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_/ ____\______   ____   ____ ___________.__.
\   __\\_  __ \_/ __ \ /    \\___   <   |  |
 |  |   |  | \/\  ___/|   |  \/    / \___  |
 |__|   |__|    \___  >___|  /_____ \/ ____|
                    \/     \/      \/\/

A high-performance Postgres wire protocol aware mirroring proxy with SSL/TLS support, connection pooling, and advanced retry mechanisms.

1.Upgrade v0.5.3 to v0.15.0.

2.Support mirror different queries by Arguments .

3.Skip BEGIN/COMMIT on mirrors to avoid transaction locks.

4.Connection pool optimize.

Features

• 🔄 Real-time Query Mirroring: Mirror production traffic to shadow instances with async processing
• 🔒 Full SSL/TLS Support: TLS 1.2/1.3 support for both proxy and backend connections
• 🏊 Advanced Connection Pooling: Configurable connection pools optimized for high concurrency (up to 200 connections)
• 🔗 Multi-command Support: Handle complex queries with multiple statements seamlessly
• 🔄 Intelligent Retry Logic: Automatic retry with exponential backoff for failed mirror operations
• 📊 Comprehensive Logging: Detailed logging with configurable levels and performance metrics
• ⚡ High Performance: Built with Go, optimized for 10x better concurrent connection handling
• 🛡️ Production Ready: Robust error handling, connection management, and memory pooling
• 🎯 Async Mirror Processing: Non-blocking mirror operations for maximum primary performance
• 🧠 Memory Optimization: Buffer pooling and GC pressure reduction
• 🔍 Memory Safety: Transaction buffer cleanup and leak prevention
• 📈 Resource Monitoring: Built-in memory usage tracking and statistics

Getting Started

Frenzy is a production-ready Postgres mirroring proxy that allows real-time mirroring of production traffic to shadow instances. It takes 1 primary connection string for production requests and multiple mirror connection strings for duplicated traffic with intelligent retry and timeout handling.

Building

Prerequisites

• Go 1.23 or later
• Make (optional)

Compile

# Quick build (recommended)
./quick_build.sh

# Using make
make

# Or directly with go
go build -o bin/frenzy ./cmd/main.go

Usage

Basic Usage

./bin/frenzy --listen :5432 \
    --primary postgresql://postgres:password@localhost:5441/postgres \
    --mirror postgresql://postgres:password@localhost:5442/postgres

High-Performance Configuration

./bin/frenzy --listen :5432 \
    --max-conns 100 \
    --min-conns 20 \
    --worker-threads 16 \
    --async-mirrors \
    --query-buffer-size 16384 \
    --mirror-timeout 120 \
    --mirror-retries 3 \
    --retry-delay 5 \
    --primary postgresql://postgres:password@localhost:5441/postgres \
    --mirror postgresql://postgres:password@localhost:5442/postgres

Production SSL/TLS Configuration

./bin/frenzy --listen :5432 \
    --enable-tls \
    --tls-cert /etc/ssl/certs/frenzy.crt \
    --tls-key /etc/ssl/private/frenzy.key \
    --tls-ca /etc/ssl/certs/ca.pem \
    --max-conns 200 \
    --min-conns 50 \
    --max-conn-lifetime 7200 \
    --max-conn-idle-time 300 \
    --async-mirrors \
    --mirror-timeout 180 \
    --mirror-retries 2 \
    --retry-delay 10 \
    --primary "postgresql://user:pass@primary.db:5432/db?sslmode=verify-full&sslrootcert=/etc/ssl/certs/db-ca.pem" \
    --mirror "postgresql://user:pass@mirror1.db:5432/db?sslmode=verify-full&sslrootcert=/etc/ssl/certs/db-ca.pem" \
    --mirror "postgresql://user:pass@mirror2.db:5432/db?sslmode=verify-full&sslrootcert=/etc/ssl/certs/db-ca.pem"

Command Line Options

Basic Options

• --listen / -l: Listening address and port (required)
• --primary / -p: Primary PostgreSQL connection string (required)
• --mirror / -m: Mirror PostgreSQL connection string (required, can be specified multiple times)

Connection Pool Options

• --max-conns: Maximum number of connections in the pool (default: 50, optimized for high concurrency)
• --min-conns: Minimum number of connections in the pool (default: 10, improved availability)
• --max-conn-lifetime: Maximum connection lifetime in seconds (default: 0, never expire)
• --max-conn-idle-time: Maximum connection idle time in seconds (default: 300, 5 minutes)

Performance Optimization Options

• --worker-threads: Number of worker threads for query processing (default: 0, auto-detect CPU cores)
• --query-buffer-size: Query buffer size in bytes (default: 8192, 8KB)
• --async-mirrors: Enable asynchronous mirror processing (default: enabled, non-blocking)

