Add last level and non-last level read statistics #9519
Conversation
jay-zhuang
changed the title
|
@jay-zhuang has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
file/random_access_file_reader.cc
Outdated
| @@ -276,6 +276,13 @@ IOStatus RandomAccessFileReader::Read(const IOOptions& opts, uint64_t offset, | |||
| IOStatsAddCountByTemperature(file_temperature_, 1); | |||
| StatisticAddBytesByTemperature(stats_, file_temperature_, result->size()); | |||
| StatisticAddCountByTemperature(stats_, file_temperature_, 1); | |||
| if (is_last_level_) { | |||
There was a problem hiding this comment.
I don't like this if. This will create branch misprediction in a critical path. Although this is unlikely to be the bottleneck but small things might add up. Is it possible to remember the two tick names when creating RandomAccessFileReader?
There was a problem hiding this comment.
It's actually the same as the temperature checks above. I'll see if we can optimize them.
There was a problem hiding this comment.
I updated that part a little bit, basically grouping the temperature checking, which reduced the temperature if checking 3 times even when it's not enabled. I added a microbenchmark test, which shows the performance is even improved when statistics not enabled:
Main: 255ns
With fix: 252ns
Old fix: 256ns
When statistics is enabled, the time is increased because more statistics recording, which is unavoidable for more statistics:
Main: 340ns
With fix: 370ns
Old fix: 374ns
Benchmark command:
$ DEBUG_LEVEL=0 make db_basic_bench
$ ./db_basic_bench --benchmark_filter=RandomAccessFileReaderRead --benchmark_repetitions=50
bac3887
to
b09e1e1
Compare
|
@jay-zhuang has updated the pull request. You must reimport the pull request before landing. |
jay-zhuang
force-pushed
the
level_info
branch
from
b09e1e1
to
b3201f9
Compare
|
@jay-zhuang has updated the pull request. You must reimport the pull request before landing. |
1 similar comment
|
@jay-zhuang has updated the pull request. You must reimport the pull request before landing. |
file/random_access_file_reader.cc
Outdated
| RecordTick(stats, LAST_LEVEL_READ_COUNT, 1); | ||
| } else { | ||
| RecordTick(stats, NON_LAST_LEVEL_READ_BYTES, size); | ||
| RecordTick(stats, NON_LAST_LEVEL_READ_COUNT, 1); |
There was a problem hiding this comment.
nit: I think it is more commonly recoreded compared to temperature, so it might make sense to move it up.
file/random_access_file_reader.cc
Outdated
| if (stats == nullptr || file_temperature == Temperature::kUnknown) { | ||
| return; | ||
| inline void RecordStats(Statistics* stats, Temperature file_temperature, | ||
| bool is_last_level, size_t size) { |
There was a problem hiding this comment.
Perhaps call it something like RecordIOStats() or something like that so that size can be more obvious to be read size from the file.
jay-zhuang
force-pushed
the
level_info
branch
from
53797c8
to
bea844f
Compare
|
@jay-zhuang has updated the pull request. You must reimport the pull request before landing. |
1 similar comment
|
@jay-zhuang has updated the pull request. You must reimport the pull request before landing. |
jay-zhuang
force-pushed
the
level_info
branch
from
8a9e6a9
to
58da985
Compare
|
@jay-zhuang has updated the pull request. You must reimport the pull request before landing. |
|
@jay-zhuang has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
Summary: Add last level and non-last level read statistics:
Test Plan: added unittest