Elasticsearch

Index observability events in Elasticsearch

status: stable delivery: at-least-once egress: batch state: stateless

Requirements

Elasticsearch’s Data streams feature requires Vector to be configured with the create bulk_action. This is not enabled by default.

Configuration

auth

optional object
Options for the authentication strategy.

auth.access_key_id

optional string literal
The AWS access key id. Used for AWS authentication when communicating with AWS services.

auth.assume_role

optional string literal
The ARN of an IAM role to assume at startup.

auth.password

required string literal
The basic authentication password.

auth.secret_access_key

optional string literal
The AWS secret access key. Used for AWS authentication when communicating with AWS services.

auth.strategy

required string enum literal
The authentication strategy to use.
Enum options
OptionDescription
awsAuthentication strategy used for AWS' hosted Elasticsearch service.
basicThe basic authentication strategy.

auth.user

required string literal
The basic authentication user name.

aws

optional object
Options for the AWS connections.

aws.region

optional string literal
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”.

batch

optional object
Configures the sink batching behavior.

batch.max_bytes

optional uint
The maximum size of a batch, in bytes, before it is flushed.
default: 1.049e+07 (bytes)

batch.timeout_secs

optional uint
The maximum age of a batch before it is flushed.
default: 1 (seconds)

buffer

optional object
Configures the sink specific buffer behavior.

buffer.max_events

optional uint
The maximum number of events allowed in the buffer.
Relevant when: type = "memory"
default: 500 (events)

buffer.max_size

required uint
The maximum size of the buffer on the disk.
Relevant when: type = "disk"

buffer.type

optional string enum literal
The buffer’s type and storage mechanism.
Enum options
OptionDescription
diskStores the sink’s buffer on disk. This is less performant, but durable. Data will not be lost between restarts. Will also hold data in memory to enhance performance. WARNING: This may stall the sink if disk performance isn’t on par with the throughput. For comparison, AWS gp2 volumes are usually too slow for common cases.
memoryStores the sink’s buffer in memory. This is more performant, but less durable. Data will be lost if Vector is restarted forcefully.
default: memory

buffer.when_full

optional string enum literal
The behavior when the buffer becomes full.
Enum options
OptionDescription
blockApplies back pressure when the buffer is full. This prevents data loss, but will cause data to pile up on the edge.
drop_newestDrops new data as it’s received. This data is lost. This should be used when performance is the highest priority.
default: block

bulk_action

optional string
Action to use when making requests to the Elasticsearch Bulk API. Currently, Vector only supports index and create. update and delete actions are not supported.
default: index

compression

common optional string enum

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

Some cloud storage API clients and browsers will handle decompression transparently, so files may not always appear to be compressed depending how they are accessed.

Enum options string literal
OptionDescription
gzipGzip standard DEFLATE compression.
noneNo compression.
syntaxliteral
default: none

data_stream

optional object
Options for the data stream mode.

data_stream.auto_routing

optional bool
Automatically routes events by deriving the data stream name using specific event fields with the `data_stream.type-data_stream.dataset-data_stream.namespace` format.

If enabled, the data_stream.* event fields will take precedence over the data_stream.type, data_stream.dataset, and data_stream.namespace settings, but will fall back to them if any of the fields are missing from the event.
default: true

data_stream.dataset

optional string template
The data stream dataset used to construct the data stream at index time.
default: generic

data_stream.namespace

optional string template
The data stream namespace used to construct the data stream at index time.
default: default

data_stream.sync_fields

optional bool
Automatically adds and syncs the data_stream.* event fields if they are missing from the event. This ensures that fields match the name of the data stream that is receiving events.
default: true

data_stream.type

optional string template
The data stream type used to construct the data stream at index time.
default: logs

doc_type

optional string
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

encoding

required object
Configures the encoding specific sink behavior.

encoding.except_fields

optional array
Prevent the sink from encoding the specified fields.

encoding.only_fields

optional array
Makes the sink encode only the specified fields.

encoding.timestamp_format

optional string enum literal
How to format event timestamps.
Enum options
OptionDescription
rfc3339Formats as a RFC3339 string
unixFormats as a unix timestamp
default: rfc3339

endpoint

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

healthcheck

common optional object
Health check options for the sink.

healthcheck.enabled

optional bool
Enables/disables the healthcheck upon Vector boot.
default: true

id_key

optional string
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.

index

common optional string
Index name to write events to.
default: vector-%F

inputs

required [string]

A list of upstream source or transform IDs. Wildcards (*) are supported but must be the last character in the ID.

