compact: Exclude last block with shortest range instead of newest one by ULID.

Fixes https://github.com/prometheus/prometheus/issues/3943 issue.

Added tests.

Signed-off-by: Bartek Plotka <bwplotka@gmail.com>
This commit is contained in:
Bartek Plotka 2018-03-13 12:30:27 +00:00
parent 16b2bf1b45
commit 483da43660
2 changed files with 94 additions and 15 deletions

View file

@ -151,16 +151,11 @@ func (c *LeveledCompactor) Plan(dir string) ([]string, error) {
if err != nil {
return nil, err
}
// We do not include the most recently created block. This gives users a window
// of a full block size to piece-wise backup new data without having to care
// about data overlap.
if len(dirs) < 1 {
return nil, nil
}
dirs = dirs[:len(dirs)-1]
var dms []dirMeta
for _, dir := range dirs {
meta, err := readMetaFile(dir)
if err != nil {
@ -172,6 +167,10 @@ func (c *LeveledCompactor) Plan(dir string) ([]string, error) {
}
func (c *LeveledCompactor) plan(dms []dirMeta) ([]string, error) {
// We do not include the most recently created block with the shortest range (the block which was just created from WAL).
// This gives users a window of a full block size to piece-wise backup new data without having to care about data overlap.
dms = excludeFreshMeta(dms)
sort.Slice(dms, func(i, j int) bool {
return dms[i].meta.MinTime < dms[j].meta.MinTime
})
@ -199,6 +198,20 @@ func (c *LeveledCompactor) plan(dms []dirMeta) ([]string, error) {
return nil, nil
}
// excludeFreshMeta removes newest block with the shortest range from given meta files.
func excludeFreshMeta(dms []dirMeta) []dirMeta {
sort.Slice(dms, func(i, j int) bool {
leftRange := dms[i].meta.MaxTime - dms[i].meta.MinTime
rightRange := dms[j].meta.MaxTime - dms[j].meta.MinTime
if leftRange == rightRange {
return dms[i].meta.MinTime < dms[j].meta.MinTime
}
return leftRange > rightRange
})
return dms[:len(dms)-1]
}
// selectDirs returns the dir metas that should be compacted into a single new block.
// If only a single block range is configured, the result is always nil.
func (c *LeveledCompactor) selectDirs(ds []dirMeta) []dirMeta {

