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Configure the Elasticsearch output

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Configure the Elasticsearch output

The Elasticsearch output sends events directly to Elasticsearch using the Elasticsearch HTTP API.

Example configuration:

output.elasticsearch:
  hosts: ["<YOUR_ES_HOST_URL>:9200"]

To enable SSL, add https to all URLs defined under hosts.

When sending data to a secured cluster through the elasticsearch output, APM Server can use any of the following authentication methods:

Basic authentication credentials (username and password).
Token-based (API key) authentication.
Public Key Infrastructure (PKI) certificates.

Basic authentication:

output.elasticsearch:
  hosts: ["<YOUR_ES_HOST_URL>:9200"]
  username: "apm_writer"
  password: "YOUR_PASSWORD"

API key authentication:

output.elasticsearch:
  hosts: ["<YOUR_ES_HOST_URL>:9200"]
  api_key: "ZCV7VnwBgnX0T19fN8Qe:KnR6yE41RrSowb0kQ0HWoA"

You must set the API key to be configured to Beats. Base64 encoded API keys are not currently supported in this configuration. For details on how to create and configure a compatible API key, refer to Create an API key for writing events.

PKI certificate authentication:

output.elasticsearch:
  hosts: ["<YOUR_ES_HOST_URL>:9200"]
  ssl.certificate: "/etc/pki/client/cert.pem"
  ssl.key: "/etc/pki/client/cert.key"

See Secure communication with Elasticsearch for details on each authentication method.

Compatibilityedit

This output works with all compatible versions of Elasticsearch. See the Elastic Support Matrix.

Configuration optionsedit

You can specify the following options in the elasticsearch section of the apm-server.yml config file:

enablededit

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.

hostsedit

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.

When a node is defined as an IP:PORT, the scheme and path are taken from the protocol and path config options.

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.

compression_leveledit

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 5.

escape_htmledit

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

The default value is false.

api_keyedit

Instead of using a username and password, you can use API keys to secure communication with Elasticsearch. The value must be the ID of the API key and the API key joined by a colon: id:api_key.

API key dropdown highlighting the Beats option

usernameedit

The basic authentication username for connecting to Elasticsearch.

This user needs the privileges required to publish events to Elasticsearch. To create a user like this, see Create a writer role.

passwordedit

The basic authentication password for connecting to Elasticsearch.

parametersedit

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

protocoledit

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.

pathedit

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.

headersedit

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

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

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

proxy_urledit

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.

max_retriesedit

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.

flush_bytesedit

The bulk request size threshold, in bytes, before flushing to Elasticsearch. If compression is enabled, this is compressed bytes. The value must have a suffix, e.g. "2MB". The default is 1MB.

flush_intervaledit

The maximum duration to accumulate events for a bulk request before being flushed to Elasticsearch. The value must have a duration suffix, e.g. "5s". The default is 1s.

backoff.initedit

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.

backoff.maxedit

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

timeoutedit

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

ssledit

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 the secure communication with Elasticsearch guide or SSL configuration reference for more information.

Secure communication with Elasticsearchedit

When sending data to a secured cluster through the elasticsearch output, APM Server can use any of the following authentication methods:

Basic authentication credentials (username and password).
Token-based API authentication.
A client certificate.

Authentication is specified in the APM Server configuration file:

To use basic authentication, specify the username and password settings under output.elasticsearch. For example:
```
output.elasticsearch:
  hosts: ["<YOUR_ES_HOST_URL>:9200"]
  username: "apm_writer" 
  password: "YOUR_PASSWORD"
```
This user needs the privileges required to publish events to Elasticsearch. To create a user like this, see Create a writer role.

To use token-based API key authentication, specify the api_key under output.elasticsearch. For example:

output.elasticsearch:
  hosts: ["<YOUR_ES_HOST_URL>:9200"]
  api_key: "KnR6yE41RrSowb0kQ0HWoA"

This API key must have the privileges required to publish events to Elasticsearch. You must set the API key to be configured to Beats. Base64 encoded API keys are not currently supported in this configuration. For details on how to create and configure a compatible API key, refer to Create an API key for writing events.

To use Public Key Infrastructure (PKI) certificates to authenticate users, specify the certificate and key settings under output.elasticsearch. For example:

output.elasticsearch:
  hosts: ["<YOUR_ES_HOST_URL>:9200"]
  ssl.certificate: "/etc/pki/client/cert.pem" 
  ssl.key: "/etc/pki/client/cert.key"

	The path to the certificate for SSL client authentication
	The client certificate key

These settings assume that the distinguished name (DN) in the certificate is mapped to the appropriate roles in the role_mapping.yml file on each node in the Elasticsearch cluster. For more information, see Using role mapping files.

By default, APM Server uses the list of trusted certificate authorities (CA) from the operating system where APM Server is running. If the certificate authority that signed your node certificates is not in the host system’s trusted certificate authorities list, you need to add the path to the .pem file that contains your CA’s certificate to the APM Server configuration. This will configure APM Server to use a specific list of CA certificates instead of the default list from the OS.

Here is an example configuration:

output.elasticsearch:
  hosts: ["<YOUR_ES_HOST_URL>:9200"]
  ssl.certificate_authorities: 
    - /etc/pki/my_root_ca.pem
    - /etc/pki/my_other_ca.pem
  ssl.certificate: "/etc/pki/client.pem" 
  ssl.key: "/etc/pki/key.pem"

	Specify the path to the local `.pem` file that contains your Certificate Authority’s certificate. This is needed if you use your own CA to sign your node certificates.
	The path to the certificate for SSL client authentication
	The client certificate key

For any given connection, the SSL/TLS certificates must have a subject that matches the value specified for hosts, or the SSL handshake fails. For example, if you specify hosts: ["foobar:9200"], the certificate MUST include foobar in the subject (CN=foobar) or as a subject alternative name (SAN). Make sure the hostname resolves to the correct IP address. If no DNS is available, then you can associate the IP address with your hostname in /etc/hosts (on Unix) or C:\windows\System32\drivers\etc\hosts (on windows).

Learn more about secure communicationedit

More information on sending data to a secured cluster is available in the configuration reference:

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