[exporter/elasticsearch] Dynamically route documents by default (open-telemetry#38500)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

Breaking change.

Overhaul in document routing. New document routing logic:
```
Documents are statically or dynamically routed to the target index / data stream in the following order. The first routing mode that applies will be used.
1. "Static mode": Route to `logs_index` for log records, `metrics_index` for data points and `traces_index` for spans, if these configs are not empty respectively. [^3]
2. "Dynamic - Index attribute mode": Route to index name specified in `elasticsearch.index` attribute (precedence: log record / data point / span attribute > scope attribute > resource attribute) if the attribute exists. [^3]
3. "Dynamic - Data stream routing mode": Route to data stream constructed from `${data_stream.type}-${data_stream.dataset}-${data_stream.namespace}`,
where `data_stream.type` is `logs` for log records, `metrics` for data points, and `traces` for spans, and is static. [^3]
In a special case with `mapping::mode: bodymap`, `data_stream.type` field (valid values: `logs`, `metrics`) can be dynamically set from attributes.
The resulting documents will contain the corresponding `data_stream.*` fields, see restrictions applied to [Data Stream Fields](https://www.elastic.co/guide/en/ecs/current/ecs-data_stream.html).
   1. `data_stream.dataset` or `data_stream.namespace` in attributes (precedence: log record / data point / span attribute > scope attribute > resource attribute)
   2. Otherwise, if scope name matches regex `/receiver/(\w*receiver)`, `data_stream.dataset` will be capture group #1
   3. Otherwise, `data_stream.dataset` falls back to `generic` and `data_stream.namespace` falls back to `default`. 
```

```
In OTel mapping mode (`mapping::mode: otel`), there is special handling in addition to the above document routing rules in [Elasticsearch document routing](#elasticsearch-document-routing).
The order to determine the routing mode is the same as [Elasticsearch document routing](#elasticsearch-document-routing).

1. "Static mode": Span events are separate documents routed to `logs_index` if non-empty.
2. "Dynamic - Index attribute mode": Span events are separate documents routed using attribute `elasticsearch.index` (precedence: span event attribute > scope attribute > resource attribute) if the attribute exists.
3. "Dynamic - Data stream routing mode":
  - For all documents, `data_stream.dataset` will always be appended with `.otel`.
  - A special case to (3)(1) in [Elasticsearch document routing](#elasticsearch-document-routing), span events are separate documents that have `data_stream.type: logs` and are routed using data stream attributes (precedence: span event attribute > scope attribute > resource attribute)

```

Effective changes:
- Deprecate and make `{logs,metrics,traces}_dynamic_index` config no-op
- Config validation error on
`{logs,metrics,traces}_dynamic_index::enabled` and
`{logs,metrics,traces}_index` set at the same time, as users who rely on
dynamic index should not set `{logs,metrics,traces}_index`.
- Remove `elasticsearch.index.{prefix,suffix}` handling. Replace it with
`elasticsearch.index` handling that uses attribute value as index
directly. Users rely on the previously supported
`elasticsearch.index.prefix` and `elasticsearch.index.suffix` should
migrate to a transform processor that sets `elasticsearch.index`.
- Fix a bug where receiver-based routing overwrites data_stream.dataset.

Should be released together with
open-telemetry#38458

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes open-telemetry#38361

<!--Describe what testing was performed and which tests were added.-->
#### Testing

<!--Describe the documentation added.-->
#### Documentation

<!--Please delete paragraphs that you did not use before submitting.-->

---------

Co-authored-by: Andrzej Stencel <[email protected]>

Author: carsonip

.chloggen/elasticsearchexporter_dynamic-routing-default.yaml

@@ -0,0 +1,32 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: elasticsearchexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Dynamically route documents by default unless `{logs,metrics,traces}_index` is non-empty
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [38361]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+  Overhaul in document routing.
+  Deprecate and make `{logs,metrics,traces}_dynamic_index` config no-op.
+  Config validation error on `{logs,metrics,traces}_dynamic_index::enabled` and `{logs,metrics,traces}_index` set at the same time, as users who rely on dynamic index should not set `{logs,metrics,traces}_index`.
+  Remove `elasticsearch.index.{prefix,suffix}` handling. Replace it with `elasticsearch.index` handling that uses attribute value as index directly. Users rely on the previously supported `elasticsearch.index.prefix` and `elasticsearch.index.suffix` should migrate to a transform processor that sets `elasticsearch.index`.
+  Fix a bug where receiver-based routing overwrites data_stream.dataset.
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

exporter/elasticsearchexporter/README.md

@@ -118,33 +118,39 @@ Using the common `batcher` functionality provides several benefits over the defa
 
