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Ignore max_compaction_bytes for compaction input that are within output key-range (#10835)

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Summary:
When picking compaction input files, we sometimes stop picking a file that is fully included in the output key-range due to hitting max_compaction_bytes. Including these input files can potentially reduce WA at the expense of larger compactions. Larger compaction should be fine as files from input level are usually 10X smaller than files from output level. This PR adds a mutable CF option `ignore_max_compaction_bytes_for_input` that is enabled by default. We can remove this option once we are sure it is safe.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10835

Test Plan:
- CI, a unit test on max_compaction_bytes fails before turning this flag off.
- Benchmark does not show much difference in WA: `./db_bench --benchmarks=fillrandom,waitforcompaction,stats,levelstats -max_background_jobs=12 -num=2000000000 -target_file_size_base=33554432 --write_buffer_size=33554432`
```
main:
** Compaction Stats [default] **
Level    Files   Size     Score Read(GB)  Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) Moved(GB) W-Amp Rd(MB/s) Wr(MB/s) Comp(sec) CompMergeCPU(sec) Comp(cnt) Avg(sec) KeyIn KeyDrop Rblob(GB) Wblob(GB)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  L0      3/0   91.59 MB   0.8     70.9     0.0     70.9     200.8    129.9       0.0   1.5     25.2     71.2   2886.55           2463.45      9725    0.297   1093M   254K       0.0       0.0
  L1      9/0   248.03 MB   1.0    392.0   129.8    262.2     391.7    129.5       0.0   3.0     69.0     68.9   5821.71           5536.90       804    7.241   6029M  5814K       0.0       0.0
  L2     87/0    2.50 GB   1.0    537.0   128.5    408.5     533.8    125.2       0.7   4.2     69.5     69.1   7912.24           7323.70      4417    1.791   8299M    36M       0.0       0.0
  L3    836/0   24.99 GB   1.0    616.9   118.3    498.7     594.5     95.8       5.2   5.0     66.9     64.5   9442.38           8490.28      4204    2.246   9749M   306M       0.0       0.0
  L4   2355/0   62.95 GB   0.3     67.3    37.1     30.2      54.2     24.0      38.9   1.5     72.2     58.2    954.37            821.18       917    1.041   1076M   173M       0.0       0.0
 Sum   3290/0   90.77 GB   0.0   1684.2   413.7   1270.5    1775.0    504.5      44.9  13.7     63.8     67.3  27017.25          24635.52     20067    1.346     26G   522M       0.0       0.0

Cumulative compaction: 1774.96 GB write, 154.29 MB/s write, 1684.19 GB read, 146.40 MB/s read, 27017.3 seconds

This PR:
** Compaction Stats [default] **
Level    Files   Size     Score Read(GB)  Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) Moved(GB) W-Amp Rd(MB/s) Wr(MB/s) Comp(sec) CompMergeCPU(sec) Comp(cnt) Avg(sec) KeyIn KeyDrop Rblob(GB) Wblob(GB)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  L0      3/0   45.71 MB   0.8     72.9     0.0     72.9     202.8    129.9       0.0   1.6     25.4     70.7   2938.16           2510.36      9741    0.302   1124M   265K       0.0       0.0
  L1      8/0   234.54 MB   0.9    384.5   129.8    254.7     384.2    129.6       0.0   3.0     69.0     68.9   5708.08           5424.43       791    7.216   5913M  5753K       0.0       0.0
  L2     84/0    2.47 GB   1.0    543.1   128.6    414.5     539.9    125.4       0.7   4.2     69.6     69.2   7989.31           7403.13      4418    1.808   8393M    36M       0.0       0.0
  L3    839/0   24.96 GB   1.0    615.6   118.4    497.2     593.2     96.0       5.1   5.0     66.6     64.1   9471.23           8489.31      4193    2.259   9726M   306M       0.0       0.0
  L4   2360/0   63.04 GB   0.3     67.6    37.3     30.3      54.4     24.1      38.9   1.5     71.5     57.6    967.30            827.99       907    1.066   1080M   173M       0.0       0.0
 Sum   3294/0   90.75 GB   0.0   1683.8   414.2   1269.6    1774.5    504.9      44.8  13.7     63.7     67.1  27074.08          24655.22     20050    1.350     26G   522M       0.0       0.0

Cumulative compaction: 1774.52 GB write, 157.09 MB/s write, 1683.77 GB read, 149.06 MB/s read, 27074.1 seconds
```

