try_files Without open_file_cache

Gixy Check ID: try_files_is_evil_too

The try_files directive is commonly used in nginx to check for file existence before falling back to other options. However, without open_file_cache, each request triggers multiple stat() system calls, which can significantly impact performance.

Why this matters

For every request, try_files performs file existence checks using stat() system calls. Without caching:

• High I/O overhead: Each request causes multiple disk operations
• Performance degradation: Under load, this becomes a bottleneck
• Increased latency: Especially on network filesystems (NFS, distributed storage)

Bad example

location / {
    try_files $uri $uri/ /index.php$is_args$args;
}

Every request will perform 2-3 stat() calls without any caching.

Good example

# Enable file cache at http or server level
open_file_cache max=1000 inactive=20s;
open_file_cache_valid 30s;
open_file_cache_min_uses 2;
open_file_cache_errors on;

location / {
    try_files $uri $uri/ /index.php$is_args$args;
}

With open_file_cache, nginx caches file metadata, dramatically reducing stat() calls.

Cache configuration options

Directive	Description
open_file_cache max=N inactive=T	Cache up to N entries, expire after T inactive
open_file_cache_valid T	How often to validate cached entries
open_file_cache_min_uses N	Min accesses before caching
open_file_cache_errors on	Cache "file not found" errors too

When to disable this check

If you're serving dynamic content where files change frequently, or using a RAM disk, the performance impact may be negligible. You can disable this specific check in your gixy configuration.

References

• nginx documentation: open_file_cache
• try_files is evil too

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