default chunk target size to ~1MB~ 1.5MB (#4388)

* default chunk target size to 1MB

Signed-off-by: Trevor Whitney <trevorjwhitney@gmail.com>

* bump up to 1.5MB

Signed-off-by: Trevor Whitney <trevorjwhitney@gmail.com>

pkg/ingester/ingester.go

@@ -97,7 +97,7 @@ func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
 	f.DurationVar(&cfg.RetainPeriod, "ingester.chunks-retain-period", 15*time.Minute, "")
 	f.DurationVar(&cfg.MaxChunkIdle, "ingester.chunks-idle-period", 30*time.Minute, "")
 	f.IntVar(&cfg.BlockSize, "ingester.chunks-block-size", 256*1024, "")
-	f.IntVar(&cfg.TargetChunkSize, "ingester.chunk-target-size", 0, "")
+	f.IntVar(&cfg.TargetChunkSize, "ingester.chunk-target-size", 1572864, "") //1.5 MB
 	f.StringVar(&cfg.ChunkEncoding, "ingester.chunk-encoding", chunkenc.EncGZIP.String(), fmt.Sprintf("The algorithm to use for compressing chunk. (%s)", chunkenc.SupportedEncoding()))
 	f.DurationVar(&cfg.SyncPeriod, "ingester.sync-period", 0, "How often to cut chunks to synchronize ingesters.")
 	f.Float64Var(&cfg.SyncMinUtilization, "ingester.sync-min-utilization", 0, "Minimum utilization of chunk when doing synchronization.")