Summary: Provide a way for users to know more detailed ditribution of a histogram metrics. Example outputs: Manually add statement fprintf(stdout, "%s\n", dbstats->getHistogramString(SST_READ_MICROS).c_str()); Will print out something like: Count: 989151 Average: 1.7659 StdDev: 1.52 Min: 0.0000 Median: 1.2071 Max: 860.0000 Percentiles: P50: 1.21 P75: 1.70 P99: 5.12 P99.9: 13.67 P99.99: 21.70 ------------------------------------------------------ [ 0, 1 ) 390839 39.513% 39.513% ######## [ 1, 2 ) 500918 50.641% 90.154% ########## [ 2, 3 ) 79358 8.023% 98.177% ## [ 3, 4 ) 6297 0.637% 98.813% [ 4, 5 ) 1712 0.173% 98.986% [ 5, 6 ) 1134 0.115% 99.101% [ 6, 7 ) 1222 0.124% 99.224% [ 7, 8 ) 1529 0.155% 99.379% [ 8, 9 ) 1264 0.128% 99.507% [ 9, 10 ) 988 0.100% 99.607% [ 10, 12 ) 1378 0.139% 99.746% [ 12, 14 ) 1828 0.185% 99.931% [ 14, 16 ) 410 0.041% 99.972% [ 16, 18 ) 72 0.007% 99.980% [ 18, 20 ) 67 0.007% 99.986% [ 20, 25 ) 106 0.011% 99.997% [ 25, 30 ) 24 0.002% 99.999% [ 30, 35 ) 1 0.000% 100.000% [ 250, 300 ) 2 0.000% 100.000% [ 300, 350 ) 1 0.000% 100.000% [ 800, 900 ) 1 0.000% 100.000% Test Plan: Manually add a print in db_bench and make sure it prints out as expected. Will add some codes to cover the function Subscribers: leveldb, dhruba Differential Revision: https://reviews.facebook.net/D43611 |
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arcanist_util | ||
build_tools | ||
coverage | ||
db | ||
doc | ||
examples | ||
hdfs | ||
include/rocksdb | ||
java | ||
port | ||
table | ||
third-party | ||
tools | ||
util | ||
utilities | ||
.arcconfig | ||
.clang-format | ||
.gitignore | ||
.travis.yml | ||
AUTHORS | ||
CMakeLists.txt | ||
CONTRIBUTING.md | ||
DUMP_FORMAT.md | ||
HISTORY.md | ||
INSTALL.md | ||
LICENSE | ||
Makefile | ||
PATENTS | ||
README.md | ||
ROCKSDB_LITE.md | ||
src.mk | ||
thirdparty.inc | ||
USERS.md | ||
Vagrantfile | ||
WINDOWS_PORT.md |
RocksDB: A Persistent Key-Value Store for Flash and RAM Storage
RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)
This code is a library that forms the core building block for a fast key value server, especially suited for storing data on flash drives. It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF) and Space-Amplification-Factor (SAF). It has multi-threaded compactions, making it specially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/master/examples
See the github wiki for more explanation.
The public interface is in include/
. Callers should not include or
rely on the details of any other header files in this package. Those
internal APIs may be changed without warning.
Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/