Summary:
Current posix advice implementation ties up the access pattern hint with the creation of a file.
It is not possible to apply different advice for different access (random get vs compaction read),
without keeping two open files for the same table. This patch extended the RandomeAccessFile interface
to accept new access hint at anytime. Particularly, we are able to set different access hint on the same
table file based on when/how the file is used.
Two options are added to set the access hint, after the file is first opened and after the file is being
compacted.
Test Plan: make check; db_stress; db_bench
Reviewers: dhruba
Reviewed By: dhruba
CC: MarkCallaghan, leveldb
Differential Revision: https://reviews.facebook.net/D10905
Summary: Enhance the statitics to report the number of open db iterators.
Test Plan: make check
Reviewers: haobo, emayanke
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10983
Summary: a new option block_size_deviation is added.
Test Plan: run db_test and db_bench
Reviewers: dhruba, haobo
Reviewed By: haobo
Differential Revision: https://reviews.facebook.net/D10821
Summary:
Added an option stats_dump_period_sec to dump leveldb.stats to LOG periodically for diagnosis.
By defauly, it's set to a very big number 3600 (1 hour).
Test Plan: make check;
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb, zshao
Differential Revision: https://reviews.facebook.net/D10761
Summary: Make Statistics usable by client
Test Plan: make check; db_bench
Reviewers: dhruba
Reviewed By: dhruba
Differential Revision: https://reviews.facebook.net/D10899
Summary:
Currently, with paranoid_check on, DB::Open will fail on any log read error on recovery.
If client is ok with losing most recent updates, we could simply skip those errors.
However, it's important to introduce an additional flag, so that paranoid_check can
still guard against more serious problems.
Test Plan: make check; db_stress
Reviewers: dhruba, emayanke
Reviewed By: emayanke
CC: leveldb, emayanke
Differential Revision: https://reviews.facebook.net/D10869
Summary:
There is an existing field Options.max_bytes_for_level_multiplier that
sets the multiplier for the size of each level in the database.
This patch introduces the ability to set different multipliers
for every level in the database. The size of a level is determined
by using both max_bytes_for_level_multiplier as well as the
per-level fanout.
size of level[i] = size of level[i-1] * max_bytes_for_level_multiplier
* fanout[i-1]
The default value of fanout is 1, so that it is backward compatible.
Test Plan: make check
Reviewers: haobo, emayanke
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10863
Summary: Statistics.h and histogram.h had double based api's to record values. Remove them as they are not used anywhere
Test Plan: make all check
Reviewers: haobo, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10815
Summary:
This diff replaces compaction_filter_args and CompactionFilter with a single compaction_filter parameter. It gives CompactionFilter better encapsulation and a similar look to Comparator and MergeOpertor, which improves consistency of the overall interface.
The change is not backward compatible. Nevertheless, the two references in fbcode are not in production yet.
Test Plan: make check
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb, zshao
Differential Revision: https://reviews.facebook.net/D10773
Summary:
Our ticker was not atomic. This was based on the assumption that we will increment counts at places only protected by Mutex. This is hard to program for and easy to make mistakes (mutex may be held a few layers above etc).
Also this increases the instructions executed when the mutex is held.
Test Plan: make check
Reviewers: haobo, dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10569
Summary:
This diff introduces a new Merge operation into rocksdb.
The purpose of this review is mostly getting feedback from the team (everyone please) on the design.
Please focus on the four files under include/leveldb/, as they spell the client visible interface change.
include/leveldb/db.h
include/leveldb/merge_operator.h
include/leveldb/options.h
include/leveldb/write_batch.h
Please go over local/my_test.cc carefully, as it is a concerete use case.
Please also review the impelmentation files to see if the straw man implementation makes sense.
Note that, the diff does pass all make check and truly supports forward iterator over db and a version
of Get that's based on iterator.
Future work:
- Integration with compaction
- A raw Get implementation
I am working on a wiki that explains the design and implementation choices, but coding comes
just naturally and I think it might be a good idea to share the code earlier. The code is
heavily commented.
Test Plan: run all local tests
Reviewers: dhruba, heyongqiang
Reviewed By: dhruba
CC: leveldb, zshao, sheki, emayanke, MarkCallaghan
Differential Revision: https://reviews.facebook.net/D9651
Summary:
- don't see a point exposing table.h to the public.
