[WIP] Add DownSampleAction to downsampling time_series index

rest-api-spec/src/main/resources/rest-api-spec/api/rollup.downsample.json

@@ -0,0 +1,41 @@
+{
+  "rollup.downsample":{
+    "documentation":{
+      "url":"https://www.elastic.co/guide/en/elasticsearch/reference/current/xpack-rollup.html",
+      "description":"Downsample an index"
+    },
+    "stability":"experimental",
+    "visibility":"public",
+    "headers":{
+      "accept": [ "application/json"],
+      "content_type": ["application/json"]
+    },
+    "url": {
+      "paths": [
+        {
+          "path": "/{index}/_downsample/{downsample_index}",
+          "methods": [
+            "POST"
+          ],
+          "parts": {
+            "index": {
+              "type": "string",
+              "description": "The index to down sample",
+              "required": true
+            },
+            "downsample_index": {
+              "type": "string",
+              "description": "The name of the down sample index to create",
+              "required": true
+            }
+          }
+        }
+      ]
+    },
+    "params":{},
+    "body":{
+      "description":"The downsample configuration",
+      "required":true
+    }
+  }
+}

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

@@ -0,0 +1,134 @@
+/*
+ * 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.core.downsample;
+
+import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.core.Nullable;
+import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramInterval;
+import org.elasticsearch.xcontent.ConstructingObjectParser;
+import org.elasticsearch.xcontent.ObjectParser.ValueType;
+import org.elasticsearch.xcontent.ParseField;
+import org.elasticsearch.xcontent.ToXContentObject;
+import org.elasticsearch.xcontent.XContentBuilder;
+import org.elasticsearch.xcontent.XContentParser;
+
+import java.io.IOException;
+import java.time.ZoneId;
+import java.util.Objects;
+
+import static org.elasticsearch.xcontent.ConstructingObjectParser.optionalConstructorArg;
+
+public class DownsampleDateHistogramConfig implements Writeable, ToXContentObject {
+    static final String NAME = "date_histogram";
+    public static final String FIXED_INTERVAL = "fixed_interval";
+    public static final String CALENDAR_INTERVAL = "calendar_interval";
+    public static final String TIME_ZONE = "time_zone";
+    public static final String DEFAULT_TIMEZONE = ZoneId.of("UTC").getId();
+
+    private static final ConstructingObjectParser<DownsampleDateHistogramConfig, Void> PARSER;
+    static {
+        PARSER = new ConstructingObjectParser<>(
+            NAME,
+            a -> new DownsampleDateHistogramConfig((DateHistogramInterval) a[0], (DateHistogramInterval) a[1], (String) a[2])
+        );
+        PARSER.declareField(
+            optionalConstructorArg(),
+            p -> new DateHistogramInterval(p.text()),
+            new ParseField(CALENDAR_INTERVAL),
+            ValueType.STRING
+        );
+        PARSER.declareField(
+            optionalConstructorArg(),
+            p -> new DateHistogramInterval(p.text()),
+            new ParseField(FIXED_INTERVAL),
+            ValueType.STRING
+        );
+        PARSER.declareString(optionalConstructorArg(), new ParseField(TIME_ZONE));
+    }
+
+    private final DateHistogramInterval calendarInterval;
+    private final DateHistogramInterval fixedInterval;
+    private final String timeZone;
+
+    public DownsampleDateHistogramConfig(
+        final @Nullable DateHistogramInterval calendarInterval,
+        final @Nullable DateHistogramInterval fixedInterval,
+        final @Nullable String timeZone
+    ) {
+        this.calendarInterval = calendarInterval;
+        this.fixedInterval = fixedInterval;
+        this.timeZone = (timeZone != null && timeZone.isEmpty() == false) ? timeZone : DEFAULT_TIMEZONE;
+    }
+
+    public DownsampleDateHistogramConfig(final StreamInput in) throws IOException {
+        this.calendarInterval = new DateHistogramInterval(in);
+        this.fixedInterval = new DateHistogramInterval(in);
+        this.timeZone = in.readString();
+    }
+
+    @Override
+    public void writeTo(final StreamOutput out) throws IOException {
+        out.writeOptionalWriteable(calendarInterval);
+        out.writeOptionalWriteable(fixedInterval);
+        out.writeString(timeZone);
+    }
+
+    @Override
+    public XContentBuilder toXContent(final XContentBuilder builder, final Params params) throws IOException {
+        builder.startObject();
+        {
+            builder.field(CALENDAR_INTERVAL, calendarInterval);
+            builder.field(FIXED_INTERVAL, fixedInterval);
+            builder.field(TIME_ZONE, timeZone);
+        }
+        return builder.endObject();
+    }
+
+    public static DownsampleDateHistogramConfig fromXContent(final XContentParser parser) throws IOException {
+        return PARSER.parse(parser, null);
+    }
+
+    public DateHistogramInterval getCalendarInterval() {
+        return calendarInterval;
+    }
+
+    public DateHistogramInterval getFixedInterval() {
+        return fixedInterval;
+    }
+
+    public String getTimeZone() {
+        return timeZone;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        DownsampleDateHistogramConfig that = (DownsampleDateHistogramConfig) o;
+        return Objects.equals(calendarInterval, that.calendarInterval)
+            && Objects.equals(fixedInterval, that.fixedInterval)
+            && Objects.equals(timeZone, that.timeZone);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(calendarInterval, fixedInterval, timeZone);
+    }
+
+    @Override
+    public String toString() {
+        return Strings.toString(this, true, true);
+    }
+}

