refactor: split 21 over-500-line skills into SKILL.md + references (#296)

This commit is contained in:
Alireza Rezvani
2026-03-08 10:14:30 +01:00
committed by GitHub
parent e7081583fb
commit fea994eb42
50 changed files with 7133 additions and 6511 deletions

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@@ -369,204 +369,7 @@ Status page: {link}
- **{Pitfall}:** {description and how to avoid}
## Reference Information
- **Architecture Diagram:** {link}
- **Monitoring Dashboard:** {link}
- **Related Runbooks:** {links to dependent service runbooks}
```
### Post-Incident Review (PIR) Framework
#### PIR Timeline and Ownership
**Timeline:**
- **24 hours:** Initial PIR draft completed by Incident Commander
- **3 business days:** Final PIR published with all stakeholder input
- **1 week:** Action items assigned with owners and due dates
- **4 weeks:** Follow-up review on action item progress
**Roles:**
- **PIR Owner:** Incident Commander (can delegate writing but owns completion)
- **Technical Contributors:** All engineers involved in response
- **Review Committee:** Engineering leadership, affected product teams
- **Action Item Owners:** Assigned based on expertise and capacity
#### Root Cause Analysis Frameworks
#### 1. Five Whys Method
The Five Whys technique involves asking "why" repeatedly to drill down to root causes:
**Example Application:**
- **Problem:** Database became unresponsive during peak traffic
- **Why 1:** Why did the database become unresponsive? → Connection pool was exhausted
- **Why 2:** Why was the connection pool exhausted? → Application was creating more connections than usual
- **Why 3:** Why was the application creating more connections? → New feature wasn't properly connection pooling
- **Why 4:** Why wasn't the feature properly connection pooling? → Code review missed this pattern
- **Why 5:** Why did code review miss this? → No automated checks for connection pooling patterns
**Best Practices:**
- Ask "why" at least 3 times, often need 5+ iterations
- Focus on process failures, not individual blame
- Each "why" should point to a actionable system improvement
- Consider multiple root cause paths, not just one linear chain
#### 2. Fishbone (Ishikawa) Diagram
Systematic analysis across multiple categories of potential causes:
**Categories:**
- **People:** Training, experience, communication, handoffs
- **Process:** Procedures, change management, review processes
- **Technology:** Architecture, tooling, monitoring, automation
- **Environment:** Infrastructure, dependencies, external factors
**Application Method:**
1. State the problem clearly at the "head" of the fishbone
2. For each category, brainstorm potential contributing factors
3. For each factor, ask what caused that factor (sub-causes)
4. Identify the factors most likely to be root causes
5. Validate root causes with evidence from the incident
#### 3. Timeline Analysis
Reconstruct the incident chronologically to identify decision points and missed opportunities:
**Timeline Elements:**
- **Detection:** When was the issue first observable? When was it first detected?
- **Notification:** How quickly were the right people informed?
- **Response:** What actions were taken and how effective were they?
- **Communication:** When were stakeholders updated?
- **Resolution:** What finally resolved the issue?
**Analysis Questions:**
- Where were there delays and what caused them?
- What decisions would we make differently with perfect information?
- Where did communication break down?
- What automation could have detected/resolved faster?
### Escalation Paths
#### Technical Escalation
**Level 1:** On-call engineer
- **Responsibility:** Initial response and common issue resolution
- **Escalation Trigger:** Issue not resolved within SLA timeframe
- **Timeframe:** 15 minutes (SEV1), 30 minutes (SEV2)
**Level 2:** Senior engineer/Team lead
- **Responsibility:** Complex technical issues requiring deeper expertise
- **Escalation Trigger:** Level 1 requests help or timeout occurs
- **Timeframe:** 30 minutes (SEV1), 1 hour (SEV2)
**Level 3:** Engineering Manager/Staff Engineer
- **Responsibility:** Cross-team coordination and architectural decisions
- **Escalation Trigger:** Issue spans multiple systems or teams
- **Timeframe:** 45 minutes (SEV1), 2 hours (SEV2)
**Level 4:** Director of Engineering/CTO
- **Responsibility:** Resource allocation and business impact decisions
- **Escalation Trigger:** Extended outage or significant business impact
- **Timeframe:** 1 hour (SEV1), 4 hours (SEV2)
#### Business Escalation
**Customer Impact Assessment:**
- **High:** Revenue loss, SLA breaches, customer churn risk
- **Medium:** User experience degradation, support ticket volume
- **Low:** Internal tools, development impact only
**Escalation Matrix:**
| Severity | Duration | Business Escalation |
|----------|----------|-------------------|
| SEV1 | Immediate | VP Engineering |
| SEV1 | 30 minutes | CTO + Customer Success VP |
| SEV1 | 1 hour | CEO + Full Executive Team |
| SEV2 | 2 hours | VP Engineering |
| SEV2 | 4 hours | CTO |
| SEV3 | 1 business day | Engineering Manager |
### Status Page Management
#### Update Principles
1. **Transparency:** Provide factual information without speculation
2. **Timeliness:** Update within committed timeframes
3. **Clarity:** Use customer-friendly language, avoid technical jargon
4. **Completeness:** Include impact scope, status, and next update time
#### Status Categories
- **Operational:** All systems functioning normally
- **Degraded Performance:** Some users may experience slowness
- **Partial Outage:** Subset of features unavailable
- **Major Outage:** Service unavailable for most/all users
- **Under Maintenance:** Planned maintenance window
#### Update Template
```
{Timestamp} - {Status Category}
{Brief description of current state}
Impact: {who is affected and how}
Cause: {root cause if known, "under investigation" if not}
Resolution: {what's being done to fix it}
Next update: {specific time}
We apologize for any inconvenience this may cause.
```
### Action Item Framework
#### Action Item Categories
1. **Immediate Fixes**
- Critical bugs discovered during incident
- Security vulnerabilities exposed
- Data integrity issues
2. **Process Improvements**
- Communication gaps
- Escalation procedure updates
- Runbook additions/updates
3. **Technical Debt**
- Architecture improvements
- Monitoring enhancements
- Automation opportunities
4. **Organizational Changes**
- Team structure adjustments
- Training requirements
- Tool/platform investments
#### Action Item Template
```
**Title:** {Concise description of the action}
**Priority:** {Critical/High/Medium/Low}
**Category:** {Fix/Process/Technical/Organizational}
**Owner:** {Assigned person}
**Due Date:** {Specific date}
**Success Criteria:** {How will we know this is complete}
**Dependencies:** {What needs to happen first}
**Related PIRs:** {Links to other incidents this addresses}
**Description:**
{Detailed description of what needs to be done and why}
**Implementation Plan:**
1. {Step 1}
2. {Step 2}
3. {Validation step}
**Progress Updates:**
- {Date}: {Progress update}
- {Date}: {Progress update}
```
→ See references/reference-information.md for details
## Usage Examples
@@ -670,4 +473,4 @@ The Incident Commander skill provides a comprehensive framework for managing inc
The key to successful incident management is preparation, practice, and continuous learning. Use this framework as a starting point, but adapt it to your organization's specific needs, culture, and technical environment.
