Elasticsearch Sink

The Vector elasticsearch sink sends logs to Elasticsearch.

Requirements

Configuration

[sinks.my_sink_id]
# General
type = "elasticsearch" # required
inputs = ["my-source-or-transform-id", "prefix-*"] # required
compression = "none" # optional, default
endpoint = "http://10.24.32.122:9000" # required
index = "vector-%F" # optional, default
pipeline = "pipeline-name" # optional, no default
# Encoding
# Healthcheck
healthcheck.enabled = true # optional, default
  • optionaltable

    auth

    Options for the authentication strategy.

    • optionalstring

      access_key_id

      The AWS access key id. Used for AWS authentication when communicating with AWS services. See AWS Authentication for more info.

      • Syntax: literal
    • optionalstring

      assume_role

      The ARN of an IAM role to assume at startup. See AWS Authentication for more info.

      • Syntax: literal
    • commonrequiredstring

      password

      The basic authentication password.

      • Syntax: literal
    • optionalstring

      secret_access_key

      The AWS secret access key. Used for AWS authentication when communicating with AWS services. See AWS Authentication for more info.

      • Syntax: literal
    • enumcommonrequiredstring

      strategy

      The authentication strategy to use.

      • Syntax: literal
      • Enum, must be one of: "aws" "basic"
    • commonrequiredstring

      user

      The basic authentication user name.

      • Syntax: literal
  • optionaltable

    aws

    Options for the AWS connections.

    • commonoptionalstring

      region

      The AWS region of the target service. This defaults to the region named in the endpoint parameter, or the value of the $AWS_REGION or $AWS_DEFAULT_REGION environment variables if that cannot be determined, or "us-east-1".

      • Syntax: literal
  • optionaltable

    batch

    Configures the sink batching behavior.

    • commonoptionaluint

      max_bytes

      The maximum size of a batch, in bytes, before it is flushed.

      • Default: 10490000 (bytes)
    • commonoptionaluint

      timeout_secs

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

      • Default: 1 (seconds)
  • optionaltable

    buffer

    Configures the sink specific buffer behavior.

    • commonoptionaluint

      max_events

      The maximum number of events allowed in the buffer. See Buffers & batches for more info.

      • Only relevant when: type = "memory"
      • Default: 500 (events)
    • commonrequired*uint

      max_size

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

      • Only required when: type = "disk"
    • enumcommonoptionalstring

      type

      The buffer's type and storage mechanism.

      • Syntax: literal
      • Default: "memory"
      • Enum, must be one of: "memory" "disk"
    • enumoptionalstring

      when_full

      The behavior when the buffer becomes full.

      • Syntax: literal
      • Default: "block"
      • Enum, must be one of: "block" "drop_newest"
  • optionalstring

    bulk_action

    Action to use when making requests to the Elasticsearch Bulk API. Supports index and create. See Conflicts and Data streams for more info.

    • Syntax: literal
    • Default: "index"
  • enumcommonoptionalstring

    compression

    The compression strategy used to compress the encoded event data before transmission.

    • Syntax: literal
    • Default: "none"
    • Enum, must be one of: "none" "gzip" "syntax"
  • optionalstring

    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.

    • Syntax: literal
    • Default: "_doc"
  • commonrequiredtable

    encoding

    Configures the encoding specific sink behavior.

    • optional[string]

      except_fields

      Prevent the sink from encoding the specified labels.

    • optional[string]

      only_fields

      Prevent the sink from encoding the specified labels.

    • enumoptionalstring

      timestamp_format

      How to format event timestamps.

      • Syntax: literal
      • Default: "rfc3339"
      • Enum, must be one of: "rfc3339" "unix"
  • commonrequiredstring

    endpoint

    The Elasticsearch endpoint to send logs to. This should be the full URL as shown in the example.

    • Syntax: literal
  • commonoptionaltable

    healthcheck

    Health check options for the sink. See Health checks for more info.

    • commonoptionalbool

      enabled

      Enables/disables the healthcheck upon Vector boot.

      • Default: true
  • optionalstring

    id_key

    The name of the event key that should map to Elasticsearch's _id field. By default, Vector does not set the _id field, which allows Elasticsearch to set this automatically. You should think carefully about setting your own Elasticsearch IDs, since this can hinder perofrmance.

    • Syntax: literal
  • commonoptionalstring

    index

    Index name to write events to. See Conflicts and Data streams for more info.

    This field supports Vector's template syntax, which enables the use of dynamic per-event values.

    • Syntax: template
    • Default: "vector-%F"
  • commonoptionalstring

    pipeline

    Name of the pipeline to apply.

    • Syntax: literal
  • optionaltable

    query

    Custom parameters to Elasticsearch query string.

  • optionaltable

    request

    Configures the sink request behavior.

    • optionaltable

      adaptive_concurrency

      Configure the adaptive concurrency algorithms. These values have been tuned by optimizing simulated results. In general you should not need to adjust these.

      • optionalfloat
        decrease_ratio

        The fraction of the current value to set the new concurrency limit when decreasing the limit. Valid values are greater than 0 and less than 1. Smaller values cause the algorithm to scale back rapidly when latency increases. Note that the new limit is rounded down after applying this ratio.

        • Default: 0.9
      • optionalfloat
        ewma_alpha

        The adaptive concurrency algorithm uses an exponentially weighted moving average (EWMA) of past RTT measurements as a reference to compare with the current RTT. This value controls how heavily new measurements are weighted compared to older ones. Valid values are greater than 0 and less than 1. Smaller values cause this reference to adjust more slowly, which may be useful if a service has unusually high response variability.

