anton-vinogradov commented on code in PR #12459: URL: https://github.com/apache/ignite/pull/12459#discussion_r2477886789
########## modules/core/src/test/java/org/apache/ignite/cache/affinity/rendezvous/MdcAffinityBackupFilterSelfTest.java: ########## @@ -0,0 +1,289 @@ +/* + * 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.ignite.cache.affinity.rendezvous; + +import java.util.Collection; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.stream.Collectors; +import org.apache.ignite.IgniteCache; +import org.apache.ignite.IgniteCheckedException; +import org.apache.ignite.IgniteSystemProperties; +import org.apache.ignite.cache.affinity.Affinity; +import org.apache.ignite.cluster.ClusterNode; +import org.apache.ignite.configuration.IgniteConfiguration; +import org.apache.ignite.internal.IgniteEx; +import org.apache.ignite.lang.IgniteBiPredicate; +import org.apache.ignite.testframework.junits.common.GridCommonAbstractTest; +import org.junit.Test; + +import static org.apache.ignite.testframework.GridTestUtils.assertThrows; + +/** + * Verifies behaviour of {@link MdcAffinityBackupFilter} - guarantees that each DC has at least one copy of every partition. + * Verified distribution uniformity in each DC separately. + */ +public class MdcAffinityBackupFilterSelfTest extends GridCommonAbstractTest { + /** */ + private static final int PARTS_CNT = 1024; + + /** */ + private int backups; + + /** */ + private String[] dcIds; + + /** */ + private IgniteBiPredicate<ClusterNode, List<ClusterNode>> filter; + + /** {@inheritDoc} */ + @Override protected IgniteConfiguration getConfiguration(String igniteInstanceName) throws Exception { + IgniteConfiguration cfg = super.getConfiguration(igniteInstanceName); + + cfg.setCacheConfiguration(defaultCacheConfiguration() + .setBackups(backups) + .setAffinity( + new RendezvousAffinityFunction(false, PARTS_CNT) + .setAffinityBackupFilter(filter))); + + return cfg; + } + + /** {@inheritDoc} */ + @Override protected void afterTest() throws Exception { + super.afterTest(); + + stopAllGrids(); + } + + /** + * Verifies that {@link MdcAffinityBackupFilter} prohibits single data center deployment. + */ + @Test + public void testSingleDcDeploymentIsProhibited() { + assertThrows(null, + () -> new MdcAffinityBackupFilter(1, 1), + IllegalArgumentException.class, + "Number of datacenters must be at least 2."); Review Comment: It's ok to have single DC, at least for case "we're planning to separate cluster". And for case "Second DC currently is down". ########## modules/core/src/main/java/org/apache/ignite/cache/affinity/rendezvous/MdcAffinityBackupFilter.java: ########## @@ -0,0 +1,155 @@ +/* + * 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.ignite.cache.affinity.rendezvous; + +import java.util.List; +import org.apache.ignite.cluster.ClusterNode; +import org.apache.ignite.internal.util.typedef.internal.S; +import org.apache.ignite.lang.IgniteBiPredicate; + +/** + * Multi-data center affinity backup filter that ensures each partition's data is distributed across multiple data centers, + * providing high availability and fault tolerance. This implementation guarantees at least one copy of the data in each + * data center and attempts to maintain the configured backup factor without discarding copies. + * <p> + * The filter works by grouping nodes based on their data center identification attribute (@see {@link ClusterNode#dataCenterId()}) + * and ensuring that for every partition, at least one node from each data center is included in the primary-backup set. + * <p> + * The filter will discard backup copies only if the number of available nodes in a given data center is less + * than the number of copies assigned to that data center. + * For example, if a partition has 4 copies (1 primary and 3 backups) and the cluster has 2 data centers, + * than 2 copies are assigned to each data center. The only scenario when just a single copy is assigned to a node in a data center is when + * the number of nodes in that data center is one. + * <p> + * This class is constructed with a number of data centers the cluster spans and a number of backups of the cache this filter is applied to. + * Implementation expects that all copies can be spread evenly across all