Remember: The goal isn't to prevent all incidents (which is impossible), but to detect them quickly, respond effectively, communicate clearly, and learn continuously.
Remember: The goal isn't to prevent all incidents (which is impossible), but to detect them quickly, respond effectively, communicate clearly, and learn continuously.

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@@ -0,0 +1,201 @@
# incident-commander reference
## Reference Information
- **Architecture Diagram:** {link}
- **Monitoring Dashboard:** {link}
- **Related Runbooks:** {links to dependent service runbooks}
```
### Post-Incident Review (PIR) Framework
#### PIR Timeline and Ownership
**Timeline:**
- **24 hours:** Initial PIR draft completed by Incident Commander
- **3 business days:** Final PIR published with all stakeholder input
- **1 week:** Action items assigned with owners and due dates
- **4 weeks:** Follow-up review on action item progress
**Roles:**
- **PIR Owner:** Incident Commander (can delegate writing but owns completion)
- **Technical Contributors:** All engineers involved in response
- **Review Committee:** Engineering leadership, affected product teams
- **Action Item Owners:** Assigned based on expertise and capacity
#### Root Cause Analysis Frameworks
#### 1. Five Whys Method
The Five Whys technique involves asking "why" repeatedly to drill down to root causes:
**Example Application:**
- **Problem:** Database became unresponsive during peak traffic
- **Why 1:** Why did the database become unresponsive? → Connection pool was exhausted
- **Why 2:** Why was the connection pool exhausted? → Application was creating more connections than usual
- **Why 3:** Why was the application creating more connections? → New feature wasn't properly connection pooling
- **Why 4:** Why wasn't the feature properly connection pooling? → Code review missed this pattern
- **Why 5:** Why did code review miss this? → No automated checks for connection pooling patterns
**Best Practices:**
- Ask "why" at least 3 times, often need 5+ iterations
- Focus on process failures, not individual blame
- Each "why" should point to a actionable system improvement
- Consider multiple root cause paths, not just one linear chain
#### 2. Fishbone (Ishikawa) Diagram
Systematic analysis across multiple categories of potential causes:
**Categories:**
- **People:** Training, experience, communication, handoffs
- **Process:** Procedures, change management, review processes
- **Technology:** Architecture, tooling, monitoring, automation
- **Environment:** Infrastructure, dependencies, external factors
**Application Method:**
1. State the problem clearly at the "head" of the fishbone
2. For each category, brainstorm potential contributing factors
3. For each factor, ask what caused that factor (sub-causes)
4. Identify the factors most likely to be root causes
5. Validate root causes with evidence from the incident
#### 3. Timeline Analysis
Reconstruct the incident chronologically to identify decision points and missed opportunities:
**Timeline Elements:**
- **Detection:** When was the issue first observable? When was it first detected?
- **Notification:** How quickly were the right people informed?
- **Response:** What actions were taken and how effective were they?
- **Communication:** When were stakeholders updated?
- **Resolution:** What finally resolved the issue?
**Analysis Questions:**
- Where were there delays and what caused them?
- What decisions would we make differently with perfect information?
- Where did communication break down?
- What automation could have detected/resolved faster?
### Escalation Paths
#### Technical Escalation
**Level 1:** On-call engineer
- **Responsibility:** Initial response and common issue resolution
- **Escalation Trigger:** Issue not resolved within SLA timeframe
- **Timeframe:** 15 minutes (SEV1), 30 minutes (SEV2)
**Level 2:** Senior engineer/Team lead
- **Responsibility:** Complex technical issues requiring deeper expertise
- **Escalation Trigger:** Level 1 requests help or timeout occurs
- **Timeframe:** 30 minutes (SEV1), 1 hour (SEV2)
**Level 3:** Engineering Manager/Staff Engineer
- **Responsibility:** Cross-team coordination and architectural decisions
- **Escalation Trigger:** Issue spans multiple systems or teams
- **Timeframe:** 45 minutes (SEV1), 2 hours (SEV2)
**Level 4:** Director of Engineering/CTO
- **Responsibility:** Resource allocation and business impact decisions
- **Escalation Trigger:** Extended outage or significant business impact
- **Timeframe:** 1 hour (SEV1), 4 hours (SEV2)
#### Business Escalation
**Customer Impact Assessment:**
- **High:** Revenue loss, SLA breaches, customer churn risk
- **Medium:** User experience degradation, support ticket volume
- **Low:** Internal tools, development impact only
**Escalation Matrix:**
| Severity | Duration | Business Escalation |
|----------|----------|-------------------|
| SEV1 | Immediate | VP Engineering |
| SEV1 | 30 minutes | CTO + Customer Success VP |
| SEV1 | 1 hour | CEO + Full Executive Team |
| SEV2 | 2 hours | VP Engineering |
| SEV2 | 4 hours | CTO |
| SEV3 | 1 business day | Engineering Manager |
### Status Page Management
#### Update Principles
1. **Transparency:** Provide factual information without speculation
2. **Timeliness:** Update within committed timeframes
3. **Clarity:** Use customer-friendly language, avoid technical jargon
4. **Completeness:** Include impact scope, status, and next update time
#### Status Categories
- **Operational:** All systems functioning normally
- **Degraded Performance:** Some users may experience slowness
- **Partial Outage:** Subset of features unavailable
- **Major Outage:** Service unavailable for most/all users
- **Under Maintenance:** Planned maintenance window
#### Update Template
```
{Timestamp} - {Status Category}
{Brief description of current state}
Impact: {who is affected and how}
Cause: {root cause if known, "under investigation" if not}
Resolution: {what's being done to fix it}
Next update: {specific time}
We apologize for any inconvenience this may cause.
