Summary: as title
Test Plan:
make all check
What else tests shall I cover?
Reviewers: igor, haobo
CC:
Differential Revision: https://reviews.facebook.net/D15339
Summary:
This diff implements a special type of iterator that doesn't create a snapshot
(can be used to read newly inserted data) and is optimized for doing sequential
reads.
TailingIterator uses current superversion number to determine whether to
invalidate its internal iterators. If the version hasn't changed, it can often
avoid doing expensive seeks over immutable structures (sst files and immutable
memtables).
Test Plan:
* new unit tests
* running LD with this patch
Reviewers: igor, dhruba, haobo, sdong, kailiu
Reviewed By: sdong
CC: leveldb, lovro, march
Differential Revision: https://reviews.facebook.net/D15285
Summary:
This diff takes an even more aggressive way to inline the functions. A decent rule that I followed is "not inline a function if it is more than 10 lines long."
Normally optimizing code by inline is ugly and hard to control, but since one of our usecase has significant amount of CPU used in functions from coding.cc, I'd like to try this diff out.
Test Plan:
1. the size for some .o file increased a little bit, but most less than 1%. So I think the negative impact of inline is negligible.
2. As the regression test shows (ran for 10 times and I calculated the average number)
Metrics Befor After
========================================================================
rocksdb.build.fillseq.qps 426595 444515 (+4.6%)
rocksdb.build.memtablefillrandom.qps 121739 123110
rocksdb.build.memtablereadrandom.qps 1285103 1280520
rocksdb.build.overwrite.qps 125816 135570 (+9%)
rocksdb.build.readrandom_fillunique_random.qps 285995 296863
rocksdb.build.readrandom_memtable_sst.qps 1027132 1027279
rocksdb.build.readrandom.qps 1041427 1054665
rocksdb.build.readrandom_smallblockcache.qps 1028631 1038433
rocksdb.build.readwhilewriting.qps 918352 914629
Reviewers: haobo, sdong, igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15291
Summary:
I created a separate class ColumnFamilySet to keep track of column families. Before we did this in VersionSet and I believe this approach is cleaner.
Let me know if you have any comments. I will commit tomorrow.
Test Plan: make check
Reviewers: dhruba, haobo, kailiu, sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15357
Summary: I'm separating code-cleanup part of https://reviews.facebook.net/D14517. This will make D14517 easier to understand and this diff easier to review.
Test Plan: make check
Reviewers: haobo, kailiu, sdong, dhruba, tnovak
Reviewed By: tnovak
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15099
Summary:
This diff fixes 2 hacks:
* The callback function can modify the existing value inplace, if the merged value fits within the existing buffer size. But currently the existing buffer size is not being modified. Now the callback recieves a int* allowing the size to be modified. Since size is encoded as a varint in the internal key for memtable. It might happen that the entire value might have be copied to the new location if the new size varint is smaller than the existing size varint.
* The callback function has 3 functionalities
1. Modify existing buffer inplace, and update size correspondingly. Now to indicate that, Returns 1.
2. Generate a new buffer indicating merged value. Returns 2.
3. Fails to do either of above, based on whatever application logic. Returns 0.
Test Plan: Just make all for now. I'm adding another unit test to test each scenario.
Reviewers: dhruba, haobo
Reviewed By: haobo
CC: leveldb, sdong, kailiu, xinyaohu, sumeet, danguo
Differential Revision: https://reviews.facebook.net/D15195
Summary:
shared_ptr is slower than unique_ptr (which literally comes with no performance cost compare with raw pointers).
In memtable and memtable rep, we use shared_ptr when we'd actually should use unique_ptr.
According to igor's previous work, we are likely to make quite some performance gain from this diff.
Test Plan: make check
Reviewers: dhruba, igor, sdong, haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15213
Summary:
When doing CompactRange(), we should first flush the memtable and then calculate max_level_with_files. Also, we want to compact all the levels that have files, including level `max_level_with_files`.
This patch fixed the unit test.
Test Plan: Added a failing unit test and a fix, so it's not failing anymore.
Reviewers: dhruba, haobo, sdong
Reviewed By: haobo
CC: leveldb, xjin
Differential Revision: https://reviews.facebook.net/D14421
Summary:
In one of CPU profiles, we see some CPU costs of string::reserve() inside Batch.Put(). This patch should be able to reduce some of the costs by allocating sufficient buffer before hand.
Since it is a trivial percentage of CPU costs, I didn't find a way to show the improvement in one of the benchmarks. I'll deploy it to same application and do the same CPU profiling to make sure those CPU costs are reduced.
