shekhar/windows-iso-downloader
1
0
Fork 0
Code Issues Pull requests Projects Releases 15 Packages Wiki Activity Actions

feat(backend): approximate distinct-source count for Sentinel rejections

Browse source 
CLI telemetry showed a growing count of Sentinel rejections but no way
to tell whether they come from one user retrying repeatedly or many
distinct users independently getting blocked.

Adds a per-day Redis HyperLogLog (msdl:telemetry:sentinel_hll:<date>)
seeded from the reporting IP whenever a CLI error contains "Sentinel",
plus a parallel daily counter. /metrics now exposes sentinel_today:
{date, errors_today, distinct_sources_est}. No raw IPs are stored --
HLL is a one-way cardinality estimator, and both keys expire after 48h.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
Shekhar Vaidya 2026-07-13 12:37:01 +05:30
parent 6e374e6a45
commit b252ba1c30
1 changed files with 35 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

35
backend/main.go
View file

@ -1675,6 +1675,20 @@ func handleTelemetry(w http.ResponseWriter, r *http.Request) {
rdb.HIncrBy(ctx, "msdl:telemetry:results", result, 1)
if !p.Success && p.Error != "" && len(p.Error) <= 200 {
rdb.HIncrBy(ctx, "msdl:telemetry:errors", p.Error, 1)
if strings.Contains(p.Error, "Sentinel") {
// Track today's Sentinel-rejection count and an approximate
// distinct-source count (via HyperLogLog on the reporting
// IP) so /metrics can show whether rejections are
// concentrated in a few sources or spread across many,
// without ever storing raw IPs.
day := time.Now().UTC().Format("2006-01-02")
countKey := "msdl:telemetry:sentinel_count:" + day
hllKey := "msdl:telemetry:sentinel_hll:" + day
rdb.Incr(ctx, countKey)
rdb.Expire(ctx, countKey, 48*time.Hour)
rdb.PFAdd(ctx, hllKey, ip)
rdb.Expire(ctx, hllKey, 48*time.Hour)
}
}
}
@ -1775,6 +1789,7 @@ func handleMetrics(w http.ResponseWriter, r *http.Request) {
evalCacheMu.RUnlock()
telemetry := loadTelemetryFromRedis()
sentinelToday := loadSentinelTodayFromRedis()
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(map[string]interface{}{
@ -1805,9 +1820,29 @@ func handleMetrics(w http.ResponseWriter, r *http.Request) {
"neg_cache_size": negSize,
"total_ms_fetches": skuFetches + linkFetches,
"telemetry": telemetry,
"sentinel_today": sentinelToday,
})
}
// loadSentinelTodayFromRedis returns today's Sentinel-rejection count and an
// approximate distinct-source count (from the HyperLogLog seeded in
// handleTelemetry). Returns nil when Redis is unavailable.
func loadSentinelTodayFromRedis() map[string]interface{} {
if rdb == nil {
return nil
}
ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
defer cancel()
day := time.Now().UTC().Format("2006-01-02")
count, _ := rdb.Get(ctx, "msdl:telemetry:sentinel_count:"+day).Int64()
distinct, _ := rdb.PFCount(ctx, "msdl:telemetry:sentinel_hll:"+day).Result()
return map[string]interface{}{
"date": day,
"errors_today": count,
"distinct_sources_est": distinct,
}
}
func warmEvalCache() {
for slug, product := range evalProductMap {
go func(s string, p EvalProduct) {