```
### Action Item Framework
#### Action Item Categories
1. **Immediate Fixes**
- Critical bugs discovered during incident
- Security vulnerabilities exposed
- Data integrity issues
2. **Process Improvements**
- Communication gaps
- Escalation procedure updates
- Runbook additions/updates
3. **Technical Debt**
- Architecture improvements
- Monitoring enhancements
- Automation opportunities
4. **Organizational Changes**
- Team structure adjustments
- Training requirements
- Tool/platform investments
#### Action Item Template
```
**Title:** {Concise description of the action}
**Priority:** {Critical/High/Medium/Low}
**Category:** {Fix/Process/Technical/Organizational}
**Owner:** {Assigned person}
**Due Date:** {Specific date}
**Success Criteria:** {How will we know this is complete}
**Dependencies:** {What needs to happen first}
**Related PIRs:** {Links to other incidents this addresses}
**Description:**
{Detailed description of what needs to be done and why}
**Implementation Plan:**
1. {Step 1}
2. {Step 2}
3. {Validation step}
**Progress Updates:**
- {Date}: {Progress update}
- {Date}: {Progress update}
```

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@@ -9,18 +9,5 @@
"homepage": "https://github.com/alirezarezvani/claude-skills/tree/main/engineering-team/playwright-pro",
"repository": "https://github.com/alirezarezvani/claude-skills",
"license": "MIT",
"keywords": [
"playwright",
"testing",
"e2e",
"qa",
"browserstack",
"testrail",
"test-automation",
"cross-browser",
"migration",
"cypress",
"selenium"
],
"skills": "./skills"
"skills": "./"
}

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@@ -419,99 +419,7 @@ python scripts/dataset_pipeline_builder.py data/final/ \
| Positional encoding | Implicit | Explicit |
## Reference Documentation
### 1. Computer Vision Architectures
See `references/computer_vision_architectures.md` for:
- CNN backbone architectures (ResNet, EfficientNet, ConvNeXt)
- Vision Transformer variants (ViT, DeiT, Swin)
- Detection heads (anchor-based vs anchor-free)
- Feature Pyramid Networks (FPN, BiFPN, PANet)
- Neck architectures for multi-scale detection
### 2. Object Detection Optimization
See `references/object_detection_optimization.md` for:
- Non-Maximum Suppression variants (NMS, Soft-NMS, DIoU-NMS)
- Anchor optimization and anchor-free alternatives
- Loss function design (focal loss, GIoU, CIoU, DIoU)
- Training strategies (warmup, cosine annealing, EMA)
- Data augmentation for detection (mosaic, mixup, copy-paste)
### 3. Production Vision Systems
See `references/production_vision_systems.md` for:
- ONNX export and optimization
- TensorRT deployment pipeline
- Batch inference optimization
- Edge device deployment (Jetson, Intel NCS)
- Model serving with Triton
- Video processing pipelines
## Common Commands
### Ultralytics YOLO
```bash
# Training
yolo detect train data=coco.yaml model=yolov8m.pt epochs=100 imgsz=640
# Validation
yolo detect val model=best.pt data=coco.yaml
# Inference
yolo detect predict model=best.pt source=images/ save=True
# Export
yolo export model=best.pt format=onnx simplify=True dynamic=True
```
### Detectron2
```bash
# Training
python train_net.py --config-file configs/COCO-Detection/faster_rcnn_R_50_FPN_3x.yaml \
--num-gpus 1 OUTPUT_DIR ./output
# Evaluation
python train_net.py --config-file configs/faster_rcnn.yaml --eval-only \
MODEL.WEIGHTS output/model_final.pth
# Inference
python demo.py --config-file configs/faster_rcnn.yaml \
--input images/*.jpg --output results/ \
--opts MODEL.WEIGHTS output/model_final.pth
```
### MMDetection
```bash
# Training
python tools/train.py configs/faster_rcnn/faster-rcnn_r50_fpn_1x_coco.py
# Testing
python tools/test.py configs/faster_rcnn.py checkpoints/latest.pth --eval bbox
# Inference
python demo/image_demo.py demo.jpg configs/faster_rcnn.py checkpoints/latest.pth
```
### Model Optimization
```bash
# ONNX export and simplify
python -c "import torch; model = torch.load('model.pt'); torch.onnx.export(model, torch.randn(1,3,640,640), 'model.onnx', opset_version=17)"
python -m onnxsim model.onnx model_sim.onnx
# TensorRT conversion
trtexec --onnx=model.onnx --saveEngine=model.engine --fp16 --workspace=4096
# Benchmark
trtexec --loadEngine=model.engine --batch=1 --iterations=1000 --avgRuns=100
```
→ See references/reference-docs-and-commands.md for details
## Performance Targets

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@@ -0,0 +1,96 @@
# senior-computer-vision reference
## Reference Documentation
### 1. Computer Vision Architectures
See `references/computer_vision_architectures.md` for:
- CNN backbone architectures (ResNet, EfficientNet, ConvNeXt)
- Vision Transformer variants (ViT, DeiT, Swin)
- Detection heads (anchor-based vs anchor-free)
- Feature Pyramid Networks (FPN, BiFPN, PANet)
- Neck architectures for multi-scale detection
### 2. Object Detection Optimization
See `references/object_detection_optimization.md` for:
- Non-Maximum Suppression variants (NMS, Soft-NMS, DIoU-NMS)
- Anchor optimization and anchor-free alternatives
- Loss function design (focal loss, GIoU, CIoU, DIoU)
- Training strategies (warmup, cosine annealing, EMA)
- Data augmentation for detection (mosaic, mixup, copy-paste)
### 3. Production Vision Systems
See `references/production_vision_systems.md` for:
- ONNX export and optimization
- TensorRT deployment pipeline
- Batch inference optimization
- Edge device deployment (Jetson, Intel NCS)
- Model serving with Triton
- Video processing pipelines
## Common Commands
### Ultralytics YOLO
```bash
# Training
yolo detect train data=coco.yaml model=yolov8m.pt epochs=100 imgsz=640
# Validation
yolo detect val model=best.pt data=coco.yaml
# Inference
yolo detect predict model=best.pt source=images/ save=True
# Export
yolo export model=best.pt format=onnx simplify=True dynamic=True
```
### Detectron2
```bash
# Training
python train_net.py --config-file configs/COCO-Detection/faster_rcnn_R_50_FPN_3x.yaml \
--num-gpus 1 OUTPUT_DIR ./output
# Evaluation
python train_net.py --config-file configs/faster_rcnn.yaml --eval-only \
MODEL.WEIGHTS output/model_final.pth
# Inference
python demo.py --config-file configs/faster_rcnn.yaml \
--input images/*.jpg --output results/ \
--opts MODEL.WEIGHTS output/model_final.pth
```
### MMDetection
```bash
# Training
python tools/train.py configs/faster_rcnn/faster-rcnn_r50_fpn_1x_coco.py
# Testing
python tools/test.py configs/faster_rcnn.py checkpoints/latest.pth --eval bbox
# Inference
python demo/image_demo.py demo.jpg configs/faster_rcnn.py checkpoints/latest.pth
```
### Model Optimization
```bash
# ONNX export and simplify
python -c "import torch; model = torch.load('model.pt'); torch.onnx.export(model, torch.randn(1,3,640,640), 'model.onnx', opset_version=17)"
python -m onnxsim model.onnx model_sim.onnx
# TensorRT conversion
trtexec --onnx=model.onnx --saveEngine=model.engine --fp16 --workspace=4096
# Benchmark
trtexec --loadEngine=model.engine --batch=1 --iterations=1000 --avgRuns=100
```

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@@ -86,627 +86,7 @@ python scripts/etl_performance_optimizer.py analyze \
