I have a batch process, written in PHP and embedded in a Docker container. Basically, it loads data from several webservices, do some computation on data (during ~1h), and post computed data to an other webservice, then the container exit (with a return code of 0 if OK, 1 if failure somewhere on the process). During the process, some logs are written on STDOUT or STDERR. The batch must be triggered once a day.
I was wondering what is the best AWS service to use to schedule, execute, and monitor my batch process :
- at the very begining, I used a EC2 machine with a crontab : no high-availibilty function here, so I decided to switch to a more PaaS approach.
- then, I was using Elastic Beanstalk for Docker, with a non-functional Webserver (only to reply to the Healthcheck), and a Crontab inside the container to wake-up my batch command once a day. With autoscalling rule min=1 max=1, I have HA (if the container crash or if the VM crash, it is restarted by AWS)
- but now, to be more efficient, I decided to move to some ECS service, and have an approach where I do not need to have EC2 instances awake 23/24 for nothing. So I tried Fargate.
- with Fargate I defined my task (Fargate type, not the EC2 type), and configure everything on it.
- I create a Cluster to run my task : I can run "by hand, one time" my task, so I know every settings are corrects.
Now, going deeper in Fargate, I want to have my task executed once a day.
It seems to work fine when I used the Scheduled Task feature of ECS : the container start on time, the process run, then the container stop. But CloudWatch is missing some metrics : CPUReservation and CPUUtilization are not reported. Also, there is no way to know if the batch quit with exit code 0 or 1 (all execution stopped with status "STOPPED"). So i Cant send a CloudWatch alarm if the container execution failed.
I use the "Services" feature of Fargate, but it cant handle a batch process, because the container is started every time it stops. This is normal, because the container do not have any daemon. There is no way to schedule a service. I want my container to be active only when it needs to work (once a day during at max 1h). But the missing metrics are correctly reported in CloudWatch.
Here are my questions : what are the best suitable AWS managed services to trigger a container once a day, let it run to do its task, and have reporting facility to track execution (CPU usage, batch duration), including alarm (SNS) when task failed ?
