public Trie build() {
            Trie[] transitions = new Trie[this.transitions.size()];
            for (int i = 0; i < this.transitions.size(); i++) {
                Builder transition = this.transitions.get(i);
                transitions[i] = transition.build();
            }
            Arrays.sort(transitions);
            return new Trie(c, terminal, transitions);
        }
    }

// purposes. For example, on POSIX-y operating systems, Reserved is usually a
// private anonymous mmap'd region with PROT_NONE set, and to transition
// to Ready would require setting PROT_READ|PROT_WRITE. However the
// underspecification of Prepared lets us use just MADV_FREE to transition from
// Ready to Prepared. Thus with the Prepared state we can set the permission
// bits just once early on, we can efficiently tell the OS that it's free to

--restore-request Days=3
```

### 4.1 Monitoring transition events

`s3:ObjectTransition:Complete` and `s3:ObjectTransition:Failed` events can be used to monitor transition events between the source cluster and transition tier. To watch lifecycle events, you can enable bucket notification on the source bucket with `mc event add`  and specify `--event ilm` flag.

Note that transition event notification is a MinIO extension.

## Explore Further

type StateTransition struct {
	// Resource is the resource this state transition is for.
	Resource ResourceID

	// Reason is a human-readable reason for the state transition.
	Reason string

	// Stack is the stack trace of the resource making the state transition.
	//
	// This is distinct from the result (Event).Stack because it pertains to

	ilmTransitionActiveTasksMD          = NewGaugeMD(transitionActiveTasks, "Number of active ILM transition tasks")
	ilmTransitionPendingTasksMD         = NewGaugeMD(transitionPendingTasks, "Number of pending ILM transition tasks in the queue")
	ilmTransitionMissedImmediateTasksMD = NewCounterMD(transitionMissedImmediateTasks, "Number of missed immediate ILM transition tasks")

	Filter              Filter              `xml:"Filter,omitempty"`
	Prefix              Prefix              `xml:"Prefix,omitempty"`
	Expiration          Expiration          `xml:"Expiration,omitempty"`
	Transition          Transition          `xml:"Transition,omitempty"`
	DelMarkerExpiration DelMarkerExpiration `xml:"DelMarkerExpiration,omitempty"`

		}
		// Write down that we've entered a syscall. Note: we might have no G or P here
		// if we're in a cgo callback or this is a transition from GoUndetermined
		// (i.e. the G has been blocked in a syscall).
		gs.syscallBegin(start, goID, ev.Stack())
	}

	// Note down the goroutine transition.
	_, inMarkAssist := gs.activeRanges["GC mark assist"]

		}
		// Write down that we've entered a syscall. Note: we might have no P here
		// if we're in a cgo callback or this is a transition from GoUndetermined
		// (i.e. the G has been blocked in a syscall).
		gs.syscallBegin(start, ev.Thread(), ev.Stack())
	}

	// Note down the goroutine transition.
	_, inMarkAssist := gs.activeRanges["GC mark assist"]

package ilm

import "github.com/minio/minio/internal/config"

const (
	transitionWorkers = "transition_workers"
	expirationWorkers = "expiration_workers"
	// EnvILMTransitionWorkers env variable to configure number of transition workers
	EnvILMTransitionWorkers = "MINIO_ILM_TRANSITION_WORKERS"
	// EnvILMExpirationWorkers env variable to configure number of expiration workers
	EnvILMExpirationWorkers = "MINIO_ILM_EXPIRATION_WORKERS"
)

var (

	return g == unordered || (init.seq == noseq || init.seq == curr.seq) && init.status == curr.status
}

func transition(gs map[uint64]gState, g uint64, init, next gState) error {
	if g == unordered {
		return nil
	}
	curr := gs[g]
	if !transitionReady(g, curr, init) {
		// See comment near the call to transition, where we're building the frontier, for details on how this could
		// possibly happen.