Sematext Logs Sink

The Vector sematext_logs sink sends logs to Sematext.

Configuration

Common
Advanced

vector.toml
vector.yaml
vector.json

[sinks.my_sink_id]
  # General
  type = "sematext_logs" # required
  inputs = ["my-source-or-transform-id", "prefix-*"] # required
  region = "us" # required, required when endpoint is not set
  token = "${SEMATEXT_TOKEN}" # required

  # Encoding

  # Healthcheck
  healthcheck.enabled = true # optional, default

8 items

commonrequired

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"
  - View examples
- enumcommonoptionalstring
  type
  The buffer's type and storage mechanism.
  - Syntax: literal
  - Default: "memory"
  - Enum, must be one of: "memory" "disk"
  - View examples
- enumoptionalstring
  when_full
  The behavior when the buffer becomes full.
  - Syntax: literal
  - Default: "block"
  - Enum, must be one of: "block" "drop_newest"
  - View examples
commonrequiredtable
encoding
Configures the encoding specific sink behavior.
- optional[string]
  except_fields
  Prevent the sink from encoding the specified fields.
  - View examples
- optional[string]
  only_fields
  Prevent the sink from encoding the specified fields.
  - View examples
- enumoptionalstring
  timestamp_format
  How to format event timestamps.
  - Syntax: literal
  - Default: "rfc3339"
  - Enum, must be one of: "rfc3339" "unix"
  - View examples
optionalstring
endpoint
The endpoint to send data to.
- Syntax: literal
- Only relevant when: region is not set
- View examples
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
  - View examples
enumcommonrequired*string
region
The region to send data to.
- Syntax: literal
- Only required when: endpoint is not set
- Enum, must be one of: "us" "eu"
- View examples
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)
- 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)
commonrequiredstring
token
The token that will be used to write to Sematext.
- Syntax: literal
- View examples

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
events_in_total
The number of events accepted by this component either from tagged origin like file and uri, or cumulatively from other origins. This metric includes the following tags:
- component_kind - The Vector component kind.
- component_name - The Vector component ID.
- component_type - The Vector component type.
- container_name - The name of the container from which the event originates.
- file - The file from which the event originates.
- instance - The Vector instance identified by host and port.
- job - The name of the job producing Vector metrics.
- mode - The connection mode used by the component.
- peer_addr - The IP from which the event originates.
- peer_path - The pathname from which the event originates.
- pod_name - The name of the pod from which the event originates.
- uri - The sanitized uri from which the event originates.
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

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:

The batch age meets or exceeds the configured timeout_secs.
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.

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.

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.

Setup

Register for a free account at Sematext.com
Create a Logs App to get a Logs Token for Sematext Logs

State

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

#Configuration

#batch

#max_bytes

#timeout_secs

#buffer

#max_events

#max_size

#type

#when_full

#encoding

#except_fields

#only_fields

#timestamp_format

#endpoint

#healthcheck

#enabled

#region

#request

#adaptive_concurrency

#decrease_ratio

#ewma_alpha

#rtt_threshold_ratio

#concurrency

#rate_limit_duration_secs

#rate_limit_num

#retry_attempts

#retry_initial_backoff_secs

#retry_max_duration_secs

#timeout_secs

#token

#Telemetry

#events_in_total

#events_out_total

#How It Works

#Buffers & batches

#Health checks

#Require health checks

#Disable health checks

#Partitioning

#Rate limits & adapative concurrency

#Adaptive Request Concurrency (ARC)

#Static rate limits

#Retry policy

#Setup

#State

Configuration

batch

max_bytes

timeout_secs

buffer

max_events

max_size

type

when_full

encoding

except_fields

only_fields

timestamp_format

endpoint

healthcheck

enabled

region

request

adaptive_concurrency

decrease_ratio

ewma_alpha

rtt_threshold_ratio

concurrency

rate_limit_duration_secs

rate_limit_num

retry_attempts

retry_initial_backoff_secs

retry_max_duration_secs

timeout_secs

token

Telemetry

events_in_total

events_out_total

How It Works

Buffers & batches

Health checks

Require health checks

Disable health checks

Partitioning

Rate limits & adapative concurrency

Adaptive Request Concurrency (ARC)

Static rate limits

Retry policy

Setup

State