data centers. In other words, (backups + 1) is divisible by + * number of data centers without remainder. Uneven distributions of copies are not supported. + * <p> + * Warning: Ensure that all nodes have a consistent and valid data center identifier attribute. Missing or inconsistent values + * may lead to unexpected placement of data. + * </pre> + * <h2 class="header">Spring Example</h2> + * Create a partitioned cache template where each data center has at least one copy of the data, and the backup count is maintained. + * <pre name="code" class="xml"> + * <property name="cacheConfiguration"> + * <list> + * <bean id="cache-template-bean" abstract="true" class="org.apache.ignite.configuration.CacheConfiguration"> + * <property name="name" value="JobcaseDefaultCacheConfig*"/> + * <property name="cacheMode" value="PARTITIONED" /> + * <property name="backups" value="3" /> + * <property name="affinity"> + * <bean class="org.apache.ignite.cache.affinity.rendezvous.RendezvousAffinityFunction"> + * <property name="affinityBackupFilter"> + * <bean class="org.apache.ignite.cache.affinity.rendezvous.MdcAffinityBackupFilter"> + * <constructor-arg value="2"/> <!-- dcsNumber --> + * <constructor-arg value="3"/> <!-- backups, the same as in the cache template --> + * </bean> + * </property> + * </bean> + * </property> + * </bean> + * </list> + * </property> + * </pre> + * <p> + * With more backups, additional replicas can be distributed across different data centers to further improve redundancy. + */ +public class MdcAffinityBackupFilter implements IgniteBiPredicate<ClusterNode, List<ClusterNode>> { + /** */ + private static final long serialVersionUID = 1L; + + /** */ + private final int partCopiesPerDc; + + /** + * @param dcsNum Number of data centers. + * @param backups Number of backups. + */ + public MdcAffinityBackupFilter(int dcsNum, int backups) { + if (dcsNum < 2) { + throw new IllegalArgumentException("MdcAffinityBackupFilter cannot be used in an environment with only one datacenter. " + + "Number of datacenters must be at least 2."); + } + + int numCopies = backups + 1; + + partCopiesPerDc = numCopies / dcsNum; + int remainder = numCopies % dcsNum; + + if (remainder != 0) { + String suggestion = "recommended "; + if (numCopies - remainder <= 0) + suggestion += "value is " + (backups + (dcsNum - remainder)); + else + suggestion += "values are " + (backups - remainder) + " and " + (backups + (dcsNum - remainder)); + + throw new IllegalArgumentException("Number of copies is not completely divisible by number of datacenters, " + + "copies cannot be distributed evenly across DCs. " + + "Please adjust the number of backups, " + suggestion); + } + + + } + + /** + * Defines a predicate which returns {@code true} if a node is acceptable for a backup + * or {@code false} otherwise. + * An acceptable node is the one that belongs to a data center that has some additional copies of partition to assign to. + * @param candidate A node that is a candidate for becoming a backup node for a partition. + * @param previouslySelected A list of primary/backup nodes already chosen for a partition. + * The primary is first. + */ + @Override public boolean apply(ClusterNode candidate, List<ClusterNode> previouslySelected) { + String candidateDcId = candidate.dataCenterId(); + int candDcCopiesAssigned = 0; + + for (int i = 0; i < previouslySelected.size(); i++) { + String prevDcId = previouslySelected.get(i).dataCenterId(); + + if (prevDcId == null) + return false; Review Comment: Should we really handle the case when DC is not set? ########## modules/core/src/test/java/org/apache/ignite/cache/affinity/rendezvous/MdcAffinityBackupFilterSelfTest.java: ########## @@ -0,0 +1,289 @@ +/* + * 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.ignite.cache.affinity.rendezvous; + +import java.util.Collection; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.stream.Collectors; +import org.apache.ignite.IgniteCache; +import org.apache.ignite.IgniteCheckedException; +import org.apache.ignite.IgniteSystemProperties; +import org.apache.ignite.cache.affinity.Affinity; +import org.apache.ignite.cluster.ClusterNode; +import org.apache.ignite.configuration.IgniteConfiguration; +import org.apache.ignite.internal.IgniteEx; +import