VladRodionov commented on code in PR #8231: URL: https://github.com/apache/hbase/pull/8231#discussion_r3236468980
########## hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/cache/TestTopologyBackedCacheAccessService.java: ########## @@ -0,0 +1,414 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.hadoop.hbase.io.hfile.cache; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertInstanceOf; +import static org.junit.jupiter.api.Assertions.assertSame; +import static org.junit.jupiter.api.Assertions.assertTrue; +import static org.mockito.Mockito.mock; +import static org.mockito.Mockito.never; +import static org.mockito.Mockito.verify; +import static org.mockito.Mockito.when; + +import java.util.List; +import java.util.Optional; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.hbase.io.hfile.BlockCacheKey; +import org.apache.hadoop.hbase.io.hfile.BlockType; +import org.apache.hadoop.hbase.io.hfile.CacheStats; +import org.apache.hadoop.hbase.io.hfile.Cacheable; +import org.apache.hadoop.hbase.io.hfile.HFileBlock; +import org.apache.hadoop.hbase.testclassification.IOTests; +import org.apache.hadoop.hbase.testclassification.SmallTests; +import org.junit.jupiter.api.Tag; +import org.junit.jupiter.api.Test; + +/** + * Tests for {@link TopologyBackedCacheAccessService}. + */ +@Tag(IOTests.TAG) +@Tag(SmallTests.TAG) +public class TestTopologyBackedCacheAccessService { + + /** + * Verifies that lookup checks topology tiers in order and returns the first cached block found. + */ + @Test + void testGetBlockChecksTiersInOrder() { + BlockCacheKey key = new BlockCacheKey("file", 1L); + Cacheable block = mock(Cacheable.class); + CacheTopology topology = mock(CacheTopology.class); + CacheTopologyView topologyView = mock(CacheTopologyView.class); + CachePlacementAdmissionPolicy policy = mock(CachePlacementAdmissionPolicy.class); + CacheEngine l1 = mock(CacheEngine.class); + CacheEngine l2 = mock(CacheEngine.class); + CacheRequestContext context = requestContext(); + + when(topology.getName()).thenReturn("tiered"); + when(topology.getView()).thenReturn(topologyView); + when(topology.getTiers()).thenReturn(List.of(CacheTier.L1, CacheTier.L2)); + when(topology.getEngine(CacheTier.L1)).thenReturn(Optional.of(l1)); + when(topology.getEngine(CacheTier.L2)).thenReturn(Optional.of(l2)); + when(l1.getBlock(key, true, false, true, BlockType.DATA)).thenReturn(null); + when(l2.getBlock(key, true, false, true, BlockType.DATA)).thenReturn(block); + when(policy.shouldPromote(key, block, CacheTier.L2, context, topologyView)) + .thenReturn(PromotionDecision.none()); + + CacheAccessService service = new TopologyBackedCacheAccessService(topology, policy); + + assertSame(block, service.getBlock(key, context)); + + verify(l1).getBlock(key, true, false, true, BlockType.DATA); + verify(l2).getBlock(key, true, false, true, BlockType.DATA); + verify(policy).shouldPromote(key, block, CacheTier.L2, context, topologyView); + } + + /** + * Verifies that a hit can trigger topology-level promotion when requested by policy. + */ + @Test + void testGetBlockPromotesOnPolicyDecision() { + BlockCacheKey key = new BlockCacheKey("file", 1L); + Cacheable block = mock(Cacheable.class); + CacheTopology topology = mock(CacheTopology.class); + CacheTopologyView topologyView = mock(CacheTopologyView.class); + CachePlacementAdmissionPolicy policy = mock(CachePlacementAdmissionPolicy.class); + CacheEngine l1 = mock(CacheEngine.class); + CacheEngine l2 = mock(CacheEngine.class); + CacheRequestContext context = requestContext(); + + when(topology.getView()).thenReturn(topologyView); + when(topology.getTiers()).thenReturn(List.of(CacheTier.L1, CacheTier.L2)); + when(topology.getEngine(CacheTier.L1)).thenReturn(Optional.of(l1)); + when(topology.getEngine(CacheTier.L2)).thenReturn(Optional.of(l2)); + when(l1.getBlock(key, true, false, true, BlockType.DATA)).thenReturn(null); + when(l2.getBlock(key, true, false, true, BlockType.DATA)).thenReturn(block); + when(policy.shouldPromote(key, block, CacheTier.L2, context, topologyView)) + .thenReturn(PromotionDecision.promoteTo(CacheTier.L1, false)); + when(topology.promote(key, block, l2, l1)).thenReturn(true); + + CacheAccessService