Skip to main content

symbol_garbage_collection_inspection

🗑️ Inspect and Manage Symbol Garbage Collection​

Ruby 2.2+ introduced GC for dynamically created symbols, but understanding its behavior is crucial for long‐running processes. Use Symbol.all_symbols in combination with GC.start and GC.stat to measure the effect of symbol creation and GC sweeps, identifying leaks in symbol-heavy workloads.

# Before creating dynamic symbols
puts GC.stat[:symbol_count]

1000.times { |i| "temp_").to_sym }

# Force a GC cycle
GC.start
puts GC.stat[:symbol_count]

By comparing :symbol_count before and after GC, you can detect excessive symbol churn. In cases where dynamic symbol generation is unavoidable, consider using string-based keys or a symbol cache with controlled eviction to minimize memory pressure.