 ### Elasticsearch document routing
 
-Telemetry data will be written to signal specific data streams by default:
-logs to `logs-generic-default`, metrics to `metrics-generic-default`, and traces to `traces-generic-default`.
+Documents are statically or dynamically routed to the target index / data stream in the following order. The first routing mode that applies will be used.
+1. "Static mode": Route to `logs_index` for log records, `metrics_index` for data points and `traces_index` for spans, if these configs are not empty respectively. [^3]
+2. "Dynamic - Index attribute mode": Route to index name specified in `elasticsearch.index` attribute (precedence: log record / data point / span attribute > scope attribute > resource attribute) if the attribute exists. [^3]
+3. "Dynamic - Data stream routing mode": Route to data stream constructed from `${data_stream.type}-${data_stream.dataset}-${data_stream.namespace}`,
+where `data_stream.type` is `logs` for log records, `metrics` for data points, and `traces` for spans, and is static. [^3]
+In a special case with `mapping::mode: bodymap`, `data_stream.type` field (valid values: `logs`, `metrics`) can be dynamically set from attributes.
+The resulting documents will contain the corresponding `data_stream.*` fields, see restrictions applied to [Data Stream Fields](https://www.elastic.co/guide/en/ecs/current/ecs-data_stream.html).
+   1. `data_stream.dataset` or `data_stream.namespace` in attributes (precedence: log record / data point / span attribute > scope attribute > resource attribute)
+   2. Otherwise, if scope name matches regex `/receiver/(\w*receiver)`, `data_stream.dataset` will be capture group #1
+   3. Otherwise, `data_stream.dataset` falls back to `generic` and `data_stream.namespace` falls back to `default`. 
+
+[^3]: See additional handling in [Document routing exceptions for OTel data mode](#document-routing-exceptions-for-otel-data-mode)
+
 This can be customised through the following settings:
 
-- `logs_index`: The [index] or [data stream] name to publish events to.  The default value is `logs-generic-default`
+- `logs_index` (optional): The [index] or [data stream] name to publish logs (and span events in OTel mapping mode) to. `logs_index` should be empty unless all logs should be sent to the same index.
 
 - `logs_dynamic_index` (optional): uses resource, scope, or log record attributes to dynamically construct index name.
-  - `enabled`(default=false): Enable/Disable dynamic index for log records.  If `data_stream.dataset` or `data_stream.namespace` exist in attributes (precedence: log record attribute > scope attribute > resource attribute), they will be used to dynamically construct index name in the form `logs-${data_stream.dataset}-${data_stream.namespace}`. In a special case with `mapping::mode: bodymap`, `data_stream.type` field (valid values: `logs`, `metrics`) is also supported to dynamically construct index in the form `${data_stream.type}-${data_stream.dataset}-${data_stream.namespace}`. Otherwise, if
-    `elasticsearch.index.prefix` or `elasticsearch.index.suffix` exist in attributes (precedence: resource attribute > scope attribute > log record attribute), they will be used to dynamically construct index name in the form `${elasticsearch.index.prefix}${logs_index}${elasticsearch.index.suffix}`. Otherwise, if scope name matches regex `/receiver/(\w*receiver)`, `data_stream.dataset` will be capture group #1. Otherwise, the index name falls back to `logs-generic-default`, and `logs_index` config will be ignored. Except for prefix/suffix attribute presence, the resulting docs will contain the corresponding `data_stream.*` fields, see restrictions applied to [Data Stream Fields](https://www.elastic.co/guide/en/ecs/current/ecs-data_stream.html).
+  - `enabled`(DEPRECATED): No-op. Documents are now always routed dynamically unless `logs_index` is not empty. Will be removed in a future version.
 
-- `metrics_index` (optional): The [index] or [data stream] name to publish metrics to. The default value is `metrics-generic-default`.
-  ⚠️ Note that metrics support is currently in development.
+- `metrics_index` (optional): The [index] or [data stream] name to publish metrics to. `metrics_index` should be empty unless all metrics should be sent to the same index. Note that metrics support is currently in development.
 
