Elasticsearch Sink

The Vector elasticsearch sink batches log events to Elasticsearch via the _bulk API endpoint.

Configuration

  • Common
  • Advanced
vector.toml
[sinks.my_sink_id]
# REQUIRED
type = "elasticsearch" # must be: "elasticsearch"
inputs = ["my-source-id"] # example
# OPTIONAL
doc_type = "_doc" # default
index = "vector-%F" # default
host = "http://10.24.32.122:9000" # example, no default

Options

13 items
tableoptional

auth

Options for the authentication strategy.

commonstringenumrequired

strategy

The authentication strategy to use.

No default
Enum, must be one of: "aws" "basic"
View examples
commonstringrequired

password

The basic authentication password.

No default
Only relevant when: strategy = "basic"
View examples
commonstringrequired

user

The basic authentication user name.

No default
Only relevant when: strategy = "basic"
View examples
tableoptional

batch

Configures the sink batching behavior.

intbytesoptional

max_size

The maximum size of a batch before it is flushed. See Buffers & Batches for more info.

Default: 10490000
View examples
intsecondsoptional

timeout_secs

The maximum age of a batch before it is flushed. See Buffers & Batches for more info.

Default: 1
View examples
tableoptional

buffer

Configures the sink buffer behavior.

inteventsoptional

max_events

The maximum number of events allowed in the buffer.

Default: 500
Only relevant when: type = "memory"
View examples
intbytesoptional

max_size

The maximum size of the buffer on the disk. See Buffers & Batches for more info.

No default
Only relevant when: type = "disk"
View examples
stringenumoptional

type

The buffer's type / location. disk buffers are persistent and will be retained between restarts.

Default: "memory"
Enum, must be one of: "memory" "disk"
View examples
stringenumoptional

when_full

The behavior when the buffer becomes full.

Default: "block"
Enum, must be one of: "block" "drop_newest"
View examples
commonstringrequired

doc_type

The doc_type for your index data. This is only relevant for Elasticsearch <= 6.X. If you are using >= 7.0 you do not need to set this option since Elasticsearch has removed it.

Default: "_doc"
View examples
stringoptional

endpoint

Custom endpoint for use with AWS-compatible services. Providing a value for this option will make region moot.

No default
View examples
tableoptional

headers

Options for custom headers.

commonstringrequired

[header-name]

A custom header to be added to each outgoing Elasticsearch request.

No default
View examples
booloptional

healthcheck

Enables/disables the sink healthcheck upon start. See Health Checks for more info.

Default: true
View examples
commonstringoptional

host

The host of your Elasticsearch cluster. This should be the full URL as shown in the example. This is required if the provider is not "aws"

No default
View examples
commontemplateablestringrequired

index

Index name to write events to. See Template Syntax for more info.

Default: "vector-%F"
View examples
tableoptional

query

Custom parameters to Elasticsearch query string.

commonstringrequired

[parameter-name]

A custom parameter to be added to each Elasticsearch request.

No default
View examples
stringoptional

region

The AWS region of the target service. If endpoint is provided it will override this value since the endpoint includes the region.

No default
View examples
tableoptional

request

Configures the sink request behavior.

intoptional

in_flight_limit

The maximum number of in-flight requests allowed at any given time. See Rate Limits for more info.

Default: 5
View examples
intsecondsoptional

rate_limit_duration_secs

The window used for the rate_limit_num option See Rate Limits for more info.

Default: 1
View examples
intoptional

rate_limit_num

The maximum number of requests allowed within the rate_limit_duration_secs window. See Rate Limits for more info.

Default: 5
View examples
intoptional

retry_attempts

The maximum number of retries to make for failed requests. See Retry Policy for more info.

Default: 5
View examples
intsecondsoptional

retry_initial_backoff_secs

The amount of time to wait before attempting the first retry for a failed request. Once, the first retry has failed the fibonacci sequence will be used to select future backoffs.

Default: 1
View examples
intsecondsoptional

retry_max_duration_secs

The maximum amount of time to wait between retries.

Default: 10
View examples
intsecondsoptional

timeout_secs

The maximum time a request can take before being aborted. It is highly recommended that you do not lower value below the service's internal timeout, as this could create orphaned requests, pile on retries, and result in deuplicate data downstream. See Buffers & Batches for more info.

Default: 60
View examples
tableoptional

tls

Configures the TLS options for connections from this sink.

stringoptional

ca_path

Absolute path to an additional CA certificate file, in DER or PEM format (X.509).

No default
View examples
stringoptional

crt_path

Absolute path to a certificate file used to identify this connection, in DER or PEM format (X.509) or PKCS#12. If this is set and is not a PKCS#12 archive, key_path must also be set.

