.env.example

# VLog Configuration
# Copy this file to .env and modify as needed.
# All values shown are the defaults.
#
# =============================================================================
# SETTINGS MIGRATION NOTICE
# =============================================================================
# VLog now supports database-backed settings that can be configured via the
# Admin UI (Settings tab) or CLI (`vlog settings` commands).
#
# Settings are organized into two categories:
#
# BOOTSTRAP SETTINGS (keep in .env):
#   - Storage paths, database URLs, server ports
#   - Authentication secrets
#   - Infrastructure settings (Redis, etc.)
#   These MUST be in .env because they're needed before the app starts.
#
# RUNTIME SETTINGS (migrate to database):
#   - Transcoding options (HLS segment duration, timeouts, etc.)
#   - Watermark configuration
#   - Worker tuning parameters
#   - Analytics cache settings
#   - Alert webhook configuration
#   These CAN be moved to the database for dynamic configuration.
#
# To migrate runtime settings to the database:
#   1. Run: vlog settings migrate-from-env
#   2. The migrated settings will be listed
#   3. You can safely remove those env vars from .env
#   4. Settings in database take precedence over env vars
#
# The env vars continue to work as fallbacks if not in the database.
# =============================================================================

# =============================================================================
# Storage Paths
# =============================================================================

# Base storage path for all video files
VLOG_STORAGE_PATH=/mnt/nas/vlog-storage

# Subdirectories within storage path
VLOG_VIDEOS_SUBDIR=videos
VLOG_UPLOADS_SUBDIR=uploads
VLOG_ARCHIVE_SUBDIR=archive

# SQLite database path (keep local for performance)
VLOG_DATABASE_PATH=./vlog.db

# PostgreSQL database URL (recommended for production)
# VLOG_DATABASE_URL=postgresql://vlog:vlog_password@localhost/vlog

# =============================================================================
# Storage Health Check
# =============================================================================

# Timeout for health check storage access test (seconds)
# Reduced default for faster failure detection on stale NFS mounts
VLOG_STORAGE_CHECK_TIMEOUT=2

# =============================================================================
# Server Ports
# =============================================================================

# Public API port (video browsing, playback, analytics)
VLOG_PUBLIC_PORT=9000

# Admin API port (uploads, management - internal only)
VLOG_ADMIN_PORT=9001

# Admin API authentication secret (optional)
# When set, all /api/* endpoints require X-Admin-Secret header
# Generate with: python -c "import secrets; print(secrets.token_urlsafe(32))"
# VLOG_ADMIN_API_SECRET=your-secret-here

# Admin session expiry in hours (for browser-based authentication)
# Sessions use HTTP-only cookies and are stored server-side
VLOG_ADMIN_SESSION_EXPIRY_HOURS=24

# =============================================================================
# API Versioning (Issue #218)
# =============================================================================

# Current API version (format: v1, v2, etc.)
# All API routes will be available at /api/v1/*, /api/v2/*, etc.
VLOG_API_VERSION=v1

# Enable deprecation notices for older API versions
# When enabled, deprecated versions include Deprecation and Sunset headers
VLOG_API_DEPRECATION_NOTICE=true

# Sunset date for deprecated API versions.
# RFC 5322 format is recommended (e.g. Sat, 01 Jan 2028 00:00:00 GMT),
# but any format supported by the HTTP Sunset header specification may be used.
# VLOG_API_DEPRECATION_SUNSET=

# Include legacy unversioned routes (/api/videos) that alias to current version
# Set to false to require explicit version in all API requests
VLOG_API_INCLUDE_LEGACY_ROUTES=true

# =============================================================================
# OpenAPI Documentation
# =============================================================================

# OpenAPI documentation title
VLOG_OPENAPI_TITLE=VLog API

# OpenAPI documentation description
VLOG_OPENAPI_DESCRIPTION=Self-hosted video platform API with versioned endpoints

# Terms of service URL (optional)
# VLOG_OPENAPI_TERMS_OF_SERVICE=https://example.com/terms

# API contact information (optional)
# VLOG_OPENAPI_CONTACT_NAME=API Support
# VLOG_OPENAPI_CONTACT_EMAIL=api@example.com

# API license information (optional)
# VLOG_OPENAPI_LICENSE_NAME=MIT
# VLOG_OPENAPI_LICENSE_URL=https://opensource.org/licenses/MIT

