postgresql-monitoring.conf

# PostgreSQL configuration for load testing monitoring
# This file is mounted into the postgres container to enable monitoring features

# Network configuration
listen_addresses = '*'                      # Listen on all interfaces for container networking

# Load pg_stat_statements extension for query performance tracking
shared_preload_libraries = 'pg_stat_statements'

# pg_stat_statements configuration
pg_stat_statements.max = 10000              # Track up to 10,000 distinct queries
pg_stat_statements.track = all              # Track all statements (top-level + nested)
pg_stat_statements.track_utility = on       # Track utility commands (CREATE, DROP, etc.)
pg_stat_statements.save = on                # Persist stats across restarts

# Logging configuration for load testing
logging_collector = on                      # Enable log collection
log_directory = 'log'                       # Directory for log files (relative to PGDATA)
log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'  # Log file naming pattern
log_rotation_age = 1d                       # Rotate logs daily
log_rotation_size = 100MB                   # Rotate when file reaches 100MB

# What to log
log_min_duration_statement = 10             # Log queries taking > 10ms (for detailed analysis)
log_line_prefix = '%t [%p]: user=%u,db=%d,app=%a '  # Detailed prefix with timestamp
log_statement = 'all'                       # Log all statements (SELECT, INSERT, UPDATE, DELETE) - useful for debugging read queries
log_connections = on                        # Log connection attempts
log_disconnections = on                     # Log session terminations
log_lock_waits = on                         # Log long lock waits (CRITICAL for contention!)
log_temp_files = 0                          # Log all temporary file usage

# Error logging
log_error_verbosity = default               # Include DETAIL, HINT, QUERY error information

# Replication settings
wal_level = replica                         # Enable WAL archiving for replication
max_wal_senders = 3                         # Allow up to 3 concurrent replication connections
wal_keep_size = 1GB                         # Keep at least 1GB of WAL files for replicas
max_replication_slots = 3                   # Allow up to 3 replication slots
hot_standby = on                            # Enable read queries on standby servers