[fix](coordinator) fix union all instance number (apache#39999)

In following plan pattern, fragment 11 has 3 child fragments aligning
with 3 exchange nodes and the union plan node only have 2 plan children,
i.e, the aggr node and the exchange node(4). In current union node's
parallelism computing, it used the plan children's size to do iteration
to find the max parallel but ignore the last fragment's. Actually, it
should use fragment's children(exclude unpartitioned ones) instead of
plan node's children to do the iteration.

11:VUNION(703)
  |
  |----10:VAGGREGATE (update finalize)(697)
  |    |  group by: brand_name[apache#23], skc[apache#24]
  |    |  sortByGroupKey:false
  |    |  cardinality=1
  |    |  final projections: '1', brand_name[apache#25], skc[apache#26]
  |    |  final project output tuple id: 11
  |    |  distribute expr lists: skc[apache#24]
  |    |
  |    9:VHASH JOIN(691)
  |    |  join op: INNER JOIN(PARTITIONED)[]
  |    |  equal join conjunct: (skc[apache#19] = skc_code[#12])
  |    |  cardinality=1
  |    |  vec output tuple id: 9
  |    |  output tuple id: 9
  |    |  vIntermediate tuple ids: 8
  |    |  hash output slot ids: 18 19
  |    |  final projections: brand_name[apache#20], skc[apache#21]
  |    |  final project output tuple id: 9
  |    |  distribute expr lists: skc[apache#19]
  |    |  distribute expr lists: skc_code[#12]
  |    |
  |    |----6:VEXCHANGE
  |    |       offset: 0
  |    |       distribute expr lists: skc_code[#12]
  |    |
  |    8:VEXCHANGE
  |       offset: 0
  |       distribute expr lists:
  |
  4:VEXCHANGE
     offset: 0
     distribute expr lists:

fe/fe-core/src/main/java/org/apache/doris/qe/Coordinator.java

@@ -1788,7 +1788,6 @@ protected void computeFragmentHosts() throws Exception {
  }
 
  Pair<PlanNode, PlanNode> pairNodes = findLeftmostNode(fragment.getPlanRoot());
- PlanNode fatherNode = pairNodes.first;
  PlanNode leftMostNode = pairNodes.second;
 
  /*
@@ -1803,25 +1802,8 @@ protected void computeFragmentHosts() throws Exception {
  // (Case B)
  // there is no leftmost scan; we assign the same hosts as those of our
  // input fragment which has a higher instance_number
-
- int inputFragmentIndex = 0;
- int maxParallelism = 0;
- // If the fragment has three children, then the first child and the second child are
- // the children(both exchange node) of shuffle HashJoinNode,
- // and the third child is the right child(ExchangeNode) of broadcast HashJoinNode.
- // We only need to pay attention to the maximum parallelism among
- // the two ExchangeNodes of shuffle HashJoinNode.
- int childrenCount = (fatherNode != null) ? fatherNode.getChildren().size() : 1;
- for (int j = 0; j < childrenCount; j++) {
- int currentChildFragmentParallelism
- = fragmentExecParamsMap.get(fragment.getChild(j).getFragmentId()).instanceExecParams.size();
- if (currentChildFragmentParallelism > maxParallelism) {
- maxParallelism = currentChildFragmentParallelism;
- inputFragmentIndex = j;
- }
- }
-
- PlanFragmentId inputFragmentId = fragment.getChild(inputFragmentIndex).getFragmentId();
+ int maxParallelFragmentIndex = findMaxParallelFragmentIndex(fragment);
+ PlanFragmentId inputFragmentId = fragment.getChild(maxParallelFragmentIndex).getFragmentId();
  // AddAll() soft copy()
  int exchangeInstances = -1;
  if (ConnectContext.get() != null && ConnectContext.get().getSessionVariable() != null) {
@@ -1978,6 +1960,27 @@ protected void computeFragmentHosts() throws Exception {
  }
  }
 