Mirror Reliability Options

• --mirror-timeout: Timeout for mirror operations in seconds (default: 120, 2 minutes)
• --mirror-retries: Number of retries for failed mirror operations (default: 2)
• --retry-delay: Delay between retries in seconds (default: 5)

Query Filtering Options

• --mirror-all-queries: Mirror all queries including SELECT statements
• --mirror-select-queries: Mirror only SELECT queries
• --mirror-ddl-only: Mirror only DDL statements (CREATE, ALTER, DROP)
• --mirror-dml-only: Mirror only DML statements (INSERT, UPDATE, DELETE)
• Default behavior: Mirror DDL + DML, exclude SELECT queries

SSL/TLS Options

• --enable-tls: Enable TLS for the proxy server
• --tls-cert: Path to TLS certificate file
• --tls-key: Path to TLS private key file
• --tls-ca: Path to TLS CA certificate file
• --tls-server-name: TLS server name for verification
• --tls-skip-verify: Skip TLS certificate verification (for testing only)

Performance Optimizations

Connection Pool Sizing Guidelines

High Concurrency Workloads

--max-conns 200 --min-conns 50 --worker-threads 32

• Use case: High-traffic production environments
• Expected improvement: 10x concurrent connection capacity
• Memory usage: ~50-100MB additional

Resource Constrained Environments

--max-conns 20 --min-conns 5 --worker-threads 4

• Use case: Development or low-resource environments
• Expected improvement: 2-3x concurrent connection capacity
• Memory usage: ~10-20MB additional

Balanced Production Setup

--max-conns 100 --min-conns 20 --worker-threads 16

• Use case: Most production environments
• Expected improvement: 5-7x concurrent connection capacity
• Memory usage: ~25-50MB additional

Mirror Configuration Strategies

Fast, Reliable Mirrors

--mirror-timeout 60 --mirror-retries 1 --retry-delay 2

• Use case: High-performance mirror databases
• Behavior: Quick failure detection, minimal retry overhead

Slow or Unreliable Mirrors

--mirror-timeout 300 --mirror-retries 5 --retry-delay 15

• Use case: Mirrors with network latency or resource constraints
• Behavior: Patient retry strategy, higher success rate

Development/Testing

--mirror-timeout 30 --mirror-retries 0

• Use case: Fast feedback during development
• Behavior: Fail fast, no retry overhead

Supported Features

Query Types

• ✅ Simple SELECT queries with connection pooling
• ✅ Multi-statement queries with async mirror processing (e.g., SET work_mem=1; SELECT * FROM table;)
• ✅ DDL statements with retry logic (CREATE, ALTER, DROP)
• ✅ DML statements with optimized connection reuse (INSERT, UPDATE, DELETE)
• ✅ PostgreSQL-specific commands (\l, \d, etc.)
• ✅ Prepared statements with connection affinity
• ✅ Transactions with proper connection lifecycle management
• ✅ Concurrent multi-client support (tested up to 200+ connections)

Transaction Behavior and Consistency

Primary Database Guarantees

• ✅ Full ACID compliance: Primary database maintains complete transactional integrity
• ✅ Immediate consistency: All primary operations are atomic and consistent
• ✅ Rollback support: Failed transactions are properly rolled back on primary

Mirror Database Behavior

• ⚠️ Best-effort mirroring: Mirrors receive transactions asynchronously
• ⚠️ No cross-database atomicity: Mirror failures don't affect primary commits
• ⚠️ Eventual consistency: Mirrors may temporarily lag behind primary

Important Consistency Notes

-- Example scenario:
BEGIN;
INSERT INTO users VALUES (1, 'Alice');  -- ✅ Primary: Success, 🔄 Mirror: Success
UPDATE users SET name='Bob' WHERE id=1; -- ✅ Primary: Success, ❌ Mirror: Failed
COMMIT; -- ✅ Primary: Committed, ⚠️ Mirror: Inconsistent

Result: Primary has complete transaction, mirror may have partial data.

Use Cases

• ✅ Production traffic shadowing: Test queries against mirror databases
• ✅ Read replica warming: Pre-populate caches and indexes
• ✅ Performance testing: Validate query performance on different hardware
• ❌ Multi-master replication: Not suitable for distributed transactions

SSL/TLS Support

• ✅ TLS 1.2 and TLS 1.3 with optimized cipher suites
• ✅ Client certificate authentication
• ✅ Certificate verification modes (require, verify-ca, verify-full)
• ✅ Custom CA certificates with proper validation
• ✅ SNI (Server Name Indication) support
• ✅ Perfect Forward Secrecy (PFS)

Connection Management

• ✅ Advanced connection pooling with separate read/write optimization
• ✅ Automatic connection recovery with exponential backoff
• ✅ Concurrent client support (200+ simultaneous connections)
• ✅ Connection lifecycle management with idle timeout
• ✅ Memory pooling for reduced GC pressure
• ✅ Worker thread optimization for CPU utilization