# =============================================================================
# Worker Settings
# =============================================================================

# Use inotify-based filesystem watcher instead of polling
VLOG_WORKER_USE_FILESYSTEM_WATCHER=true

# Fallback poll interval in seconds (safety net)
VLOG_WORKER_FALLBACK_POLL_INTERVAL=60

# Debounce delay in seconds after file event
VLOG_WORKER_DEBOUNCE_DELAY=1.0

# Progress update rate limiting (prevents database overload during transcoding)
VLOG_PROGRESS_UPDATE_INTERVAL=5.0

# =============================================================================
# Remote Worker Settings (Distributed Transcoding)
# =============================================================================

# Worker API port (for remote transcoder registration and job claiming)
VLOG_WORKER_API_PORT=9002

# HTTP health server port for K8s liveness/readiness probes
VLOG_WORKER_HEALTH_PORT=8080

# Worker API URL (used by remote workers to connect to the server)
VLOG_WORKER_API_URL=http://localhost:9002

# Worker API key (issued when registering via `vlog worker register`)
# VLOG_WORKER_API_KEY=vlog_xxxx...

# Admin secret for worker management endpoints (register, list, revoke)
# Generate with: python -c "import secrets; print(secrets.token_urlsafe(32))"
# VLOG_WORKER_ADMIN_SECRET=your-secret-here

# [MIGRATABLE] These worker tuning settings can be moved to the database:
# Heartbeat interval in seconds (how often workers send status updates)
VLOG_WORKER_HEARTBEAT_INTERVAL=30

# How long a worker can claim a job before it expires (minutes)
VLOG_WORKER_CLAIM_DURATION=30

# How often remote workers poll for new jobs (seconds)
VLOG_WORKER_POLL_INTERVAL=10

# Local directory for remote workers to use during transcoding
VLOG_WORKER_WORK_DIR=/tmp/vlog-worker

# Minutes before a worker is considered offline (no heartbeat)
VLOG_WORKER_OFFLINE_THRESHOLD=2

# How often to check for stale jobs from offline workers (seconds)
VLOG_STALE_JOB_CHECK_INTERVAL=60

# =============================================================================
# Soft Delete
# =============================================================================

# Days to keep archived videos before permanent deletion
VLOG_ARCHIVE_RETENTION_DAYS=30

# =============================================================================
# HLS Settings [MIGRATABLE]
# =============================================================================

# Segment duration in seconds
VLOG_HLS_SEGMENT_DURATION=6

# =============================================================================
# Thumbnail Settings
# =============================================================================

# Maximum custom thumbnail upload size in bytes (10MB default)
VLOG_MAX_THUMBNAIL_SIZE=10485760

# Thumbnail width in pixels (height auto-calculated to maintain aspect ratio)
VLOG_THUMBNAIL_WIDTH=640

# =============================================================================
# Hardware Acceleration
# =============================================================================

# Hardware acceleration type: auto, nvidia, intel, none
VLOG_HWACCEL_TYPE=auto

# Preferred codec: h264, hevc, av1
VLOG_HWACCEL_PREFERRED_CODEC=h264

# Fall back to CPU if GPU encoding fails
VLOG_HWACCEL_FALLBACK_TO_CPU=true

# Maximum concurrent GPU encoding sessions (consumer GPUs have limits)
VLOG_HWACCEL_MAX_SESSIONS=3

# VAAPI device path (Intel GPU, leave empty for auto-detect)
# VLOG_HWACCEL_VAAPI_DEVICE=/dev/dri/renderD128

# =============================================================================
# Parallel Quality Encoding
# =============================================================================

# Number of qualities to encode simultaneously (1 = sequential)
# Recommended: 3 for GPUs, 1 for CPU-only
VLOG_PARALLEL_QUALITIES=1

# Auto-detect optimal parallelism based on GPU capabilities
# When true: uses min(3, gpu.max_sessions - 1) for GPUs
VLOG_PARALLEL_QUALITIES_AUTO=true

# =============================================================================
# Transcoding Settings
# =============================================================================