 - `metrics_dynamic_index` (optional): uses resource, scope or data point attributes to dynamically construct index name.
-  ⚠️ Note that metrics support is currently in development.
-  - `enabled`(default=true): Enable/disable dynamic index for metrics. If `data_stream.dataset` or `data_stream.namespace` exist in attributes (precedence: data point attribute > scope attribute > resource attribute), they will be used to dynamically construct index name in the form `metrics-${data_stream.dataset}-${data_stream.namespace}`. Otherwise, if
- `elasticsearch.index.prefix` or `elasticsearch.index.suffix` exist in attributes (precedence: resource attribute > scope attribute > data point attribute), they will be used to dynamically construct index name in the form `${elasticsearch.index.prefix}${metrics_index}${elasticsearch.index.suffix}`. Otherwise, if scope name matches regex `/receiver/(\w*receiver)`, `data_stream.dataset` will be capture group #1. Otherwise, the index name falls back to `metrics-generic-default`, and `metrics_index` config will be ignored. Except for prefix/suffix attribute presence, the resulting docs will contain the corresponding `data_stream.*` fields, see restrictions applied to [Data Stream Fields](https://www.elastic.co/guide/en/ecs/current/ecs-data_stream.html).
+  - `enabled`(DEPRECATED): No-op. Documents are now always routed dynamically unless `metrics_index` is not empty. Will be removed in a future version.
 
-- `traces_index`: The [index] or [data stream] name to publish traces to. The default value is `traces-generic-default`.
+- `traces_index` (optional): The [index] or [data stream] name to publish traces to. `traces_index` should be empty unless all traces should be sent to the same index.
 
 - `traces_dynamic_index` (optional): uses resource, scope, or span attributes to dynamically construct index name.
-  - `enabled`(default=false): Enable/Disable dynamic index for trace spans. If `data_stream.dataset` or `data_stream.namespace` exist in attributes (precedence: span attribute > scope attribute > resource attribute), they will be used to dynamically construct index name in the form `traces-${data_stream.dataset}-${data_stream.namespace}`. Otherwise, if
-    `elasticsearch.index.prefix` or `elasticsearch.index.suffix` exist in attributes (precedence: resource attribute > scope attribute > span attribute), they will be used to dynamically construct index name in the form `${elasticsearch.index.prefix}${traces_index}${elasticsearch.index.suffix}`. Otherwise, if scope name matches regex `/receiver/(\w*receiver)`, `data_stream.dataset` will be capture group #1. Otherwise, the index name falls back to `traces-generic-default`, and `traces_index` config will be ignored. Except for prefix/suffix attribute presence, the resulting docs will contain the corresponding `data_stream.*` fields, see restrictions applied to [Data Stream Fields](https://www.elastic.co/guide/en/ecs/current/ecs-data_stream.html). There is an exception for span events under OTel mapping mode (`mapping::mode: otel`), where span event attributes instead of span attributes are considered, and `data_stream.type` is always `logs` instead of `traces` such that documents are routed to `logs-${data_stream.dataset}-${data_stream.namespace}`.
+  - `enabled`(DEPRECATED): No-op. Documents are now always routed dynamically unless `traces_index` is not empty. Will be removed in a future version.
 
 - `logstash_format` (optional): Logstash format compatibility. Logs, metrics and traces can be written into an index in Logstash format.
-  - `enabled`(default=false):  Enable/disable Logstash format compatibility. When `logstash_format.enabled` is `true`, the index name is composed using `(logs|metrics|traces)_index` or `(logs|metrics|traces)_dynamic_index` as prefix and the date as suffix,
-    e.g: If `logs_index` or `logs_dynamic_index` is equal to `logs-generic-default`, your index will become `logs-generic-default-YYYY.MM.DD`.
+  - `enabled`(default=false):  Enable/disable Logstash format compatibility. When `logstash_format::enabled` is `true`, the index name is composed using the above dynamic routing rules as prefix and the date as suffix,
+    e.g: If the computed index name is `logs-generic-default`, the resulting index will be `logs-generic-default-YYYY.MM.DD`.
     The last string appended belongs to the date when the data is being generated.
   - `prefix_separator`(default=`-`): Set a separator between logstash_prefix and date.
   - `date_format`(default=`%Y.%m.%d`): Time format (based on strftime) to generate the second part of the Index name.
@@ -154,6 +160,19 @@ This can be customised through the following settings:
 