Mirror Reliability

• ✅ Asynchronous mirror processing (non-blocking primary responses)
• ✅ Intelligent retry logic with configurable attempts
• ✅ Timeout handling per mirror operation
• ✅ Independent mirror failure handling (primary unaffected)
• ✅ Detailed mirror operation logging and metrics

Testing

Basic Connection Test

PGPASSWORD=password psql -U postgres -h localhost -p 5432 -c "SELECT version();"

High-Concurrency Test

# Test 100 concurrent connections
for i in {1..100}; do
  PGPASSWORD=password psql -U postgres -h localhost -p 5432 -c "SELECT pg_backend_pid(), now(), 'connection_$i';" &
done
wait

Multi-command Test

PGPASSWORD=password psql -U postgres -h localhost -p 5432 -c "SET work_mem='1MB'; SELECT current_setting('work_mem'); SELECT pg_backend_pid();"

SSL Performance Test

# Test SSL connection with high concurrency
for i in {1..50}; do
  PGPASSWORD=password psql -U postgres -h localhost -p 5432 -c "SELECT version();" --set=sslmode=require &
done
wait

Mirror Reliability Test

# Test mirror retry behavior (check logs for retry attempts)
PGPASSWORD=password psql -U postgres -h localhost -p 5432 -c "
BEGIN;
INSERT INTO test_table VALUES (1, 'test');
UPDATE test_table SET value = 'updated' WHERE id = 1;
COMMIT;
"

Logging and Monitoring

Log Levels

Frenzy supports configurable logging levels optimized for production:

• ERROR: Only error messages and critical failures
• WARN: Warnings, retry attempts, and errors
• INFO: General information, connection events (default)
• DEBUG: Detailed debugging information, query tracing

Environment Variables

# Set log level for production (reduced verbosity)
export FRENZY_LOG_LEVEL=info
./bin/frenzy --listen :5432 --primary ... --mirror ...

# Enable debug logging for troubleshooting
export FRENZY_LOG_LEVEL=debug
./bin/frenzy --listen :5432 --primary ... --mirror ...

Performance Metrics

Monitor these key metrics in logs:

• Connection pool utilization: acquired_conns, idle_conns, total_conns
• Mirror operation success rate: Retry attempts vs successes
• Query latency: Primary response time vs mirror processing time
• Memory usage: Buffer pool efficiency and GC frequency

Performance Benchmarks

Expected Performance Improvements

Based on optimization implementations:

Concurrent Connections

• Before: ~10-20 concurrent connections
• After: 200+ concurrent connections (10x improvement)

Mirror Processing Latency

• Before: Mirrors block primary response (100-500ms additional latency)
• After: Async processing (0ms additional primary latency)

Memory Efficiency

• Before: High GC pressure under load
• After: 50-80% reduction in memory allocations

CPU Utilization

• Before: Single-threaded bottlenecks
• After: Multi-core utilization with worker threads

Benchmark Commands

# Baseline performance test
pgbench -h localhost -p 5432 -U postgres -c 10 -j 2 -T 60 postgres

# High concurrency test
pgbench -h localhost -p 5432 -U postgres -c 100 -j 10 -T 60 postgres

# SSL performance test
pgbench -h localhost -p 5432 -U postgres -c 50 -j 5 -T 60 "sslmode=require" postgres

Troubleshooting

Common Issues and Solutions

Mirror Timeout Errors

ERROR: Mirror operation failed after all retries: context deadline exceeded

Solutions:

• Increase --mirror-timeout (e.g., from 120 to 300 seconds)
• Increase --mirror-retries (e.g., from 2 to 5)
• Check mirror database performance and network connectivity

Connection Pool Exhaustion

ERROR: Failed to acquire connection from pool

Solutions:

• Increase --max-conns (e.g., from 50 to 100)
• Decrease --max-conn-idle-time to recycle connections faster
• Monitor connection pool statistics in logs

TLS Handshake Failures

ERROR: TLS handshake failed: EOF

Solutions:

# Test TLS connectivity
openssl s_client -connect localhost:5432 -CAfile ca.pem

# Check certificate validity
openssl x509 -in server.crt -text -noout

# Verify certificate matches hostname
openssl x509 -in server.crt -noout -subject

High Memory Usage

Solutions:

• Reduce --query-buffer-size if processing small queries
• Decrease --max-conns if memory constrained
• Monitor GC frequency and adjust GOGC environment variable
• Check for transaction buffer overflow warnings in logs
• Verify cleanup routine is running (should see cleanup messages every 5 minutes)

Transaction Buffer Issues

ERROR: Transaction buffer overflow: session_123, query_count: 1000

Solutions:

• Check for long-running transactions that exceed 1000 queries
• Verify transactions are being committed or rolled back properly
• Monitor for stuck transactions using buffer statistics
• Consider breaking large transactions into smaller batches

Debug Mode

Enable comprehensive debugging:

export FRENZY_LOG_LEVEL=debug
export GOGC=100  # Tune garbage collection
./bin/frenzy --listen :5432 --primary ... --mirror ...