org.apache.ignite.lang.IgniteBiPredicate; +import org.apache.ignite.testframework.junits.common.GridCommonAbstractTest; +import org.junit.Test; + +import static org.apache.ignite.testframework.GridTestUtils.assertThrows; + +/** + * Verifies behaviour of {@link MdcAffinityBackupFilter} - guarantees that each DC has at least one copy of every partition. + * Verified distribution uniformity in each DC separately. + */ +public class MdcAffinityBackupFilterSelfTest extends GridCommonAbstractTest { + /** */ + private static final int PARTS_CNT = 1024; + + /** */ + private int backups; + + /** */ + private String[] dcIds; + + /** */ + private IgniteBiPredicate<ClusterNode, List<ClusterNode>> filter; + + /** {@inheritDoc} */ + @Override protected IgniteConfiguration getConfiguration(String igniteInstanceName) throws Exception { + IgniteConfiguration cfg = super.getConfiguration(igniteInstanceName); + + cfg.setCacheConfiguration(defaultCacheConfiguration() + .setBackups(backups) + .setAffinity( + new RendezvousAffinityFunction(false, PARTS_CNT) + .setAffinityBackupFilter(filter))); + + return cfg; + } + + /** {@inheritDoc} */ + @Override protected void afterTest() throws Exception { + super.afterTest(); + + stopAllGrids(); + } + + /** + * Verifies that {@link MdcAffinityBackupFilter} prohibits single data center deployment. + */ + @Test + public void testSingleDcDeploymentIsProhibited() { + assertThrows(null, + () -> new MdcAffinityBackupFilter(1, 1), + IllegalArgumentException.class, + "Number of datacenters must be at least 2."); + } + + /** + * Verifies that {@link MdcAffinityBackupFilter} enforces even number of partition copies per datacenter. + */ + @Test + public void testUniformNumberOfPartitionCopiesPerDcIsEnforced() { + assertThrows(null, + () -> new MdcAffinityBackupFilter(3, 1), + IllegalArgumentException.class, + "recommended value is 2"); + + assertThrows(null, + () -> new MdcAffinityBackupFilter(3, 7), + IllegalArgumentException.class, + "recommended values are 5 and 8"); + } + + /** + * Verifies that partition copies are assigned evenly across a cluster in two data centers. + * <p/> + * When a node from one data center is stopped, partition distribution is that data center should stay uniform. + * + * @throws Exception If failed. + */ + @Test + public void test2DcDistribution() throws Exception { + dcIds = new String[] {"DC_0", "DC_1"}; + int nodesPerDc = 4; + backups = 3; + filter = new MdcAffinityBackupFilter(dcIds.length, backups); + + IgniteEx srv = startClusterAcrossDataCenters(dcIds, nodesPerDc); + + verifyDistributionProperties(srv, dcIds, nodesPerDc, backups); + + //stopping one node in DC_1 should not compromise distribution as there are additional nodes in the same DC + stopGrid(5); + + awaitPartitionMapExchange(); + + verifyDistributionProperties(srv, dcIds, nodesPerDc, backups); + + //stopping another node in DC_1 should not compromise distribution as well + stopGrid(6); Review Comment: let's stop the whole cluster as well and check there is no rebalance happened. ########## modules/core/src/main/java/org/apache/ignite/cache/affinity/rendezvous/MdcAffinityBackupFilter.java: ########## @@ -0,0 +1,155 @@ +/* + * 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.ignite.cache.affinity.rendezvous; + +import java.util.List; +import org.apache.ignite.cluster.ClusterNode; +import org.apache.ignite.internal.util.typedef.internal.S; +import org.apache.ignite.lang.IgniteBiPredicate; + +/** + * Multi-data center affinity backup filter that ensures each partition's data is distributed across multiple data centers, + * providing high availability and fault tolerance. This implementation guarantees at least one copy of the data in each + * data center and attempts to maintain the configured backup factor without discarding copies. + * <p> + * The filter works by grouping nodes based on their data center identification attribute (@see {@link ClusterNode#dataCenterId()}) + * and ensuring that for every partition, at least one node from each data center is included in the primary-backup set. + * <p> + * The filter will discard backup copies only if the number of available nodes in a given data center is less + * than the number of copies assigned to that