Fix downsample persistent task params serialization bwc (#106878) (#1…

…06896)

Missing a check on the transport version results in unreadable cluster state
if it includes a serialized instance of DownsampleShardTaskParams.
serie indices.
Reading an optional array requires reading a boolean first which is required to
know if an array of values exists in serialized form. From 8.13 on we try to
read such a boolean which is not there because older versions don't write any
boolean nor any string array. Here we include the check on versions for backward
compatibility skipping reading any boolean or array whatsoever whenever not possible.

Customers using downsampling might have cluster states including such serielized
objects and would be unable to upgrade to version 8.13. They will be able to
upgrade to any version including this fix.

This fix has a side effect #106880

Co-authored-by: Salvatore Campagna <93581129+salvatore-campagna@users.noreply.github.com>

docs/changelog/106878.yaml

@@ -0,0 +1,5 @@
+pr: 106878
+summary: Gate reading of optional string array for bwc
+area: Downsampling
+type: bug
+issues: []

x-pack/plugin/downsample/qa/mixed-cluster/build.gradle

@@ -0,0 +1,49 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import org.elasticsearch.gradle.Version
+import org.elasticsearch.gradle.internal.info.BuildParams
+import org.elasticsearch.gradle.testclusters.StandaloneRestIntegTestTask
+
+apply plugin: 'elasticsearch.internal-yaml-rest-test'
+apply plugin: 'elasticsearch.internal-test-artifact'
+apply plugin: 'elasticsearch.bwc-test'
+
+
+dependencies {
+  testImplementation project(path: ':test:test-clusters')
+  yamlRestTestImplementation project(path: xpackModule('rollup'))
+}
+
+restResources {
+  restApi {
+    include '_common', 'bulk', 'cluster', 'indices', 'search', 'ingest.put_pipeline', 'ingest.delete_pipeline'
+  }
+}
+
+def supportedVersion = bwcVersion -> {
+  return bwcVersion.onOrAfter("8.8.0");
+}
+
+BuildParams.bwcVersions.withWireCompatible(supportedVersion) { bwcVersion, baseName ->
+
+  def yamlRestTest = tasks.register("v${bwcVersion}#yamlRestTest", StandaloneRestIntegTestTask) {
+    usesDefaultDistribution()
+    usesBwcDistribution(bwcVersion)
+    systemProperty("tests.old_cluster_version", bwcVersion)
+    testClassesDirs = sourceSets.yamlRestTest.output.classesDirs
+    classpath = sourceSets.yamlRestTest.runtimeClasspath
+  }
+
+  tasks.register(bwcTaskName(bwcVersion)) {
+    dependsOn yamlRestTest
+  }
+}
+
+tasks.named("yamlRestTest") {
+  enabled = false
+}

x-pack/plugin/downsample/qa/mixed-cluster/src/yamlRestTest/java/org/elasticsearch/xpack/downsample/MixedClusterDownsampleRestIT.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.downsample;
+
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
+import org.elasticsearch.test.cluster.ElasticsearchCluster;
+import org.elasticsearch.test.cluster.local.distribution.DistributionType;
+import org.elasticsearch.test.cluster.util.Version;
+import org.elasticsearch.test.rest.yaml.ClientYamlTestCandidate;
+import org.elasticsearch.test.rest.yaml.ESClientYamlSuiteTestCase;
+import org.junit.ClassRule;
+
+public class MixedClusterDownsampleRestIT extends ESClientYamlSuiteTestCase {
+
+    @ClassRule
+    public static ElasticsearchCluster cluster = ElasticsearchCluster.local()
+        .distribution(DistributionType.DEFAULT)
+        .withNode(node -> node.version(getOldVersion()))
+        .withNode(node -> node.version(Version.CURRENT))
+        .setting("xpack.security.enabled", "false")
+        .setting("xpack.license.self_generated.type", "trial")
+        .build();
+
+    static Version getOldVersion() {
+        return Version.fromString(System.getProperty("tests.old_cluster_version"));
+    }
+
+    @Override
+    protected String getTestRestCluster() {
+        return cluster.getHttpAddresses();
+    }
+
+    public MixedClusterDownsampleRestIT(final ClientYamlTestCandidate testCandidate) {
+        super(testCandidate);
+    }
+
+    @ParametersFactory
+    public static Iterable<Object[]> parameters() throws Exception {
+        return ESClientYamlSuiteTestCase.createParameters();
+    }
+
+}

x-pack/plugin/downsample/qa/mixed-cluster/src/yamlRestTest/resources/rest-api-spec/test/downsample/10_basic.yml