---
## Workflows
### Workflow 1: Building a Batch ETL Pipeline
**Scenario:** Extract data from PostgreSQL, transform with dbt, load to Snowflake.
#### Step 1: Define Source Schema
```sql
-- Document source tables
SELECT
table_name,
column_name,
data_type,
is_nullable
FROM information_schema.columns
WHERE table_schema = 'source_schema'
ORDER BY table_name, ordinal_position;
```
#### Step 2: Generate Extraction Config
```bash
python scripts/pipeline_orchestrator.py generate \
--type airflow \
--source postgres \
--tables orders,customers,products \
--mode incremental \
--watermark updated_at \
--output dags/extract_source.py
```
#### Step 3: Create dbt Models
```sql
-- models/staging/stg_orders.sql
WITH source AS (
SELECT * FROM {{ source('postgres', 'orders') }}
),
renamed AS (
SELECT
order_id,
customer_id,
order_date,
total_amount,
status,
_extracted_at
FROM source
WHERE order_date >= DATEADD(day, -3, CURRENT_DATE)
)
SELECT * FROM renamed
```
```sql
-- models/marts/fct_orders.sql
{{
config(
materialized='incremental',
unique_key='order_id',
cluster_by=['order_date']
)
}}
SELECT
o.order_id,
o.customer_id,
c.customer_segment,
o.order_date,
o.total_amount,
o.status
FROM {{ ref('stg_orders') }} o
LEFT JOIN {{ ref('dim_customers') }} c
ON o.customer_id = c.customer_id
{% if is_incremental() %}
WHERE o._extracted_at > (SELECT MAX(_extracted_at) FROM {{ this }})
{% endif %}
```
#### Step 4: Configure Data Quality Tests
```yaml
# models/marts/schema.yml
version: 2
models:
- name: "fct-orders"
description: "Order fact table"
columns:
- name: "order-id"
tests:
- unique
- not_null
- name: "total-amount"
tests:
- not_null
- dbt_utils.accepted_range:
min_value: 0
max_value: 1000000
- name: "order-date"
tests:
- not_null
- dbt_utils.recency:
datepart: day
field: order_date
interval: 1
```
#### Step 5: Create Airflow DAG
```python
# dags/daily_etl.py
from airflow import DAG
from airflow.providers.postgres.operators.postgres import PostgresOperator
from airflow.operators.bash import BashOperator
from airflow.utils.dates import days_ago
from datetime import timedelta
default_args = {
'owner': 'data-team',
'depends_on_past': False,
'email_on_failure': True,
'email': ['data-alerts@company.com'],
'retries': 2,
'retry_delay': timedelta(minutes=5),
}
with DAG(
'daily_etl_pipeline',
default_args=default_args,
description='Daily ETL from PostgreSQL to Snowflake',
schedule_interval='0 5 * * *',
start_date=days_ago(1),
catchup=False,
tags=['etl', 'daily'],
) as dag:
extract = BashOperator(
task_id='extract_source_data',
bash_command='python /opt/airflow/scripts/extract.py --date {{ ds }}',
)
transform = BashOperator(
task_id='run_dbt_models',
bash_command='cd /opt/airflow/dbt && dbt run --select marts.*',
)
test = BashOperator(
task_id='run_dbt_tests',
bash_command='cd /opt/airflow/dbt && dbt test --select marts.*',
)
notify = BashOperator(
task_id='send_notification',
bash_command='python /opt/airflow/scripts/notify.py --status success',
trigger_rule='all_success',
)
extract >> transform >> test >> notify
```
#### Step 6: Validate Pipeline
```bash
# Test locally
dbt run --select stg_orders fct_orders
dbt test --select fct_orders
# Validate data quality
python scripts/data_quality_validator.py validate \
--table fct_orders \
--checks all \
--output reports/quality_report.json
```
---
### Workflow 2: Implementing Real-Time Streaming
**Scenario:** Stream events from Kafka, process with Flink/Spark Streaming, sink to data lake.
#### Step 1: Define Event Schema
```json
{
"$schema": "http://json-schema.org/draft-07/schema#",
"title": "UserEvent",
"type": "object",
"required": ["event_id", "user_id", "event_type", "timestamp"],
"properties": {
"event_id": {"type": "string", "format": "uuid"},
"user_id": {"type": "string"},
"event_type": {"type": "string", "enum": ["page_view", "click", "purchase"]},
"timestamp": {"type": "string", "format": "date-time"},
"properties": {"type": "object"}
}
}
```
#### Step 2: Create Kafka Topic
```bash
# Create topic with appropriate partitions
kafka-topics.sh --create \
--bootstrap-server localhost:9092 \
--topic user-events \
--partitions 12 \
--replication-factor 3 \
--config retention.ms=604800000 \
--config cleanup.policy=delete
# Verify topic
kafka-topics.sh --describe \
--bootstrap-server localhost:9092 \
--topic user-events
```
#### Step 3: Implement Spark Streaming Job
```python
# streaming/user_events_processor.py
from pyspark.sql import SparkSession
from pyspark.sql.functions import (
from_json, col, window, count, avg,
to_timestamp, current_timestamp
)
from pyspark.sql.types import (
StructType, StructField, StringType,
TimestampType, MapType
)
# Initialize Spark
spark = SparkSession.builder \
.appName("UserEventsProcessor") \
.config("spark.sql.streaming.checkpointLocation", "/checkpoints/user-events") \
.config("spark.sql.shuffle.partitions", "12") \
.getOrCreate()
# Define schema
event_schema = StructType([
StructField("event_id", StringType(), False),
StructField("user_id", StringType(), False),
StructField("event_type", StringType(), False),
StructField("timestamp", StringType(), False),
StructField("properties", MapType(StringType(), StringType()), True)
])
# Read from Kafka
events_df = spark.readStream \
.format("kafka") \
.option("kafka.bootstrap.servers", "localhost:9092") \
.option("subscribe", "user-events") \
.option("startingOffsets", "latest") \
.option("failOnDataLoss", "false") \
.load()
# Parse JSON
parsed_df = events_df \
.select(from_json(col("value").cast("string"), event_schema).alias("data")) \
.select("data.*") \
.withColumn("event_timestamp", to_timestamp(col("timestamp")))
# Windowed aggregation
aggregated_df = parsed_df \
.withWatermark("event_timestamp", "10 minutes") \
.groupBy(
window(col("event_timestamp"), "5 minutes"),
col("event_type")
) \
.agg(
count("*").alias("event_count"),
approx_count_distinct("user_id").alias("unique_users")
)
# Write to Delta Lake
query = aggregated_df.writeStream \
.format("delta") \
.outputMode("append") \
.option("checkpointLocation", "/checkpoints/user-events-aggregated") \
.option("path", "/data/lake/user_events_aggregated") \
.trigger(processingTime="1 minute") \
.start()
query.awaitTermination()
```
#### Step 4: Handle Late Data and Errors
```python
# Dead letter queue for failed records
from pyspark.sql.functions import current_timestamp, lit
def process_with_error_handling(batch_df, batch_id):
try:
# Attempt processing
valid_df = batch_df.filter(col("event_id").isNotNull())
invalid_df = batch_df.filter(col("event_id").isNull())
# Write valid records
valid_df.write \
.format("delta") \
.mode("append") \
.save("/data/lake/user_events")
# Write invalid to DLQ
if invalid_df.count() > 0:
invalid_df \
.withColumn("error_timestamp", current_timestamp()) \
.withColumn("error_reason", lit("missing_event_id")) \
.write \
.format("delta") \
.mode("append") \
.save("/data/lake/dlq/user_events")
except Exception as e:
# Log error, alert, continue
logger.error(f"Batch {batch_id} failed: {e}")
raise
# Use foreachBatch for custom processing
query = parsed_df.writeStream \
.foreachBatch(process_with_error_handling) \
.option("checkpointLocation", "/checkpoints/user-events") \
.start()
```
#### Step 5: Monitor Stream Health
```python
# monitoring/stream_metrics.py
from prometheus_client import Gauge, Counter, start_http_server
# Define metrics
RECORDS_PROCESSED = Counter(
'stream_records_processed_total',
'Total records processed',
['stream_name', 'status']
)
PROCESSING_LAG = Gauge(
'stream_processing_lag_seconds',
'Current processing lag',
['stream_name']
)
BATCH_DURATION = Gauge(
'stream_batch_duration_seconds',
'Last batch processing duration',
['stream_name']
)
def emit_metrics(query):
"""Emit Prometheus metrics from streaming query."""
