map

Map Benchmark

This benchmark tests the performance of regular maps versus sync.Maps focusing on the primitive operations of get, put, and delete while under contention. For the use case of AIStore, we want the read times to be as fast as possible.

Getting started

Run

$ go run main.go -maxsize 1000000

This will start the benchmark with the map size to be 1 million elements.

The list of available options are:

• -iter int - Number of iterations to run (default 10)
• -maxsize int - Maximum size of map (default 1000000)
• -minsize int - Shrink size of map (default 10000)
• -numread int - Number of random reads (default 200000)
• -putpct int - Percentage of puts (default 10)
• -shrink bool - Enable shrink (deletion) of map keys (default true)
• -workers int - Number of Read/Write go-routines (default 8)

Result

From the results of the benchmark, sync.Map does appear to out perform regular maps for read operations when there is contention from multiple go routines. The performance of sync.Map for put and delete operations are usually slower than regular maps, but if we expect > 80% of the requests to be reads, sync.Map will be faster than regular maps. Overall, if we expect that the maps will have much higher read requests than put/delete requests, sync.Maps are the better option.