Skip to main content

TTL & Expiration

Clustron DKV allows you to attach a time-to-live (TTL) to keys.

TTL automatically removes data after a specified duration.

What is TTL?​

TTL (time-to-live) defines how long a key should exist.

After the TTL expires:

  • The key is automatically removed
  • The value is no longer accessible

Setting TTL​

You can set TTL when storing a value:

await client.PutAsync(
    "session:abc123",
    "active",
    ttl: TimeSpan.FromMinutes(10));

This key will expire after 10 minutes.

Reading Expiring Keys​

var result = await client.GetAsync<string>("session:abc123");

if (result.Success)
{
    Console.WriteLine(result.Value);
}

Once the TTL expires:

  • Success will be false
  • The key behaves as if it does not exist

Updating TTL​

You can reset the TTL by writing the key again:

await client.PutAsync(
    "session:abc123",
    "active",
    ttl: TimeSpan.FromMinutes(10));

This effectively extends the lifetime of the key.

When to Use TTL​

TTL is useful for:

  • Sessions and temporary data
  • Caching with automatic cleanup
  • Time-based invalidation
  • Resource tracking

Expiration Behavior​

  • Expiration happens automatically
  • No manual cleanup is required
  • Expired keys are removed consistently across the cluster

TTL in Distributed Mode​

In distributed mode:

  • TTL is managed across all nodes
  • Expiration is coordinated
  • All clients observe consistent behavior

Beyond TTL​

TTL introduces the idea of lifecycle management.

Clustron extends this further with:

  • Leases → control ownership and lifecycle of resources
  • Coordination primitives → react to state changes

What’s Next​

👉 Continue to Consistency Model to understand how data behaves across nodes