Summary: as title
Test Plan: build with mock_env_test.cc
Reviewers: sdong, yhchiang, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D28107
Summary:
This diff replaces BlockBasedTable in flush_job_test with TableMock, making it depend on less things and making it closer to an unit test than integration test.
It also introduces a framework to compile mock classes -- Any file named *mock.cc will not be compiled into the build. It will only get compiled into the tests. What way we can mock out most other classes, Version, VersionSet, DBImpl, etc.
Test Plan: flush_job_test
Reviewers: ljin, rven, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D27681
Summary: RocksDB already depends on C++11, so we might as well all the goodness that C++11 provides. This means that we don't need AtomicPointer anymore. The less things in port/, the easier it will be to port to other platforms.
Test Plan: make check + careful visual review verifying that NoBarried got memory_order_relaxed, while Acquire/Release methods got memory_order_acquire and memory_order_release
Reviewers: rven, yhchiang, ljin, sdong
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D27543
Summary:
Before this diff, there are two places with rocksdb versions. After the diff:
1. we only have one source of truth for rocksdb version
2. we have a script that we can use to get the version that we can use in other compilations (java, go, etc).
Test Plan: make
Reviewers: yhchiang, sdong, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D24333
Summary:
I put together a script to assist in the generation of deb's and
rpm's. I've tested that this works on ubuntu via vagrant. I've included the
Vagrantfile here, but I can remove it if it's not useful. The package.sh
script should work on any ubuntu or centos machine, I just added a bit of
logic in there to allow a base Ubuntu or Centos machine to be able to build
RocksDB from scratch.
Example output on Ubuntu 14.04:
```
root@vagrant-ubuntu-trusty-64:/vagrant# ./tools/package.sh
[+] g++-4.7 is already installed. skipping.
[+] libgflags-dev is already installed. skipping.
[+] ruby-all-dev is already installed. skipping.
[+] fpm is already installed. skipping.
Created package {:path=>"rocksdb_3.5_amd64.deb"}
root@vagrant-ubuntu-trusty-64:/vagrant# dpkg --info rocksdb_3.5_amd64.deb
new debian package, version 2.0.
size 17392022 bytes: control archive=1518 bytes.
275 bytes, 11 lines control
2911 bytes, 38 lines md5sums
Package: rocksdb
Version: 3.5
License: BSD
Vendor: Facebook
Architecture: amd64
Maintainer: rocksdb@fb.com
Installed-Size: 83358
Section: default
Priority: extra
Homepage: http://rocksdb.org/
Description: RocksDB is an embeddable persistent key-value store for fast storage.
```
Example output on CentOS 6.5:
```
[root@localhost vagrant]# rpm -qip rocksdb-3.5-1.x86_64.rpm
Name : rocksdb Relocations: /usr
Version : 3.5 Vendor: Facebook
Release : 1 Build Date: Mon 29 Sep 2014 01:26:11 AM UTC
Install Date: (not installed) Build Host: localhost
Group : default Source RPM: rocksdb-3.5-1.src.rpm
Size : 96231106 License: BSD
Signature : (none)
Packager : rocksdb@fb.com
URL : http://rocksdb.org/
Summary : RocksDB is an embeddable persistent key-value store for fast storage.
Description :
RocksDB is an embeddable persistent key-value store for fast storage.
```
Test Plan:
How this gets used is really up to the RocksDB core team. If you
want to actually get this into mainline, you might have to change `make
install` such that it install the RocksDB shared object file as well, which
would require you to link against gflags (maybe?) and that would require some
potential modifications to the script here (basically add a depends on that
package).
Currently, this will install the headers and a pre-compiled statically linked
object file. If that's what you want out of life, than this requires no
modifications.
Reviewers: ljin, yhchiang, igor
Reviewed By: igor
Differential Revision: https://reviews.facebook.net/D24141
Summary: I want to use open source build rather than fbcode one. This enables me to run `ROCKSDB_NO_FBCODE=1 make` and run it with my system g++.
Test Plan:
ROCKSDB_NO_FBCODE=1 make
make
Reviewers: sdong, ljin, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D23613
Summary:
That way we can see when this graph goes up and be happy.