Test Plan: make all check
Reviewers: haobo, kailiu, igor
Reviewed By: haobo
CC: leveldb, nkg-
Differential Revision: https://reviews.facebook.net/D15135
Summary:
In one of CPU profiles, we see some CPU costs of string::reserve() inside Batch.Put(). This patch should be able to reduce some of the costs by allocating sufficient buffer before hand.
Since it is a trivial percentage of CPU costs, I didn't find a way to show the improvement in one of the benchmarks. I'll deploy it to same application and do the same CPU profiling to make sure those CPU costs are reduced.
Test Plan: make all check
Reviewers: haobo, kailiu, igor
Reviewed By: haobo
CC: leveldb, nkg-
Differential Revision: https://reviews.facebook.net/D15135
Summary: The application can set a callback function, which is applied on the previous value. And calculates the new value. This new value can be set, either inplace, if the previous value existed in memtable, and new value is smaller than previous value. Otherwise the new value is added normally.
Test Plan: fbmake. Added unit tests. All unit tests pass.
Reviewers: dhruba, haobo
Reviewed By: haobo
CC: sdong, kailiu, xinyaohu, sumeet, leveldb
Differential Revision: https://reviews.facebook.net/D14745
Summary:
WriteBatch::Data() now is easily to be misuse by users. Also, there is no cheap way for user of WriteBatch to know the data size accumulated. This patch fix the problem by:
(1) return a constant reference to Data() so it's obvious to caller what it means.
(2) add a function to return data size directly
Test Plan: make all check
Reviewers: haobo, igor, kailiu
Reviewed By: kailiu
CC: zshao, leveldb
Differential Revision: https://reviews.facebook.net/D15123
Summary:
Added an option (max_successive_merges) that can be used to specify the
maximum number of successive merge operations on a key in the memtable.
This can be used to improve performance of the "get" operation. If many
successive merge operations are performed on a key, the performance of "get"
operations on the key deteriorates, as the value has to be computed for each
"get" operation by applying all the successive merge operations.
FB Task ID: #3428853
Test Plan:
make all check
db_bench --benchmarks=readrandommergerandom
counter_stress_test
Reviewers: haobo, vamsi, dhruba, sdong
Reviewed By: haobo
CC: zshao
Differential Revision: https://reviews.facebook.net/D14991
Summary:
In some use cases, table readers for all live files should always be cached. In that case, there will be an opportunity to avoid the table cache look-up while Get() and NewIterator().
We define options.max_open_files = -1 to be the mode that table readers for live files will always be kept. In that mode, table readers are cached in FileMetaData (with a reference count hold in table cache). So that when executing table_cache.Get() and table_cache.newInterator(), LRU cache checking can be by-passed, to reduce latency.
Test Plan: add a test case in db_test
Reviewers: haobo, kailiu
Reviewed By: haobo
CC: dhruba, igor, leveldb
Differential Revision: https://reviews.facebook.net/D15039
Summary:
Implement a mem table, in which keys are hashed based on prefixes. In each bucket, entries are organized in a sorted linked list. It has the same thread safety guarantee as skip list.
The motivation is to optimize memory usage for the case that prefix hashing is primary way of seeking to the entry. Compared to hash skip list implementation, this implementation is more memory efficient, but inside each bucket, search is always linear. The target scenario is that there are only very limited number of records in each hash bucket.
Test Plan: Add a test case in db_test
Reviewers: haobo, kailiu, dhruba
Reviewed By: haobo
CC: igor, nkg-, leveldb
Differential Revision: https://reviews.facebook.net/D14979
Summary:
This diff introduces some features that were requested by two internal customers:
* Ability for backups not to share table files, because we can't guarantee that equal filename means equal content accross replicas
* Ability for two threads to call EnableFileDeletions() and DisableFileDeletions()
* Ability to stop backup from another thread and not slow down the DB close
* Copy the files to the temporary folder first and then atomically rename
Test Plan: Added some tests to backupable_db_test
Reviewers: dhruba, sanketh, muthu, sdong, haobo
Reviewed By: haobo
CC: leveldb, sanketh, muthu
Differential Revision: https://reviews.facebook.net/D14769
Summary: Use two vectors for different types of memory allocation.
Test Plan: run all unit tests.
Reviewers: haobo, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15027
Summary:
I have added three new value types:
* kTypeColumnFamilyDeletion
* kTypeColumnFamilyValue
* kTypeColumnFamilyMerge
which include column family Varint32 before the data (value, deletion and merge). These values are used only in WAL (not in memtables yet).
