3 ms·

How's the latency when using this method? I'd imagine if you foresee your site being low usage, startup times would be quite bad. At least, on the order of seco

by Meegul 9y ago

How's the latency when using this method? I'd imagine if you foresee your site being low usage, startup times would be quite bad. At least, on the order of seconds rather than milliseconds.

foob 9y ago
It depends a little bit on whether there's a warm container or not, but I think that the overhead is much closer to ~100 milliseconds than to multiple seconds. The CircleCI artifacts API that I linked to takes less than one second to return an artifact, and there's a lot more going on there than a single request/response pair. The endpoint makes an external request to CircleCI's API, does some processing on the response, returns a 301 redirect, and then the redirect is followed by the client and another request is made to actually download the file from S3. You can test this directly by running time curl -L 'https://circleci.intoli.com/artifacts/intoli/exodus/coverage-report/total-coverage.json' which outputs something like the following (the timing will vary a bit obviously). { "coverage": "92.43%" } real 0m0.798s user 0m0.046s sys 0m0.010s
- audiolion 9y ago
  I just ping my functions every 4 minutes to keep them warm. I am still in the free quota doing that
andreineculau 9y ago
It is not. You obviously get into a different set of problems than you're accustomed with, but it is not seconds, even on "cold" lambdas. https://read.acloud.guru/cold-starting-lambdas-2c663055589e https://read.acloud.guru/cold-starting-lambdas-2c663055589e
- arbie 9y ago
  From your linked article: "In the absolute worst case it could be as high as 2.8 seconds."
  - andreineculau 9y ago
    One is the latency of starting up the "cold" lambda, one is the latency of actually starting it up and running your code. The latter is a moving target, subject to the setup i.e. size of loaded code, available memory/CPU, etc, and subject to the actual computation and the latency of its dependencies e.g. network calls, database queries, etc.

by Meegul 9y ago

How's the latency when using this method? I'd imagine if you foresee your site being low usage, startup times would be quite bad. At least, on the order of seconds rather than milliseconds.

foob 9y ago

It depends a little bit on whether there's a warm container or not, but I think that the overhead is much closer to ~100 milliseconds than to multiple seconds. The CircleCI artifacts API that I linked to takes less than one second to return an artifact, and there's a lot more going on there than a single request/response pair. The endpoint makes an external request to CircleCI's API, does some processing on the response, returns a 301 redirect, and then the redirect is followed by the client and another request is made to actually download the file from S3. You can test this directly by running time curl -L 'https://circleci.intoli.com/artifacts/intoli/exodus/coverage-report/total-coverage.json' which outputs something like the following (the timing will vary a bit obviously). { "coverage": "92.43%" } real 0m0.798s user 0m0.046s sys 0m0.010s

audiolion 9y ago
I just ping my functions every 4 minutes to keep them warm. I am still in the free quota doing that

andreineculau 9y ago

It is not. You obviously get into a different set of problems than you're accustomed with, but it is not seconds, even on "cold" lambdas. https://read.acloud.guru/cold-starting-lambdas-2c663055589e https://read.acloud.guru/cold-starting-lambdas-2c663055589e

arbie 9y ago
From your linked article: "In the absolute worst case it could be as high as 2.8 seconds."
- andreineculau 9y ago
  One is the latency of starting up the "cold" lambda, one is the latency of actually starting it up and running your code. The latter is a moving target, subject to the setup i.e. size of loaded code, available memory/CPU, etc, and subject to the actual computation and the latency of its dependencies e.g. network calls, database queries, etc.