 
 
+#### Document routing exceptions for OTel data mode
+
+In OTel mapping mode (`mapping::mode: otel`), there is special handling in addition to the above document routing rules in [Elasticsearch document routing](#elasticsearch-document-routing).
+The order to determine the routing mode is the same as [Elasticsearch document routing](#elasticsearch-document-routing).
+
+1. "Static mode": Span events are separate documents routed to `logs_index` if non-empty.
+2. "Dynamic - Index attribute mode": Span events are separate documents routed using attribute `elasticsearch.index` (precedence: span event attribute > scope attribute > resource attribute) if the attribute exists.
+3. "Dynamic - Data stream routing mode":
+  - For all documents, `data_stream.dataset` will always be appended with `.otel`.
+  - A special case to (3)(1) in [Elasticsearch document routing](#elasticsearch-document-routing), span events are separate documents that have `data_stream.type: logs` and are routed using data stream attributes (precedence: span event attribute > scope attribute > resource attribute)
+
+
+
 ### Elasticsearch document mapping
 
 The Elasticsearch exporter supports several document schemas and preprocessing
@@ -198,7 +217,9 @@ scheme that maps these as `constant_keyword` fields.
 `data_stream.dataset` will always be appended with `.otel` if [dynamic data stream routing mode](#elasticsearch-document-routing) is active.
 
 Span events are stored in separate documents. They will be routed with `data_stream.type` set to
-`logs` if `traces_dynamic_index::enabled` is `true`.
+`logs` if [dynamic data stream routing mode](#elasticsearch-document-routing) is active.
+
+Attribute `elasticsearch.index` will be removed from the final document if exists.
 
 | Signal    | Supported          |
 | --------- | ------------------ |

exporter/elasticsearchexporter/attribute.go

@@ -7,8 +7,6 @@ import "go.opentelemetry.io/collector/pdata/pcommon"
 
 // dynamic index attribute key constants
 const (
-	indexPrefix                   = "elasticsearch.index.prefix"
-	indexSuffix                   = "elasticsearch.index.suffix"
 	defaultDataStreamDataset      = "generic"
 	defaultDataStreamNamespace    = "default"
 	defaultDataStreamTypeLogs     = "logs"

exporter/elasticsearchexporter/config.go

@@ -40,19 +40,19 @@ type Config struct {
 	// NumWorkers configures the number of workers publishing bulk requests.
 	NumWorkers int `mapstructure:"num_workers"`
 
-	// This setting is required when logging pipelines used.
-	LogsIndex string `mapstructure:"logs_index"`
-	// fall back to pure LogsIndex, if 'elasticsearch.index.prefix' or 'elasticsearch.index.suffix' are not found in resource or attribute (prio: resource > attribute)
+	// LogsIndex configures the static index used for document routing for logs.
+	// It should be empty if dynamic document routing is preferred.
+	LogsIndex        string              `mapstructure:"logs_index"`
 	LogsDynamicIndex DynamicIndexSetting `mapstructure:"logs_dynamic_index"`
 
-	// This setting is required when the exporter is used in a metrics pipeline.
-	MetricsIndex string `mapstructure:"metrics_index"`
-	// fall back to pure MetricsIndex, if 'elasticsearch.index.prefix' or 'elasticsearch.index.suffix' are not found in resource attributes
+	// MetricsIndex configures the static index used for document routing for metrics.
+	// It should be empty if dynamic document routing is preferred.
+	MetricsIndex        string              `mapstructure:"metrics_index"`
 	MetricsDynamicIndex DynamicIndexSetting `mapstructure:"metrics_dynamic_index"`
 
-	// This setting is required when traces pipelines used.
-	TracesIndex string `mapstructure:"traces_index"`
-	// fall back to pure TracesIndex, if 'elasticsearch.index.prefix' or 'elasticsearch.index.suffix' are not found in resource or attribute (prio: resource > attribute)
+	// TracesIndex configures the static index used for document routing for metrics.
+	// It should be empty if dynamic document routing is preferred.
+	TracesIndex        string              `mapstructure:"traces_index"`
 	TracesDynamicIndex DynamicIndexSetting `mapstructure:"traces_dynamic_index"`
 