@@ -0,0 +1,152 @@
+setup:
+  - skip:
+      version: " - 8.4.99"
+      reason: "rollup renamed to downsample in 8.5.0"
+
+  - do:
+      indices.create:
+        index: test
+        body:
+          settings:
+            number_of_shards: 1
+            index:
+              mode: time_series
+              routing_path: [metricset, k8s.pod.uid]
+              time_series:
+                start_time: 2021-04-28T00:00:00Z
+                end_time: 2021-04-29T00:00:00Z
+          mappings:
+            properties:
+              "@timestamp":
+                type: date
+              metricset:
+                type: keyword
+                time_series_dimension: true
+              k8s:
+                properties:
+                  pod:
+                    properties:
+                      uid:
+                        type: keyword
+                        time_series_dimension: true
+                      name:
+                        type: keyword
+                      created_at:
+                        type: date_nanos
+                      running:
+                        type: boolean
+                      number_of_containers:
+                        type: integer
+                      ip:
+                        type: ip
+                      tags:
+                        type: keyword
+                      values:
+                        type: integer
+                      multi-counter:
+                        type: long
+                        time_series_metric: counter
+                      scaled-counter:
+                        type: scaled_float
+                        scaling_factor: 100
+                        time_series_metric: counter
+                      multi-gauge:
+                        type: integer
+                        time_series_metric: gauge
+                      scaled-gauge:
+                        type: scaled_float
+                        scaling_factor: 100
+                        time_series_metric: gauge
+                      network:
+                        properties:
+                          tx:
+                            type: long
+                            time_series_metric: gauge
+                          rx:
+                            type: long
+                            time_series_metric: gauge
+  - do:
+      bulk:
+        refresh: true
+        index: test
+        body:
+          - '{"index": {}}'
+          - '{"@timestamp": "2021-04-28T18:50:04.467Z", "metricset": "pod", "k8s": {"pod": {"name": "cat", "uid":"947e4ced-1786-4e53-9e0c-5c447e959507", "ip": "10.10.55.1", "multi-counter" : [10, 11, 12], "scaled-counter": 10.0, "multi-gauge": [100, 200, 150], "scaled-gauge": 100.0,  "network": {"tx": 2001818691, "rx": 802133794}, "created_at": "2021-04-28T19:34:00.000Z", "running": false, "number_of_containers": 2, "tags": ["backend", "prod"], "values": [2, 3, 6]}}}'
+          - '{"index": {}}'
+          - '{"@timestamp": "2021-04-28T18:50:24.467Z", "metricset": "pod", "k8s": {"pod": {"name": "cat", "uid":"947e4ced-1786-4e53-9e0c-5c447e959507", "ip": "10.10.55.26", "multi-counter" : [21, 22, 23], "scaled-counter": 20.0, "multi-gauge": [90, 91, 95], "scaled-gauge": 90.0, "network": {"tx": 2005177954, "rx": 801479970}, "created_at": "2021-04-28T19:35:00.000Z", "running": true, "number_of_containers": 2, "tags": ["backend", "prod", "us-west1"], "values": [1, 1, 3]}}}'
+          - '{"index": {}}'
+          - '{"@timestamp": "2021-04-28T20:50:44.467Z", "metricset": "pod", "k8s": {"pod": {"name": "cat", "uid":"947e4ced-1786-4e53-9e0c-5c447e959507", "ip": "10.10.55.41", "multi-counter" : [1, 5, 10], "scaled-counter": 1.0, "multi-gauge": [103, 110, 109], "scaled-gauge": 104.0, "network": {"tx": 2006223737, "rx": 802337279}, "created_at": "2021-04-28T19:36:00.000Z", "running": true, "number_of_containers": 2, "tags": ["backend", "prod", "us-west2"], "values": [4, 1, 2]}}}'
+          - '{"index": {}}'
+          - '{"@timestamp": "2021-04-28T20:51:04.467Z", "metricset": "pod", "k8s": {"pod": {"name": "cat", "uid":"947e4ced-1786-4e53-9e0c-5c447e959507", "ip": "10.10.55.22", "multi-counter" : [101, 102, 105], "scaled-counter": 100.0, "multi-gauge": [100, 100, 100], "scaled-gauge": 102.0, "network": {"tx": 2012916202, "rx": 803685721}, "created_at": "2021-04-28T19:37:00.000Z", "running": true, "number_of_containers": 2, "tags": ["backend", "prod"], "values": [2, 3, 1]}}}'
+          - '{"index": {}}'