Reviewed By: ajkr

Differential Revision: D40518319

Pulled By: cbi42

fbshipit-source-id: f4ea614bc0ebefe007ffaf05bb9aec9a8ca25b60
main
Changyu Bi 2 years ago committed by Facebook GitHub Bot
parent 8dd4bf6cff
commit 333abe9c55
9 changed files with 37 additions and 2 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 1
      HISTORY.md
  2. 6
      db/compaction/compaction_picker.cc
  3. 3
      db/compaction/compaction_picker_test.cc
  4. 11
      include/rocksdb/advanced_options.h
  5. 7
      options/cf_options.cc
  6. 4
      options/cf_options.h
  7. 4
      options/options.cc
  8. 2
      options/options_helper.cc
  9. 1
      options/options_settable_test.cc

1
HISTORY.md
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@ -8,6 +8,7 @@
* FIFO compaction now supports migrating from a multi-level DB via DB::Open(). During the migration phase, FIFO compaction picker will:
* picks the sst file with the smallest starting key in the bottom-most non-empty level.
* Note that during the migration phase, the file purge order will only be an approximation of "FIFO" as files in lower-level might sometime contain newer keys than files in upper-level.
* Added an option `ignore_max_compaction_bytes_for_input` to ignore max_compaction_bytes limit when adding files to be compacted from input level. This should help reduce write amplification. The option is enabled by default.
### Bug Fixes
* Fix a bug in io_uring_prep_cancel in AbortIO API for posix which expects sqe->addr to match with read request submitted and wrong paramter was being passed.

6
db/compaction/compaction_picker.cc
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@ -526,7 +526,8 @@ bool CompactionPicker::SetupOtherInputs(
try_overlapping_inputs = false;
}
if (try_overlapping_inputs && expanded_inputs.size() > inputs->size() &&
output_level_inputs_size + expanded_inputs_size < limit &&
(mutable_cf_options.ignore_max_compaction_bytes_for_input ||
output_level_inputs_size + expanded_inputs_size < limit) &&
!AreFilesInCompaction(expanded_inputs.files)) {
InternalKey new_start, new_limit;
GetRange(expanded_inputs, &new_start, &new_limit);
@ -549,7 +550,8 @@ bool CompactionPicker::SetupOtherInputs(
base_index, nullptr);
expanded_inputs_size = TotalFileSize(expanded_inputs.files);
if (expanded_inputs.size() > inputs->size() &&
output_level_inputs_size + expanded_inputs_size < limit &&
(mutable_cf_options.ignore_max_compaction_bytes_for_input ||
output_level_inputs_size + expanded_inputs_size < limit) &&
!AreFilesInCompaction(expanded_inputs.files)) {
expand_inputs = true;
}

3
db/compaction/compaction_picker_test.cc
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@ -1340,6 +1340,7 @@ TEST_F(CompactionPickerTest, CompactionPriMinOverlapping4) {
ioptions_.compaction_pri = kMinOverlappingRatio;
mutable_cf_options_.max_bytes_for_level_base = 10000000;
mutable_cf_options_.max_bytes_for_level_multiplier = 10;
mutable_cf_options_.ignore_max_compaction_bytes_for_input = false;
// file 7 and 8 over lap with the same file, but file 8 is smaller so
// it will be picked.
@ -2358,6 +2359,7 @@ TEST_F(CompactionPickerTest, IsBottommostLevelTest) {
TEST_F(CompactionPickerTest, MaxCompactionBytesHit) {
mutable_cf_options_.max_bytes_for_level_base = 1000000u;
mutable_cf_options_.max_compaction_bytes = 800000u;
mutable_cf_options_.ignore_max_compaction_bytes_for_input = false;
ioptions_.level_compaction_dynamic_level_bytes = false;
NewVersionStorage(6, kCompactionStyleLevel);
// A compaction should be triggered and pick file 2 and 5.
@ -2384,6 +2386,7 @@ TEST_F(CompactionPickerTest, MaxCompactionBytesHit) {
TEST_F(CompactionPickerTest, MaxCompactionBytesNotHit) {
mutable_cf_options_.max_bytes_for_level_base = 800000u;
mutable_cf_options_.max_compaction_bytes = 1000000u;
mutable_cf_options_.ignore_max_compaction_bytes_for_input = false;
ioptions_.level_compaction_dynamic_level_bytes = false;
NewVersionStorage(6, kCompactionStyleLevel);
// A compaction should be triggered and pick file 2 and 5.

11
include/rocksdb/advanced_options.h
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@ -684,6 +684,17 @@ struct AdvancedColumnFamilyOptions {
// Dynamically changeable through SetOptions() API
uint64_t max_compaction_bytes = 0;
// When setting up compaction input files, we ignore the
// `max_compaction_bytes` limit when pulling in input files that are entirely
// within output key range.
//
// Default: true
//
// Dynamically changeable through SetOptions() API
// We could remove this knob and always ignore the limit once it is proven
// safe.
bool ignore_max_compaction_bytes_for_input = true;
// All writes will be slowed down to at least delayed_write_rate if estimated
// bytes needed to be compaction exceed this threshold.
//

