The enabled config is a boolean setting to enable or disable the output. If set to false, the output is disabled.

The default value is true.

The list of Elasticsearch nodes to connect to. The events are distributed to these nodes in round robin order. If one node becomes unreachable, the event is automatically sent to another node. Each Elasticsearch node can be defined as a URL or IP:PORT. For example: http://192.15.3.2, https://es.found.io:9230 or 192.24.3.2:9300. If no port is specified, 9200 is used.

output.elasticsearch:
  hosts: ["10.45.3.2:9220", "10.45.3.1:9230"]
  protocol: https
  path: /elasticsearch

In the previous example, the Elasticsearch nodes are available at https://10.45.3.2:9220/elasticsearch and https://10.45.3.1:9230/elasticsearch.

The gzip compression level. Setting this value to 0 disables compression. The compression level must be in the range of 1 (best speed) to 9 (best compression).

Increasing the compression level will reduce the network usage but will increase the cpu usage.

The default value is 0.

Configure escaping of HTML in strings. Set to true to enable escaping.

The default value is false.

The number of workers per configured host publishing events to Elasticsearch. This is best used with load balancing mode enabled. Example: If you have 2 hosts and 3 workers, in total 6 workers are started (3 for each host).

The default value is 1.

Instead of using usernames and passwords, you can use API keys to secure communication with Elasticsearch. For more information, see Grant access using API keys.

The basic authentication username for connecting to Elasticsearch.

The basic authentication password for connecting to Elasticsearch.

Dictionary of HTTP parameters to pass within the url with index operations.

The name of the protocol Elasticsearch is reachable on. The options are: http or https. The default is http. However, if you specify a URL for hosts, the value of protocol is overridden by whatever scheme you specify in the URL.

An HTTP path prefix that is prepended to the HTTP API calls. This is useful for the cases where Elasticsearch listens behind an HTTP reverse proxy that exports the API under a custom prefix.

Custom HTTP headers to add to each request created by the Elasticsearch output. Example:

output.elasticsearch.headers:
  X-My-Header: Header contents

It is generally possible to specify multiple header values for the same header name by separating them with a comma.

The URL of the proxy to use when connecting to the Elasticsearch servers. The value may be either a complete URL or a "host[:port]", in which case the "http" scheme is assumed. If a value is not specified through the configuration file then proxy environment variables are used. See the Go documentation for more information about the environment variables.

The index name to write events to. The default is "apm-%{[observer.version]}-{type}-%{+yyyy.MM.dd}" (for example, "apm-7.7.1-transaction-2023-12-07"). See Exploring data in Elasticsearch for more information on default index configuration.

You can set the index dynamically by using a format string to access any event field. For example, this configuration uses the field, processor.event, to set the index:

output.elasticsearch:
  hosts: ["http://localhost:9200"]
  index: "apm-%{[observer.version]}-%{[processor.event]}-%{+yyyy.MM.dd}\" 

With this configuration, all events are separated by their processor.event into different indices.

See the indices setting for other ways to set the index dynamically.

An array of index selector rules. Each rule specifies the index to use for events that match the rule. During publishing, APM Server uses the first matching rule in the array. Rules can contain conditionals, format string-based fields, and name mappings. If the indices setting is missing or no rule matches, the index setting is used.

Rule settings:

The following example sets the index based on whether the processor.event field contains the specified string:

output.elasticsearch:
  hosts: ["http://localhost:9200"]
  indices:
   - index: "apm-%{[observer.version]}-sourcemap"
      when.contains:
        processor.event: "sourcemap"

   - index: "apm-%{[observer.version]}-error-%{+yyyy.MM.dd}"
      when.contains:
        processor.event: "error"

   - index: "apm-%{[observer.version]}-transaction-%{+yyyy.MM.dd}"
      when.contains:
        processor.event: "transaction"

   - index: "apm-%{[observer.version]}-span-%{+yyyy.MM.dd}"
      when.contains:
        processor.event: "span"

   - index: "apm-%{[observer.version]}-metric-%{+yyyy.MM.dd}"
      when.contains:
        processor.event: "metric"

   - index: "apm-%{[observer.version]}-onboarding-%{+yyyy.MM.dd}"
      when.contains:
        processor.event: "onboarding"

This is the default configuration for APM Server and results in indices named in the following format: "apm-%{[observer.version]}-{type}-%{+yyyy.MM.dd}" For example: "apm-7.7.1-transaction-2023-12-07".

