Struct BrowserPoolConfig 

pub struct BrowserPoolConfig {
    pub max_pool_size: usize,
    pub warmup_count: usize,
    pub ping_interval: Duration,
    pub browser_ttl: Duration,
    pub max_ping_failures: u32,
    pub warmup_timeout: Duration,
}

Configuration for browser pool behavior and limits.

Controls pool size, browser lifecycle, and health monitoring parameters. Use BrowserPoolConfigBuilder for validation and convenience.

Fields Overview

Field	Default	Description
max_pool_size	5	Maximum browsers in pool
warmup_count	3	Browsers to pre-create
ping_interval	15s	Health check frequency
browser_ttl	1 hour	Browser lifetime
max_ping_failures	3	Failures before removal
warmup_timeout	60s	Warmup time limit

Example

use html2pdf_api::BrowserPoolConfig;

// Use defaults
let config = BrowserPoolConfig::default();
assert_eq!(config.max_pool_size, 5);

Fields

max_pool_size: usize

Maximum number of browsers to keep in the pool (idle + active).

This is a soft limit - active browsers may temporarily exceed this during high load.

Default

5 browsers

Considerations

• Higher values = more memory usage, better concurrency
• Lower values = less memory, potential queuing under load

warmup_count: usize

Number of browsers to pre-create during warmup phase.

Must be d max_pool_size. Reduces first-request latency.

Default

3 browsers

Considerations

• Set to max_pool_size for fastest first requests
• Set to 0 for lazy initialization (browsers created on demand)

ping_interval: Duration

Interval between health check pings for active browsers.

Shorter intervals = faster failure detection, higher overhead.

Default

15 seconds

Considerations

• Too short: Unnecessary CPU/memory overhead
• Too long: Slow detection of crashed browsers

browser_ttl: Duration

Time-to-live for each browser instance before forced retirement.

Prevents memory leaks from long-running browser processes.

Default

1 hour (3600 seconds)

Considerations

• Chrome can accumulate memory over time
• Shorter TTL = more browser restarts, fresher instances
• Longer TTL = fewer restarts, potential memory growth

max_ping_failures: u32

Maximum consecutive ping failures before removing a browser.

Higher values = more tolerance for transient failures.

Default

3 consecutive failures

Considerations

• Set to 1 for aggressive failure detection
• Set higher if experiencing transient network issues

warmup_timeout: Duration

Maximum time allowed for warmup process to complete.

If warmup doesn’t complete in this time, it fails with timeout error.

Default

60 seconds

Considerations

• Should be at least warmup_count * ~5 seconds per browser
• Increase if running on slow hardware or with many warmup browsers

Trait Implementations

impl Clone for BrowserPoolConfig

fn clone(&self) -> BrowserPoolConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BrowserPoolConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for BrowserPoolConfig

fn default() -> Self

Production-ready default configuration.

• Pool size: 5 browsers
• Warmup: 3 browsers
• Health checks: Every 15 seconds
• TTL: 1 hour
• Failure tolerance: 3 consecutive failures
• Warmup timeout: 60 seconds

Example

use html2pdf_api::BrowserPoolConfig;
use std::time::Duration;

let config = BrowserPoolConfig::default();

assert_eq!(config.max_pool_size, 5);
assert_eq!(config.warmup_count, 3);
assert_eq!(config.ping_interval, Duration::from_secs(15));
assert_eq!(config.browser_ttl, Duration::from_secs(3600));
assert_eq!(config.max_ping_failures, 3);
assert_eq!(config.warmup_timeout, Duration::from_secs(60));