ifesdjeen commented on code in PR #4630: URL: https://github.com/apache/cassandra/pull/4630#discussion_r3001832731
########## src/java/org/apache/cassandra/db/SystemPeersValidator.java: ########## @@ -0,0 +1,185 @@ +/* + * 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.cassandra.db; + +import java.net.InetAddress; +import java.util.HashMap; +import java.util.HashSet; +import java.util.Map; +import java.util.Objects; +import java.util.Set; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.cassandra.cql3.UntypedResultSet; +import org.apache.cassandra.db.marshal.UTF8Type; +import org.apache.cassandra.db.virtual.PeersTable; +import org.apache.cassandra.locator.InetAddressAndPort; +import org.apache.cassandra.schema.SchemaConstants; +import org.apache.cassandra.tcm.ClusterMetadata; +import org.apache.cassandra.tcm.membership.Location; +import org.apache.cassandra.tcm.membership.NodeAddresses; +import org.apache.cassandra.tcm.membership.NodeId; +import org.apache.cassandra.utils.FBUtilities; + +import static org.apache.cassandra.cql3.QueryProcessor.executeInternal; +import static org.apache.cassandra.db.SystemKeyspace.LEGACY_PEERS; +import static org.apache.cassandra.db.SystemKeyspace.PEERS_V2; + +/** + * Validator to ensure system.peers and system.peers_v2 tables match ClusterMetadata. + * These tables are maintained for existing clients and tools which read from them to determine + * topology and schema information, while Cassandra itself uses ClusterMetadata as the source of truth. + * + * This validator detects inconsistencies and automatically repairs them by synchronizing + * the peers tables with the current ClusterMetadata. + * + * The system_views.peers virtual table provides a live view on the current ClusterMetadata + * and includes all members of the cluster, unlike the legacy tables which exclude the local node. + */ +public final class SystemPeersValidator +{ + private static final Logger logger = LoggerFactory.getLogger(SystemPeersValidator.class); + private static final String SELECT_PEERS_V2_QUERY = String.format("SELECT * FROM %s.%s", + SchemaConstants.SYSTEM_KEYSPACE_NAME, PEERS_V2); + private static final String SELECT_PEERS_QUERY = String.format("SELECT * FROM %s.%s", + SchemaConstants.SYSTEM_KEYSPACE_NAME, LEGACY_PEERS); + private static final String DELETE_PEERS_V2_QUERY = String.format("DELETE FROM %s.%s WHERE peer = ? AND peer_port = ?", + SchemaConstants.SYSTEM_KEYSPACE_NAME, PEERS_V2); + private static final String DELETE_PEERS_QUERY = String.format("DELETE FROM %s.%s WHERE peer = ?", + SchemaConstants.SYSTEM_KEYSPACE_NAME, LEGACY_PEERS); + + public static void validateAndRepair(ClusterMetadata metadata) + { + Map<InetAddressAndPort, UntypedResultSet.Row> peersV2Rows = getPeersV2Rows(); + Map<InetAddress, UntypedResultSet.Row> peersRows = getPeersRows(); + + Map<InetAddressAndPort, NodeId> knownEndpoints = new HashMap<>(); + Set<InetAddress> knownAddresses = new HashSet<>(); + InetAddressAndPort localEndpoint = FBUtilities.getBroadcastAddressAndPort(); + for (InetAddressAndPort endpoint : metadata.directory.allJoinedEndpoints()) + { + if (endpoint.equals(localEndpoint)) + continue; + knownEndpoints.put(endpoint, metadata.directory.peerId(endpoint)); + knownAddresses.add(endpoint.getAddress()); + } + + for (InetAddressAndPort endpoint : peersV2Rows.keySet()) + { + if (!knownEndpoints.containsKey(endpoint)) + { + logger.info("Removing stale peer {} from {}", endpoint, PEERS_V2); + executeInternal(DELETE_PEERS_V2_QUERY, endpoint.getAddress(), endpoint.getPort()); + } + } + + for (InetAddress address : peersRows.keySet()) + { + if (!knownAddresses.contains(address)) + { + logger.info("Removing stale peer {} from {}", address, LEGACY_PEERS); + executeInternal(DELETE_PEERS_QUERY, address); + } + } + + for (Map.Entry<InetAddressAndPort, NodeId> entry : knownEndpoints.entrySet()) + { + NodeId nodeId = entry.getValue(); + InetAddressAndPort endpoint = entry.getKey(); + UntypedResultSet.Row peersV2Row = peersV2Rows.get(endpoint); + UntypedResultSet.Row peersRow = peersRows.get(endpoint.getAddress()); + + boolean peersV2NeedsRepair = needsRepair(peersV2Row, endpoint, PEERS_V2, nodeId, metadata); + boolean peersNeedsRepair = needsRepair(peersRow, endpoint, LEGACY_PEERS, nodeId, metadata); + + if (peersV2NeedsRepair || peersNeedsRepair) + PeersTable.updateLegacyPeerTable(nodeId, metadata, metadata); + } + } + + private static boolean needsRepair(UntypedResultSet.Row row, InetAddressAndPort endpoint, + String table, NodeId nodeId, ClusterMetadata metadata) + { + if (row == null) + { + logger.info("Adding missing peer {} to {}", endpoint, table); + return true; + } + boolean isEquivalent = PEERS_V2.equals(table) + ? peersV2RowIsEquivalent(row, nodeId, metadata) + : peersRowIsEquivalent(row, nodeId, metadata); + if (!isEquivalent) + { + logger.info("Repairing mismatched peer {} in {}: {}", endpoint, table, row); + return true; + } + return false; + } + + private static boolean peersV2RowIsEquivalent(UntypedResultSet.Row row, NodeId nodeId, ClusterMetadata metadata) + { + NodeAddresses addresses = metadata.directory.getNodeAddresses(nodeId); + return commonColumnsAreEquivalent(row, nodeId, addresses, metadata) + && row.has("preferred_port") && row.getInt("preferred_port") == addresses.broadcastAddress.getPort() + && row.has("native_port") && row.getInt("native_port") == addresses.nativeAddress.getPort(); + } + + private static boolean peersRowIsEquivalent(UntypedResultSet.Row row, NodeId nodeId, ClusterMetadata metadata) + { + NodeAddresses addresses = metadata.directory.getNodeAddresses(nodeId); + return commonColumnsAreEquivalent(row, nodeId, addresses, metadata); + } + + private static boolean commonColumnsAreEquivalent(UntypedResultSet.Row row, NodeId nodeId, + NodeAddresses addresses, ClusterMetadata metadata) + { + Location location = metadata.directory.location(nodeId); + // This column is differently named in the peers and peers_v2 tables + String nativeAddressColumn = row.has("native_address") ? "native_address" : "rpc_address"; Review Comment: should we just pass from outside which table we're dealing with and assert correspondingly? -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
