Table of Contents

Soft-Delete Recovery

What it shows

DeleteTreeAsync is a soft delete: the tree is immediately made inaccessible (reads and writes throw InvalidOperationException) but its data is retained for a configurable grace window. During that window RecoverTreeAsync brings the tree - and all its data - back. This sample deletes a populated tree, shows reads are blocked, recovers it with data intact, then contrasts that with PurgeTreeAsync, which destroys the data immediately and makes recovery impossible.

Run it

dotnet run --project samples/SoftDeleteRecovery

Expected output

Silo starting... ready.

Seeding tree 'customers' with 5 keys...
  accessible = True, count = 5

Soft-deleting the tree (DeleteTreeAsync)...
  accessible after delete = False (expected False)
  attempting a read... blocked: This tree has been deleted and is no longer accessible.

Recovering the tree (RecoverTreeAsync)...
  accessible after recover = True (expected True)
  count after recover      = 5 (expected 5)
  customer:3               = "name-3" (data intact)

Now permanently destroying the tree (DeleteTreeAsync + PurgeTreeAsync)...
  attempting RecoverTreeAsync after purge... refused: Cannot recover a tree whose data has already been purged.

Done: soft-delete blocked access and was reversible; purge was permanent.

When to use

  • Guarding against accidental deletion: a soft delete with a retention window (LatticeOptions.SoftDeleteDuration, default 72 hours) gives operators time to undo a mistaken DeleteTreeAsync.
  • Decommissioning a tree while keeping a safety net until you are certain the data is no longer needed.
  • Use RecoverTreeAsync any time before the grace window elapses and purge begins.

When not to use

  • When you must reclaim storage immediately and are certain recovery will never be needed: PurgeTreeAsync (shown at the end) bypasses the grace window and destroys the data now - the call waits a bounded time, and a tree too large to purge in that time finishes purging in the background. It is irreversible - recovery after purge is refused, as it is while a purge is still running.
  • Per-key removal - use DeleteAsync / DeleteRangeAsync; tree deletion is for disposing of an entire tree.

Feature doc