The following example sets the index by taking the name returned by the index format string and mapping it to a new name that’s used for the index:

output.elasticsearch:
  hosts: ["http://localhost:9200"]
  indices:
    - index: "%{[processor.event]}"
      mappings:
        sourcemap:    "apm-sourcemap"
        error:        "apm-error"
        transaction:  "apm-transaction"
        span:         "apm-span"
        metric:       "apm-metric"
        onboarding:   "apm-onboarding"
      default:        "apm"

This configuration results in indices named apm-sourcemap, apm-error, etc.

The mappings setting simplifies the configuration, but is limited to string values. You cannot specify format strings within the mapping pairs.

A format string value that specifies the ingest node pipeline to write events to.

output.elasticsearch:
  hosts: ["http://localhost:9200"]
  pipeline: my_pipeline_id

For more information, see Parse data using ingest node pipelines.

You can set the ingest node pipeline dynamically by using a format string to access any event field. For example, this configuration uses the field, processor.event, to set the pipeline for each event:

output.elasticsearch:
  hosts: ["http://localhost:9200"]
  pipeline: "%{[processor.event]}_pipeline"

With this configuration, all events with processor.event: transaction are sent to a pipeline named transaction_pipeline. Similarly, all events with processor.event: error are sent to a pipeline named error_pipeline.

The default pipeline is apm. It adds user agent and geo ip information to events. To disable this, or any other pipeline, set output.elasticsearch.pipeline: _none.

See the pipelines setting for other ways to set the ingest node pipeline dynamically.

An array of pipeline selector rules. Each rule specifies the ingest node pipeline to use for events that match the rule. During publishing, APM Server uses the first matching rule in the array. Rules can contain conditionals, format string-based fields, and name mappings. If the pipelines setting is missing or no rule matches, the pipeline setting is used.

Rule settings:

The following example sends events to a specific pipeline based on whether the processor.event field contains the specified string:

output.elasticsearch:
  hosts: ["http://localhost:9200"]
  pipelines:
    - pipeline: "sourcemap_pipeline"
      when.contains:
        processor.event: "sourcemap"

    - pipeline: "error_pipeline"
      when.contains:
        processor.event: "error"

    - pipeline: "transaction_pipeline"
      when.contains:
        processor.event: "transaction"

    - pipeline: "span_pipeline"
      when.contains:
        processor.event: "span"

    - pipeline: "metric_pipeline"
      when.contains:
        processor.event: "metric"

    - pipeline: "onboarding_pipeline"
      when.contains:
        processor.event: "onboarding"

The following example sets the pipeline by taking the name returned by the pipeline format string and mapping it to a new name that’s used for the pipeline:

output.elasticsearch:
  hosts: ["http://localhost:9200"]
  pipelines:
    - pipeline: "%{[processor.event]}"
      mappings:
        sourcemap:    "sourcemap_pipeline"
        error:        "error_pipeline"
        transaction:  "transaction_pipeline"
        span:         "span_pipeline"
        metric:       "metric_pipeline"
        onboarding:   "onboarding_pipeline"
      default: "apm_pipeline"

With this configuration, all events with processor.event: transaction are sent to a pipeline named transaction_pipeline, all events with processor.event: error are sent to a pipeline named error_pipeline, etc.

For more information about ingest node pipelines, see Parse data using ingest node pipelines.

The number of times to retry publishing an event after a publishing failure. After the specified number of retries, the events are typically dropped.

Set max_retries to a value less than 0 to retry until all events are published.

The default is 3.

The maximum number of events to bulk in a single Elasticsearch bulk API index request. The default is 50.

Events can be collected into batches. APM Server will split batches larger than bulk_max_size into multiple batches.

Specifying a larger batch size can improve performance by lowering the overhead of sending events. However big batch sizes can also increase processing times, which might result in API errors, killed connections, timed-out publishing requests, and, ultimately, lower throughput.

Setting bulk_max_size to values less than or equal to 0 disables the splitting of batches. When splitting is disabled, the queue decides on the number of events to be contained in a batch.

The number of seconds to wait before trying to reconnect to Elasticsearch after a network error. After waiting backoff.init seconds, APM Server tries to reconnect. If the attempt fails, the backoff timer is increased exponentially up to backoff.max. After a successful connection, the backoff timer is reset. The default is 1s.

The maximum number of seconds to wait before attempting to connect to Elasticsearch after a network error. The default is 60s.

The http request timeout in seconds for the Elasticsearch request. The default is 90.

Configuration options for SSL parameters like the certificate authority to use for HTTPS-based connections. If the ssl section is missing, the host CAs are used for HTTPS connections to Elasticsearch.

See SSL output settings for more information.