data center. + * For example, if a partition has 4 copies (1 primary and 3 backups) and the cluster has 2 data centers, + * than 2 copies are assigned to each data center. The only scenario when just a single copy is assigned to a node in a data center is when + * the number of nodes in that data center is one. + * <p> + * This class is constructed with a number of data centers the cluster spans and a number of backups of the cache this filter is applied to. + * Implementation expects that all copies can be spread evenly across all data centers. In other words, (backups + 1) is divisible by + * number of data centers without remainder. Uneven distributions of copies are not supported. + * <p> + * Warning: Ensure that all nodes have a consistent and valid data center identifier attribute. Missing or inconsistent values + * may lead to unexpected placement of data. + * </pre> + * <h2 class="header">Spring Example</h2> + * Create a partitioned cache template where each data center has at least one copy of the data, and the backup count is maintained. + * <pre name="code" class="xml"> + * <property name="cacheConfiguration"> + * <list> + * <bean id="cache-template-bean" abstract="true" class="org.apache.ignite.configuration.CacheConfiguration"> + * <property name="name" value="JobcaseDefaultCacheConfig*"/> + * <property name="cacheMode" value="PARTITIONED" /> + * <property name="backups" value="3" /> + * <property name="affinity"> + * <bean class="org.apache.ignite.cache.affinity.rendezvous.RendezvousAffinityFunction"> + * <property name="affinityBackupFilter"> + * <bean class="org.apache.ignite.cache.affinity.rendezvous.MdcAffinityBackupFilter"> + * <constructor-arg value="2"/> <!-- dcsNumber --> + * <constructor-arg value="3"/> <!-- backups, the same as in the cache template --> + * </bean> + * </property> + * </bean> + * </property> + * </bean> + * </list> + * </property> + * </pre> + * <p> + * With more backups, additional replicas can be distributed across different data centers to further improve redundancy. + */ +public class MdcAffinityBackupFilter implements IgniteBiPredicate<ClusterNode, List<ClusterNode>> { + /** */ + private static final long serialVersionUID = 1L; + + /** */ + private final int partCopiesPerDc; + + /** + * @param dcsNum Number of data centers. + * @param backups Number of backups. + */ + public MdcAffinityBackupFilter(int dcsNum, int backups) { + if (dcsNum < 2) { + throw new IllegalArgumentException("MdcAffinityBackupFilter cannot be used in an environment with only one datacenter. " + + "Number of datacenters must be at least 2."); + } + + int numCopies = backups + 1; + + partCopiesPerDc = numCopies / dcsNum; + int remainder = numCopies % dcsNum; + + if (remainder != 0) { + String suggestion = "recommended "; + if (numCopies - remainder <= 0) + suggestion += "value is " + (backups + (dcsNum - remainder)); + else + suggestion += "values are " + (backups - remainder) + " and " + (backups + (dcsNum - remainder)); + + throw new IllegalArgumentException("Number of copies is not completely divisible by number of datacenters, " + + "copies cannot be distributed evenly across DCs. " + + "Please adjust the number of backups, " + suggestion); + } Review Comment: Looks overcomplicated and error-prone to me. We should **always** have the same number at each DC, rounded up `numCopies / DC_count`. If % provides us a non-zero value, let's do what we have to, but with a warning. This should simplify logic. ########## modules/core/src/main/java/org/apache/ignite/cache/affinity/rendezvous/MdcAffinityBackupFilter.java: ########## @@ -0,0 +1,155 @@ +/* + * 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.ignite.cache.affinity.rendezvous; + +import java.util.List; +import org.apache.ignite.cluster.ClusterNode; +import org.apache.ignite.internal.util.typedef.internal.S; +import org.apache.ignite.lang.IgniteBiPredicate; + +/** + * Multi-data center affinity backup filter that ensures each partition's data is distributed across multiple data centers, + * providing high availability and fault tolerance. This implementation guarantees at least one copy of the data in each + * data center and attempts to maintain the configured backup factor without discarding