// ComputeStatsForRange computes the stats for a given range by
// iterating over all key ranges for the given range that should
// be accounted for in its stats.
func ComputeStatsForRange(
d *roachpb.RangeDescriptor, e engine.Reader, nowNanos int64,
) (enginepb.MVCCStats, error) {
iter := e.NewIterator(false)
defer iter.Close()
ms := enginepb.MVCCStats{}
for _, r := range makeReplicatedKeyRanges(d) {
msDelta, err := iter.ComputeStats(r.start, r.end, nowNanos)
if err != nil {
return enginepb.MVCCStats{}, err
}
ms.Add(msDelta)
}
return ms, nil
}
// ComputeMVCCStats immediately computes correct total MVCC usage statistics
// for the store, returning the computed values (but without modifying the
// store).
func (s *Store) ComputeMVCCStats() (enginepb.MVCCStats, error) {
var totalStats enginepb.MVCCStats
var err error
visitor := newStoreRangeSet(s)
now := s.Clock().PhysicalNow()
visitor.Visit(func(r *Replica) bool {
var stats enginepb.MVCCStats
stats, err = ComputeStatsForRange(r.Desc(), s.Engine(), now)
if err != nil {
return false
}
totalStats.Add(stats)
return true
})
return totalStats, err
}
func copySeqCache(
e engine.ReadWriter,
ms *enginepb.MVCCStats,
srcID, dstID roachpb.RangeID,
keyMin, keyMax engine.MVCCKey,
) (int, error) {
var scratch [64]byte
var count int
var meta enginepb.MVCCMetadata
// TODO(spencer): look into making this an MVCCIteration and writing
// the values using MVCC so we can avoid the ugliness of updating
// the MVCCStats by hand below.
err := e.Iterate(keyMin, keyMax,
func(kv engine.MVCCKeyValue) (bool, error) {
// Decode the key, skipping on error. Otherwise, write it to the
// corresponding key in the new cache.
txnID, err := decodeAbortCacheMVCCKey(kv.Key, scratch[:0])
if err != nil {
return false, errors.Errorf("could not decode an abort cache key %s: %s", kv.Key, err)
}
key := keys.AbortCacheKey(dstID, txnID)
encKey := engine.MakeMVCCMetadataKey(key)
// Decode the MVCCMetadata value.
if err := proto.Unmarshal(kv.Value, &meta); err != nil {
return false, errors.Errorf("could not decode mvcc metadata %s [% x]: %s", kv.Key, kv.Value, err)
}
value := engine.MakeValue(meta)
value.ClearChecksum()
value.InitChecksum(key)
meta.RawBytes = value.RawBytes
keyBytes, valBytes, err := engine.PutProto(e, encKey, &meta)
if err != nil {
return false, err
}
count++
if ms != nil {
ms.SysBytes += keyBytes + valBytes
ms.SysCount++
}
return false, nil
})
return count, err
}
func (r *rocksDBIterator) ComputeStats(start, end MVCCKey, nowNanos int64) (enginepb.MVCCStats, error) {
result := C.MVCCComputeStats(r.iter, goToCKey(start), goToCKey(end), C.int64_t(nowNanos))
ms := enginepb.MVCCStats{}
if err := statusToError(result.status); err != nil {
return ms, err
}
ms.ContainsEstimates = false
ms.LiveBytes = int64(result.live_bytes)
ms.KeyBytes = int64(result.key_bytes)
ms.ValBytes = int64(result.val_bytes)
ms.IntentBytes = int64(result.intent_bytes)
ms.LiveCount = int64(result.live_count)
ms.KeyCount = int64(result.key_count)
ms.ValCount = int64(result.val_count)
ms.IntentCount = int64(result.intent_count)
ms.IntentAge = int64(result.intent_age)
ms.GCBytesAge = int64(result.gc_bytes_age)
ms.SysBytes = int64(result.sys_bytes)
ms.SysCount = int64(result.sys_count)
ms.LastUpdateNanos = nowNanos
return ms, nil
}
// TestStoreRangeSplitStats starts by splitting the system keys from user-space
// keys and verifying that the user space side of the split (which is empty),
// has all zeros for stats. It then writes random data to the user space side,
// splits it halfway and verifies the two splits have stats exactly equaling
// the pre-split.