No default
View examples
stringoptional

key_pass

Pass phrase used to unlock the encrypted key file. This has no effect unless key_pass above is set.

No default
View examples
stringoptional

key_path

Absolute path to a certificate key file used to identify this connection, in DER or PEM format (PKCS#8). If this is set, crt_path must also be set.

No default
View examples
booloptional

verify_certificate

If true (the default), Vector will validate the TLS certificate of the remote host. Do NOT set this to false unless you understand the risks of not verifying the remote certificate.

Default: true
View examples
booloptional

verify_hostname

If true (the default), Vector will validate the configured remote host name against the remote host's TLS certificate. Do NOT set this to false unless you understand the risks of not verifying the remote hostname.

Default: true
View examples

Env Vars

2 items
stringoptional

AWS_ACCESS_KEY_ID

Used for AWS authentication when communicating with AWS services. See relevant AWS components for more info. See AWS Authentication for more info.

No default
View examples
stringoptional

AWS_SECRET_ACCESS_KEY

Used for AWS authentication when communicating with AWS services. See relevant AWS components for more info. See AWS Authentication for more info.

No default
View examples

Output

The elasticsearch sink batches log events to Elasticsearch via the _bulk API endpoint. Batches are flushed via the batch_size or batch_timeout options. You can learn more in the buffers & batches section. For example:

POST <host>/_bulk HTTP/1.1
Host: <host>
Content-Type: application/x-ndjson
Content-Length: <byte_size>
{ "index" : { "_index" : "<index>" } }
<json_encoded_log>
{ "index" : { "_index" : "<index>" } }
<json_encoded_log>
{ "index" : { "_index" : "<index>" } }
<json_encoded_log>

How It Works

AWS Authentication

Vector checks for AWS credentials in the following order:

  1. Environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY.
  2. The credential_process command in the AWS config file. (usually located at ~/.aws/config)
  3. The AWS credentials file. (usually located at ~/.aws/credentials)
  4. The IAM instance profile. (will only work if running on an EC2 instance with an instance profile/role)

If credentials are not found the healtcheck will fail and an error will be logged.

Obtaining an access key

In general, we recommend using instance profiles/roles whenever possible. In cases where this is not possible you can generate an AWS access key for any user within your AWS account. AWS provides a detailed guide on how to do this.

Buffers & Batches

The elasticsearch sink buffers & batches data as shown in the diagram above. You'll notice that Vector treats these concepts differently, instead of treating them as global concepts, Vector treats them as sink specific concepts. This isolates sinks, ensuring services disruptions are contained and delivery guarantees are honored.

Batches are flushed when 1 of 2 conditions are met:

  1. The batch age meets or exceeds the configured timeout_secs.
  2. The batch size meets or exceeds the configured max_size.

Buffers are controlled via the buffer.* options.

Environment Variables

Environment variables are supported through all of Vector's configuration. Simply add ${MY_ENV_VAR} in your Vector configuration file and the variable will be replaced before being evaluated.

You can learn more in the Environment Variables section.

Health Checks

Health checks ensure that the downstream service is accessible and ready to accept data. This check is performed upon sink initialization. If the health check fails an error will be logged and Vector will proceed to start.

Require Health Checks

If you'd like to exit immediately upon a health check failure, you can pass the --require-healthy flag:

vector --config /etc/vector/vector.toml --require-healthy

Disable Health Checks

If you'd like to disable health checks for this sink you can set the healthcheck option to false.

Nested Documents

Vector will explode events into nested documents before writing them to Elasticsearch. Vector assumes keys with a . delimit nested fields. You can read more about how Vector handles nested documents in the Data Model document.

Rate Limits

Vector offers a few levers to control the rate and volume of requests to the downstream service. Start with the rate_limit_duration_secs and rate_limit_num options to ensure Vector does not exceed the specified number of requests in the specified window. You can further control the pace at which this window is saturated with the in_flight_limit option, which will guarantee no more than the specified number of requests are in-flight at any given time.

Please note, Vector's defaults are carefully chosen and it should be rare that you need to adjust these. If you found a good reason to do so please share it with the Vector team by opening an issie.

Retry Policy

Vector will retry failed requests (status == 429, >= 500, and != 501). Other responses will not be retried. You can control the number of retry attempts and backoff rate with the retry_attempts and retry_backoff_secs options.

Template Syntax

The index options support Vector's template syntax, enabling dynamic values derived from the event's data. This syntax accepts strptime specifiers as well as the {{ field_name }} syntax for accessing event fields. For example:

vector.toml
[sinks.my_elasticsearch_sink_id]
# ...
index = "application-{{ application_id }}-%Y-%m-%d"
index = "vector-%Y-%m-%d"
# ...

You can read more about the complete syntax in the template syntax section.