# Checkpoint interval in seconds
VLOG_CHECKPOINT_INTERVAL=30

# Seconds before a job is considered stale (30 min default)
VLOG_JOB_STALE_TIMEOUT=1800

# Maximum retry attempts for failed jobs
VLOG_MAX_RETRY_ATTEMPTS=3

# Backoff base in seconds (doubles each retry)
VLOG_RETRY_BACKOFF_BASE=60

# Clean up partial files on failure
VLOG_CLEANUP_PARTIAL_ON_FAILURE=true

# Clean up source files when transcoding permanently fails (after max retries)
VLOG_CLEANUP_SOURCE_ON_PERMANENT_FAILURE=true

# Keep completed qualities on retry (don't re-transcode)
VLOG_KEEP_COMPLETED_QUALITIES=true

# =============================================================================
# Streaming Format Settings (Issue #222)
# =============================================================================

# Output format: "hls_ts" (MPEG-TS segments) or "cmaf" (fMP4 segments)
# CMAF enables DASH streaming and better seeking performance
VLOG_STREAMING_FORMAT=cmaf

# Video codec for streaming: "h264", "hevc", or "av1"
# HEVC/AV1 require CMAF format and may not work on all devices
VLOG_STREAMING_CODEC=hevc

# Enable DASH manifest generation (only available with CMAF format)
VLOG_STREAMING_ENABLE_DASH=true

# =============================================================================
# FFmpeg Timeout Settings
# =============================================================================

# Base timeout multiplier (timeout = video_duration * multiplier * resolution_factor)
VLOG_FFMPEG_TIMEOUT_BASE_MULTIPLIER=2.0

# Minimum timeout in seconds (5 minutes)
VLOG_FFMPEG_TIMEOUT_MINIMUM=300

# Maximum timeout in seconds (1 hour)
VLOG_FFMPEG_TIMEOUT_MAXIMUM=3600

# =============================================================================
# Worker Reliability Settings
# =============================================================================

# Timeout for extracting TAR archives from remote workers (seconds)
# Default: 600 (10 minutes) - sufficient for large quality archives on slow NAS
VLOG_TAR_EXTRACTION_TIMEOUT=600

# Enable automatic cleanup of orphaned quality directories
# Orphans occur when workers crash mid-transcode, leaving partial directories
VLOG_ORPHAN_CLEANUP_ENABLED=true

# How often to run orphan cleanup check (seconds, default: 1 hour)
VLOG_ORPHAN_CLEANUP_INTERVAL=3600

# Minimum age before a directory is considered orphaned (seconds, default: 24 hours)
# Directories younger than this are not cleaned up to allow time for job completion
VLOG_ORPHAN_CLEANUP_MIN_AGE=86400

# =============================================================================
# Transcription Settings (Whisper) [MIGRATABLE]
# =============================================================================

# Whisper model: tiny, base, small, medium, large-v3
VLOG_WHISPER_MODEL=medium

# Enable/disable auto-transcription
VLOG_TRANSCRIPTION_ENABLED=true

# Language code for transcription (leave empty for auto-detect)
# VLOG_TRANSCRIPTION_LANGUAGE=en

# Auto-transcribe new uploads
VLOG_TRANSCRIPTION_ON_UPLOAD=true

# Compute type for faster-whisper: float16, int8, int8_float16
VLOG_TRANSCRIPTION_COMPUTE_TYPE=int8

# Transcription timeout in seconds (1 hour)
VLOG_TRANSCRIPTION_TIMEOUT=3600

# Audio extraction timeout in seconds (5 minutes)
VLOG_AUDIO_EXTRACTION_TIMEOUT=300

# =============================================================================
# Upload Limits
# =============================================================================

# Maximum upload size in bytes (100GB default)
VLOG_MAX_UPLOAD_SIZE=107374182400

# Upload chunk size in bytes (1MB default)
VLOG_UPLOAD_CHUNK_SIZE=1048576

# HLS archive extraction limits (tar bomb protection)
# Max files in HLS archive (50k supports ~8hr videos with all qualities)
VLOG_MAX_HLS_ARCHIVE_FILES=50000
# Max total extracted size in bytes (200GB)
VLOG_MAX_HLS_ARCHIVE_SIZE=214748364800
# Max single file size in bytes (500MB)
VLOG_MAX_HLS_SINGLE_FILE_SIZE=524288000

# =============================================================================
# CORS Configuration
# =============================================================================

# Allowed origins for public API (comma-separated)
# Leave empty for same-origin only
# VLOG_CORS_ORIGINS=http://localhost:9000,http://localhost:9001