+          - '{"@timestamp": "2021-04-28T18:50:03.142Z", "metricset": "pod", "k8s": {"pod": {"name": "dog", "uid":"df3145b3-0563-4d3b-a0f7-897eb2876ea9", "ip": "10.10.55.33", "multi-counter" : [7, 11, 44], "scaled-counter": 7.0, "multi-gauge": [100, 100, 102], "scaled-gauge": 100.0, "network": {"tx": 1434521831, "rx": 530575198}, "created_at": "2021-04-28T19:42:00.000Z", "running": false, "number_of_containers": 1, "tags": ["backend", "test"], "values": [2, 3, 4]}}}'
+          - '{"index": {}}'
+          - '{"@timestamp": "2021-04-28T18:50:23.142Z", "metricset": "pod", "k8s": {"pod": {"name": "dog", "uid":"df3145b3-0563-4d3b-a0f7-897eb2876ea9", "ip": "10.10.55.56", "multi-counter" : [0, 0, 1], "scaled-counter": 0.0, "multi-gauge": [101, 102, 102], "scaled-gauge": 101.0, "network": {"tx": 1434577921, "rx": 530600088}, "created_at": "2021-04-28T19:43:00.000Z", "running": false, "number_of_containers": 1, "tags": ["backend", "test", "us-west2"], "values": [2, 1, 1]}}}'
+          - '{"index": {}}'
+          - '{"@timestamp": "2021-04-28T19:50:53.142Z", "metricset": "pod", "k8s": {"pod": {"name": "dog", "uid":"df3145b3-0563-4d3b-a0f7-897eb2876ea9", "ip": "10.10.55.37", "multi-counter" : [1000, 1001, 1002], "scaled-counter": 1000.0, "multi-gauge": [99, 100, 110], "scaled-gauge": 99.0, "network": {"tx": 1434587694, "rx": 530604797}, "created_at": "2021-04-28T19:44:00.000Z", "running": true, "number_of_containers": 1, "tags": ["backend", "test", "us-west1"], "values": [4, 5, 2]}}}'
+          - '{"index": {}}'
+          - '{"@timestamp": "2021-04-28T19:51:03.142Z", "metricset": "pod", "k8s": {"pod": {"name": "dog", "uid":"df3145b3-0563-4d3b-a0f7-897eb2876ea9", "ip": "10.10.55.120", "multi-counter" : [76, 77, 78], "scaled-counter": 70.0, "multi-gauge": [95, 98, 100], "scaled-gauge": 95.0, "network": {"tx": 1434595272, "rx": 530605511}, "created_at": "2021-04-28T19:45:00.000Z", "running": true, "number_of_containers": 1, "tags": ["backend", "test", "us-west1"], "values": [3, 2, 1]}}}'
+
+  - do:
+      indices.put_settings:
+        index: test
+        body:
+          index.blocks.write: true
+
+---
+"Downsample index":
+
+  - do:
+      indices.downsample:
+        index: test
+        target_index: test-downsample
+        body:  >
+          {
+            "fixed_interval": "1h"
+          }
+  - is_true: acknowledged
+
+  - do:
+      search:
+        index: test-downsample
+        body:
+          sort: [ "@timestamp" ]
+
+  - length: { hits.hits: 4 }
+  - match:  { hits.hits.0._source._doc_count: 2 }
+  - match:  { hits.hits.0._source.metricset: pod }
+
+  # Assert rollup index settings
+  - do:
+      indices.get_settings:
+        index: test-downsample
+
+  - match: { test-downsample.settings.index.mode: time_series }
+  - match: { test-downsample.settings.index.time_series.end_time:   2021-04-29T00:00:00Z }
+  - match: { test-downsample.settings.index.time_series.start_time: 2021-04-28T00:00:00Z }
+  - match: { test-downsample.settings.index.routing_path: [ "metricset", "k8s.pod.uid"] }
+  - match: { test-downsample.settings.index.downsample.source.name: test }
+
+  # Assert rollup index mapping
+  - do:
+      indices.get_mapping:
+        index: test-downsample
+
+  - match: { test-downsample.mappings.properties.@timestamp.type: date }
+  - match: { test-downsample.mappings.properties.@timestamp.meta.fixed_interval: 1h }
+  - match: { test-downsample.mappings.properties.@timestamp.meta.time_zone: UTC }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.multi-gauge.type: aggregate_metric_double }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.multi-gauge.metrics: [ "min", "max", "sum", "value_count" ] }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.multi-gauge.default_metric: max }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.multi-gauge.time_series_metric: gauge }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.multi-counter.type: long }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.multi-counter.time_series_metric: counter }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.scaled-counter.type: scaled_float }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.scaled-counter.scaling_factor: 100 }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.scaled-counter.time_series_metric: counter }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.scaled-gauge.type: aggregate_metric_double }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.scaled-gauge.metrics: [ "min", "max", "sum", "value_count" ] }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.scaled-gauge.default_metric: max }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.scaled-gauge.time_series_metric: gauge }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.uid.type: keyword }
+  - match: { test-downsample.mappings.properties.k8s.properties.pod.properties.uid.time_series_dimension: true }

