[improvement](decommission be) decommission check replica num #32748

fe/fe-core/src/main/java/org/apache/doris/alter/SystemHandler.java

@@ -33,24 +33,34 @@
 import org.apache.doris.analysis.ModifyFrontendHostNameClause;
 import org.apache.doris.catalog.Database;
 import org.apache.doris.catalog.Env;
+import org.apache.doris.catalog.MysqlCompatibleDatabase;
 import org.apache.doris.catalog.OlapTable;
+import org.apache.doris.catalog.Partition;
+import org.apache.doris.catalog.ReplicaAllocation;
+import org.apache.doris.catalog.Table;
 import org.apache.doris.catalog.TabletInvertedIndex;
 import org.apache.doris.common.Config;
 import org.apache.doris.common.DdlException;
 import org.apache.doris.common.UserException;
+import org.apache.doris.common.util.DebugPointUtil;
 import org.apache.doris.common.util.NetUtils;
 import org.apache.doris.ha.FrontendNodeType;
+import org.apache.doris.resource.Tag;
 import org.apache.doris.system.Backend;
 import org.apache.doris.system.SystemInfoService;
 import org.apache.doris.system.SystemInfoService.HostInfo;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
 import org.apache.commons.lang3.NotImplementedException;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 /*
  * SystemHandler is for
@@ -220,12 +230,81 @@ public static List<Backend> checkDecommission(List<HostInfo> hostInfos)
             decommissionBackends.add(backend);
         }
 
-        // TODO(cmy): check if replication num can be met
+        checkDecommissionWithReplicaAllocation(decommissionBackends);
+
         // TODO(cmy): check remaining space
 
         return decommissionBackends;
     }
 
+    private static void checkDecommissionWithReplicaAllocation(List<Backend> decommissionBackends)
+            throws DdlException {
+        if (decommissionBackends.isEmpty()
+                || DebugPointUtil.isEnable("SystemHandler.decommission_no_check_replica_num")) {
+            return;
+        }
+
+        Set<Tag> decommissionTags = decommissionBackends.stream().map(be -> be.getLocationTag())
+                .collect(Collectors.toSet());
+        Map<Tag, Integer> tagAvailBackendNums = Maps.newHashMap();
+        for (Backend backend : Env.getCurrentSystemInfo().getAllBackends()) {
+            long beId = backend.getId();
+            if (!backend.isScheduleAvailable()
+                    || decommissionBackends.stream().anyMatch(be -> be.getId() == beId)) {
+                continue;
+            }
+
+            Tag tag = backend.getLocationTag();
+            if (tag != null) {
+                tagAvailBackendNums.put(tag, tagAvailBackendNums.getOrDefault(tag, 0) + 1);
+            }
+        }
+
+        Env env = Env.getCurrentEnv();
+        List<Long> dbIds = env.getInternalCatalog().getDbIds();
+        for (Long dbId : dbIds) {
+            Database db = env.getInternalCatalog().getDbNullable(dbId);
+            if (db == null) {
+                continue;
+            }
+
+            if (db instanceof MysqlCompatibleDatabase) {
+                continue;
+            }
+
+            for (Table table : db.getTables()) {
+                table.readLock();
+                try {
+                    if (!table.isManagedTable()) {
+                        continue;
+                    }
+
+                    OlapTable tbl = (OlapTable) table;
+                    for (Partition partition : tbl.getAllPartitions()) {
+                        ReplicaAllocation replicaAlloc = tbl.getPartitionInfo().getReplicaAllocation(partition.getId());
+                        for (Map.Entry<Tag, Short> entry : replicaAlloc.getAllocMap().entrySet()) {
+                            Tag tag = entry.getKey();
+                            if (!decommissionTags.contains(tag)) {
+                                continue;
+                            }
+                            int replicaNum = (int) entry.getValue();
+                            int backendNum = tagAvailBackendNums.getOrDefault(tag, 0);
+                            if (replicaNum > backendNum) {
+                                throw new DdlException("After decommission, partition " + partition.getName()
+                                        + " of table " + db.getFullName() + "." + tbl.getName()
+                                        + " 's replication allocation { " + replicaAlloc
+                                        + " } > available backend num " + backendNum + " on tag " + tag
+                                        + ", otherwise need to decrease the partition's replication num.");
+                            }
+                        }
+                    }
+                } finally {
+                    table.readUnlock();
+                }
+            }
+        }
+    }
+
     @Override
     public synchronized void cancel(CancelStmt stmt) throws DdlException {
         CancelAlterSystemStmt cancelAlterSystemStmt = (CancelAlterSystemStmt) stmt;

regression-test/framework/src/main/groovy/org/apache/doris/regression/suite/Suite.groovy

@@ -570,6 +570,9 @@ class Suite implements GroovyInterceptable {
         assert p.exitValue() == 0
     }
 