# Allowed origins for admin API cross-origin requests (comma-separated)
# Defaults to empty (same-origin only) - no configuration needed for typical setups
# Only set this if admin UI is served from a different host than the API
# VLOG_ADMIN_CORS_ORIGINS=http://192.168.1.100:3000,http://devbox.local:3000

# =============================================================================
# Rate Limiting
# =============================================================================

# Enable/disable rate limiting
VLOG_RATE_LIMIT_ENABLED=true

# Public API rate limits
VLOG_RATE_LIMIT_PUBLIC_DEFAULT=100/minute
VLOG_RATE_LIMIT_PUBLIC_VIDEOS_LIST=60/minute
VLOG_RATE_LIMIT_PUBLIC_ANALYTICS=120/minute

# Admin API rate limits
VLOG_RATE_LIMIT_ADMIN_DEFAULT=200/minute
VLOG_RATE_LIMIT_ADMIN_UPLOAD=10/hour

# Worker API rate limits
VLOG_RATE_LIMIT_WORKER_DEFAULT=300/minute
VLOG_RATE_LIMIT_WORKER_REGISTER=5/hour
VLOG_RATE_LIMIT_WORKER_PROGRESS=600/minute

# Rate limit storage backend
# SECURITY: In-memory rate limiting doesn't work with multiple API instances.
# Attackers can bypass rate limits by distributing requests across instances.
#
# AUTO-DETECTION: If VLOG_REDIS_URL is set (below), rate limiting will
# automatically use Redis. No need to set this explicitly in most cases.
#
# Explicit override (takes precedence over auto-detection):
# VLOG_RATE_LIMIT_STORAGE_URL=redis://localhost:6379/0
#
# Force in-memory (single instance deployments only!):
# VLOG_RATE_LIMIT_STORAGE_URL=memory://

# Trusted proxy IPs for X-Forwarded-For header (comma-separated)
# Leave empty to never trust X-Forwarded-For (prevents rate limit bypass)
# VLOG_TRUSTED_PROXIES=127.0.0.1,10.0.0.1

# =============================================================================
# Metrics Configuration (Issue #436)
# =============================================================================

# Enable or disable the /metrics endpoint entirely
# Default: true (enabled for backwards compatibility)
VLOG_METRICS_ENABLED=true

# Require authentication for /metrics endpoint
# When true, requires X-Admin-Secret header (uses VLOG_ADMIN_API_SECRET for Admin API,
# VLOG_WORKER_ADMIN_SECRET for Worker API)
# Default: false (disabled for backwards compatibility with existing Prometheus configs)
# SECURITY NOTE: For production, enable this OR use network-level isolation
# to prevent metrics leaking system information to unauthorized users
VLOG_METRICS_AUTH_REQUIRED=false

# =============================================================================
# Video Downloads (Issue #202)
# Allow users to download videos
# =============================================================================

# Master switch for download feature - disabled by default for security
# Set to true to enable download buttons on the watch page
VLOG_DOWNLOADS_ENABLED=false

# Allow downloading original source files (as uploaded)
# Original files may be very large and not optimized for streaming
VLOG_DOWNLOADS_ALLOW_ORIGINAL=false

# Allow downloading transcoded quality variants (e.g., 1080p MP4)
# Note: Not yet implemented - planned for future release
VLOG_DOWNLOADS_ALLOW_TRANSCODED=true

# Rate limit for download requests per IP (requests per hour)
# Set to 0 to disable rate limiting for downloads
# NOTE: This rate limit is configured at startup. Changing it requires a restart.
VLOG_DOWNLOADS_RATE_LIMIT_PER_HOUR=10

# Maximum concurrent downloads per IP (prevents bandwidth abuse)
# This is tracked in-memory so resets on server restart
VLOG_DOWNLOADS_MAX_CONCURRENT=2

# =============================================================================
# Playback Settings (Issue #211) [MIGRATABLE]
# Autoplay and "Up Next" video suggestions
# =============================================================================

# Enable autoplay feature globally (can be overridden by user preferences)
# When enabled, the next video will automatically play after the current ends
VLOG_AUTOPLAY_ENABLED=true

# Enable "Up Next" suggestions after video ends
# Shows a countdown overlay with the next recommended video
VLOG_UPNEXT_ENABLED=true

