Memory so high, and when clean not reduce size

[teng231]

What is the issue you are having?

What is BigCache doing that it shouldn't?

Environment:

• Version (git sha or release): 3.1.0
• OS (e.g. from /etc/os-release or winver.exe):
• go version: 1.18

[janisz]

Could you share your configuration. Bigcache does not free once allocated memory to system.

[teng231]

func getConfig(config *BigCacheConfig) bigcache.Config {
    return bigcache.Config{
        // number of shards (must be a power of 2)
        Shards: 16,

        // time after which entry can be evicted
        LifeWindow: 10 * time.Hour, // 5 * time.Minute,

        // Interval between removing expired entries (clean up).
        // If set to <= 0 then no action is performed.
        // Setting to < 1 second is counterproductive — bigcache has a one second resolution.
        CleanWindow: 5 * time.Minute,

        // rps * lifeWindow, used only in initial memory allocation
        MaxEntriesInWindow: 1000 * 10 * 60,

        // max entry size in bytes, used only in initial memory allocation
        MaxEntrySize: 100,

        // prints information about additional memory allocation
        Verbose: false,

        // cache will not allocate more memory than this limit, value in MB
        // if value is reached then the oldest entries can be overridden for the new ones
        // 0 value means no size limit
        HardMaxCacheSize: 500,

        // callback fired when the oldest entry is removed because of its expiration time or no space left
        // for the new entry, or because delete was called. A bitmask representing the reason will be returned.
        // Default value is nil which means no callback and it prevents from unwrapping the oldest entry.
        OnRemove: nil,

        // OnRemoveWithReason is a callback fired when the oldest entry is removed because of its expiration time or no space left
        // for the new entry, or because delete was called. A constant representing the reason will be passed through.
        // Default value is nil which means no callback and it prevents from unwrapping the oldest entry.
        // Ignored if OnRemove is specified.
        OnRemoveWithReason: nil,
    }
}

[janisz]

so in your example cache uses 400MB while max size it's 500MB. I think it's correct behavior.

[teng231]

so in your example cache uses 400MB while max size it's 500MB. I think it's correct behavior.

mem start with 90mb my data limit 2000 items but after 10 days increase 1gb

i setup limit resource on k8s pod will be restarted when memory equal 1GB. if not limit maybe can increase more

[janisz]

Go 1.19 introduced GOMEMLIMIT maybe it's worth to use it. Although bigcache should not consume more memory then HardMaxCacheSize there is still some room for underlying map and a chance that Go does not release once allocated memory.