- fixed make clean to remove also *.d files.
Test Plan: make check; db_stress
Reviewers: dhruba, heyongqiang
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10479
Summary:
- removed the compaction_filter_value from the callback interface. Restrict compaction filter to purging values.
- modify some comments to reflect curent status.
Test Plan: make check
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10335
Summary: Primarily a refactor. Introduced LDBTool interface to which customers can plug in their options and this will create their own version of ldb tool.
Test Plan: made ldb tool and tried it.
Reviewers: dhruba, heyongqiang
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10191
Summary: as subject. This is causing problem in adsconv. Ideally, this flags should be set in open. But that is only supported in Linux kernel ≥2.6.23 and glibc ≥2.7.
Test Plan:
db_test
run db_test
Reviewers: dhruba, MarkCallaghan, haobo
Reviewed By: dhruba
CC: leveldb, chip
Differential Revision: https://reviews.facebook.net/D10089
Summary:
Earlier Statistics object was a raw pointer. This meant the user had to clear up
the Statistics object after creating the database. In most use cases the database is created in a function and the statistics pointer is out of scope. Hence the statistics object would never be deleted.
Now Using a shared_ptr to manage this.
Want this in before the next release.
Test Plan: make all check.
Reviewers: dhruba, emayanke
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D9735
Summary:
This patch allows an application to specify whether to use bufferedio,
reads-via-mmaps and writes-via-mmaps per database. Earlier, there
was a global static variable that was used to configure this functionality.
The default setting remains the same (and is backward compatible):
1. use bufferedio
2. do not use mmaps for reads
3. use mmap for writes
4. use readaheads for reads needed for compaction
I also added a parameter to db_bench to be able to explicitly specify
whether to do readaheads for compactions or not.
Test Plan: make check
Reviewers: sheki, heyongqiang, MarkCallaghan
Reviewed By: sheki
CC: leveldb
Differential Revision: https://reviews.facebook.net/D9429
Summary: Makefile had options to ignore sign-comparisons and unused-parameters, which should be there. Also fixed the specific errors in the code-base
Test Plan: make
Reviewers: chip, dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D9531
Summary:
1. Create only 2 levels so that manual compactions are fast.
2. Set target file size to a large value
Test Plan: make clean check
Reviewers: kailiu, zshao
Reviewed By: zshao
CC: leveldb
Differential Revision: https://reviews.facebook.net/D9231
Summary:
Store the last flushed, seq no. in db_impl. Check against it in
transaction Log iterator. Do not attempt to read ahead if we do not know
if the data is flushed completely.
Does not work if flush is disabled. Any ideas on fixing that?
* Minor change, iter->Next is called the first time automatically for
* the first time.
Test Plan:
existing test pass.
More ideas on testing this?
Planning to run some stress test.
Reviewers: dhruba, heyongqiang
CC: leveldb
Differential Revision: https://reviews.facebook.net/D9087
Summary:
Add a shortcut function to make it easier for people
to efficiently bulk_load data into RocksDB.
Test Plan:
Tried ldb with "--bulk_load" and "--bulk_load --compact" and verified the outcome.
Needs to consult the team on how to test this automatically.
Reviewers: sheki, dhruba, emayanke, heyongqiang
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8907
Summary:
This adds the rate_delay_limit_milliseconds option to make the delay
configurable in MakeRoomForWrite when the max compaction score is too high.
This delay is called the Ln slowdown. This change also counts the Ln slowdown
per level to make it possible to see where the stalls occur.
From IO-bound performance testing, the Level N stalls occur:
* with compression -> at the largest uncompressed level. This makes sense
because compaction for compressed levels is much
slower. When Lx is uncompressed and Lx+1 is compressed
then files pile up at Lx because the (Lx,Lx+1)->Lx+1
compaction process is the first to be slowed by
compression.
* without compression -> at level 1
Task ID: #1832108
Blame Rev:
Test Plan:
run with real data, added test
Revert Plan:
Database Impact:
Memcache Impact:
Other Notes:
EImportant:
- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -
Reviewers: dhruba
Reviewed By: dhruba
Differential Revision: https://reviews.facebook.net/D9045
Summary:
Rocks accumulates recent writes and deletes in the in-memory memtable.
When the memtable is full, it writes the contents on the memtable to
a file in L0.