        • Default: 0.7
      • optionalfloat
        rtt_threshold_ratio

        When comparing the past RTT average to the current measurements, we ignore changes that are less than this ratio higher than the past RTT. Valid values are greater than or equal to 0. Larger values cause the algorithm to ignore larger increases in the RTT.

        • Default: 0.05
    • commonoptionaluint

      concurrency

      The maximum number of in-flight requests allowed at any given time, or "adaptive" to allow Vector to automatically set the limit based on current network and service conditions.

      • Default: 5 (requests)
    • optionaltable

      headers

      Options for custom headers.

    • commonoptionaluint

      rate_limit_duration_secs

      The time window, in seconds, used for the rate_limit_num option.

      • Default: 1 (seconds)
    • commonoptionaluint

      rate_limit_num

      The maximum number of requests allowed within the rate_limit_duration_secs time window.

      • Default: 5
    • optionaluint

      retry_attempts

      The maximum number of retries to make for failed requests. The default, for all intents and purposes, represents an infinite number of retries.

      • Default: 18446744073709552000
    • optionaluint

      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 (seconds)
    • optionaluint

      retry_max_duration_secs

      The maximum amount of time, in seconds, to wait between retries.

      • Default: 10 (seconds)
    • commonoptionaluint

      timeout_secs

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

      • Default: 60 (seconds)
  • optionaltable

    tls

    Configures the TLS options for incoming connections.

    • optionalstring

      ca_file

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

      • Syntax: literal
    • commonoptionalstring

      crt_file

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

      • Syntax: literal
    • commonoptionalstring

      key_file

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

      • Syntax: literal
    • optionalstring

      key_pass

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

      • Syntax: literal
    • optionalbool

      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

Telemetry

This component provides the following metrics that can be retrieved through the internal_metrics source. See the metrics section in the monitoring page for more info.

  • counter

    missing_keys_total

    The total number of failed template renders due to missed keys from the event. This metric includes the following tags:

    • instance - The Vector instance identified by host and port.

    • job - The name of the job producing Vector metrics.

  • counter

    events_in_total

    The total number of events accepted by this component. This metric includes the following tags:

    • component_kind - The Vector component kind.

    • component_name - The Vector component ID.

    • component_type - The Vector component type.

    • instance - The Vector instance identified by host and port.

    • job - The name of the job producing Vector metrics.

  • counter

    events_out_total

    The total number of events emitted by this component. This metric includes the following tags:

    • component_kind - The Vector component kind.

    • component_name - The Vector component ID.

    • component_type - The Vector component type.

    • instance - The Vector instance identified by host and port.

    • job - The name of the job producing Vector metrics.

How It Works

AWS Authentication

Vector checks for AWS credentials in the following order:

  1. Options access_key_id and secret_access_key.
  2. Environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY.
  3. The credential_process command in the AWS config file. (usually located at ~/.aws/config)
  4. The AWS credentials file. (usually located at ~/.aws/credentials)
  5. 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. Such created AWS access keys can be used via access_key_id and secret_access_key options.

Assuming roles

Vector can assume an AWS IAM role via the assume_role option. This is an optional setting that is helpful for a variety of use cases, such as cross account access.

Buffers & batches

This component 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 <% if component.options.batch.children.respond_to?(:max_size) %>max_size<% else %>max_events<% end %>.

Buffers are controlled via the buffer.* options.

Conflicts

Vector batches data flushes it to Elasticsearch's _bulk API endpoint. By default, all events are inserted via the index action which will update documents if an existing one has the same id. If bulk_action is configured with create, Elasticsearch will not replace an existing document and instead return a conflict error.

Data streams

By default, Vector will use the index action with Elasticsearch's Bulk API. To use Data streams, bulk_action must be configured with the create option.

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.

Partial Failures

By default, Elasticsearch will allow partial bulk ingestion failures. This is typically due to type Elasticsearch index mapping errors, where data keys are not consistently typed. To change this behavior please refer to the Elasticsearch ignore_malformed setting.

Partitioning

Vector supports dynamic configuration values through a simple template syntax. If an option supports templating, it will be noted with a badge and you can use event fields to create dynamic values. For example:

vector.toml
[sinks.my-sink]
dynamic_option = "application={{ application_id }}"

In the above example, the application_id for each event will be used to partition outgoing data.

Rate limits & adapative concurrency

Adaptive Request Concurrency (ARC)

Adaptive Requst Concurrency is a feature of Vector that does away with static rate limits and automatically optimizes HTTP concurrency limits based on downstream service responses. The underlying mechanism is a feedback loop inspired by TCP congestion control algorithms. Checkout the announcement blog post,

We highly recommend enabling this feature as it improves performance and reliability of Vector and the systems it communicates with.

To enable, set the request.concurrency option to adaptive:

vector.toml
[sinks.my-sink]
request.concurrency = "adaptive"

Static rate limits

If Adaptive Request Concurrency is not for you, you can manually set static rate limits with the request.rate_limit_duration_secs, request.rate_limit_num, and request.concurrency options:

vector.toml
[sinks.my-sink]
request.rate_limit_duration_secs = 1
request.rate_limit_num = 10
request.concurrency = 10

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 request.retry_attempts and request.retry_backoff_secs options.

State

This component is stateless, meaning its behavior is consistent across each input.

Transport Layer Security (TLS)

Vector uses Openssl for TLS protocols for it's maturity. You can enable and adjust TLS behavior via the tls.* options.