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EstimatedNumKeys Counter Inaccurate

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This commit is contained in:
SherlockNoMad 2015-12-07 10:51:08 -08:00
parent a9ca9107b9
commit 355fa94365
3 changed files with 36 additions and 11 deletions
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3
db/version_builder.cc
View file

@ -338,7 +338,8 @@ class VersionBuilder::Rep {
void MaybeAddFile(VersionStorageInfo* vstorage, int level, FileMetaData* f) {
if (levels_[level].deleted_files.count(f->fd.GetNumber()) > 0) {
// File is deleted: do nothing
// f is to-be-delected table file
vstorage->RemoveCurrentStats(f);
} else {
vstorage->AddFile(level, f, info_log_);
}

33
db/version_set.cc
View file

@ -738,24 +738,24 @@ uint64_t VersionStorageInfo::GetEstimatedActiveKeys() const {
// (2) keys are directly overwritten
// (3) deletion on non-existing keys
// (4) low number of samples
if (num_samples_ == 0) {
if (current_num_samples_ == 0) {
return 0;
}
if (accumulated_num_non_deletions_ <= accumulated_num_deletions_) {
if (current_num_non_deletions_ <= current_num_deletions_) {
return 0;
}
uint64_t est = accumulated_num_non_deletions_ - accumulated_num_deletions_;
uint64_t est = current_num_non_deletions_ - current_num_deletions_;
uint64_t file_count = 0;
for (int level = 0; level < num_levels_; ++level) {
file_count += files_[level].size();
}
if (num_samples_ < file_count) {
if (current_num_samples_ < file_count) {
// casting to avoid overflowing
return (est * static_cast<double>(file_count) / num_samples_);
return (est * static_cast<double>(file_count) / current_num_samples_);
} else {
return est;
}
@ -826,7 +826,9 @@ VersionStorageInfo::VersionStorageInfo(
accumulated_raw_value_size_(0),
accumulated_num_non_deletions_(0),
accumulated_num_deletions_(0),
num_samples_(0),
current_num_non_deletions_(0),
current_num_deletions_(0),
current_num_samples_(0),
estimated_compaction_needed_bytes_(0),
finalized_(false) {
if (ref_vstorage != nullptr) {
@ -836,7 +838,9 @@ VersionStorageInfo::VersionStorageInfo(
accumulated_num_non_deletions_ =
ref_vstorage->accumulated_num_non_deletions_;
accumulated_num_deletions_ = ref_vstorage->accumulated_num_deletions_;
num_samples_ = ref_vstorage->num_samples_;
current_num_non_deletions_ = ref_vstorage->current_num_non_deletions_;
current_num_deletions_ = ref_vstorage->current_num_deletions_;
current_num_samples_ = ref_vstorage->current_num_samples_;
}
}
@ -993,7 +997,20 @@ void VersionStorageInfo::UpdateAccumulatedStats(FileMetaData* file_meta) {
accumulated_num_non_deletions_ +=
file_meta->num_entries - file_meta->num_deletions;
accumulated_num_deletions_ += file_meta->num_deletions;
num_samples_++;
current_num_non_deletions_ +=
file_meta->num_entries - file_meta->num_deletions;
current_num_deletions_ += file_meta->num_deletions;
current_num_samples_++;
}
void VersionStorageInfo::RemoveCurrentStats(FileMetaData* file_meta) {
if (file_meta->init_stats_from_file) {
current_num_non_deletions_ -=
file_meta->num_entries - file_meta->num_deletions;
current_num_deletions_ -= file_meta->num_deletions;
current_num_samples_--;
}
}
void Version::UpdateAccumulatedStats(bool update_stats) {

11
db/version_set.h
View file

@ -111,6 +111,9 @@ class VersionStorageInfo {
// Update the accumulated stats from a file-meta.
void UpdateAccumulatedStats(FileMetaData* file_meta);
// Decrease the current stat form a to-be-delected file-meta
void RemoveCurrentStats(FileMetaData* file_meta);
void ComputeCompensatedSizes();
// Updates internal structures that keep track of compaction scores
@ -400,8 +403,12 @@ class VersionStorageInfo {
uint64_t accumulated_num_non_deletions_;
// total number of deletion entries
uint64_t accumulated_num_deletions_;
// the number of samples
uint64_t num_samples_;
// current number of non_deletion entries
uint64_t current_num_non_deletions_;
// current number of delection entries
uint64_t current_num_deletions_;
// current number of file samples
uint64_t current_num_samples_;
// Estimated bytes needed to be compacted until all levels' size is down to
// target sizes.
uint64_t estimated_compaction_needed_bytes_;