# Countdown duration in seconds before autoplay starts (5-30)
VLOG_AUTOPLAY_COUNTDOWN_SECONDS=10

# =============================================================================
# Cookie Security
# =============================================================================

# Set secure flag on cookies (requires HTTPS)
# Disable for local development without HTTPS
VLOG_SECURE_COOKIES=true

# =============================================================================
# Analytics Caching [MIGRATABLE]
# =============================================================================

# Enable/disable analytics caching
VLOG_ANALYTICS_CACHE_ENABLED=true

# Server-side cache TTL in seconds
VLOG_ANALYTICS_CACHE_TTL=60

# Client-side Cache-Control max-age in seconds
VLOG_ANALYTICS_CLIENT_CACHE_MAX_AGE=60

# Analytics cache storage backend
# Use "memory://" for single instance, or Redis URL for multi-instance:
# VLOG_ANALYTICS_CACHE_STORAGE_URL=redis://localhost:6379/0
VLOG_ANALYTICS_CACHE_STORAGE_URL=memory://

# =============================================================================
# Audit Logging
# =============================================================================

# Enable/disable audit logging for administrative actions
VLOG_AUDIT_LOG_ENABLED=true

# Path to audit log file (directory will be created if it doesn't exist)
VLOG_AUDIT_LOG_PATH=/var/log/vlog/audit.log

# Audit log level (DEBUG, INFO, WARNING, ERROR)
VLOG_AUDIT_LOG_LEVEL=INFO

# Maximum audit log file size in bytes before rotation (10MB default)
VLOG_AUDIT_LOG_MAX_BYTES=10485760

# Number of backup audit log files to keep
VLOG_AUDIT_LOG_BACKUP_COUNT=5

# =============================================================================
# Error Message Settings
# =============================================================================

# Maximum length for brief error summaries (shown in API responses)
VLOG_ERROR_SUMMARY_MAX_LENGTH=100

# Maximum length for detailed error messages
VLOG_ERROR_DETAIL_MAX_LENGTH=500

# Maximum length for full error logs
VLOG_ERROR_LOG_MAX_LENGTH=2000

# =============================================================================
# Alerting Configuration [MIGRATABLE]
# =============================================================================

# Webhook URL for sending alerts (stale jobs, max retries exceeded, etc.)
# Leave empty to disable webhook alerts
# VLOG_ALERT_WEBHOOK_URL=https://hooks.slack.com/services/xxx

# Timeout for webhook requests in seconds
VLOG_ALERT_WEBHOOK_TIMEOUT=10

# Minimum interval between alerts for the same event type (seconds)
# Prevents alert flooding when multiple jobs fail in quick succession
VLOG_ALERT_RATE_LIMIT_SECONDS=300

# =============================================================================
# Redis Configuration
# =============================================================================

# Redis URL for job queue and pub/sub (leave empty to disable Redis features)
# Include password in URL: redis://:YOUR_PASSWORD@host:6379
# Generate a strong password: python -c "import secrets; print(secrets.token_urlsafe(32))"
# VLOG_REDIS_URL=redis://:YOUR_REDIS_PASSWORD@localhost:6379

# Redis connection pool size
VLOG_REDIS_POOL_SIZE=10

# Redis socket timeouts in seconds
VLOG_REDIS_SOCKET_TIMEOUT=5.0
VLOG_REDIS_SOCKET_CONNECT_TIMEOUT=5.0

# Redis health check interval in seconds
VLOG_REDIS_HEALTH_CHECK_INTERVAL=30

# Job queue mode: database (default), redis, or hybrid
VLOG_JOB_QUEUE_MODE=database

# Redis Streams settings
VLOG_REDIS_STREAM_MAX_LEN=10000
VLOG_REDIS_CONSUMER_GROUP=vlog-workers
VLOG_REDIS_CONSUMER_BLOCK_MS=5000
VLOG_REDIS_PENDING_TIMEOUT_MS=300000

# Redis Pub/Sub channel prefix
VLOG_REDIS_PUBSUB_PREFIX=vlog

# SSE (Server-Sent Events) settings
VLOG_SSE_HEARTBEAT_INTERVAL=30
VLOG_SSE_RECONNECT_TIMEOUT_MS=3000

# =============================================================================
# CLI Configuration
# =============================================================================

