@mock_only Feature: Context tier runtime promotion, demotion, and eviction logic As an ACMS developer I want the ContextTierService to automatically manage fragment lifecycle So that frequently accessed fragments are promoted, stale fragments are demoted, and budget limits are enforced without manual intervention Background: Given a context tier service with default settings # ----------------------------------------------------------------- # Auto-promotion on access # ----------------------------------------------------------------- Scenario: Fragment promoted from cold to warm after reaching access threshold Given a fragment "frag-cold-01" stored in the cold tier with 50 tokens When I access "frag-cold-01" via get 5 times Then fragment "frag-cold-01" should be in the warm tier Scenario: Fragment promoted from warm to hot after reaching access threshold Given a fragment "frag-warm-01" stored in the warm tier with 50 tokens When I access "frag-warm-01" via get 5 times Then fragment "frag-warm-01" should be in the hot tier Scenario: Fragment not promoted before reaching access threshold Given a fragment "frag-cold-02" stored in the cold tier with 50 tokens When I access "frag-cold-02" via get 3 times Then fragment "frag-cold-02" should be in the cold tier Scenario: Promoted fragment requires fresh accesses for next promotion Given a fragment "frag-chain-01" stored in the cold tier with 50 tokens When I access "frag-chain-01" via get 5 times Then fragment "frag-chain-01" should be in the warm tier When I access "frag-chain-01" via get 1 times Then fragment "frag-chain-01" should be in the warm tier When I access "frag-chain-01" via get 5 times Then fragment "frag-chain-01" should be in the hot tier # ----------------------------------------------------------------- # Staleness enforcement # ----------------------------------------------------------------- Scenario: Stale hot fragment demoted to warm on staleness enforcement Given a fragment "frag-stale-hot" stored in the hot tier with stale timestamp of 25 hours When I invoke enforce_staleness on the service Then fragment "frag-stale-hot" should be in the warm tier Scenario: Fresh hot fragment not demoted on staleness enforcement Given a fragment "frag-fresh-hot" stored in the hot tier with fresh timestamp When I invoke enforce_staleness on the service Then fragment "frag-fresh-hot" should be in the hot tier Scenario: Stale warm fragment demoted to cold on staleness enforcement Given a fragment "frag-stale-warm" stored in the warm tier with stale timestamp of 25 hours When I invoke enforce_staleness on the service Then fragment "frag-stale-warm" should be in the cold tier Scenario: Staleness enforcement returns list of demoted fragment IDs Given a fragment "frag-stale-a" stored in the hot tier with stale timestamp of 25 hours And a fragment "frag-stale-b" stored in the hot tier with stale timestamp of 30 hours When I invoke enforce_staleness on the service Then the staleness result should contain 2 fragment IDs # ----------------------------------------------------------------- # Budget enforcement on store # ----------------------------------------------------------------- Scenario: Storing in hot tier when budget allows does not evict Given a service with hot tier budget of 200 tokens And a fragment "frag-a" stored in the hot tier with 50 tokens When I store fragment "frag-b" in the hot tier with 50 tokens Then fragment "frag-a" should be in the hot tier And fragment "frag-b" should be in the hot tier Scenario: Storing in hot tier over budget evicts oldest fragment Given a service with hot tier budget of 100 tokens And a fragment "frag-old" stored in the hot tier with 50 tokens and old timestamp And a fragment "frag-new" stored in the hot tier with 50 tokens and recent timestamp When I store fragment "frag-overflow" in the hot tier with 50 tokens Then fragment "frag-old" should not be in any tier And fragment "frag-new" should be in the hot tier And fragment "frag-overflow" should be in the hot tier Scenario: Oversized fragment redirected to warm tier instead of hot Given a service with hot tier budget of 100 tokens When I store fragment "frag-oversized" in the hot tier with 200 tokens Then fragment "frag-oversized" should be in the warm tier Scenario: Promotion to hot falls back to warm when budget evicts promoted fragment Given a context tier service with an event bus and hot budget of 100 tokens And a fragment "frag-resident" stored in the hot tier with 80 tokens and recent timestamp