See configuration for more info.

Array string literal
Examples
[
  "my-source-or-transform-id",
  "prefix-*"
]

metrics

optional object
Options for metrics.

metrics.host_tag

optional string literal
Tag key that identifies the source host.
default: hostname

metrics.timezone

optional string literal
The name of the time zone to apply to timestamp conversions that do not contain an explicit time zone. This overrides the global timezone option. The time zone name may be any name in the TZ database, or local to indicate system local time.
default: local

mode

common optional string
The type of index mechanism. If data_stream mode is enabled, the bulk_action is set to create.
default: normal

pipeline

common optional string
Name of the pipeline to apply.

query

optional object
Custom parameters to Elasticsearch query string.

request

optional object
Configures the sink request behavior.

request.adaptive_concurrency

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

request.concurrency

optional uint
The maximum number of in-flight requests allowed at any given time.
default: 5 (requests)

request.headers

optional object
Options for custom headers.

request.rate_limit_duration_secs

optional uint
The time window, in seconds, used for the rate_limit_num option.
default: 1 (seconds)

request.rate_limit_num

optional uint
The maximum number of requests allowed within the rate_limit_duration_secs time window.
default: 5

request.retry_attempts

optional uint
The maximum number of retries to make for failed requests. The default, for all intents and purposes, represents an infinite number of retries.
default: 1.8446744073709552e+19

request.retry_initial_backoff_secs

optional uint
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)

request.retry_max_duration_secs

optional uint
The maximum amount of time, in seconds, to wait between retries.
default: 10 (seconds)

request.timeout_secs

optional uint
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.
default: 60 (seconds)

tls

optional object
Configures the TLS options for incoming connections.

tls.ca_file

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

tls.crt_file

optional string literal
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.

tls.key_file

optional string literal
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.

tls.key_pass

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

tls.verify_hostname

optional bool
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

Metrics

link

events_discarded_total

counter
The total number of events discarded by this component.

events_in_total

counter
The number of events accepted by this component either from tagged origin like file and uri, or cumulatively from other origins.
component_kind required
The Vector component kind.
component_name required
The Vector component name.
component_type required
The Vector component type.
container_name optional
The name of the container from which the event originates.
file optional
The file from which the event originates.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the event originates.
peer_path optional
The pathname from which the event originates.
pod_name optional
The name of the pod from which the event originates.
uri optional
The sanitized URI from which the event originates.

events_out_total

counter
The total number of events emitted by this component.
component_kind required
The Vector component kind.
component_name required
The Vector component name.
component_type required
The Vector component type.

processing_errors_total

counter
The total number of processing errors encountered by this component.
component_kind required
The Vector component kind.
component_name required
The Vector component name.
component_type required
The Vector component type.
error_type required
The type of the error

How it works

AWS authentication

Vector checks for AWS credentials in the following order:

  1. The access_key_id and secret_access_key options.
  2. The AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables.
  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 (only works if running on an EC2 instance with an instance profile/role).

If no credentials are found, Vector’s health check fails and an error is logged. If your AWS credentials expire, Vector will automatically search for up-to-date credentials in the places (and order) described above.

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 and batches

Group 2 Created with Sketch.

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 max_size or max_events.

Buffers are controlled via the buffer.* options.

Conflicts

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

Data streams

By default, Vector uses the index action with Elasticsearch’s Bulk API. To use Data streams, set the mode to data_stream. Use the combination of data_stream.type, data_stream.dataset and data_stream.namespace instead of index.

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 allows partial bulk ingestion failures. This is typically due to Elasticsearch index mapping errors, where data keys aren’t consistently typed. To change this behavior, 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:

[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:

[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:

[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 due to OpenSSL’s maturity. You can enable and adjust TLS behavior using the tls.* options.