Running Adhoc Instances in PaaSTA

PaaSTA allows users to pre-define and run adhoc (a.k.a. one-off) instances. These instances can be used to run batch jobs, test suites, etc.

Creating an adhoc instance

Adhoc instances can be defined by creating an adhoc-[clustername].yaml file in a service’s soa_configs. The specification for these files is defined in the yelpsoa configs documentation.

Running an adhoc instance

Adhoc instances can be run using paasta local-run like any other instance. A sample use case where one needs to ssh onto an adhoc batch machine and run the adhoc instance example_instance for the service example_service would use the command:

paasta local-run --pull --service example_service --instance example_instance

The ‘interactive’ instance

Running paasta local-run without specifying the --instance flag launches an interactive instance of a service running a bash shell. This interactive instace can be used to run adhoc jobs that aren’t run frequently enough to be added to soa_configs. The defaults values for the cpu, mem and disk that are allocated to the interactive instance are very generous, but they can be further increased by editing adhoc-[clustername].yaml for the cluster the interactive service is being used in and creating an interactive instance config. The interactive instance can be configured like any other adhoc instance, e.g. by adding additional mounted volumes or changing the networking type. See the examples below for more details.

Example Adhoc YAML Definitions

Example adhoc definition for a batch we run periodically that need external files on the host:

$ cat adhoc-norcal-prod.yaml
backfill_batch:
  deploy_group: prod.non_canary
  cpus: 1
  mem: 1000
  extra_volumes:
  - {containerPath: /tmp/, hostPath: /tmp, mode: RW}
  cmd: "python -m batch.adhoc.backfill_batch --dest=/tmp/backfill.csv"

Example “interactive” definition that users will get when they run paasta local-run --pull --interactive. It needs lots of ram and defaults to an ipython repl. Also uses the canary version of the code:

# This is the default config that is run when you don't specify an instance
# This config is optional and any parameters specified here will override the
# global defaults
interactive:
  deploy_group: prod.canary
  mem: 10000