Couple of changes:
1. title
2. fix db_bench to delete column families before deleting the DB. this was asserting when compiled in debug mode
3. don't sync manifest when disableDataSync. We discussed this offline. I can move it to separate diff if you'd like
Test Plan: ran it
Reviewers: sdong, yhchiang, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D22815
* Script for building the unity.cc file via Makefile
* Unity executable Makefile target for testing builds
* Source code changes to fix compilation of unity build
Summary:
Fixed some make and linking issues of RocksDBJava. Specifically:
* Add JAVA_LDFLAGS, which does not include gflags
* rocksdbjava library now uses JAVA_LDFLAGS instead of LDFLAGS
* java/Makefile now includes build_config.mk
* rearrange make rocksdbjava workflow to ensure the library file is correctly
included in the jar file.
Test Plan:
make rocksdbjava
make jdb_bench
java/jdb_bench.sh
Reviewers: dhruba, swapnilghike, zzbennett, rsumbaly, ankgup87
Reviewed By: ankgup87
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D20289
Summary:
Changes:
- Adding numa_aware flag to db_bench.cc
- Using numa.h library to bind memory and cpu of threads to a fixed NUMA node
Result: There seems to be no significant change in the micros/op time with numa_aware enabled. I also tried this with other implementations, including a combination of pthread_setaffinity_np, sched_setaffinity and set_mempolicy methods. It'd be great if someone could point out where I'm going wrong and if we can achieve a better micors/op.
Test Plan:
Ran db_bench tests using following command:
./db_bench --db=/mnt/tmp --num_levels=6 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --block_size=4096 --cache_size=17179869184 --cache_numshardbits=6 --compression_type=none --compression_ratio=1 --min_level_to_compress=-1 --disable_seek_compaction=1 --hard_rate_limit=2 --write_buffer_size=134217728 --max_write_buffer_number=2 --level0_file_num_compaction_trigger=8 --target_file_size_base=134217728 --max_bytes_for_level_base=1073741824 --disable_wal=0 --wal_dir=/mnt/tmp --sync=0 --disable_data_sync=1 --verify_checksum=1 --delete_obsolete_files_period_micros=314572800 --max_grandparent_overlap_factor=10 --max_background_compactions=4 --max_background_flushes=0 --level0_slowdown_writes_trigger=16 --level0_stop_writes_trigger=24 --statistics=0 --stats_per_interval=0 --stats_interval=1048576 --histogram=0 --use_plain_table=1 --open_files=-1 --mmap_read=1 --mmap_write=0 --memtablerep=prefix_hash --bloom_bits=10 --bloom_locality=1 --perf_level=0 --duration=300 --benchmarks=readwhilewriting --use_existing_db=1 --num=157286400 --threads=24 --writes_per_second=10240 --numa_aware=[False/True]
The tests were run in private devserver with 24 cores and the db was prepopulated using filluniquerandom test. The tests resulted in 0.145 us/op with numa_aware=False and 0.161 us/op with numa_aware=True.
Reviewers: sdong, yhchiang, ljin, igor
Reviewed By: ljin, igor
Subscribers: igor, leveldb
Differential Revision: https://reviews.facebook.net/D19353
Summary:
As discussed in our internal group, we don't get much use of seek compaction at the moment, while it's making code more complicated and slower in some cases.
This diff removes seek compaction and (hopefully) all code that was introduced to support seek compaction.
There is one test case that relied on didIO information. I'll try to find another way to implement it.
Test Plan: make check
Reviewers: sdong, haobo, yhchiang, ljin, dhruba
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19161
Summary:
collect in-memory workload get/seek metrics so that we can alert on
regression
Test Plan: ran locally
Reviewers: igor
Reviewed By: igor
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D18969
Summary:
388d2054c7
added extra line to db_bench output, breaking regression tests. This diff makes it more robust and fixes the issue
Test Plan: ran it
Reviewers: ljin, sdong
Reviewed By: sdong
Subscribers: sdong, leveldb
Differential Revision: https://reviews.facebook.net/D18897
Summary:
Newer gflags switched from `google` namespace to `gflags` namespace. See: https://github.com/facebook/rocksdb/issues/139 and https://github.com/facebook/rocksdb/issues/102
Unfortunately, they don't define any macro with their namespace, so we need to actually try to compile gflags with two different namespace to figure out which one is the correct one.
Test Plan: works in fbcode environemnt. I'll also try in ubutnu with newer gflags
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18537
Summary: We have a lot of problems with gflags. However, when compiling rocksdb static library, we don't need gflags dependency. Reorganize INSTALL.md such that first-time customers don't need any dependency installed to actually build rocksdb static library.