 	// LogsDynamicID configures whether log record attribute `elasticsearch.document_id` is set as the document ID in ES.
@@ -121,6 +121,9 @@ type LogstashFormatSettings struct {
 }
 
 type DynamicIndexSetting struct {
+	// Enabled enables dynamic index routing.
+	//
+	// Deprecated: [v0.122.0] This config is now ignored. Dynamic index routing is always done by default.
 	Enabled bool `mapstructure:"enabled"`
 }
 
@@ -288,6 +291,16 @@ func (cfg *Config) Validate() error {
 		return errors.New("retry::max_retries should be non-negative")
 	}
 
+	if cfg.LogsIndex != "" && cfg.LogsDynamicIndex.Enabled {
+		return errors.New("must not specify both logs_index and logs_dynamic_index; logs_index should be empty unless all documents should be sent to the same index")
+	}
+	if cfg.MetricsIndex != "" && cfg.MetricsDynamicIndex.Enabled {
+		return errors.New("must not specify both metrics_index and metrics_dynamic_index; metrics_index should be empty unless all documents should be sent to the same index")
+	}
+	if cfg.TracesIndex != "" && cfg.TracesDynamicIndex.Enabled {
+		return errors.New("must not specify both traces_index and traces_dynamic_index; traces_index should be empty unless all documents should be sent to the same index")
+	}
+
 	return nil
 }
 
@@ -397,4 +410,13 @@ func handleDeprecatedConfig(cfg *Config, logger *zap.Logger) {
 		// Do not set cfg.Retry.Enabled = false if cfg.Retry.MaxRequest = 1 to avoid breaking change on behavior
 		logger.Warn("retry::max_requests has been deprecated, and will be removed in a future version. Use retry::max_retries instead.")
 	}
+	if cfg.LogsDynamicIndex.Enabled {
+		logger.Warn("logs_dynamic_index::enabled has been deprecated, and will be removed in a future version. It is now a no-op. Dynamic document routing is now the default. See Elasticsearch Exporter README.")
+	}
+	if cfg.MetricsDynamicIndex.Enabled {
+		logger.Warn("metrics_dynamic_index::enabled has been deprecated, and will be removed in a future version. It is now a no-op. Dynamic document routing is now the default. See Elasticsearch Exporter README.")
+	}
+	if cfg.TracesDynamicIndex.Enabled {
+		logger.Warn("traces_dynamic_index::enabled has been deprecated, and will be removed in a future version. It is now a no-op. Dynamic document routing is now the default. See Elasticsearch Exporter README.")
+	}
 }

exporter/elasticsearchexporter/config_test.go

@@ -63,13 +63,11 @@ func TestConfig(t *testing.T) {
 					QueueSize:    exporterhelper.NewDefaultQueueConfig().QueueSize,
 				},
 				Endpoints: []string{"https://elastic.example.com:9200"},
-				LogsIndex: "logs-generic-default",
 				LogsDynamicIndex: DynamicIndexSetting{
 					Enabled: false,
 				},
-				MetricsIndex: "metrics-generic-default",
 				MetricsDynamicIndex: DynamicIndexSetting{
-					Enabled: true,
+					Enabled: false,
 				},
 				TracesIndex: "trace_index",
 				TracesDynamicIndex: DynamicIndexSetting{
@@ -145,11 +143,9 @@ func TestConfig(t *testing.T) {
 				LogsDynamicIndex: DynamicIndexSetting{
 					Enabled: false,
 				},
-				MetricsIndex: "metrics-generic-default",
 				MetricsDynamicIndex: DynamicIndexSetting{
-					Enabled: true,
+					Enabled: false,
 				},
-				TracesIndex: "traces-generic-default",
 				TracesDynamicIndex: DynamicIndexSetting{
 					Enabled: false,
 				},
@@ -219,15 +215,13 @@ func TestConfig(t *testing.T) {
 					QueueSize:    exporterhelper.NewDefaultQueueConfig().QueueSize,
 				},
 				Endpoints: []string{"http://localhost:9200"},
-				LogsIndex: "logs-generic-default",
 				LogsDynamicIndex: DynamicIndexSetting{
 					Enabled: false,
 				},
 				MetricsIndex: "my_metric_index",
 				MetricsDynamicIndex: DynamicIndexSetting{
-					Enabled: true,
+					Enabled: false,
 				},
-				TracesIndex: "traces-generic-default",
 				TracesDynamicIndex: DynamicIndexSetting{
 					Enabled: false,
 				},