progress = query.lastProgress
if progress:
RECORDS_PROCESSED.labels(
stream_name='user-events',
status='success'
).inc(progress['numInputRows'])
if progress['sources']:
# Calculate lag from latest offset
for source in progress['sources']:
end_offset = source.get('endOffset', {})
# Parse Kafka offsets and calculate lag
```
---
### Workflow 3: Data Quality Framework Setup
**Scenario:** Implement comprehensive data quality monitoring with Great Expectations.
#### Step 1: Initialize Great Expectations
```bash
# Install and initialize
pip install great_expectations
great_expectations init
# Connect to data source
great_expectations datasource new
```
#### Step 2: Create Expectation Suite
```python
# expectations/orders_suite.py
import great_expectations as gx
context = gx.get_context()
# Create expectation suite
suite = context.add_expectation_suite("orders_quality_suite")
# Add expectations
validator = context.get_validator(
batch_request={
"datasource_name": "warehouse",
"data_asset_name": "orders",
},
expectation_suite_name="orders_quality_suite"
)
# Schema expectations
validator.expect_table_columns_to_match_ordered_list(
column_list=[
"order_id", "customer_id", "order_date",
"total_amount", "status", "created_at"
]
)
# Completeness expectations
validator.expect_column_values_to_not_be_null("order_id")
validator.expect_column_values_to_not_be_null("customer_id")
validator.expect_column_values_to_not_be_null("order_date")
# Uniqueness expectations
validator.expect_column_values_to_be_unique("order_id")
# Range expectations
validator.expect_column_values_to_be_between(
"total_amount",
min_value=0,
max_value=1000000
)
# Categorical expectations
validator.expect_column_values_to_be_in_set(
"status",
["pending", "confirmed", "shipped", "delivered", "cancelled"]
)
# Freshness expectation
validator.expect_column_max_to_be_between(
"order_date",
min_value={"$PARAMETER": "now - timedelta(days=1)"},
max_value={"$PARAMETER": "now"}
)
# Referential integrity
validator.expect_column_values_to_be_in_set(
"customer_id",
value_set={"$PARAMETER": "valid_customer_ids"}
)
validator.save_expectation_suite(discard_failed_expectations=False)
```
#### Step 3: Create Data Quality Checks with dbt
```yaml
# models/marts/schema.yml
version: 2
models:
- name: "fct-orders"
description: "Order fact table with data quality checks"
tests:
# Row count check
- dbt_utils.equal_rowcount:
compare_model: ref('stg_orders')
# Freshness check
- dbt_utils.recency:
datepart: hour
field: created_at
interval: 24
columns:
- name: "order-id"
description: "Unique order identifier"
tests:
- unique
- not_null
- relationships:
to: ref('dim_orders')
field: order_id
- name: "total-amount"
tests:
- not_null
- dbt_utils.accepted_range:
min_value: 0
max_value: 1000000
inclusive: true
- dbt_expectations.expect_column_values_to_be_between:
min_value: 0
row_condition: "status != 'cancelled'"
- name: "customer-id"
tests:
- not_null
- relationships:
to: ref('dim_customers')
field: customer_id
severity: warn
```
#### Step 4: Implement Data Contracts
```yaml
# contracts/orders_contract.yaml
contract:
name: "orders-data-contract"
version: "1.0.0"
owner: data-team@company.com
schema:
type: object
properties:
order_id:
type: string
format: uuid
description: "Unique order identifier"
customer_id:
type: string
not_null: true
order_date:
type: date
not_null: true
total_amount:
type: decimal
precision: 10
scale: 2
minimum: 0
status:
type: string
enum: ["pending", "confirmed", "shipped", "delivered", "cancelled"]
sla:
freshness:
max_delay_hours: 1
completeness:
min_percentage: 99.9
accuracy:
duplicate_tolerance: 0.01
consumers:
- name: "analytics-team"
usage: "Daily reporting dashboards"
- name: "ml-team"
usage: "Churn prediction model"
```
#### Step 5: Set Up Quality Monitoring Dashboard
```python
# monitoring/quality_dashboard.py
from datetime import datetime, timedelta
import pandas as pd
def generate_quality_report(connection, table_name: "str-dict"
"""Generate comprehensive data quality report."""
report = {
"table": table_name,
"timestamp": datetime.now().isoformat(),
"checks": {}
}
# Row count check
row_count = connection.execute(
f"SELECT COUNT(*) FROM {table_name}"
).fetchone()[0]
report["checks"]["row_count"] = {
"value": row_count,
"status": "pass" if row_count > 0 else "fail"
}
# Freshness check
max_date = connection.execute(
f"SELECT MAX(created_at) FROM {table_name}"
).fetchone()[0]
hours_old = (datetime.now() - max_date).total_seconds() / 3600
report["checks"]["freshness"] = {
"max_timestamp": max_date.isoformat(),
"hours_old": round(hours_old, 2),
"status": "pass" if hours_old < 24 else "fail"
}
# Null rate check
null_query = f"""
SELECT
SUM(CASE WHEN order_id IS NULL THEN 1 ELSE 0 END) as null_order_id,
SUM(CASE WHEN customer_id IS NULL THEN 1 ELSE 0 END) as null_customer_id,
COUNT(*) as total
FROM {table_name}
"""
null_result = connection.execute(null_query).fetchone()
report["checks"]["null_rates"] = {
"order_id": null_result[0] / null_result[2] if null_result[2] > 0 else 0,
"customer_id": null_result[1] / null_result[2] if null_result[2] > 0 else 0,
"status": "pass" if null_result[0] == 0 and null_result[1] == 0 else "fail"
}
# Duplicate check
dup_query = f"""
SELECT COUNT(*) - COUNT(DISTINCT order_id) as duplicates
FROM {table_name}
"""
duplicates = connection.execute(dup_query).fetchone()[0]
report["checks"]["duplicates"] = {
"count": duplicates,
"status": "pass" if duplicates == 0 else "fail"
}
# Overall status
all_passed = all(
check["status"] == "pass"
for check in report["checks"].values()
)
report["overall_status"] = "pass" if all_passed else "fail"
return report
```
---
→ See references/workflows.md for details
## Architecture Decision Framework
@@ -810,183 +190,5 @@ See `references/dataops_best_practices.md` for:
---
## Troubleshooting
→ See references/troubleshooting.md for details
### Pipeline Failures
**Symptom:** Airflow DAG fails with timeout
```
Task exceeded max execution time
```
**Solution:**
1. Check resource allocation
2. Profile slow operations
3. Add incremental processing
