Tell about the influence of GOGC on Garbage Collector operation and how to optimize memory usage.

In Go, the environment variable or runtime parameter GOGC determines the threshold at which the garbage collector (GC) is triggered. The GOGC value is the percentage ratio of the heap size after the last garbage collection to its size during the last collection. By default, GOGC=100, which means GC is triggered when the heap doubles in size.

If GOGC is decreased (for example, to 50), GC will run more frequently, reducing peak memory consumption but increasing CPU load due to frequent collections. If GOGC is increased (for example, to 200), GC will run less often, reducing CPU load but increasing memory usage.

Optimizing memory usage considering GOGC:

• For applications with strict memory constraints, it is advisable to lower GOGC so that GC runs more often and prevents large heap growth.
• For applications where performance is critical and higher memory consumption is acceptable, GOGC can be increased to reduce the frequency of collections.
• It is important to profile the application using pprof to understand how memory usage and GC time change.

Example of setting GOGC:

GOGC=75 go run main.go

Thus, proper GOGC tuning helps balance response time, CPU load, and memory consumption.