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/downsample/action/DownSampleAction.java

@@ -0,0 +1,108 @@
+/*
+ * 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.core.downsample.action;
+
+import org.elasticsearch.action.ActionRequestValidationException;
+import org.elasticsearch.action.ActionType;
+import org.elasticsearch.action.IndicesRequest;
+import org.elasticsearch.action.support.IndicesOptions;
+import org.elasticsearch.action.support.master.AcknowledgedResponse;
+import org.elasticsearch.action.support.master.MasterNodeRequest;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.xcontent.ToXContentObject;
+import org.elasticsearch.xcontent.XContentBuilder;
+import org.elasticsearch.xpack.core.downsample.DownsampleDateHistogramConfig;
+
+import java.io.IOException;
+import java.util.Objects;
+
+public class DownSampleAction extends ActionType<AcknowledgedResponse> {
+    public static final DownSampleAction INSTANCE = new DownSampleAction();
+    public static final String NAME = "indices:admin/xpack/downsample";
+
+    private DownSampleAction() {
+        super(NAME, AcknowledgedResponse::readFrom);
+    }
+
+    public static class Request extends MasterNodeRequest<DownSampleAction.Request> implements IndicesRequest, ToXContentObject {
+        private String sourceIndex;
+        private String downsampleIndex;
+        private DownsampleDateHistogramConfig downsampleConfig;
+
+        public Request(String sourceIndex, String downsampleIndex, DownsampleDateHistogramConfig downsampleConfig) {
+            this.sourceIndex = sourceIndex;
+            this.downsampleIndex = downsampleIndex;
+            this.downsampleConfig = downsampleConfig;
+        }
+
+        public Request() {}
+
+        public Request(StreamInput in) throws IOException {
+            super(in);
+            sourceIndex = in.readString();
+            downsampleIndex = in.readString();
+            downsampleConfig = new DownsampleDateHistogramConfig(in);
+        }
+
+        @Override
+        public ActionRequestValidationException validate() {
+            return null;
+        }
+
+        @Override
+        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+            builder.startObject();
+            builder.field("source_index", sourceIndex);
+            builder.field("downsample_index", downsampleIndex);
+            downsampleConfig.toXContent(builder, params);
+            builder.endObject();
+            return builder;
+        }
+
+        @Override
+        public String[] indices() {
+            return new String[] { sourceIndex };
+        }
+
+        @Override
+        public IndicesOptions indicesOptions() {
+            return IndicesOptions.STRICT_SINGLE_INDEX_NO_EXPAND_FORBID_CLOSED;
+        }
+
+        public String getSourceIndex() {
+            return sourceIndex;
+        }
+
+        public String getDownsampleIndex() {
+            return downsampleIndex;
+        }
+
+        public DownsampleDateHistogramConfig getDownsampleConfig() {
+            return downsampleConfig;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (o == null || getClass() != o.getClass()) {
+                return false;
+            }
+            Request request = (Request) o;
+            return Objects.equals(sourceIndex, request.sourceIndex)
+                && Objects.equals(downsampleIndex, request.downsampleIndex)
+                && Objects.equals(downsampleConfig, request.downsampleConfig);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(sourceIndex, downsampleIndex, downsampleConfig);
+        }
+    }
+}