Test Plan: none
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18501
Summary:
There are some projects in fbcode that define lz4 dependency on r108. We, however, defined dependency on r117. That produced some interesting issues and our build system was not happy.
This diff makes rocksdb work with both r108 and r117. Hopefully this will fix our problems.
Test Plan: compiled rocksdb with both r108 and r117 lz4
Reviewers: dhruba, sdong, haobo
Reviewed By: sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18465
Summary: Added benchmark functionality on the lines of folly/Benchmark.h
Test Plan: Added unit tests
Reviewers: igor, haobo, sdong, ljin, yhchiang, dhruba
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17973
Summary:
Introducing RocksDBLite! Removes all the non-essential features and reduces the binary size. This effort should help our adoption on mobile.
Binary size when compiling for IOS (`TARGET_OS=IOS m static_lib`) is down to 9MB from 15MB (without stripping)
Test Plan: compiles :)
Reviewers: dhruba, haobo, ljin, sdong, yhchiang
Reviewed By: yhchiang
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17835
Summary:
I had to make number of changes to the code and Makefile:
* Add `make lib`, that will create static library without debug info. We need this to avoid growing binary too much. Currently it's 14MB.
* Remove cpuinfo() function and use __SSE4_2__ macro. We actually used the macro as part of Fast_CRC32() function.
As a result, I also accidentally fixed this issue: https://www.facebook.com/groups/rocksdb.dev/permalink/549700778461774/?stream_ref=2
* Remove __thread locals in OS_MACOSX
Test Plan: `make lib PLATFORM=IOS`
Reviewers: ljin, haobo, dhruba, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17475
Summary:
Added an option for readrandom benchmark to run with tailing iterator instead of Get. Benefit of tailing iterator is that it doesn't require locking DB mutex on access.
I also have some results when running on my machine. The results highly depend on number of cache shards. With our current benchmark setting of 4 table cache shards and 6 block cache shards, I don't see much improvements of using tailing iterator. In that case, we're probably seeing cache mutex contention.
Here are the results for different number of shards
cache shards tailing iterator get
6 1.38M 1.16M
10 1.58M 1.15M
As soon as we get rid of cache mutex contention, we're seeing big improvements in using tailing iterator vs. ordinary get.
Test Plan: ran regression test
Reviewers: dhruba, haobo, ljin, kailiu, sding
Reviewed By: haobo
CC: tnovak
Differential Revision: https://reviews.facebook.net/D15867
Summary: Change all occurrences of "rocksdb" to its canonical form "RocksDB".
Test Plan: N/A
Reviewers: igor
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15549
Summary:
* Add a change log for rocksdb releases.
* Remove the hacky parts of make_new_version.sh, which are either
no longer useful or will be done in our dedicated 3rd-party release
tool.
Test Plan: N/A
Reviewers: igor, haobo, sdong, dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15543
Summary:
It looks like we might have some trouble when building the new release with 4.8, since fbcode is using glibc2.17-fb by default and we are using glibc2.17. It was reported by Benjamin Renard in our internal group.
This diff moves our fbcode build to use glibc2.17-fb by default. I got some linker errors when compiling, complaining that `google::SetUsageMessage()` was undefined. After deleting all offending lines, the compile was successful and everything works.
Test Plan:
Compiled
Ran ./db_bench ./db_stress ./db_repl_stress
Reviewers: kailiu
Reviewed By: kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15405
Summary:
* make sure when some pre-check fails, the script won't halt immediately.
* change fburl to google's short url.
* Fix a bug in this script: now it checks the uncommitted code only.
Test Plan: Ran the script under differnet environments.
Reviewers: igor
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15231
Summary:
Added a script that reformat only the affected lines in a given diff.
I planned to make that file as pre-commit hook but looks it's a little bit more difficult than I thought. Since I don't want to spend too much time on this task right now, I eventually added a "make command" to achieve this with a few additional key strokes.
Also make the clang-format solely inherited from Google's style -- there are still debates on some of the style issues, but we can address them later once we reach a consensus.
Test Plan: Did some ugly format change and ran "make format", all affected lines are formatted as expected.
Reviewers: igor, sdong, haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15147
Summary:
Per request, some users need to use dynamic rocksdb library instead of static one.
However currently the dynamic libraries have to be manually compiled by default, which is inconvenient. I made dymamic libraries to be compiled by default.
Test Plan: make clean; make; make clean;
Reviewers: haobo, sdong, dhruba, igor
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15117
Summary:
Added readwhilewriting benchmark to our regression tests.