```python
# Increase timeout
default_args = {
'execution_timeout': timedelta(hours=2),
}
# Or use incremental loads
WHERE updated_at > '{{ prev_ds }}'
```
---
**Symptom:** Spark job OOM
```
java.lang.OutOfMemoryError: Java heap space
```
**Solution:**
1. Increase executor memory
2. Reduce partition size
3. Use disk spill
```python
spark.conf.set("spark.executor.memory", "8g")
spark.conf.set("spark.sql.shuffle.partitions", "200")
spark.conf.set("spark.memory.fraction", "0.8")
```
---
**Symptom:** Kafka consumer lag increasing
```
Consumer lag: 1000000 messages
```
**Solution:**
1. Increase consumer parallelism
2. Optimize processing logic
3. Scale consumer group
```bash
# Add more partitions
kafka-topics.sh --alter \
--bootstrap-server localhost:9092 \
--topic user-events \
--partitions 24
```
---
### Data Quality Issues
**Symptom:** Duplicate records appearing
```
Expected unique, found 150 duplicates
```
**Solution:**
1. Add deduplication logic
2. Use merge/upsert operations
```sql
-- dbt incremental with dedup
{{
config(
materialized='incremental',
unique_key='order_id'
)
}}
SELECT * FROM (
SELECT
*,
ROW_NUMBER() OVER (
PARTITION BY order_id
ORDER BY updated_at DESC
) as rn
FROM {{ source('raw', 'orders') }}
) WHERE rn = 1
```
---
**Symptom:** Stale data in tables
```
Last update: 3 days ago
```
**Solution:**
1. Check upstream pipeline status
2. Verify source availability
3. Add freshness monitoring
```yaml
# dbt freshness check
sources:
- name: "raw"
freshness:
warn_after: {count: 12, period: hour}
error_after: {count: 24, period: hour}
loaded_at_field: _loaded_at
```
---
**Symptom:** Schema drift detected
```
Column 'new_field' not in expected schema
```
**Solution:**
1. Update data contract
2. Modify transformations
3. Communicate with producers
```python
# Handle schema evolution
df = spark.read.format("delta") \
.option("mergeSchema", "true") \
.load("/data/orders")
```
---
### Performance Issues
**Symptom:** Query takes hours
```
Query runtime: 4 hours (expected: 30 minutes)
```
**Solution:**
1. Check query plan
2. Add proper partitioning
3. Optimize joins
```sql
-- Before: Full table scan
SELECT * FROM orders WHERE order_date = '2024-01-15';
-- After: Partition pruning
-- Table partitioned by order_date
SELECT * FROM orders WHERE order_date = '2024-01-15';
-- Add clustering for frequent filters
ALTER TABLE orders CLUSTER BY (customer_id);
```
---
**Symptom:** dbt model takes too long
```
Model fct_orders completed in 45 minutes
```
**Solution:**
1. Use incremental materialization
2. Reduce upstream dependencies
3. Pre-aggregate where possible
```sql
-- Convert to incremental
{{
config(
materialized='incremental',
unique_key='order_id',
on_schema_change='sync_all_columns'
)
}}
SELECT * FROM {{ ref('stg_orders') }}
{% if is_incremental() %}
WHERE _loaded_at > (SELECT MAX(_loaded_at) FROM {{ this }})
{% endif %}
```

View File

@@ -0,0 +1,183 @@
# senior-data-engineer reference
## Troubleshooting
### Pipeline Failures
**Symptom:** Airflow DAG fails with timeout
```
Task exceeded max execution time
```
**Solution:**
1. Check resource allocation
2. Profile slow operations
3. Add incremental processing
```python
# Increase timeout
default_args = {
'execution_timeout': timedelta(hours=2),
}
# Or use incremental loads
WHERE updated_at > '{{ prev_ds }}'
```
---
**Symptom:** Spark job OOM
```
java.lang.OutOfMemoryError: Java heap space
```
**Solution:**
1. Increase executor memory
2. Reduce partition size
3. Use disk spill
```python
spark.conf.set("spark.executor.memory", "8g")
spark.conf.set("spark.sql.shuffle.partitions", "200")
spark.conf.set("spark.memory.fraction", "0.8")
```
---
**Symptom:** Kafka consumer lag increasing
```
Consumer lag: 1000000 messages
```
**Solution:**
1. Increase consumer parallelism
2. Optimize processing logic
3. Scale consumer group
```bash
# Add more partitions
kafka-topics.sh --alter \
--bootstrap-server localhost:9092 \
--topic user-events \
--partitions 24
```
---
### Data Quality Issues
**Symptom:** Duplicate records appearing
```
Expected unique, found 150 duplicates
```
**Solution:**
1. Add deduplication logic
2. Use merge/upsert operations
```sql
-- dbt incremental with dedup
{{
config(
materialized='incremental',
unique_key='order_id'
)
}}
SELECT * FROM (
SELECT
*,
ROW_NUMBER() OVER (
PARTITION BY order_id
ORDER BY updated_at DESC
) as rn
FROM {{ source('raw', 'orders') }}
) WHERE rn = 1
```
---
**Symptom:** Stale data in tables
```
Last update: 3 days ago
```
**Solution:**
1. Check upstream pipeline status
2. Verify source availability
3. Add freshness monitoring
```yaml
# dbt freshness check
sources:
- name: "raw"
freshness:
warn_after: {count: 12, period: hour}
error_after: {count: 24, period: hour}
loaded_at_field: _loaded_at
```
---
**Symptom:** Schema drift detected
```
Column 'new_field' not in expected schema
```
**Solution:**
1. Update data contract
2. Modify transformations
3. Communicate with producers
```python
# Handle schema evolution
df = spark.read.format("delta") \
.option("mergeSchema", "true") \
.load("/data/orders")
```
---
### Performance Issues
**Symptom:** Query takes hours
```
Query runtime: 4 hours (expected: 30 minutes)
```
**Solution:**
1. Check query plan
2. Add proper partitioning
3. Optimize joins
```sql
-- Before: Full table scan
SELECT * FROM orders WHERE order_date = '2024-01-15';
-- After: Partition pruning
-- Table partitioned by order_date
SELECT * FROM orders WHERE order_date = '2024-01-15';
-- Add clustering for frequent filters
ALTER TABLE orders CLUSTER BY (customer_id);
```
---
**Symptom:** dbt model takes too long
```
Model fct_orders completed in 45 minutes
```
**Solution:**
1. Use incremental materialization
2. Reduce upstream dependencies
3. Pre-aggregate where possible
```sql
-- Convert to incremental
{{
config(
materialized='incremental',
unique_key='order_id',
on_schema_change='sync_all_columns'
)
}}
SELECT * FROM {{ ref('stg_orders') }}
{% if is_incremental() %}
WHERE _loaded_at > (SELECT MAX(_loaded_at) FROM {{ this }})
{% endif %}
```

View File