+    List<String> getFrontendIpHttpPort() {
+        return sql_return_maparray("show frontends").collect { it.Host + ":" + it.HttpPort };
+    }
 
     void getBackendIpHttpPort(Map<String, String> backendId_to_backendIP, Map<String, String> backendId_to_backendHttpPort) {
         List<List<Object>> backends = sql("show backends");

regression-test/pipeline/p0/conf/fe.conf

@@ -78,6 +78,8 @@ enable_map_type=true
 enable_struct_type=true
 enable_feature_binlog=true
 
+enable_debug_points=true
+
 # enable mtmv
 enable_mtmv = true
 

regression-test/pipeline/p1/conf/be.conf

@@ -71,3 +71,4 @@ enable_set_in_bitmap_value=true
 enable_feature_binlog=true
 max_sys_mem_available_low_water_mark_bytes=69206016
 enable_merge_on_write_correctness_check=false
+enable_debug_points=true

regression-test/pipeline/p1/conf/fe.conf

@@ -75,6 +75,8 @@ remote_fragment_exec_timeout_ms=60000
 fuzzy_test_type=p1
 use_fuzzy_session_variable=true
 
+enable_debug_points=true
+
 # enable mtmv
 enable_mtmv = true
 

regression-test/suites/alter_p0/test_decommission_with_replica_num_fail.groovy

@@ -0,0 +1,55 @@
+// 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.
+
+suite('test_decommission_with_replica_num_fail') {
+    def tbl = 'test_decommission_with_replica_num_fail'
+    def backends = sql_return_maparray('show backends')
+    def replicaNum = 0
+    def targetBackend = null
+    for (def be : backends) {
+        def alive = be.Alive.toBoolean()
+        def decommissioned = be.SystemDecommissioned.toBoolean()
+        if (alive && !decommissioned) {
+            replicaNum++
+            targetBackend = be
+        }
+    }
+    assertTrue(replicaNum > 0)
+
+    sql "DROP TABLE IF EXISTS ${tbl} FORCE"
+    sql """
+        CREATE TABLE ${tbl}
+        (
+            k1 int,
+            k2 int
+        )
+        DISTRIBUTED BY HASH(k1) BUCKETS 6
+        PROPERTIES
+        (
+            "replication_num" = "${replicaNum}"
+        );
+    """
+    try {
+        test {
+            sql "ALTER SYSTEM DECOMMISSION BACKEND '${targetBackend.Host}:${targetBackend.HeartbeatPort}'"
+            exception "otherwise need to decrease the partition's replication num"
+        }
+    } finally {
+        sql "CANCEL DECOMMISSION BACKEND '${targetBackend.Host}:${targetBackend.HeartbeatPort}'"
+    }
+    sql "DROP TABLE IF EXISTS ${tbl} FORCE"
+}

regression-test/suites/node_p0/test_backend.groovy

@@ -39,4 +39,44 @@ suite("test_backend") {
         result = sql """SHOW BACKENDS;"""
         logger.info("result:${result}")
     }
+
+    if (context.config.jdbcUser.equals("root")) {
+        def decommissionBe = null
+        try {
+            GetDebugPoint().enableDebugPointForAllFEs("SystemHandler.decommission_no_check_replica_num");
+            try_sql """admin set frontend config("drop_backend_after_decommission" = "false")"""
+            def result = sql_return_maparray """SHOW BACKENDS;"""
+            logger.info("show backends result:${result}")
+            for (def res : result) {
+                decommissionBe = res
+                break
+            }
+            sql """CANCEL DECOMMISSION BACKEND "${decommissionBe.Host}:${decommissionBe.HeartbeatPort}" """
+            result = sql """ALTER SYSTEM DECOMMISSION BACKEND "${decommissionBe.Host}:${decommissionBe.HeartbeatPort}" """
+            logger.info("ALTER SYSTEM DECOMMISSION BACKEND ${result}")
+            result = sql_return_maparray """SHOW BACKENDS;"""
+            for (def res : result) {
+                if (res.BackendId == "${decommissionBe.BackendId}") {
+                    assertTrue(res.SystemDecommissioned.toBoolean())
+                }
+            }
+        } finally {
+            try {
+                if (decommissionBe != null) {
+                    def result = sql """CANCEL DECOMMISSION BACKEND "${decommissionBe.Host}:${decommissionBe.HeartbeatPort}" """
+                    logger.info("CANCEL DECOMMISSION BACKEND ${result}")
+
+                    result = sql_return_maparray """SHOW BACKENDS;"""
+                    for (def res : result) {
+                        if (res.BackendId == "${decommissionBe.BackendId}") {
+                            assertFalse(res.SystemDecommissioned.toBoolean())
+                        }
+                    }
+                }
+            } finally {
+                GetDebugPoint().disableDebugPointForAllFEs('SystemHandler.decommission_no_check_replica_num');
+                try_sql """admin set frontend config("drop_backend_after_decommission" = "true")"""
+            }
+        }
+    }
 }