This endeavour required changing some WriteBatch internals.
Test Plan: Added a unittest
Reviewers: dhruba, haobo, sdong, kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15045
Summary:
In addition to implementing OpenWithColumnFamilies, this diff also includes some minor changes:
* Changed all column family names from Slice() to std::string. The performance of column family name handling is not critical, and it's more convenient and cleaner to have names as std::strings
* Implemented ColumnFamilyOptions(const Options&) and DBOptions(const Options&)
* Added ColumnFamilyOptions to VersionSet::ColumnFamilyData. ColumnFamilyOptions are specified on OpenWithColumnFamilies() and CreateColumnFamily()
I will keep the diff in the Phabricator for a day or two and will push to the branch then. Feel free to comment even after the diff has been pushed.
Test Plan: Added a simple unit test
Reviewers: dhruba, haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15033
Summary:
This diff provides basic implementations of CreateColumnFamily(), DropColumnFamily() and ListColumnFamilies(). It builds on top of https://reviews.facebook.net/D14733
It also includes a bug fix for DBImplReadOnly, where Get implementation would be redirected to DBImpl instead of DBImplReadOnly.
Test Plan: Added unit test
Reviewers: dhruba, haobo, kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15021
Summary:
<This diff is for Column Family branch>
Added fields in manifest file to support adding and deleting column families.
Pretty simple change, each version edit record can be:
1. add column family
2. drop column family
3. add and delete N files from a single column family (compactions and flushes will generate such records)
Test Plan: make check works, the code is backward compatible
Reviewers: dhruba, haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14733
Summary:
We don't want two threads to clash if they concurrently call DisableFileDeletions() and EnableFileDeletions(). I'm adding a counter that will enable file deletions only after all DisableFileDeletions() calls have been negated with EnableFileDeletions().
However, we also don't want to break the old behavior, so I added a parameter force to EnableFileDeletions(). If force is true, we will still enable file deletions after every call to EnableFileDeletions(), which is what is happening now.
Test Plan: make check
Reviewers: dhruba, haobo, sanketh
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14781
Summary:
In some places we have NotFound status created with empty message, but it doesn't avoid a malloc. With this patch, the malloc is avoided for that case.
The motivation of it is that I found in db_bench readrandom test when all keys are not existing, about 4% of the total running time is spent on malloc of Status, plus a similar amount of CPU spent on free of them, which is not necessary.
Test Plan: make all check
Reviewers: dhruba, haobo, igor
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14691
Summary:
Some changes to PlainTable format:
(1) support variable key length
(2) use user defined slice transformer to extract prefixes
(3) Run some test cases against PlainTable in db_test and table_test
Test Plan: test db_test
Reviewers: haobo, kailiu
CC: dhruba, igor, leveldb, nkg-
Differential Revision: https://reviews.facebook.net/D14457
Summary:
<This diff is for Column Family branch>
Sharing some of the work I've done so far. This diff compiles and passes the tests.
The biggest change is in options.h - I broke down Options into two parts - DBOptions and ColumnFamilyOptions. DBOptions is DB-specific (env, create_if_missing, block_cache, etc.) and ColumnFamilyOptions is column family-specific (all compaction options, compresion options, etc.). Note that this does not break backwards compatibility at all.
Further, I created DBWithColumnFamily which inherits DB interface and adds new functions with column family support. Clients can transparently switch to DBWithColumnFamily and it will not break their backwards compatibility.
There are few methods worth checking out: ListColumnFamilies(), MultiNewIterator(), MultiGet() and GetSnapshot(). [GetSnapshot() returns the snapshot across all column families for now - I think that's what we agreed on]
Finally, I made small changes to WriteBatch so we are able to atomically insert data across column families.
Please provide feedback.
Test Plan: make check works, the code is backward compatible
Reviewers: dhruba, haobo, sdong, kailiu, emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14445
Summary:
This is the last diff that adds the property block to plain table.
The format resembles that of the block-based table: https://github.com/facebook/rocksdb/wiki/Rocksdb-table-format
[data block]
[meta block 1: stats block]
[meta block 2: future extended block]
...
[meta block K: future extended block] (we may add more meta blocks in the future)
[metaindex block]
[index block: we only have the placeholder here, we can add persistent index block in the future]
[Footer: contains magic number, handle to metaindex block and index block]
<end_of_file>
Test Plan: extended existing property block test.
