initialDelaySec property

The initial delay is the number of seconds that a new VM takes to initialize and run its startup script.

During a VM's initial delay period, the MIG ignores unsuccessful health checks because the VM might be in the startup process. This prevents the MIG from prematurely recreating a VM. If the health check receives a healthy response during the initial delay, it indicates that the startup process is complete and the VM is ready. The value of initial delay must be between 0 and 3600 seconds. The default value is 0.