
- mlthoughts2018 7y ago“function as a service” absolutely does need to support request/response as a primary use case.
- deleted 7y ago[deleted]