func TestStoreRangeSplitStats(t *testing.T) {
defer leaktest.AfterTest(t)()
defer config.TestingDisableTableSplits()()
store, stopper, manual := createTestStore(t)
defer stopper.Stop()
// Split the range after the last table data key.
keyPrefix := keys.MakeTablePrefix(keys.MaxReservedDescID + 1)
keyPrefix = keys.MakeRowSentinelKey(keyPrefix)
args := adminSplitArgs(roachpb.KeyMin, keyPrefix)
if _, pErr := client.SendWrapped(rg1(store), nil, &args); pErr != nil {
t.Fatal(pErr)
}
// Verify empty range has empty stats.
rng := store.LookupReplica(keyPrefix, nil)
// NOTE that this value is expected to change over time, depending on what
// we store in the sys-local keyspace. Update it accordingly for this test.
if err := verifyRangeStats(store.Engine(), rng.RangeID, enginepb.MVCCStats{LastUpdateNanos: manual.UnixNano()}); err != nil {
t.Fatal(err)
}
// Write random data.
writeRandomDataToRange(t, store, rng.RangeID, keyPrefix)
// Get the range stats now that we have data.
snap := store.Engine().NewSnapshot()
defer snap.Close()
var ms enginepb.MVCCStats
if err := engine.MVCCGetRangeStats(context.Background(), snap, rng.RangeID, &ms); err != nil {
t.Fatal(err)
}
if err := verifyRecomputedStats(snap, rng.Desc(), ms, manual.UnixNano()); err != nil {
t.Fatalf("failed to verify range's stats before split: %v", err)
}
if inMemMS := rng.GetMVCCStats(); inMemMS != ms {
t.Fatalf("in-memory and on-disk diverged:\n%+v\n!=\n%+v", inMemMS, ms)
}
manual.Increment(100)
// Split the range at approximate halfway point ("Z" in string "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz").
midKey := append([]byte(nil), keyPrefix...)
midKey = append(midKey, []byte("Z")...)
midKey = keys.MakeRowSentinelKey(midKey)
args = adminSplitArgs(keyPrefix, midKey)
if _, pErr := client.SendWrappedWith(rg1(store), nil, roachpb.Header{
RangeID: rng.RangeID,
}, &args); pErr != nil {
t.Fatal(pErr)
}
snap = store.Engine().NewSnapshot()
defer snap.Close()
var msLeft, msRight enginepb.MVCCStats
if err := engine.MVCCGetRangeStats(context.Background(), snap, rng.RangeID, &msLeft); err != nil {
t.Fatal(err)
}
rngRight := store.LookupReplica(midKey, nil)
if err := engine.MVCCGetRangeStats(context.Background(), snap, rngRight.RangeID, &msRight); err != nil {
t.Fatal(err)
}
// The stats should be exactly equal when added.
expMS := enginepb.MVCCStats{
LiveBytes: msLeft.LiveBytes + msRight.LiveBytes,
KeyBytes: msLeft.KeyBytes + msRight.KeyBytes,
ValBytes: msLeft.ValBytes + msRight.ValBytes,
IntentBytes: msLeft.IntentBytes + msRight.IntentBytes,
LiveCount: msLeft.LiveCount + msRight.LiveCount,
KeyCount: msLeft.KeyCount + msRight.KeyCount,
ValCount: msLeft.ValCount + msRight.ValCount,
IntentCount: msLeft.IntentCount + msRight.IntentCount,
}
ms.SysBytes, ms.SysCount = 0, 0
ms.LastUpdateNanos = 0
if expMS != ms {
t.Errorf("expected left plus right ranges to equal original, but\n %+v\n+\n %+v\n!=\n %+v", msLeft, msRight, ms)
}
// Stats should both have the new timestamp.
now := manual.UnixNano()
if lTs := msLeft.LastUpdateNanos; lTs != now {
t.Errorf("expected left range stats to have new timestamp, want %d, got %d", now, lTs)
}
if rTs := msRight.LastUpdateNanos; rTs != now {
t.Errorf("expected right range stats to have new timestamp, want %d, got %d", now, rTs)
}
// Stats should agree with recomputation.
if err := verifyRecomputedStats(snap, rng.Desc(), msLeft, now); err != nil {
t.Fatalf("failed to verify left range's stats after split: %v", err)
}
if err := verifyRecomputedStats(snap, rngRight.Desc(), msRight, now); err != nil {
t.Fatalf("failed to verify right range's stats after split: %v", err)
}
}