+ private int findMaxParallelFragmentIndex(PlanFragment fragment) {
+ Preconditions.checkState(!fragment.getChildren().isEmpty(), "fragment has no children");
+
+ // exclude broadcast join right side's child fragments
+ List<PlanFragment> childFragmentCandidates = fragment.getChildren().stream()
+ .filter(e -> e.getOutputPartition() != DataPartition.UNPARTITIONED)
+ .collect(Collectors.toList());
+
+ int maxParallelism = 0;
+ int maxParaIndex = 0;
+ for (int i = 0; i < childFragmentCandidates.size(); i++) {
+ PlanFragmentId childFragmentId = childFragmentCandidates.get(i).getFragmentId();
+ int currentChildFragmentParallelism = fragmentExecParamsMap.get(childFragmentId).instanceExecParams.size();
+ if (currentChildFragmentParallelism > maxParallelism) {
+ maxParallelism = currentChildFragmentParallelism;
+ maxParaIndex = i;
+ }
+ }
+ return maxParaIndex;
+ }
+
  private TNetworkAddress getGroupCommitBackend(Map<TNetworkAddress, Long> addressToBackendID) {
  // Used for Nereids planner Group commit insert BE select.
  TNetworkAddress execHostport = new TNetworkAddress(groupCommitBackend.getHost(),

regression-test/suites/query_p0/union/test_union_instance.groovy

@@ -0,0 +1,88 @@
+// 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_union_instance") {
+ multi_sql """
+ drop table if exists t1;
+ drop table if exists t2;
+ drop table if exists t3;
+ drop table if exists t4;
+ CREATE TABLE `t1` (
+ `c1` int NULL,
+ `c2` int NULL,
+ `c3` int NULL
+ ) ENGINE=OLAP
+ DUPLICATE KEY(`c1`, `c2`, `c3`)
+ DISTRIBUTED BY HASH(`c1`) BUCKETS 3
+ PROPERTIES (
+ "replication_allocation" = "tag.location.default: 1");
+ 
+ insert into t1 values (1,1,1);
+ insert into t1 values (2,2,2);
+ insert into t1 values (3,3,3);
+
+ CREATE TABLE `t2` (
+ `year_week` varchar(45) NULL
+ ) ENGINE=OLAP
+ DUPLICATE KEY(`year_week`)
+ DISTRIBUTED BY HASH(`year_week`) BUCKETS 1
+ PROPERTIES (
+ "replication_allocation" = "tag.location.default: 1");
+ 
+ CREATE TABLE `t3` (
+ `unique_key` varchar(2999) NULL,
+ `brand_name` varchar(96) NULL,
+ `skc` varchar(150) NULL
+ ) ENGINE=OLAP
+ UNIQUE KEY(`unique_key`)
+ DISTRIBUTED BY HASH(`unique_key`) BUCKETS 20
+ PROPERTIES (
+ "replication_allocation" = "tag.location.default: 1");
+ 
+ CREATE TABLE `t4` (
+ `skc_code` varchar(150) NULL
+ ) ENGINE=OLAP
+ UNIQUE KEY(`skc_code`)
+ DISTRIBUTED BY HASH(`skc_code`) BUCKETS 1
+ PROPERTIES (
+ "replication_allocation" = "tag.location.default: 1");
+ 
+ set parallel_pipeline_task_num=1;
+ set disable_nereids_rules='PRUNE_EMPTY_PARTITION';
+ """
+ explain {
+ sql """
+ SELECT `t`.`year_week` AS `year_week`
+ ,'' AS `brand_name`
+ , '' AS `skc_code`
+ FROM `t1` a
+ CROSS JOIN `t2` t
+ union all
+ SELECT '1' AS `year_week`
+ ,`a`.`brand_name` AS `brand_name`
+ ,`a`.`skc` AS `skc_code`
+ FROM `t3` a
+ INNER JOIN[shuffle] `t4` b ON `a`.`skc` = `b`.`skc_code`
+ GROUP BY 1, 2, 3;
+ """
+ contains "3:VNESTED LOOP JOIN"
+ contains "4:VEXCHANGE"
+ contains "8:VEXCHANGE"
+ contains "6:VEXCHANGE"
+ contains "11:VUNION"
+ }
+}