service = new TopologyBackedCacheAccessService(topology, policy); + + assertSame(block, service.getBlock(key, context)); + + verify(policy).shouldPromote(key, block, CacheTier.L2, context, topologyView); + verify(topology).promote(key, block, l2, l1); + } + + /** + * Verifies that cache insertion is skipped when admission policy rejects the block. + */ + @Test + void testCacheBlockSkipsInsertionWhenRejected() { + BlockCacheKey key = new BlockCacheKey("file", 1L); + Cacheable block = mock(Cacheable.class); + CacheTopology topology = mock(CacheTopology.class); + CacheTopologyView topologyView = mock(CacheTopologyView.class); + CachePlacementAdmissionPolicy policy = mock(CachePlacementAdmissionPolicy.class); + CacheEngine engine = mock(CacheEngine.class); + CacheWriteContext context = writeContext(); + + when(topology.getView()).thenReturn(topologyView); + when(topology.getEngine(CacheTier.SINGLE)).thenReturn(Optional.of(engine)); + when(policy.shouldAdmit(key, block, context, AdmissionPriority.NORMAL, topologyView)) + .thenReturn(AdmissionDecision.reject("rejected")); + + CacheAccessService service = new TopologyBackedCacheAccessService(topology, policy); + + service.cacheBlock(key, block, context); + + verify(policy).shouldAdmit(key, block, context, AdmissionPriority.NORMAL, topologyView); + verify(policy, never()).selectTier(key, block, context, topologyView); + verify(engine, never()).cacheBlock(key, block, true, true); + } + + /** + * Verifies that admitted blocks are inserted into policy-selected tiers. + */ + @Test + void testCacheBlockInsertsIntoSelectedTier() { + BlockCacheKey key = new BlockCacheKey("file", 1L); + Cacheable block = mock(Cacheable.class); + CacheTopology topology = mock(CacheTopology.class); + CacheTopologyView topologyView = mock(CacheTopologyView.class); + CachePlacementAdmissionPolicy policy = mock(CachePlacementAdmissionPolicy.class); + CacheEngine engine = mock(CacheEngine.class); + CacheWriteContext context = writeContext(); + + when(topology.getView()).thenReturn(topologyView); + when(topology.getEngine(CacheTier.SINGLE)).thenReturn(Optional.of(engine)); + when(policy.shouldAdmit(key, block, context, AdmissionPriority.NORMAL, topologyView)) + .thenReturn(AdmissionDecision.admit()); + when(policy.selectRepresentation(key, block, context, topologyView)) + .thenReturn(RepresentationDecision.CURRENT_HBASE_DEFAULT); Review Comment: Good question. No, I do not expect multiple TopologyBackedCacheAccessService implementations per cache engine. The intended model is: ```text CacheAccessService -> CacheTopology -> CacheEngine(s) -> CachePlacementAdmissionPolicy ``` So TopologyBackedCacheAccessService would be the common topology-based service. Different implementations plug in below it as different CacheEngine implementations, and different behavior plugs in as different CachePlacementAdmissionPolicy implementations. For example, future wiring could choose either: ```text BlockCacheBackedCacheAccessService -> existing BlockCache ``` for compatibility mode, or: ```text TopologyBackedCacheAccessService -> TieredExclusiveTopology -> LruCacheEngine + BucketCacheEngine -> Default policy ``` and later swap only the engine/policy, for example: ```text LruCacheEngine + CarrotCacheEngine Carrot-aware policy ``` This PR does not wire runtime configuration yet, but future configuration would likely happen in BlockCacheFactory, using settings such as service type, topology type, L1/L2 engines, and policy. Example: ```properties hbase.blockcache.access.service = topology hbase.blockcache.topology = tiered-exclusive hbase.blockcache.l1.engine = lru hbase.blockcache.l2.engine = bucket hbase.blockcache.policy = default ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