# Admin API URL for CLI (overrides VLOG_ADMIN_PORT if set)
# VLOG_ADMIN_API_URL=http://localhost:9001

# API request timeout in seconds
VLOG_API_TIMEOUT=30

# Upload timeout in seconds (2 hours default for large files)
VLOG_UPLOAD_TIMEOUT=7200

# Download timeout for yt-dlp in seconds
VLOG_DOWNLOAD_TIMEOUT=3600

# =============================================================================
# Watermark Settings [MIGRATABLE]
# =============================================================================

# Enable/disable client-side watermark overlay on video player
VLOG_WATERMARK_ENABLED=false

# Watermark type: image or text
VLOG_WATERMARK_TYPE=image

# Path to watermark image file (PNG, JPEG, WebP, SVG, GIF)
# Can be uploaded via Admin API or placed directly in storage
# VLOG_WATERMARK_IMAGE=watermark.png

# Text to display as watermark (used when VLOG_WATERMARK_TYPE=text)
# VLOG_WATERMARK_TEXT=© 2025 MyBrand

# Text watermark font size in pixels (8-72)
VLOG_WATERMARK_TEXT_SIZE=16

# Text watermark color (CSS color value)
VLOG_WATERMARK_TEXT_COLOR=white

# Watermark position: top-left, top-right, bottom-left, bottom-right, center
VLOG_WATERMARK_POSITION=bottom-right

# Watermark opacity (0.0-1.0)
VLOG_WATERMARK_OPACITY=0.5

# Padding from edge in pixels
VLOG_WATERMARK_PADDING=16

# Maximum watermark width as percentage of video width (1-50, images only)
VLOG_WATERMARK_MAX_WIDTH_PERCENT=15

# =============================================================================
# Sprite Sheet Settings
# =============================================================================

# Enable sprite sheet generation for video thumbnails (hover preview)
VLOG_SPRITE_SHEET_ENABLED=true

# Automatically generate sprite sheets for new videos
VLOG_SPRITE_SHEET_AUTO_GENERATE=false

# Seconds between frames in sprite sheets
VLOG_SPRITE_SHEET_FRAME_INTERVAL=5

# Width of each thumbnail in pixels
VLOG_SPRITE_SHEET_THUMBNAIL_WIDTH=160

# Number of thumbnails per row/column in each sprite sheet
VLOG_SPRITE_SHEET_TILE_SIZE=10

# JPEG quality for sprite sheets (lower = smaller files)
VLOG_SPRITE_SHEET_JPEG_QUALITY=60

# Maximum number of sprite sheets per video
VLOG_SPRITE_SHEET_MAX_SHEETS=100

# Maximum video duration to process for sprites (in seconds, default 4 hours)
# Videos longer than this will be skipped for sprite generation
VLOG_SPRITE_SHEET_MAX_VIDEO_DURATION=14400

# Timeout settings for sprite generation
# Timeout = video_duration * multiplier, clamped to min/max
VLOG_SPRITE_SHEET_TIMEOUT_MULTIPLIER=0.5
VLOG_SPRITE_SHEET_TIMEOUT_MINIMUM=60
VLOG_SPRITE_SHEET_TIMEOUT_MAXIMUM=600

# =============================================================================
# Streaming Upload Settings
# =============================================================================

# Enable streaming segment upload (uploads segments as they're encoded)
# Reduces memory usage and enables faster job completion detection
VLOG_WORKER_STREAMING_UPLOAD=false

# =============================================================================
# Testing
# =============================================================================

# Set to skip directory creation (for CI/tests)
# VLOG_TEST_MODE=1

# =============================================================================
# Structured Logging (Issue #208)
# =============================================================================

# Log format: "json" for production (log aggregation), "text" for development
VLOG_LOG_FORMAT=json

# Default log level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
VLOG_LOG_LEVEL=INFO

# Module-specific log levels (comma-separated, e.g., "api.auth=DEBUG,worker=WARNING")
# VLOG_LOG_LEVELS=

# Optional log file output (in addition to stdout)
# Leave empty to only log to stdout
# VLOG_LOG_FILE=/var/log/vlog/app.log

# Log file rotation settings (only applies when VLOG_LOG_FILE is set)
VLOG_LOG_FILE_MAX_BYTES=10485760
VLOG_LOG_FILE_BACKUP_COUNT=5