x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/Rollup.java

@@ -37,6 +37,7 @@
 import org.elasticsearch.xcontent.NamedXContentRegistry;
 import org.elasticsearch.xpack.core.action.XPackInfoFeatureAction;
 import org.elasticsearch.xpack.core.action.XPackUsageFeatureAction;
+import org.elasticsearch.xpack.core.downsample.action.DownSampleAction;
 import org.elasticsearch.xpack.core.rollup.RollupField;
 import org.elasticsearch.xpack.core.rollup.action.DeleteRollupJobAction;
 import org.elasticsearch.xpack.core.rollup.action.GetRollupCapsAction;
@@ -66,7 +67,9 @@
 import org.elasticsearch.xpack.rollup.rest.RestRollupSearchAction;
 import org.elasticsearch.xpack.rollup.rest.RestStartRollupJobAction;
 import org.elasticsearch.xpack.rollup.rest.RestStopRollupJobAction;
+import org.elasticsearch.xpack.rollup.v2.RestDownSampleAction;
 import org.elasticsearch.xpack.rollup.v2.RestRollupAction;
+import org.elasticsearch.xpack.rollup.v2.TransportDownSampleAction;
 import org.elasticsearch.xpack.rollup.v2.TransportRollupAction;
 import org.elasticsearch.xpack.rollup.v2.TransportRollupIndexerAction;
 
@@ -142,6 +145,7 @@ public List<RestHandler> getRestHandlers(
 
         if (RollupV2.isEnabled()) {
             handlers.add(new RestRollupAction());
+            handlers.add(new RestDownSampleAction());
         }
 
         return handlers;
@@ -167,6 +171,7 @@ public List<RestHandler> getRestHandlers(
         if (RollupV2.isEnabled()) {
             actions.add(new ActionHandler<>(RollupIndexerAction.INSTANCE, TransportRollupIndexerAction.class));
             actions.add(new ActionHandler<>(RollupAction.INSTANCE, TransportRollupAction.class));
+            actions.add(new ActionHandler<>(DownSampleAction.INSTANCE, TransportDownSampleAction.class));
         }
 
         return actions;

x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/v2/RestDownSampleAction.java

@@ -0,0 +1,42 @@
+/*
+ * 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.rollup.v2;
+
+import org.elasticsearch.client.internal.node.NodeClient;
+import org.elasticsearch.rest.BaseRestHandler;
+import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.action.RestToXContentListener;
+import org.elasticsearch.xpack.core.downsample.DownsampleDateHistogramConfig;
+import org.elasticsearch.xpack.core.downsample.action.DownSampleAction;
+
+import java.io.IOException;
+import java.util.List;
+
+import static org.elasticsearch.rest.RestRequest.Method.POST;
+
+public class RestDownSampleAction extends BaseRestHandler {
+    @Override
+    public List<Route> routes() {
+        return List.of(new Route(POST, "/{index}/_downsample/{downsample_index}"));
+    }
+
+    @Override
+    protected RestChannelConsumer prepareRequest(RestRequest restRequest, NodeClient client) throws IOException {
+        String index = restRequest.param("index");
+        String downsampleIndex = restRequest.param("downsample_index");
+        DownsampleDateHistogramConfig config = DownsampleDateHistogramConfig.fromXContent(restRequest.contentParser());
+        DownSampleAction.Request request = new DownSampleAction.Request(index, downsampleIndex, config);
+        return channel -> client.execute(DownSampleAction.INSTANCE, request, new RestToXContentListener<>(channel));
+    }
+
+    @Override
+    public String getName() {
+        return "downsample_action";
+    }
+
+}