copies. + * <p> + * The filter works by grouping nodes based on their data center identification attribute (@see {@link ClusterNode#dataCenterId()}) + * and ensuring that for every partition, at least one node from each data center is included in the primary-backup set. + * <p> + * The filter will discard backup copies only if the number of available nodes in a given data center is less + * than the number of copies assigned to that data center. + * For example, if a partition has 4 copies (1 primary and 3 backups) and the cluster has 2 data centers, + * than 2 copies are assigned to each data center. The only scenario when just a single copy is assigned to a node in a data center is when + * the number of nodes in that data center is one. + * <p> + * This class is constructed with a number of data centers the cluster spans and a number of backups of the cache this filter is applied to. + * Implementation expects that all copies can be spread evenly across all data centers. In other words, (backups + 1) is divisible by + * number of data centers without remainder. Uneven distributions of copies are not supported. + * <p> + * Warning: Ensure that all nodes have a consistent and valid data center identifier attribute. Missing or inconsistent values + * may lead to unexpected placement of data. + * </pre> + * <h2 class="header">Spring Example</h2> + * Create a partitioned cache template where each data center has at least one copy of the data, and the backup count is maintained. + * <pre name="code" class="xml"> + * <property name="cacheConfiguration"> + * <list> + * <bean id="cache-template-bean" abstract="true" class="org.apache.ignite.configuration.CacheConfiguration"> + * <property name="name" value="JobcaseDefaultCacheConfig*"/> + * <property name="cacheMode" value="PARTITIONED" /> + * <property name="backups" value="3" /> + * <property name="affinity"> + * <bean class="org.apache.ignite.cache.affinity.rendezvous.RendezvousAffinityFunction"> + * <property name="affinityBackupFilter"> + * <bean class="org.apache.ignite.cache.affinity.rendezvous.MdcAffinityBackupFilter"> + * <constructor-arg value="2"/> <!-- dcsNumber --> + * <constructor-arg value="3"/> <!-- backups, the same as in the cache template --> + * </bean> + * </property> + * </bean> + * </property> + * </bean> + * </list> + * </property> + * </pre> + * <p> + * With more backups, additional replicas can be distributed across different data centers to further improve redundancy. + */ +public class MdcAffinityBackupFilter implements IgniteBiPredicate<ClusterNode, List<ClusterNode>> { + /** */ + private static final long serialVersionUID = 1L; + + /** */ + private final int partCopiesPerDc; + + /** + * @param dcsNum Number of data centers. + * @param backups Number of backups. + */ + public MdcAffinityBackupFilter(int dcsNum, int backups) { + if (dcsNum < 2) { + throw new IllegalArgumentException("MdcAffinityBackupFilter cannot be used in an environment with only one datacenter. " + + "Number of datacenters must be at least 2."); + } + + int numCopies = backups + 1; + + partCopiesPerDc = numCopies / dcsNum; + int remainder = numCopies % dcsNum; + + if (remainder != 0) { + String suggestion = "recommended "; + if (numCopies - remainder <= 0) + suggestion += "value is " + (backups + (dcsNum - remainder)); + else + suggestion += "values are " + (backups - remainder) + " and " + (backups + (dcsNum - remainder)); + + throw new IllegalArgumentException("Number of copies is not completely divisible by number of datacenters, " + + "copies cannot be distributed evenly across DCs. " + + "Please adjust the number of backups, " + suggestion); + } + + + } + + /** + * Defines a predicate which returns {@code true} if a node is acceptable for a backup + * or {@code false} otherwise. + * An acceptable node is the one that belongs to a data center that has some additional copies of partition to assign to. + * @param candidate A node that is a candidate for becoming a backup node for a partition. + * @param previouslySelected A list of primary/backup nodes already chosen for a partition. + * The primary is first. + */ Review Comment: No need to define javadoc for overridden methods. -- 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]
