Objective
Develop an unsupervised machine learning system to detect anomalies in cloud load balancer access logs, identifying potential security threats, performance issues, and operational problems through pattern analysis.
Business Value
For Cloud Operations Teams:- Proactive Issue Detection: Identify performance degradation before user impact
- Security Threat Identification: Detect DDoS attacks, bot traffic, and exploitation attempts
- Capacity Planning: Understand traffic patterns for auto-scaling optimization
- Cost Optimization: Identify inefficient traffic routing and resource usage
For DevOps and SRE:- Service Reliability: Monitor application health through traffic pattern analysis
- Automated Incident Response: Trigger alerts and remediation for detected anomalies
- Performance Optimization: Identify bottlenecks and optimization opportunities
- Compliance Monitoring: Ensure traffic patterns meet security and regulatory requirements
Core Libraries
- pandas & numpy: Log data processing and time series analysis
- scikit-learn: Isolation Forest and clustering algorithms for anomaly detection
- matplotlib & seaborn: Traffic pattern visualization and anomaly analysis
- boto3: AWS integration for CloudFront and ALB log processing
- pytz: Timezone handling for global load balancer deployments
Dataset
Source: Cloud Load Balancer Access Logs (AWS ALB/CloudFront, Azure Load Balancer, GCP Load Balancer)- Request Patterns: HTTP methods, status codes, response times, byte counts
- Client Analysis: IP addresses, user agents, geographic distributions
- Backend Health: Origin response times, error rates, failover patterns
- Time Series: Traffic volume trends, seasonal patterns, burst detection
Key Log Fields:- Temporal: Timestamp, request duration, backend response time
- Request Attributes: HTTP method, URI path, query parameters, status code
- Client Information: Source IP, user agent, referrer, geographic location
- Backend Metrics: Target IP, response size, SSL handshake time
Step-by-Step Guide
1. Log Data Collection and Preprocessing
# Load and parse load balancer logs
import pandas as pd
import re
from urllib.parse import urlparse
def parse_alb_logs(log_file):
# Parse AWS ALB log format
columns = ['type', 'time', 'elb', 'client_ip', 'client_port',
'target_ip', 'target_port', 'request_processing_time',
'target_processing_time', 'response_processing_time',
'elb_status_code', 'target_status_code', 'received_bytes',
'sent_bytes', 'request', 'user_agent', 'ssl_cipher', 'ssl_protocol']
df = pd.read_csv(log_file, sep=' ', names=columns, parse_dates=['time'])
return df
2. Feature Engineering for Anomaly Detection
# Create features from log entries
def extract_features(df):
# Parse request information
df[['method', 'uri', 'protocol']] = df['request'].str.extract(r'(\w+) (.) (HTTP/.)')
# Time-based features
df['hour'] = df['time'].dt.hour
df['day_of_week'] = df['time'].dt.dayofweek
# Response time metrics
df['total_response_time'] = (df['request_processing_time'] +
df['target_processing_time'] +
df['response_processing_time'])
# Error rate indicators
df['is_error'] = (df['elb_status_code'] >= 400).astype(int)
df['is_5xx'] = (df['elb_status_code'] >= 500).astype(int)
return df
3. Temporal Pattern Analysis
# Aggregate metrics by time windows
def create_time_series_features(df, window='5min'):
time_series = df.set_index('time').resample(window).agg({
'client_ip': 'nunique',           # Unique clients
'request': 'count',               # Request volume
'total_response_time': 'mean',    # Average response time
'is_error': 'mean',              # Error rate
'sent_bytes': 'sum',             # Total bytes sent
'target_ip': 'nunique'           # Backend diversity
})
return time_series
4. Anomaly Detection Model Training
# Train Isolation Forest on normal traffic patterns
from sklearn.ensemble import IsolationForest
from sklearn.preprocessing import StandardScaler
# Prepare features for anomaly detection
feature_columns = ['unique_clients', 'request_count', 'avg_response_time',
'error_rate', 'bytes_sent', 'backend_count']
# Scale features
scaler = StandardScaler()
X_scaled = scaler.fit_transform(time_series[feature_columns])
# Train anomaly detection model
anomaly_detector = IsolationForest(
contamination=0.1,  # Expect 10% anomalies
random_state=42,
n_estimators=100
)
anomaly_scores = anomaly_detector.fit_predict(X_scaled)
5. Multi-dimensional Anomaly Analysis
# Detect different types of anomalies
def classify_anomaly_type(row):
if row['error_rate'] > 0.1:
return 'Error_Spike'
elif row['avg_response_time'] > threshold_response:
return 'Performance_Degradation'
elif row['request_count'] > threshold_volume:
return 'Traffic_Spike'
elif row['unique_clients'] < threshold_clients:
return 'Bot_Traffic'
else:
return 'Unknown_Anomaly'
# Apply anomaly classification
anomalies = time_series[anomaly_scores == -1].copy()
anomalies['anomaly_type'] = anomalies.apply(classify_anomaly_type, axis=1)
6. Security Threat Detection
# Identify potential security threats
def detect_security_patterns(df):
# SQL injection attempts
sql_patterns = df['uri'].str.contains(r'(union|select|insert|delete)',
case=False, na=False)
# XSS attempts
xss_patterns = df['uri'].str.contains(r'(