And a fragment "frag-to-promote" stored in the warm tier with 80 tokens and old timestamp When I promote fragment "frag-to-promote" Then fragment "frag-to-promote" should be in the warm tier And a TIER_PROMOTED event should have been emitted for "frag-to-promote" # ----------------------------------------------------------------- # Event emission # ----------------------------------------------------------------- Scenario: Promotion emits TIER_PROMOTED event with correct tier details Given a context tier service with an event bus And a fragment "frag-evt-01" stored in the cold tier with 50 tokens When I promote fragment "frag-evt-01" Then a TIER_PROMOTED event should have been emitted for "frag-evt-01" And the last TIER_PROMOTED event should have from_tier "cold" and to_tier "warm" Scenario: Demotion emits TIER_DEMOTED event with correct tier details Given a context tier service with an event bus And a fragment "frag-evt-02" stored in the hot tier with 50 tokens When I demote fragment "frag-evt-02" Then a TIER_DEMOTED event should have been emitted for "frag-evt-02" And the last TIER_DEMOTED event should have from_tier "hot" and to_tier "warm" Scenario: Budget eviction emits TIER_EVICTED event Given a context tier service with an event bus and hot budget of 100 tokens And a fragment "frag-evt-03" stored in the hot tier with 60 tokens and old timestamp When I store fragment "frag-evt-04" in the hot tier with 60 tokens Then a TIER_EVICTED event should have been emitted for "frag-evt-03" Scenario: Explicit evict_lru emits TIER_EVICTED events Given a context tier service with an event bus And a fragment "frag-evict-01" stored in the hot tier with 50 tokens and old timestamp And a fragment "frag-evict-02" stored in the hot tier with 50 tokens and recent timestamp When I evict 1 LRU fragment from the hot tier Then a TIER_EVICTED event should have been emitted for "frag-evict-01" Scenario: Oversized fragment redirect emits TIER_DEMOTED event Given a context tier service with an event bus and hot budget of 100 tokens When I store fragment "frag-oversized-evt" in the hot tier with 200 tokens Then fragment "frag-oversized-evt" should be in the warm tier And a TIER_DEMOTED event should have been emitted for "frag-oversized-evt" Scenario: Event emission failure does not break tier operation Given a context tier service with a failing event bus And a fragment "frag-evt-safe" stored in the cold tier with 50 tokens When I promote fragment "frag-evt-safe" Then fragment "frag-evt-safe" should be in the warm tier # ----------------------------------------------------------------- # Edge cases # ----------------------------------------------------------------- Scenario: Getting a nonexistent fragment returns nothing When I access "no-such-fragment" via get 1 times Then fragment "no-such-fragment" should not be in any tier Scenario: Promoting a hot-tier fragment has no effect Given a fragment "frag-already-hot" stored in the hot tier with 50 tokens When I promote fragment "frag-already-hot" Then fragment "frag-already-hot" should be in the hot tier Scenario: Demoting a cold-tier fragment has no effect Given a fragment "frag-already-cold" stored in the cold tier with 50 tokens When I demote fragment "frag-already-cold" Then fragment "frag-already-cold" should be in the cold tier Scenario: Staleness enforcement with mixed stale hot and warm fragments Given a context tier service with default settings And a fragment "mixed-hot" stored in the hot tier with stale timestamp of 25 hours And a fragment "mixed-warm" stored in the warm tier with stale timestamp of 25 hours When I invoke enforce_staleness on the service Then fragment "mixed-hot" should be in the warm tier And fragment "mixed-warm" should be in the cold tier And the staleness result should contain 2 fragment IDs Scenario: Demoted fragment requires fresh accesses before re-promotion Given a context tier service with default settings And a fragment "frag-pop" stored in the hot tier with 50 tokens When I access "frag-pop" via get 10 times And I invoke enforce_staleness on the service with a hot TTL of 0 hours And I access "frag-pop" via get 1 times Then fragment "frag-pop" should be in the warm tier Scenario: Promotion threshold of 1 promotes on first access without chain promotion Given a context tier service with promotion threshold 1 And a fragment "frag-thresh" stored in the cold tier with 50 tokens When I access "frag-thresh" via get 1 times Then fragment "frag-thresh" should be in the warm tier