Changed block cache shards from 16 to 64, as Mark found that cache mutex contention is a big bottleneck.
Test Plan: Ran it.
Reviewers: dhruba, haobo, MarkCallaghan, xjin
Reviewed By: MarkCallaghan
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15075
Summary: Added a script that prepares the repo for facebook's new rocksdb release, which will automatically do some necessary work to make sure this repo is ready for 3rdparty release.
Test Plan:
Run this script and observed:
* new version was created (both in local and remote repo) as a git tag.
* build_version.cc was updated
* build_detect_platform was changed so that it won't create any new change.
Reviewers: haobo, dhruba, sdong, igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15003
Summary: @MarkCallaghan's tests indicate that performance with 8k rows in memtable is much worse than empty memtable. I wanted to add a regression tests that measures this effect, so we could optimize it. However, current config shows 634461 QPS on my devbox. Mark, any idea why this is so much faster than your measurements?
Test Plan: Ran the regression test.
Reviewers: MarkCallaghan, dhruba, haobo
Reviewed By: MarkCallaghan
CC: leveldb, MarkCallaghan
Differential Revision: https://reviews.facebook.net/D14511
Branch detection did not work in Jenkins. I realized that it set
GIT_BRANCH env variable to point to the current branch, so let's try
using this for branch detection.
Summary: When running regression tests on other branches, this will push values to entity rocksdb_build.$git_branch
Test Plan: Ran regression test on regression branch, observed values send to ODS in entity rocksdb_build.regression
Reviewers: kailiu
Reviewed By: kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14493
Summary: Added readrandom benchmark with 300MB block cache, while database has 1GB of data
Test Plan: Ran it
Reviewers: dhruba, MarkCallaghan
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14373
Summary: The old regression tests didn't cover memtable part at all. This is an atempt to also measure memtable performance in regression tests.
Test Plan: Ran regression_build_test.sh
Reviewers: dhruba, haobo, kailiu, emayanke
Reviewed By: dhruba
CC: leveldb, reconnect.grayhat
Differential Revision: https://reviews.facebook.net/D14325
Summary: Add asan_check rule to Makefile. After we add this, we will create Jenkins run that will check for asan errors!
Test Plan: make asan_check
Reviewers: dhruba, kailiu, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14205
Summary: We don't need that dependency
Test Plan: make check
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14199
Summary:
For some reason, snappy on CentOS 5.2 when compiled with gcc 4.8.1 segfaults on strcmp. (!?)
Add an if to compile with gcc4.7.1 if you're compiling on CentOS 5.2. Please update your devservers to CentOS 6.
Test Plan:
make clean; make check
on both my devserver (CentOS 6) and dhruba's (CentOS 5.2)
Reviewers: dhruba, kailiu
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14169
Summary: We also need to use custom glibc and libgcc includes instead of system ones.
Test Plan:
'make clean; make check'.
Will also try on @dhruba's dev server.
Reviewers: dhruba, kailiu
Reviewed By: kailiu
CC: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D14157
Summary:
1. Moved the compiler back to 4.8.1 and uses Centos 5.2 binaries if OS is Centos 5.2.
2. Fixes this issue: https://github.com/facebook/rocksdb/issues/7
3. We use lot of c++11 features, so we can't pretend we can compile without them. Makes it a first class dependency.
4. Fix blob_store_test, which failes on Ubuntu with "too many files opened" error
5. Removed dependency on port/port_chromium.h, which does not even exist on our system
Test Plan: make clean; make check
Reviewers: dhruba, kailiu
Reviewed By: kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14145
Summary: Dhruba can't compile on gcc4.8.1 so I'm moving temporarily back to 4.7.1 until we figure out what's wrong with 4.8. on his server.
Test Plan: It can compile on my devserver, but please 'arc patch' this diff and try compiling on your machine
Reviewers: dhruba, kailiu
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14139
Summary:
Argumentation here: https://github.com/facebook/rocksdb/issues/9
Even though we include snappy in the distribution, we do not link with it if we don't have snappy installed on the system.
Installing snappy is easy nowadays, just type:
sudo apt-get install libsnappy-dev
Test Plan: compile on ubuntu
Reviewers: dhruba, kailiu
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14133
Summary:
Finally did it - the trick was in using --dynamic-linker option. This is first step to running ASAN.