7
options/cf_options.cc
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@ -270,6 +270,11 @@ static std::unordered_map<std::string, OptionTypeInfo>
{offsetof(struct MutableCFOptions, max_compaction_bytes),
OptionType::kUInt64T, OptionVerificationType::kNormal,
OptionTypeFlags::kMutable}},
{"ignore_max_compaction_bytes_for_input",
{offsetof(struct MutableCFOptions,
ignore_max_compaction_bytes_for_input),
OptionType::kBoolean, OptionVerificationType::kNormal,
OptionTypeFlags::kMutable}},
{"expanded_compaction_factor",
{0, OptionType::kInt, OptionVerificationType::kDeprecated,
OptionTypeFlags::kMutable}},
@ -1034,6 +1039,8 @@ void MutableCFOptions::Dump(Logger* log) const {
level0_stop_writes_trigger);
ROCKS_LOG_INFO(log, " max_compaction_bytes: %" PRIu64,
max_compaction_bytes);
ROCKS_LOG_INFO(log, " ignore_max_compaction_bytes_for_input: %s",
ignore_max_compaction_bytes_for_input ? "true" : "false");
ROCKS_LOG_INFO(log, " target_file_size_base: %" PRIu64,
target_file_size_base);
ROCKS_LOG_INFO(log, " target_file_size_multiplier: %d",

4
options/cf_options.h
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@ -130,6 +130,8 @@ struct MutableCFOptions {
level0_slowdown_writes_trigger(options.level0_slowdown_writes_trigger),
level0_stop_writes_trigger(options.level0_stop_writes_trigger),
max_compaction_bytes(options.max_compaction_bytes),
ignore_max_compaction_bytes_for_input(
options.ignore_max_compaction_bytes_for_input),
target_file_size_base(options.target_file_size_base),
target_file_size_multiplier(options.target_file_size_multiplier),
max_bytes_for_level_base(options.max_bytes_for_level_base),
@ -192,6 +194,7 @@ struct MutableCFOptions {
level0_slowdown_writes_trigger(0),
level0_stop_writes_trigger(0),
max_compaction_bytes(0),
ignore_max_compaction_bytes_for_input(true),
target_file_size_base(0),
target_file_size_multiplier(0),
max_bytes_for_level_base(0),
@ -273,6 +276,7 @@ struct MutableCFOptions {
int level0_slowdown_writes_trigger;
int level0_stop_writes_trigger;
uint64_t max_compaction_bytes;
bool ignore_max_compaction_bytes_for_input;
uint64_t target_file_size_base;
int target_file_size_multiplier;
uint64_t max_bytes_for_level_base;

4
options/options.cc
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@ -71,6 +71,8 @@ AdvancedColumnFamilyOptions::AdvancedColumnFamilyOptions(const Options& options)
max_bytes_for_level_multiplier_additional(
options.max_bytes_for_level_multiplier_additional),
max_compaction_bytes(options.max_compaction_bytes),
ignore_max_compaction_bytes_for_input(
options.ignore_max_compaction_bytes_for_input),
soft_pending_compaction_bytes_limit(
options.soft_pending_compaction_bytes_limit),
hard_pending_compaction_bytes_limit(
@ -281,6 +283,8 @@ void ColumnFamilyOptions::Dump(Logger* log) const {
ROCKS_LOG_HEADER(
log, " Options.max_compaction_bytes: %" PRIu64,
max_compaction_bytes);
ROCKS_LOG_HEADER(log, " Options.ignore_max_compaction_bytes_for_input: %s",
ignore_max_compaction_bytes_for_input ? "true" : "false");
ROCKS_LOG_HEADER(
log,
" Options.arena_block_size: %" ROCKSDB_PRIszt,

2
options/options_helper.cc
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@ -229,6 +229,8 @@ void UpdateColumnFamilyOptions(const MutableCFOptions& moptions,
moptions.level0_slowdown_writes_trigger;
cf_opts->level0_stop_writes_trigger = moptions.level0_stop_writes_trigger;
cf_opts->max_compaction_bytes = moptions.max_compaction_bytes;
cf_opts->ignore_max_compaction_bytes_for_input =
moptions.ignore_max_compaction_bytes_for_input;
cf_opts->target_file_size_base = moptions.target_file_size_base;
cf_opts->target_file_size_multiplier = moptions.target_file_size_multiplier;
cf_opts->max_bytes_for_level_base = moptions.max_bytes_for_level_base;

1
options/options_settable_test.cc
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@ -486,6 +486,7 @@ TEST_F(OptionsSettableTest, ColumnFamilyOptionsAllFieldsSettable) {
"max_write_buffer_number=84;"
"write_buffer_size=1653;"
"max_compaction_bytes=64;"
"ignore_max_compaction_bytes_for_input=true;"
"max_bytes_for_level_multiplier=60;"
"memtable_factory=SkipListFactory;"
"compression=kNoCompression;"

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