This patch removes redundant records at the time of the flush. If there
are multiple versions of the same key in the memtable, then only the
most recent one is dumped into the output file. The purging of
redundant records occur only if the most recent snapshot is earlier
than the earliest record in the memtable.
Should we switch on this feature by default or should we keep this feature
turned off in the default settings?
Test Plan: Added test case to db_test.cc
Reviewers: sheki, vamsi, emayanke, heyongqiang
Reviewed By: sheki
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8991
Summary:
Use only the counter mechanism. Do away with
incNumFileOpens, incNumFileClose, incNumFileErrors
s/NULL/nullptr/g in db/table_cache.cc
Test Plan: make clean check
Reviewers: dhruba, heyongqiang, emayanke
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8841
Summary: just record time consumed in compaction
Test Plan: compile
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8781
Summary:
* Counters for bytes read and write.
as a part of this diff, I want to=>
* Measure compaction times. @dhruba can you point which function, should
* I time to get Compaction-times. Was looking at CompactRange.
Test Plan: db_test
Reviewers: dhruba, emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8763
Summary:
* Introduce is histogram in statistics.h
* stop watch to measure time.
* introduce two timers as a poc.
Replaced NULL with nullptr to fight some lint errors
Should be useful for google.
Test Plan:
ran db_bench and check stats.
make all check
Reviewers: dhruba, heyongqiang
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8637
Summary:
* Add a SplitByTTLLogger to enable this feature. In this diff I implemented generalized AutoSplitLoggerBase class to simplify the
development of such classes.
* Refactor the existing AutoSplitLogger and fix several bugs.
Test Plan:
* Added a unit tests for different types of "auto splitable" loggers individually.
* Tested the composited logger which allows the log files to be splitted by both TTL and log size.
Reviewers: heyongqiang, dhruba
Reviewed By: heyongqiang
CC: zshao, leveldb
Differential Revision: https://reviews.facebook.net/D8037
Summary:
Added function to `RandomAccessFile` to generate an unique ID for that file. Currently only `PosixRandomAccessFile` has this behaviour implemented and only on Linux.
Changed how key is generated in `Table::BlockReader`.
Added tests to check whether the unique ID is stable, unique and not a prefix of another unique ID. Added tests to see that `Table` uses the cache more efficiently.
Test Plan: make check
Reviewers: chip, vamsi, dhruba
Reviewed By: chip
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8145
Summary:
Previously, if you opened a db with num_levels set lower than
the database, you received the unhelpful message "Corruption:
VersionEdit: new-file entry." Now you get a more verbose message
describing the issue.
Also, fix handling of compression_levels (both the run-over-the-end
issue and the memory management of it).
Lastly, unique_ptr'ify a couple of minor calls.
Test Plan: make check
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8151
Summary:
On some filesystems, pre-allocation can be a considerable
amount of space. xfs in our production environment pre-allocates by
1GB, for instance. By using fallocate to inform the kernel of our
expected file sizes, we eliminate this wasteage (that isn't recovered
until the file is closed which, in the case of LOG files, can be a
considerable amount of time).
Test Plan:
created an xfs loopback filesystem, mounted with
allocsize=4M, and ran db_stress. LOG file without this change was 4M,
and with it it was 128k then grew to normal size.
Reviewers: dhruba
Reviewed By: dhruba
CC: adsharma, leveldb
Differential Revision: https://reviews.facebook.net/D7953
Summary:
Replace manual memory management with std::unique_ptr in a
number of places; not exhaustive, but this fixes a few leaks with file
handles as well as clarifies semantics of the ownership of file handles
with log classes.
Test Plan: db_stress, make check
Reviewers: dhruba
Reviewed By: dhruba
CC: zshao, leveldb, heyongqiang
Differential Revision: https://reviews.facebook.net/D8043
Summary: a function added to status.h to check whether Status::code is InvalidArgument and similarly for NotSupported state
Test Plan: visual inspection
Reviewers: heyongqiang, dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7989
Summary:
Check in LogAndApply if the file size is more than the limit set in
Options.
Things to consider : will this be expensive?
Test Plan: make all check. Inputs on a new unit test?
