github.com/cockroachdb/cockroach@v20.2.0-alpha.1+incompatible/pkg/kv/kvserver/replica_split_load.go (about)

     1  // Copyright 2019 The Cockroach Authors.
     2  //
     3  // Use of this software is governed by the Business Source License
     4  // included in the file licenses/BSL.txt.
     5  //
     6  // As of the Change Date specified in that file, in accordance with
     7  // the Business Source License, use of this software will be governed
     8  // by the Apache License, Version 2.0, included in the file
     9  // licenses/APL.txt.
    10  
    11  package kvserver
    12  
    13  import (
    14  	"context"
    15  
    16  	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/spanset"
    17  	"github.com/cockroachdb/cockroach/pkg/roachpb"
    18  	"github.com/cockroachdb/cockroach/pkg/settings"
    19  	"github.com/cockroachdb/cockroach/pkg/util/timeutil"
    20  )
    21  
    22  // SplitByLoadEnabled wraps "kv.range_split.by_load_enabled".
    23  var SplitByLoadEnabled = settings.RegisterPublicBoolSetting(
    24  	"kv.range_split.by_load_enabled",
    25  	"allow automatic splits of ranges based on where load is concentrated",
    26  	true,
    27  )
    28  
    29  // SplitByLoadQPSThreshold wraps "kv.range_split.load_qps_threshold".
    30  var SplitByLoadQPSThreshold = settings.RegisterPublicIntSetting(
    31  	"kv.range_split.load_qps_threshold",
    32  	"the QPS over which, the range becomes a candidate for load based splitting",
    33  	2500, // 2500 req/s
    34  )
    35  
    36  // SplitByLoadQPSThreshold returns the QPS request rate for a given replica.
    37  func (r *Replica) SplitByLoadQPSThreshold() float64 {
    38  	return float64(SplitByLoadQPSThreshold.Get(&r.store.cfg.Settings.SV))
    39  }
    40  
    41  // SplitByLoadEnabled returns whether load based splitting is enabled.
    42  // Although this is a method of *Replica, the configuration is really global,
    43  // shared across all stores.
    44  func (r *Replica) SplitByLoadEnabled() bool {
    45  	return SplitByLoadEnabled.Get(&r.store.cfg.Settings.SV) &&
    46  		!r.store.TestingKnobs().DisableLoadBasedSplitting
    47  }
    48  
    49  // recordBatchForLoadBasedSplitting records the batch's spans to be considered
    50  // for load based splitting.
    51  func (r *Replica) recordBatchForLoadBasedSplitting(
    52  	ctx context.Context, ba *roachpb.BatchRequest, spans *spanset.SpanSet,
    53  ) {
    54  	if !r.SplitByLoadEnabled() {
    55  		return
    56  	}
    57  	shouldInitSplit := r.loadBasedSplitter.Record(timeutil.Now(), len(ba.Requests), func() roachpb.Span {
    58  		return spans.BoundarySpan(spanset.SpanGlobal)
    59  	})
    60  	if shouldInitSplit {
    61  		r.store.splitQueue.MaybeAddAsync(ctx, r, r.store.Clock().Now())
    62  	}
    63  }