@@ -0,0 +1,624 @@
# senior-data-engineer reference
## Workflows
### Workflow 1: Building a Batch ETL Pipeline
**Scenario:** Extract data from PostgreSQL, transform with dbt, load to Snowflake.
#### Step 1: Define Source Schema
```sql
-- Document source tables
SELECT
table_name,
column_name,
data_type,
is_nullable
FROM information_schema.columns
WHERE table_schema = 'source_schema'
ORDER BY table_name, ordinal_position;
```
#### Step 2: Generate Extraction Config
```bash
python scripts/pipeline_orchestrator.py generate \
--type airflow \
--source postgres \
--tables orders,customers,products \
--mode incremental \
--watermark updated_at \
--output dags/extract_source.py
```
#### Step 3: Create dbt Models
```sql
-- models/staging/stg_orders.sql
WITH source AS (
SELECT * FROM {{ source('postgres', 'orders') }}
),
renamed AS (
SELECT
order_id,
customer_id,
order_date,
total_amount,
status,
_extracted_at
FROM source
WHERE order_date >= DATEADD(day, -3, CURRENT_DATE)
)
SELECT * FROM renamed
```
```sql
-- models/marts/fct_orders.sql
{{
config(
materialized='incremental',
unique_key='order_id',
cluster_by=['order_date']
)
}}
SELECT
o.order_id,
o.customer_id,
c.customer_segment,
o.order_date,
o.total_amount,
o.status
FROM {{ ref('stg_orders') }} o
LEFT JOIN {{ ref('dim_customers') }} c
ON o.customer_id = c.customer_id
{% if is_incremental() %}
WHERE o._extracted_at > (SELECT MAX(_extracted_at) FROM {{ this }})
{% endif %}
```
#### Step 4: Configure Data Quality Tests
```yaml
# models/marts/schema.yml
version: 2
models:
- name: "fct-orders"
description: "Order fact table"
columns:
- name: "order-id"
tests:
- unique
- not_null
- name: "total-amount"
tests:
- not_null
- dbt_utils.accepted_range:
min_value: 0
max_value: 1000000
- name: "order-date"
tests:
- not_null
- dbt_utils.recency:
datepart: day
field: order_date
interval: 1
```
#### Step 5: Create Airflow DAG
```python
# dags/daily_etl.py
from airflow import DAG
from airflow.providers.postgres.operators.postgres import PostgresOperator
from airflow.operators.bash import BashOperator
from airflow.utils.dates import days_ago
from datetime import timedelta
default_args = {
'owner': 'data-team',
'depends_on_past': False,
'email_on_failure': True,
'email': ['data-alerts@company.com'],
'retries': 2,
'retry_delay': timedelta(minutes=5),
}
with DAG(
'daily_etl_pipeline',
default_args=default_args,
description='Daily ETL from PostgreSQL to Snowflake',
schedule_interval='0 5 * * *',
start_date=days_ago(1),
catchup=False,
tags=['etl', 'daily'],
) as dag:
extract = BashOperator(
task_id='extract_source_data',
bash_command='python /opt/airflow/scripts/extract.py --date {{ ds }}',
)
transform = BashOperator(
task_id='run_dbt_models',
bash_command='cd /opt/airflow/dbt && dbt run --select marts.*',
)
test = BashOperator(
task_id='run_dbt_tests',
bash_command='cd /opt/airflow/dbt && dbt test --select marts.*',
)
notify = BashOperator(
task_id='send_notification',
bash_command='python /opt/airflow/scripts/notify.py --status success',
trigger_rule='all_success',
)
extract >> transform >> test >> notify
```
#### Step 6: Validate Pipeline
```bash
# Test locally
dbt run --select stg_orders fct_orders
dbt test --select fct_orders
# Validate data quality
python scripts/data_quality_validator.py validate \
--table fct_orders \
--checks all \
--output reports/quality_report.json
```
---
### Workflow 2: Implementing Real-Time Streaming
**Scenario:** Stream events from Kafka, process with Flink/Spark Streaming, sink to data lake.
#### Step 1: Define Event Schema
```json
{
"$schema": "http://json-schema.org/draft-07/schema#",
"title": "UserEvent",
"type": "object",
"required": ["event_id", "user_id", "event_type", "timestamp"],
"properties": {
"event_id": {"type": "string", "format": "uuid"},
"user_id": {"type": "string"},
"event_type": {"type": "string", "enum": ["page_view", "click", "purchase"]},
"timestamp": {"type": "string", "format": "date-time"},
"properties": {"type": "object"}
}
}
```
#### Step 2: Create Kafka Topic
```bash
# Create topic with appropriate partitions
kafka-topics.sh --create \
--bootstrap-server localhost:9092 \
--topic user-events \
--partitions 12 \
--replication-factor 3 \
--config retention.ms=604800000 \
--config cleanup.policy=delete
# Verify topic
kafka-topics.sh --describe \
--bootstrap-server localhost:9092 \
--topic user-events
```
#### Step 3: Implement Spark Streaming Job
```python
# streaming/user_events_processor.py
from pyspark.sql import SparkSession
from pyspark.sql.functions import (
from_json, col, window, count, avg,
to_timestamp, current_timestamp
)
from pyspark.sql.types import (
StructType, StructField, StringType,
TimestampType, MapType
)
# Initialize Spark
spark = SparkSession.builder \
.appName("UserEventsProcessor") \
.config("spark.sql.streaming.checkpointLocation", "/checkpoints/user-events") \
.config("spark.sql.shuffle.partitions", "12") \
.getOrCreate()
# Define schema
event_schema = StructType([
StructField("event_id", StringType(), False),
StructField("user_id", StringType(), False),
StructField("event_type", StringType(), False),
StructField("timestamp", StringType(), False),
StructField("properties", MapType(StringType(), StringType()), True)
])
# Read from Kafka
events_df = spark.readStream \
.format("kafka") \
.option("kafka.bootstrap.servers", "localhost:9092") \
.option("subscribe", "user-events") \
.option("startingOffsets", "latest") \
.option("failOnDataLoss", "false") \
.load()
# Parse JSON
parsed_df = events_df \
.select(from_json(col("value").cast("string"), event_schema).alias("data")) \
.select("data.*") \
.withColumn("event_timestamp", to_timestamp(col("timestamp")))
# Windowed aggregation
aggregated_df = parsed_df \
.withWatermark("event_timestamp", "10 minutes") \
.groupBy(
window(col("event_timestamp"), "5 minutes"),
col("event_type")
) \
.agg(
count("*").alias("event_count"),
approx_count_distinct("user_id").alias("unique_users")
)
# Write to Delta Lake
query = aggregated_df.writeStream \
.format("delta") \
.outputMode("append") \
.option("checkpointLocation", "/checkpoints/user-events-aggregated") \
.option("path", "/data/lake/user_events_aggregated") \
.trigger(processingTime="1 minute") \
.start()
query.awaitTermination()
```
#### Step 4: Handle Late Data and Errors
```python
# Dead letter queue for failed records
from pyspark.sql.functions import current_timestamp, lit
def process_with_error_handling(batch_df, batch_id):
try:
# Attempt processing
valid_df = batch_df.filter(col("event_id").isNotNull())
invalid_df = batch_df.filter(col("event_id").isNull())
# Write valid records
valid_df.write \
.format("delta") \
.mode("append") \
.save("/data/lake/user_events")
# Write invalid to DLQ
if invalid_df.count() > 0:
invalid_df \
.withColumn("error_timestamp", current_timestamp()) \
.withColumn("error_reason", lit("missing_event_id")) \
.write \
.format("delta") \
.mode("append") \
.save("/data/lake/dlq/user_events")
except Exception as e:
# Log error, alert, continue
logger.error(f"Batch {batch_id} failed: {e}")
raise
# Use foreachBatch for custom processing
query = parsed_df.writeStream \
.foreachBatch(process_with_error_handling) \
.option("checkpointLocation", "/checkpoints/user-events") \
.start()
```
#### Step 5: Monitor Stream Health
```python
# monitoring/stream_metrics.py
from prometheus_client import Gauge, Counter, start_http_server
# Define metrics
RECORDS_PROCESSED = Counter(
'stream_records_processed_total',
'Total records processed',
['stream_name', 'status']
)
PROCESSING_LAG = Gauge(
'stream_processing_lag_seconds',
'Current processing lag',
['stream_name']
)
BATCH_DURATION = Gauge(
'stream_batch_duration_seconds',
'Last batch processing duration',
['stream_name']
)
def emit_metrics(query):
"""Emit Prometheus metrics from streaming query."""