x-pack/plugin/downsample/src/main/java/org/elasticsearch/xpack/downsample/DownsampleShardIndexer.java

@@ -557,6 +557,15 @@ public XContentBuilder buildDownsampleDocument() throws IOException {
                 fieldProducer.write(builder);
             }
 
+            if (dimensions.length == 0) {
+                logger.debug("extracting dimensions from legacy tsid");
+                Map<?, ?> dimensions = (Map<?, ?>) DocValueFormat.TIME_SERIES_ID.format(tsid);
+                for (Map.Entry<?, ?> e : dimensions.entrySet()) {
+                    assert e.getValue() != null;
+                    builder.field((String) e.getKey(), e.getValue());
+                }
+            }
+
             builder.endObject();
             return builder;
         }

x-pack/plugin/downsample/src/main/java/org/elasticsearch/xpack/downsample/DownsampleShardTaskParams.java

@@ -10,6 +10,7 @@
 import org.elasticsearch.TransportVersion;
 import org.elasticsearch.TransportVersions;
 import org.elasticsearch.action.downsample.DownsampleConfig;
+import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.index.shard.ShardId;
@@ -36,6 +37,7 @@ public record DownsampleShardTaskParams(
     String[] dimensions
 ) implements PersistentTaskParams {
 
+    private static final TransportVersion V_8_13_0 = TransportVersions.ML_MODEL_IN_SERVICE_SETTINGS;
     public static final String NAME = DownsampleShardTask.TASK_NAME;
     private static final ParseField DOWNSAMPLE_CONFIG = new ParseField("downsample_config");
     private static final ParseField DOWNSAMPLE_INDEX = new ParseField("rollup_index");
@@ -71,7 +73,7 @@ public record DownsampleShardTaskParams(
             new ShardId(in),
             in.readStringArray(),
             in.readStringArray(),
-            in.readOptionalStringArray()
+            in.getTransportVersion().onOrAfter(V_8_13_0) ? in.readOptionalStringArray() : new String[] {}
         );
     }
 
@@ -85,7 +87,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         builder.field(SHARD_ID.getPreferredName(), shardId);
         builder.array(METRICS.getPreferredName(), metrics);
         builder.array(LABELS.getPreferredName(), labels);
-        builder.array(DIMENSIONS.getPreferredName(), dimensions);
+        if (dimensions.length > 0) {
+            builder.array(DIMENSIONS.getPreferredName(), dimensions);
+        }
         return builder.endObject();
     }
 
@@ -108,7 +112,9 @@ public void writeTo(StreamOutput out) throws IOException {
         shardId.writeTo(out);
         out.writeStringArray(metrics);
         out.writeStringArray(labels);
-        out.writeOptionalStringArray(dimensions);
+        if (out.getTransportVersion().onOrAfter(V_8_13_0)) {
+            out.writeOptionalStringArray(dimensions);
+        }
     }
 
     public static DownsampleShardTaskParams fromXContent(XContentParser parser) throws IOException {
@@ -157,7 +163,7 @@ public static class Builder {
         ShardId shardId;
         String[] metrics;
         String[] labels;
-        String[] dimensions;
+        String[] dimensions = Strings.EMPTY_ARRAY;
 
         public Builder downsampleConfig(final DownsampleConfig downsampleConfig) {
             this.downsampleConfig = downsampleConfig;
@@ -212,4 +218,9 @@ public DownsampleShardTaskParams build() {
             );
         }
     }
+
+    @Override
+    public String toString() {
+        return Strings.toString(this, true, true);
+    }
 }