vlast3k / dontdie

Dontdie is a web server that ignores SIGTERM signals. Don't ask me why.

dontdie

Dontdie is a web server that ignores SIGTERM signals.

Push app

git clone https://github.com/vlast3k/dontdie
cd dontdie/
cf push

Test cf restart-app-instance

export URL="https://$(cf curl /v3/apps/`cf app dontdie --guid`/routes | jq -r .resources[0].url)"
cf restart dontdie
curl "$URL"
cf restart-app-instance dontdie 0
while true; do sleep 1; echo "$(date) |  $(curl -s "$URL")"; done

Output

Note how "instance 0" is still being requested, despite it being in graceful shutdown (which is 60 seconds)

Restarting instance 0 of process web of app dontdie in org i024148 / space dev as provisioned_user_cf_admin...
OK

Fri Sep 15 03:00:06 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:08 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:09 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:10 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:11 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:12 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:13 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 03:00:14 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:15 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:17 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:18 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 03:00:19 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:20 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:21 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 03:00:22 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:23 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:25 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:26 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 03:00:27 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:28 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:29 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:30 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:31 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 03:00:33 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:34 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 03:00:35 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 03:00:36 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1

Expected Output

Restarting instance 0 of process web of app dontdie in org i024148 / space dev as provisioned_user_cf_admin...
OK

Fri Sep 15 02:46:20 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 02:46:21 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1

... up to <graceful_shutdown_time (60s in this example)> + some reconciliation buffer only responses from "instance 1", but no errors

Fri Sep 15 02:47:56 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 02:47:57 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 02:47:58 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 02:47:59 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 02:48:00 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 02:48:02 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 02:48:03 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 02:48:04 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 02:48:05 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 02:48:06 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 02:48:07 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 0
Fri Sep 15 02:48:09 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1
Fri Sep 15 02:48:10 AM UTC 2023 |  This could be a meaningful HTTP response coming from instance 1

Analyze

Problems

• App still receving request - The biggest problem are the requests that reach the app, because they do it is in graceful shutdown mode and their processing is undefined, as the app no longer expects to get new requests.
  • some will go through successfully
  • some will be terminated, because they did not get the full graceful shutdown time
  • and some may not be able to be processed at all, depending on how the app does graceful shutdown