KBEC-00226 - Abort and force abort implementation

Description

When a CloudBees CD (CloudBees Flow) step is aborted or force aborted, what mechanism is being used in the OS?

Solution

For force abort, the server:

1. sends an abort command to the agent
2. marks the step aborted (without waiting for the agent to finish aborting the step)

After the agent receives the message, it:

1. sends a SIGTERM signal to ecwrapper
2. waits for ecwrapper to complete
   1. ecwrapper in turn sends a SIGTERM to the actual running command even though this is a force abort.
   2. If the command does not complete in 2 minutes, ecwrapper sends a kill -9 to all child processes associated with this step.

In other words, regardless of regular abort or force abort, the agent waits two minutes before kill -9’ing the step.