View file

@ -172,8 +172,7 @@ func TestLeveledCompactor_plan(t *testing.T) {
},
expected: nil,
},
// We should wait for a third block of size 20 to appear before compacting
// the existing ones.
// We should wait for four blocks of size 20 to appear before compacting.
{
metas: []dirMeta{
metaRange("1", 0, 20, nil),
@ -181,26 +180,49 @@ func TestLeveledCompactor_plan(t *testing.T) {
},
expected: nil,
},
// We should wait for a next block of size 20 to appear before compacting
// the existing ones. We have three, but we ignore the fresh one with shortest range.
{
metas: []dirMeta{
metaRange("1", 0, 20, nil),
metaRange("2", 20, 40, nil),
metaRange("3", 40, 60, nil),
},
expected: nil,
},
// Block to fill the entire parent range appeared should be compacted.
{
metas: []dirMeta{
metaRange("1", 0, 20, nil),
metaRange("2", 20, 40, nil),
metaRange("3", 40, 60, nil),
metaRange("4", 60, 80, nil),
},
expected: []string{"1", "2", "3"},
},
// Block for the next parent range appeared. Nothing will happen in the first one
// anymore and we should compact it.
// Block for the next parent range appeared with gap with size 20. Nothing will happen in the first one
// anymore but we ignore fresh one still, so no compaction.
{
metas: []dirMeta{
metaRange("1", 0, 20, nil),
metaRange("2", 20, 40, nil),
metaRange("3", 60, 80, nil),
},
expected: nil,
},
// Block for the next parent range appeared, and we have a gap with size 20 between second and third block.
// We will not get this missed gap anymore and we should compact just these two.
{
metas: []dirMeta{
metaRange("1", 0, 20, nil),
metaRange("2", 20, 40, nil),
metaRange("3", 60, 80, nil),
metaRange("4", 80, 100, nil),
},
expected: []string{"1", "2"},
},
{
// We have 20, 20, 20, 60, 60 range blocks. "3" is marked as fresh one, so we ignore it during compaction.
metas: []dirMeta{
metaRange("1", 0, 20, nil),
metaRange("2", 20, 40, nil),
@ -208,27 +230,54 @@ func TestLeveledCompactor_plan(t *testing.T) {
metaRange("4", 60, 120, nil),
metaRange("5", 120, 180, nil),
},
expected: []string{"1", "2", "3"},
expected: []string{"1", "2"},
},
{
// We have 20, 60, 60, 240 range blocks. We can compact 60 + 60 only, because the newest one with the
// shortest range is not included in planning (4).
metas: []dirMeta{
metaRange("2", 20, 40, nil),
metaRange("4", 60, 120, nil),
metaRange("5", 120, 180, nil),
metaRange("6", 720, 960, nil),
},
expected: []string{"4", "5"},
},
{
// We got fresh block if size 20. We can compact 20 + 60 + 60.
metas: []dirMeta{
metaRange("2", 20, 40, nil),
metaRange("4", 60, 120, nil),
metaRange("5", 120, 180, nil),
metaRange("6", 720, 960, nil),
metaRange("7", 960, 980, nil),
},
expected: []string{"2", "4", "5"},
},
{
// We have 60, 20, 20, 20 range blocks.
// Fresh block with shortest range block is ignored (6), so nothing can be compacted.
metas: []dirMeta{
metaRange("1", 0, 60, nil),
metaRange("4", 60, 80, nil),
metaRange("5", 80, 100, nil),
metaRange("6", 100, 120, nil),
},
expected: nil,
},
{
// We have 60, 20, 20, 20, 20 range blocks.
// Fresh block with shortest range block is ignored but compaction 20 + 20 + 20 is possible.
metas: []dirMeta{
metaRange("1", 0, 60, nil),
metaRange("4", 60, 80, nil),
metaRange("5", 80, 100, nil),
metaRange("6", 100, 120, nil),
metaRange("6", 120, 140, nil),
},
expected: []string{"4", "5", "6"},
},
// Select large blocks that have many tombstones.
// Do not select large blocks that have many tombstones when there is no fresh block.
{
metas: []dirMeta{
metaRange("1", 0, 720, &BlockStats{
@ -236,15 +285,27 @@ func TestLeveledCompactor_plan(t *testing.T) {
NumTombstones: 3,
}),
},
expected: nil,
},
// Select large blocks that have many tombstones when fresh appears.
{
metas: []dirMeta{
metaRange("1", 0, 720, &BlockStats{
NumSeries: 10,
NumTombstones: 3,
}),
metaRange("2", 720, 740, nil),
},
expected: []string{"1"},
},
// For small blocks, do not compact tombstones.
// For small blocks, do not compact tombstones, even when fresh appears.
{
metas: []dirMeta{
metaRange("1", 0, 30, &BlockStats{
NumSeries: 10,
NumTombstones: 3,
}),
metaRange("2", 720, 740, nil),
},
expected: nil,
},
@ -256,16 +317,21 @@ func TestLeveledCompactor_plan(t *testing.T) {
NumSeries: 0,
NumTombstones: 0,
}),
metaRange("2", 720, 740, nil),
},
expected: nil,
},
}
for _, c := range cases {
res, err := compactor.plan(c.metas)
testutil.Ok(t, err)
if !t.Run("", func(t *testing.T) {
res, err := compactor.plan(c.metas)
testutil.Ok(t, err)
testutil.Equals(t, c.expected, res)
testutil.Equals(t, c.expected, res)
}) {
return
}
}
}