All of our code seems to compile just fine on 4.8.1. However, I still left fbcode.471.sh in the 'build_tools/' just in case.
Test Plan: make clean; make
Reviewers: dhruba, haobo, kailiu, emayanke, sdong
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14109
Summary: This diff invoves some more complicated issues in the posix environment.
Test Plan: works under mac os. will need to verify dev box.
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14061
Summary: The work to make sure mac os compiles rocksdb is not completed yet. But at least we can start cleaning some warnings captured only by g++ from mac os..
Test Plan: ran make in mac os
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14049
Summary: Converted db_stress, db_repl_stress and db_bench to use gflags
Test Plan: I tested by printing out all the flags from old and new versions. Tried defaults, + various combinations with "interesting flags". Also, tested by running db_crashtest.py and db_crashtest2.py.
Reviewers: emayanke, dhruba, haobo, kailiu, sdong
Reviewed By: emayanke
CC: leveldb, xjin
Differential Revision: https://reviews.facebook.net/D13581
Summary:
Create a new type of file on startup if it doesn't already exist called DBID.
This will store a unique number generated from boost library's uuid header file.
The use-case is to identify the case of a db losing all its data and coming back up either empty or from an image(backup/live replica's recovery)
the key point to note is that DBID is not stored in a backup or db snapshot
It's preferable to use Boost for uuid because:
1) A non-standard way of generating uuid is not good
2) /proc/sys/kernel/random/uuid generates a uuid but only on linux environments and the solution would not be clean
3) c++ doesn't have any direct way to get a uuid
4) Boost is a very good library that was already having linkage in rocksdb from third-party
Note: I had to update the TOOLCHAIN_REV in build files to get latest verison of boost from third-party as the older version had a bug.
I had to put Wno-uninitialized in Makefile because boost-1.51 has an unitialized variable and rocksdb would not comiple otherwise. Latet open-source for boost is 1.54 but is not there in third-party. I have notified the concerned people in fbcode about it.
@kailiu : While releasing to third-party, an additional dependency will need to be created for boost in TARGETS file. I can help identify.
Test Plan:
Expand db_test to test 2 cases
1) Restarting db with Id file present - verify that no change to Id
2)Restarting db with Id file deleted - verify that a different Id is there after reopen
Also run make all check
Reviewers: dhruba, haobo, kailiu, sdong
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13587
Summary: The pupose of this diff is to expose per user-call level precise timing of block read, so that we can answer questions like: a Get() costs me 100ms, is that somehow related to loading blocks from file system, or sth else? We will answer that with EXACTLY how many blocks have been read, how much time was spent on transfering the bytes from os, how much time was spent on checksum verification and how much time was spent on block decompression, just for that one Get. A nano second stopwatch was introduced to track time with higher precision. The cost/precision of the stopwatch is also measured in unit-test. On my dev box, retrieving one time instance costs about 30ns, on average. The deviation of timing results is good enough to track 100ns-1us level events. And the overhead could be safely ignored for 100us level events (10000 instances/s), for example, a viewstate thrift call.
Test Plan: perf_context_test, also testing with viewstate shadow traffic.
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb, xjin
Differential Revision: https://reviews.facebook.net/D12351
Summary: Previously, RocksDB's build scripts used relative pathnames like ./build_detect_platform. This can cause problems if the user uses CDPATH. Also, it just doesn't seem right to me.
Test Plan:
make clean
make -j32 check
Reviewers: MarkCallaghan, dhruba, kailiu
Reviewed By: kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12459
Summary:
* Added LIBNAME to enable configurable library name.
* remove/check fPIC in linux platform from build_detect_platform
Test Plan: make
Reviewers: emayanke
Differential Revision: https://reviews.facebook.net/D12321
Summary:
Previously I changed the line `source ./fbcode.gcc471.sh` to `source fbcode.gcc471.sh`. It works in my devbox but failed in some jenkin servers. I revert the previous code to make sure it works well under all circumstances.
Test Plan:
Test in the jenkin server as well as dev box.
Reviewers:
CC:
Task ID: #
Blame Rev:
Summary: As Aaron suggested, there are quite some problems with our Makefile and scripts. So in this diff I did some cleanup for them and revise some part of the scripts/makefile to help people better understand some mysterious parts.
Test Plan:
Ran make in several modes;
Ran the updated scripts.
Reviewers: dhruba, emayanke, akushner
Differential Revision: https://reviews.facebook.net/D12285
Lei Jin