Add cache eviction low and high watermarks (#8958)

To allow better control the cache eviction process.

Introduce MINIO_CACHE_WATERMARK_LOW and 
MINIO_CACHE_WATERMARK_HIGH env. variables to specify 
when to stop/start cache eviction process. 

Deprecate MINIO_CACHE_EXPIRY environment variable. Cache 
gc sweeps at 30 minute intervals whenever high watermark is
reached to clear least recently accessed entries in the cache
until sufficient space is cleared to reach the low watermark.

Garbage collection uses an adaptive file scoring approach based
on last access time, with greater weights assigned to larger
objects and those with more hits to find the candidates for eviction.

Thanks to @klauspost for this file scoring algorithm

Co-authored-by: Klaus Post <klauspost@minio.io>
This commit is contained in:
poornas
2020-02-23 05:33:39 -08:00
committed by GitHub
parent 51a9d1bdb7
commit 224b4f13b8
18 changed files with 585 additions and 175 deletions

View File

@@ -26,25 +26,31 @@ import (
// Cache ENVs
const (
Drives = "drives"
Exclude = "exclude"
Expiry = "expiry"
MaxUse = "maxuse"
Quota = "quota"
After = "after"
Drives = "drives"
Exclude = "exclude"
Expiry = "expiry"
MaxUse = "maxuse"
Quota = "quota"
After = "after"
WatermarkLow = "watermark_low"
WatermarkHigh = "watermark_high"
EnvCacheDrives = "MINIO_CACHE_DRIVES"
EnvCacheExclude = "MINIO_CACHE_EXCLUDE"
EnvCacheExpiry = "MINIO_CACHE_EXPIRY"
EnvCacheMaxUse = "MINIO_CACHE_MAXUSE"
EnvCacheQuota = "MINIO_CACHE_QUOTA"
EnvCacheAfter = "MINIO_CACHE_AFTER"
EnvCacheDrives = "MINIO_CACHE_DRIVES"
EnvCacheExclude = "MINIO_CACHE_EXCLUDE"
EnvCacheExpiry = "MINIO_CACHE_EXPIRY"
EnvCacheMaxUse = "MINIO_CACHE_MAXUSE"
EnvCacheQuota = "MINIO_CACHE_QUOTA"
EnvCacheAfter = "MINIO_CACHE_AFTER"
EnvCacheWatermarkLow = "MINIO_CACHE_WATERMARK_LOW"
EnvCacheWatermarkHigh = "MINIO_CACHE_WATERMARK_HIGH"
EnvCacheEncryptionMasterKey = "MINIO_CACHE_ENCRYPTION_MASTER_KEY"
DefaultExpiry = "90"
DefaultQuota = "80"
DefaultAfter = "0"
DefaultExpiry = "90"
DefaultQuota = "80"
DefaultAfter = "0"
DefaultWaterMarkLow = "70"
DefaultWaterMarkHigh = "80"
)
// DefaultKVS - default KV settings for caching.
@@ -70,6 +76,14 @@ var (
Key: After,
Value: DefaultAfter,
},
config.KV{
Key: WatermarkLow,
Value: DefaultWaterMarkLow,
},
config.KV{
Key: WatermarkHigh,
Value: DefaultWaterMarkHigh,
},
}
)
@@ -87,7 +101,6 @@ func Enabled(kvs config.KVS) bool {
// variables and merge them with provided CacheConfiguration.
func LookupConfig(kvs config.KVS) (Config, error) {
cfg := Config{}
if err := config.CheckValidKeys(config.CacheSubSys, kvs, DefaultKVS); err != nil {
return cfg, err
}
@@ -154,5 +167,33 @@ func LookupConfig(kvs config.KVS) (Config, error) {
}
}
if lowWMStr := env.Get(EnvCacheWatermarkLow, kvs.Get(WatermarkLow)); lowWMStr != "" {
cfg.WatermarkLow, err = strconv.Atoi(lowWMStr)
if err != nil {
return cfg, config.ErrInvalidCacheWatermarkLow(err)
}
// WatermarkLow should be a valid percentage.
if cfg.WatermarkLow < 0 || cfg.WatermarkLow > 100 {
err := errors.New("config min watermark value should be between 0 and 100")
return cfg, config.ErrInvalidCacheWatermarkLow(err)
}
}
if highWMStr := env.Get(EnvCacheWatermarkHigh, kvs.Get(WatermarkHigh)); highWMStr != "" {
cfg.WatermarkHigh, err = strconv.Atoi(highWMStr)
if err != nil {
return cfg, config.ErrInvalidCacheWatermarkHigh(err)
}
// MaxWatermark should be a valid percentage.
if cfg.WatermarkHigh < 0 || cfg.WatermarkHigh > 100 {
err := errors.New("config high watermark value should be between 0 and 100")
return cfg, config.ErrInvalidCacheWatermarkHigh(err)
}
}
if cfg.WatermarkLow > cfg.WatermarkHigh {
err := errors.New("config high watermark value should be greater than low watermark value")
return cfg, config.ErrInvalidCacheWatermarkHigh(err)
}
return cfg, nil
}