app/vmselect: add -search.cacheTimestampOffset command-line flag

This flag can be used for removing gaps on graphs if the difference between the current time
and the timestamps from the ingested data exceeds 5 minutes.

This is the case when the time between data sources and VictoriaMetrics is improperly synchronized.

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/312
This commit is contained in:
Aliaksandr Valialkin 2020-02-21 13:54:10 +02:00
parent c70822db50
commit d5c2a0ce64

View File

@ -19,7 +19,12 @@ import (
"github.com/VictoriaMetrics/metrics"
)
var disableCache = flag.Bool("search.disableCache", false, "Whether to disable response caching. This may be useful during data backfilling")
var (
disableCache = flag.Bool("search.disableCache", false, "Whether to disable response caching. This may be useful during data backfilling")
cacheTimestampOffset = flag.Duration("search.cacheTimestampOffset", 5*time.Minute, "The maximum duration since the current time for response data, "+
"which is always queried from the original raw data, without using the response cache. Increase this value if you see gaps in responses "+
"due to time synchronization issues between VictoriaMetrics and data sources")
)
var rollupResultCacheV = &rollupResultCache{
c: workingsetcache.New(1024*1024, time.Hour), // This is a cache for testing.
@ -220,10 +225,10 @@ func (rrc *rollupResultCache) Put(ec *EvalConfig, expr metricsql.Expr, window in
return
}
// Remove values up to currentTime - step - maxSilenceInterval,
// Remove values up to currentTime - step - cacheTimestampOffset,
// since these values may be added later.
timestamps := tss[0].Timestamps
deadline := (time.Now().UnixNano() / 1e6) - ec.Step - maxSilenceInterval
deadline := (time.Now().UnixNano() / 1e6) - ec.Step - cacheTimestampOffset.Milliseconds()
i := len(timestamps) - 1
for i >= 0 && timestamps[i] > deadline {
i--