Can't send traces to tempo via vector

[abdulgalimov]

Question

otel-collector config:

receivers:
  otlp:
    protocols:
      http:

processors:
  batch: {}

exporters:
  otlphttp:
    endpoint: http://vector:4318
    tls:
      insecure: true
service:
  pipelines:
    traces:
      receivers: [otlp]
      processors: [batch]
      exporters: [otlphttp]

tempo config:

server:
  http_listen_port: 3200

distributor:
  log_received_spans:
    enabled: true
    include_all_attributes: true
  log_discarded_spans:
    enabled: true
    include_all_attributes: true
  receivers:
    otlp:
      protocols:
        http:
          endpoint: tempo:4318

storage:
  trace:
    backend: local
    wal:
      path: /var/tempo/wal
    local:
      path: /var/tempo/traces

compactor:
  compaction:
    block_retention: 48h

metrics_generator:
  registry:
    external_labels:
      source: tempo
  storage:
    path: /var/tempo/generator

If I send traces from nodejs to otel-collector, and then directly to tempo (i.e. specifying exporters.otlphttp.endpoint = http://tempo:4318) - then everything works fine.

And if I try via vector, as indicated in the configs above, then I get the error 400 Bad Request. Please tell me what the problem is?

Vector Config

[sources.otlp]
type = "opentelemetry"
  [sources.otlp.grpc]
  address = "0.0.0.0:4317"
  [sources.otlp.http]
  address = "0.0.0.0:4318"
  headers = [ "*" ]
    [sources.otlp.http.keepalive]
    max_connection_age_jitter_factor = 0.1
    max_connection_age_secs = 300

[sinks.tempo]
type = "opentelemetry"
inputs = ["otlp.traces"]
  [sinks.tempo.protocol]
  type = "http"
  uri  = "http://tempo:4318/v1/traces"
  method = "post"
  [sinks.tempo.protocol.encoding]
  codec = "json"

Vector Logs

vector  | 2025-08-24T08:55:50.925175Z ERROR sink{component_kind="sink" component_id=tempo component_type=opentelemetry}:request{request_id=1}: vector::sinks::util::retries: Not retriable; dropping the request. reason="Http status: 400 Bad Request" internal_log_rate_limit=true
vector  | 2025-08-24T08:55:50.925449Z ERROR sink{component_kind="sink" component_id=tempo component_type=opentelemetry}:request{request_id=1}: vector_common::internal_event::service: Service call failed. No retries or retries exhausted. error=None request_id=1 error_type="request_failed" stage="sending" internal_log_rate_limit=true
vector  | 2025-08-24T08:55:50.925488Z ERROR sink{component_kind="sink" component_id=tempo component_type=opentelemetry}:request{request_id=1}: vector_common::internal_event::component_events_dropped: Events dropped intentional=false count=2 reason="Service call failed. No retries or retries exhausted." internal_log_rate_limit=true

[pront]

Hi @abdulgalimov, this comment is relevant here. The Vector OTEL source is creating a custom mapping so you will have to remap it back to a OTLP format manually.