Use Continue-As-New to keep long-running Temporal workflows within Event History limits while carrying state forward

Documented steps

1. Know the limits that force the pattern: a Workflow Execution's Event History is limited to 51,200 Events or 50 MB, and Temporal warns once you pass 10,240 Events or 10 MB.
2. Design the workflow's input type to double as its own checkpoint shape, e.g. Python `@dataclass class ClusterManagerInput: state: Optional[ClusterManagerState] = None`, so the same type serves both the first start and every continued run.
3. Detect when to continue: Python `workflow.info().is_continue_as_new_suggested()`; TypeScript `wf.workflowInfo().continueAsNewSuggested`. Both reflect Temporal's own signal that you are approaching performance or scalability problems based on history size and event count.
4. Optionally track history growth directly for tests or custom thresholds: Python `workflow.info().get_current_history_length()`, TypeScript `wf.workflowInfo().historyLength`, compared against your own threshold to force an earlier continue-as-new (useful to exercise the path in fast test runs).
5. Check the suggestion at safe checkpoint boundaries — points in your implementation where you are genuinely ready to serialize state — rather than at an arbitrary loop iteration.
6. Continue: Python `workflow.continue_as_new(NewInput(...))`; TypeScript `await wf.continueAsNew<typeof myWorkflow>({...})`, passing the input type populated with current in-memory state. This stops the current run and atomically starts a new one with the same Workflow ID, a new Run ID, and a fresh Event History.
7. Also use Continue-As-New for versioning hygiene: the docs recommend continuing-as-new periodically depending on deploy frequency, so long-lived workflows do not straddle many incompatible code versions.
8. Never call continue-as-new from inside a Signal or Update handler. Wait for in-progress handlers to complete (`workflow.all_handlers_finished` / `wf.allHandlersFinished`), then continue-as-new from the main workflow method.
9. Reference docs: https://docs.temporal.io/workflow-execution/limits | https://docs.temporal.io/workflow-execution/continue-as-new | https://docs.temporal.io/develop/python/workflows/continue-as-new | https://docs.temporal.io/develop/typescript/continue-as-new