progress = query.lastProgress
if progress:
RECORDS_PROCESSED.labels(
stream_name='user-events',
status='success'
).inc(progress['numInputRows'])
if progress['sources']:
# Calculate lag from latest offset
for source in progress['sources']:
end_offset = source.get('endOffset', {})
# Parse Kafka offsets and calculate lag
```
---
### Workflow 3: Data Quality Framework Setup
**Scenario:** Implement comprehensive data quality monitoring with Great Expectations.
#### Step 1: Initialize Great Expectations
```bash
# Install and initialize
pip install great_expectations
great_expectations init
# Connect to data source
great_expectations datasource new
```
#### Step 2: Create Expectation Suite
```python
# expectations/orders_suite.py
import great_expectations as gx
context = gx.get_context()
# Create expectation suite
suite = context.add_expectation_suite("orders_quality_suite")
# Add expectations
validator = context.get_validator(
batch_request={
"datasource_name": "warehouse",
"data_asset_name": "orders",
},
expectation_suite_name="orders_quality_suite"
)
# Schema expectations
validator.expect_table_columns_to_match_ordered_list(
column_list=[
"order_id", "customer_id", "order_date",
"total_amount", "status", "created_at"
]
)
# Completeness expectations
validator.expect_column_values_to_not_be_null("order_id")
validator.expect_column_values_to_not_be_null("customer_id")
validator.expect_column_values_to_not_be_null("order_date")
# Uniqueness expectations
validator.expect_column_values_to_be_unique("order_id")
# Range expectations
validator.expect_column_values_to_be_between(
"total_amount",
min_value=0,
max_value=1000000
)
# Categorical expectations
validator.expect_column_values_to_be_in_set(
"status",
["pending", "confirmed", "shipped", "delivered", "cancelled"]
)
# Freshness expectation
validator.expect_column_max_to_be_between(
"order_date",
min_value={"$PARAMETER": "now - timedelta(days=1)"},
max_value={"$PARAMETER": "now"}
)
# Referential integrity
validator.expect_column_values_to_be_in_set(
"customer_id",
value_set={"$PARAMETER": "valid_customer_ids"}
)
validator.save_expectation_suite(discard_failed_expectations=False)
```
#### Step 3: Create Data Quality Checks with dbt
```yaml
# models/marts/schema.yml
version: 2
models:
- name: "fct-orders"
description: "Order fact table with data quality checks"
tests:
# Row count check
- dbt_utils.equal_rowcount:
compare_model: ref('stg_orders')
# Freshness check
- dbt_utils.recency:
datepart: hour
field: created_at
interval: 24
columns:
- name: "order-id"
description: "Unique order identifier"
tests:
- unique
- not_null
- relationships:
to: ref('dim_orders')
field: order_id
- name: "total-amount"
tests:
- not_null
- dbt_utils.accepted_range:
min_value: 0
max_value: 1000000
inclusive: true
- dbt_expectations.expect_column_values_to_be_between:
min_value: 0
row_condition: "status != 'cancelled'"
- name: "customer-id"
tests:
- not_null
- relationships:
to: ref('dim_customers')
field: customer_id
severity: warn
```
#### Step 4: Implement Data Contracts
```yaml
# contracts/orders_contract.yaml
contract:
name: "orders-data-contract"
version: "1.0.0"
owner: data-team@company.com
schema:
type: object
properties:
order_id:
type: string
format: uuid
description: "Unique order identifier"
customer_id:
type: string
not_null: true
order_date:
type: date
not_null: true
total_amount:
type: decimal
precision: 10
scale: 2
minimum: 0
status:
type: string
enum: ["pending", "confirmed", "shipped", "delivered", "cancelled"]
sla:
freshness:
max_delay_hours: 1
completeness:
min_percentage: 99.9
accuracy:
duplicate_tolerance: 0.01
consumers:
- name: "analytics-team"
usage: "Daily reporting dashboards"
- name: "ml-team"
usage: "Churn prediction model"
```
#### Step 5: Set Up Quality Monitoring Dashboard
```python
# monitoring/quality_dashboard.py
from datetime import datetime, timedelta
import pandas as pd
def generate_quality_report(connection, table_name: "str-dict"
"""Generate comprehensive data quality report."""
report = {
"table": table_name,
"timestamp": datetime.now().isoformat(),
"checks": {}
}
# Row count check
row_count = connection.execute(
f"SELECT COUNT(*) FROM {table_name}"
).fetchone()[0]
report["checks"]["row_count"] = {
"value": row_count,
"status": "pass" if row_count > 0 else "fail"
}
# Freshness check
max_date = connection.execute(
f"SELECT MAX(created_at) FROM {table_name}"
).fetchone()[0]
hours_old = (datetime.now() - max_date).total_seconds() / 3600
report["checks"]["freshness"] = {
"max_timestamp": max_date.isoformat(),
"hours_old": round(hours_old, 2),
"status": "pass" if hours_old < 24 else "fail"
}
# Null rate check
null_query = f"""
SELECT
SUM(CASE WHEN order_id IS NULL THEN 1 ELSE 0 END) as null_order_id,
SUM(CASE WHEN customer_id IS NULL THEN 1 ELSE 0 END) as null_customer_id,
COUNT(*) as total
FROM {table_name}
"""
null_result = connection.execute(null_query).fetchone()
report["checks"]["null_rates"] = {
"order_id": null_result[0] / null_result[2] if null_result[2] > 0 else 0,
"customer_id": null_result[1] / null_result[2] if null_result[2] > 0 else 0,
"status": "pass" if null_result[0] == 0 and null_result[1] == 0 else "fail"
}
# Duplicate check
dup_query = f"""
SELECT COUNT(*) - COUNT(DISTINCT order_id) as duplicates
FROM {table_name}
"""
duplicates = connection.execute(dup_query).fetchone()[0]
report["checks"]["duplicates"] = {
"count": duplicates,
"status": "pass" if duplicates == 0 else "fail"
}
# Overall status
all_passed = all(
check["status"] == "pass"
for check in report["checks"].values()
)
report["overall_status"] = "pass" if all_passed else "fail"
return report
```
---