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7701
Summary:
Specific changes:
1) Turn on -Werror so all warnings are errors
2) Fix some warnings the above now complains about
3) Add proper dependency support so changing a .h file forces a .c file
to rebuild
4) Automatically use fbcode gcc on any internal machine rather than
whatever system compiler is laying around
5) Fix jemalloc to once again be used in the builds (seemed like it
wasn't being?)
6) Fix issue where 'git' would fail in build_detect_version because of
LD_LIBRARY_PATH being set in the third-party build system
Test Plan:
make, make check, make clean, touch a header file, make sure
rebuild is expected
Reviewers: dhruba
Reviewed By: dhruba
Differential Revision: https://reviews.facebook.net/D7887
Summary:
Leveldb has an api OpenForReadOnly() that opens the database
in readonly mode. This call had an option to not process the
transaction log. This patch removes this option and always
processes all transactions that had been committed. It has
been done in such a way that it does not create/write to
any new files in the process. The invariant of "no-writes"
to the leveldb data directory is still true.
This enhancement allows multiple threads to open the same database
in readonly mode and access all trancations that were committed right
upto the OpenForReadOnly call.
I changed the public API to match the new semantics because
there are no users who are currently using this api.
Test Plan: make clean check
Reviewers: sheki
Reviewed By: sheki
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7479
Summary:
1. The OpenForReadOnly() call should not lock the db. This is useful
so that multiple processes can open the same database concurrently
for reading.
2. GetUpdatesSince should not error out if the archive directory
does not exist.
3. A new constructor for WriteBatch that can takes a serialized
string as a parameter of the constructor.
Test Plan: make clean check
Reviewers: sheki
Reviewed By: sheki
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7449
Summary:
WriteBatch is now used by the GetUpdatesSinceAPI. This API is external
and will be used by the rocks server. Rocks Server and others will need
to know about the Sequence Number in the WriteBatch. This public method
will allow for that.
Test Plan: make all check.
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7293
Summary:
Expose the serialized string that represents a WriteBatch. This
is helpful to replicate a writebatch operation from one machine
to another.
Test Plan: make clean check
Reviewers: sheki
Reviewed By: sheki
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7317
Summary:
Implement a interface to retrieve the most current transaction
id from the database.
Test Plan: Added unit test.
Reviewers: sheki
Reviewed By: sheki
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7269
Summary:
How it works:
* GetUpdatesSince takes a SequenceNumber.
* A LogFile with the first SequenceNumber nearest and lesser than the requested Sequence Number is found.
* Seek in the logFile till the requested SeqNumber is found.
* Return an iterator which contains logic to return record's one by one.
Test Plan:
* Test case included to check the good code path.
* Will update with more test-cases.
* Feedback required on test-cases.
Reviewers: dhruba, emayanke
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7119
Summary:
Create a directory "archive" in the DB directory.
During DeleteObsolteFiles move the WAL files (*.log) to the Archive directory,
instead of deleting.
Test Plan: Created a DB using DB_Bench. Reopened it. Checked if files move.
Reviewers: dhruba
Reviewed By: dhruba
Differential Revision: https://reviews.facebook.net/D6975
Summary:
Scripted and removed all trailing spaces and converted all tabs to
spaces.
Also fixed other lint errors.
All lint errors from this point of time should be taken seriously.
Test Plan: make all check
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7059
Summary:
The compaction process takes some files from LevelK and
merges it into LevelK+1. The number of files it picks from
LevelK was capped such a way that the total amount of
data picked does not exceed the maxfilesize of that level.
This essentially meant that only one file from LevelK
is picked for a single compaction.
For bulkloads, we would like to take many many file from
LevelK and compact them using a single compaction run.
This patch introduces a option called the 'source_compaction_factor'
(similar to expanded_compaction_factor). It is a multiplier
that is multiplied by the maxfilesize of that level to arrive
at the limit that is used to throttle the number of source
files from LevelK. For bulk loads, set source_compaction_factor
to a very high number so that multiple files from the same
level are picked for compaction in a single compaction.
The default value of source_compaction_factor is 1, so that
we can keep backward compatibilty with existing compaction semantics.
Test Plan: make clean check
Reviewers: emayanke, sheki
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D6867
Summary:
This option is needed for fast bulk uploads. The goal is to load
all the data into files in L0 without any interference from
background compactions.
Test Plan: make clean check
Reviewers: sheki
Reviewed By: sheki
CC: leveldb
Differential Revision: https://reviews.facebook.net/D6849
