What factors influence latency when working with Garbage Collector?

Latency during Garbage Collector (GC) operation in Go depends on several factors:

• Amount of allocated memory and number of objects: The more objects and memory that need to be scanned, the longer the pause may last.
• Frequency of garbage collections: Frequent collections with less work can reduce latency but increase overall load.
• GC parallelism: Go's GC runs in parallel with the application, but at certain stages (e.g., stop-the-world), the application is paused, affecting latency.
• GOGC settings: The GOGC parameter determines the heap growth threshold for triggering GC. A lower value results in more frequent, but less costly collections, reducing latency.
• Memory fragmentation and object distribution: Poor distribution and fragmentation can increase scan times.

Example of GOGC setting to reduce latency:

// Reduce GC trigger threshold to 50% heap growth
runtime/debug.SetGCPercent(50)

Overall, to reduce latency, it is important to balance the frequency and amount of GC work, as well as optimize memory allocation in the application.