Datadog Logs
Search, process, and archive logs with cost awareness.
Prerequisites
Datadog Pup (dd-pup/pup) should already be installed:
bashcargo install --git https://github.com/DataDog/pup
Quick Start
bashpup auth login
Search Logs
bash# Basic search pup logs search --query="status:error" --from="1h" # With filters pup logs search --query="service:api status:error" --from="1h" --limit 100 # JSON output is the default pup logs search --query="@http.status_code:>=500" --from="1h"
Search Syntax
| Query | Meaning |
|---|---|
error | Full-text search |
status:error | Tag equals |
@http.status_code:500 | Attribute equals |
@http.status_code:>=400 | Numeric range |
service:api AND env:prod | Boolean |
@message:*timeout* | Wildcard |
Trace IDs in Log Results
Logs that show a linked trace in the Datadog UI may not include dd.trace_id /
dd.span_id in API results. When a trace ID attribute is remapped for trace
correlation (via JSON preprocessing or a Trace Remapper processor), the source
attribute is removed and the value is stored as an internal attribute that the
Logs Search API does not return. The UI's "trace" link reads that internal
attribute, so UI and API results differ.
This is expected Datadog Log Management behavior, not a pup bug or an instrumentation problem. Do not retry queries or change instrumentation to "fix" it. Datadog is tracking making these values queryable (support reference FRLOGSS-4306).
Workarounds until then:
- Emit the trace ID under a separate attribute that is not remapped (e.g.
@custom.trace_id) and query that. - Pivot the other way: search spans by the log's service/time window via
pup traces search, or use the trace link in the Datadog UI.
Pipelines
Process logs before indexing:
bash# List pipelines pup obs-pipelines list # Create pipeline (JSON) pup obs-pipelines create --file pipeline.json
Common Processors
json{ "name": "API Logs", "filter": {"query": "service:api"}, "processors": [ { "type": "grok-parser", "name": "Parse nginx", "source": "message", "grok": {"match_rules": "%{IPORHOST:client_ip} %{DATA:method} %{DATA:path} %{NUMBER:status}"} }, { "type": "status-remapper", "name": "Set severity", "sources": ["level", "severity"] }, { "type": "attribute-remapper", "name": "Remap user_id", "sources": ["user_id"], "target": "usr.id" } ] }
⚠️ Exclusion Filters (Cost Control)
Index only what matters:
json{ "name": "Drop debug logs", "filter": {"query": "status:debug"}, "is_enabled": true }
High-Volume Exclusions
bash# Find noisiest log sources pup logs search --query="*" --from="1h" | jq 'group_by(.service) | map({service: .[0].service, count: length}) | sort_by(-.count)[:10]'
| Exclude | Query |
|---|---|
| Health checks | @http.url:"/health" OR @http.url:"/ready" |
| Debug logs | status:debug |
| Static assets | @http.url:*.css OR @http.url:*.js |
| Heartbeats | @message:*heartbeat* |
Archives
Store logs cheaply for compliance:
bash# List archives pup logs archives list # Archive config (S3 example) { "name": "compliance-archive", "query": "*", "destination": { "type": "s3", "bucket": "my-logs-archive", "path": "/datadog" }, "rehydration_tags": ["team:platform"] }
Log-Based Metrics
Inspect log-based metrics:
bash# List existing log-based metrics pup logs metrics list
⚠️ Cardinality warning: Group by bounded values only.
Sensitive Data
Scrubbing Rules
json{ "type": "hash-remapper", "name": "Hash emails", "sources": ["email", "@user.email"] }
Never Log
python# In your app - sanitize before sending import re def sanitize_log(message: str) -> str: # Remove credit cards message = re.sub(r'\b\d{4}[-\s]?\d{4}[-\s]?\d{4}[-\s]?\d{4}\b', '[REDACTED]', message) # Remove SSNs message = re.sub(r'\b\d{3}-\d{2}-\d{4}\b', '[REDACTED]', message) return message
Troubleshooting
| Problem | Fix |
|---|---|
| Logs not appearing | Check agent, pipeline filters |
| High costs | Add exclusion filters |
| Search slow | Narrow time range, use indexes |
| Missing attributes | Check grok parser |
dd.trace_id missing but UI shows a trace | Expected: remapped trace IDs become internal attributes (see Trace IDs in Log Results) |