Performance Tuning

# OS-level optimizations
ulimit -n 65536  # Increase file descriptor limit
echo 'net.core.somaxconn = 65536' >> /etc/sysctl.conf

# Go runtime optimizations
export GOMAXPROCS=$(nproc)  # Use all CPU cores
export GOGC=100  # Tune garbage collection frequency

Memory Management

Transaction Buffer Safety

Frenzy implements automatic cleanup mechanisms to prevent memory leaks:

Automatic Cleanup Features

• Session Timeout: Transaction buffers auto-expire after 30 minutes of inactivity
• Connection Cleanup: Buffers are cleaned when clients disconnect unexpectedly
• Size Limits: Maximum 1000 queries per transaction buffer
• Periodic Cleanup: Background cleanup runs every 5 minutes

Memory Monitoring

Monitor these key metrics for memory health:

# Check transaction buffer statistics in logs
grep "transaction buffer" frenzy.log

# Monitor memory usage patterns
grep "memory\|buffer\|cleanup" frenzy.log

# Look for buffer overflow warnings
grep "Transaction buffer overflow" frenzy.log

# Monitor cleanup activity
grep "Cleaned up expired transaction buffers" frenzy.log

Memory Optimization Settings

# Reduce memory usage for resource-constrained environments
./bin/frenzy --listen :5432 \
    --max-conns 20 \
    --query-buffer-size 4096 \
    --mirror-timeout 60 \
    --primary ... --mirror ...

# High-memory configuration for large transactions
./bin/frenzy --listen :5432 \
    --max-conns 200 \
    --query-buffer-size 32768 \
    --mirror-timeout 300 \
    --primary ... --mirror ...

Memory Leak Prevention

• Automatic cleanup on disconnect: Transaction buffers are cleaned when clients disconnect unexpectedly
• Periodic cleanup routine: Background process runs every 5 minutes to remove expired buffers
• Transaction timeout: Buffers auto-expire after 30 minutes of inactivity
• Size limits enforced: Maximum 1000 queries per transaction buffer to prevent runaway growth
• Connection pool lifecycle: Connection pools have configurable lifetime limits
• Memory usage tracking: Built-in statistics for monitoring buffer usage

Production Deployment

Recommended Configuration

./bin/frenzy --listen :5432 \
    --max-conns 200 \
    --min-conns 50 \
    --max-conn-lifetime 7200 \
    --max-conn-idle-time 300 \
    --worker-threads 32 \
    --async-mirrors \
    --query-buffer-size 16384 \
    --mirror-timeout 180 \
    --mirror-retries 3 \
    --retry-delay 10 \
    --enable-tls \
    --tls-cert /etc/ssl/certs/frenzy.crt \
    --tls-key /etc/ssl/private/frenzy.key \
    --tls-ca /etc/ssl/certs/ca.pem \
    --primary "postgresql://user:pass@primary.db:5432/db?sslmode=verify-full&sslrootcert=/etc/ssl/certs/db-ca.pem" \
    --mirror "postgresql://user:pass@mirror1.db:5432/db?sslmode=verify-full&sslrootcert=/etc/ssl/certs/db-ca.pem" \
    --mirror "postgresql://user:pass@mirror2.db:5432/db?sslmode=verify-full&sslrootcert=/etc/ssl/certs/db-ca.pem"

Docker Deployment

FROM golang:1.23-alpine AS builder
WORKDIR /app
COPY . .
RUN go build -o frenzy ./cmd/main.go

FROM alpine:latest
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /app/frenzy .
EXPOSE 5432
CMD ["./frenzy"]

Kubernetes Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: frenzy-proxy
spec:
  replicas: 3
  selector:
    matchLabels:
      app: frenzy-proxy
  template:
    metadata:
      labels:
        app: frenzy-proxy
    spec:
      containers:
      - name: frenzy
        image: frenzy:latest
        ports:
        - containerPort: 5432
        env:
        - name: FRENZY_LOG_LEVEL
          value: "info"
        - name: GOMAXPROCS
          value: "4"
        resources:
          requests:
            memory: "256Mi"
            cpu: "500m"
          limits:
            memory: "1Gi"
            cpu: "2000m"

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes with tests
4. Run performance benchmarks
5. Submit a pull request with performance impact analysis

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Built with pgx for high-performance PostgreSQL connectivity
• Uses psql-wire for wire protocol handling
• Logging powered by zap for structured, high-performance logging
• Performance optimizations inspired by production PostgreSQL proxy patterns