Reviewers: haobo, sdong, dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14523
Summary: This diff will help us to figure out the memory usage for the cache part.
Test Plan: added a new memory usage test for cache
Reviewers: haobo, sdong, dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14559
Summary: In get operations, merge_operands is only used in few cases. Lazily initialize it can reduce average latency in some cases
Test Plan: make all check
Reviewers: haobo, kailiu, dhruba
Reviewed By: haobo
CC: igor, nkg-, leveldb
Differential Revision: https://reviews.facebook.net/D14415
Conflicts:
db/db_impl.cc
db/memtable.cc
Summary: as title
Test Plan: dynamic_bloom_test
Reviewers: dhruba, sdong, kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14385
Summary: We now delete backups with newer sequence number, so the clients don't have to handle confusing situations when they restore from backup.
Test Plan: added a unit test
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14547
Summary: This will allow us to access constant via `DB::GetOptions().table_cache.GetCapacity()` or `DB::GetOptions().block_cache.GetCapacity()` since GetOptions() is also constant method.
Summary:
In this diff I present you BackupableDB v1. You can easily use it to backup your DB and it will do incremental snapshots for you.
Let's first describe how you would use BackupableDB. It's inheriting StackableDB interface so you can easily construct it with your DB object -- it will add a method RollTheSnapshot() to the DB object. When you call RollTheSnapshot(), current snapshot of the DB will be stored in the backup dir. To restore, you can just call RestoreDBFromBackup() on a BackupableDB (which is a static method) and it will restore all files from the backup dir. In the next version, it will even support automatic backuping every X minutes.
There are multiple things you can configure:
1. backup_env and db_env can be different, which is awesome because then you can easily backup to HDFS or wherever you feel like.
2. sync - if true, it *guarantees* backup consistency on machine reboot
3. number of snapshots to keep - this will keep last N snapshots around if you want, for some reason, be able to restore from an earlier snapshot. All the backuping is done in incremental fashion - if we already have 00010.sst, we will not copy it again. *IMPORTANT* -- This is based on assumption that 00010.sst never changes - two files named 00010.sst from the same DB will always be exactly the same. Is this true? I always copy manifest, current and log files.
4. You can decide if you want to flush the memtables before you backup, or you're fine with backing up the log files -- either way, you get a complete and consistent view of the database at a time of backup.
5. More things you can find in BackupableDBOptions
Here is the directory structure I use:
backup_dir/CURRENT_SNAPSHOT - just 4 bytes holding the latest snapshot
0, 1, 2, ... - files containing serialized version of each snapshot - containing a list of files
files/*.sst - sst files shared between snapshots - if one snapshot references 00010.sst and another one needs to backup it from the DB, it will just reference the same file
files/ 0/, 1/, 2/, ... - snapshot directories containing private snapshot files - current, manifest and log files
All the files are ref counted and deleted immediatelly when they get out of scope.
Some other stuff in this diff:
1. Added GetEnv() method to the DB. Discussed with @haobo and we agreed that it seems right thing to do.
2. Fixed StackableDB interface. The way it was set up before, I was not able to implement BackupableDB.
Test Plan:
I have a unittest, but please don't look at this yet. I just hacked it up to help me with debugging. I will write a lot of good tests and update the diff.
Also, `make asan_check`
Reviewers: dhruba, haobo, emayanke
Reviewed By: dhruba
CC: leveldb, haobo
Differential Revision: https://reviews.facebook.net/D14295
Summary: In get operations, merge_operands is only used in few cases. Lazily initialize it can reduce average latency in some cases
Test Plan: make all check
Reviewers: haobo, kailiu, dhruba
Reviewed By: haobo
CC: igor, nkg-, leveldb
Differential Revision: https://reviews.facebook.net/D14415
Summary: This change will allow other table to reuse the code for meta blocks.
Test Plan: all existing unit tests passed
Reviewers: dhruba, haobo, sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14475
Summary: As title
Test Plan: make clean and make
Reviewers: igor
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14469
Summary: This would enable rocksdb users to get the db identity without depending on implementation details(storing that in IDENTITY file)
Test Plan: db/db_test (has identity checks)
Reviewers: dhruba, haobo, igor, kailiu
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14463
Summary:
PlainTableReader to use a more customized hash table. This patch assumes the SST file is smaller than 2GB:
(1) Every bucket uses 32-bit integer
(2) no key is stored in bucket
(3) use the first bit of the bucket value to distinguish it points to the file offset or a second level index.
This index schema fits the use case that most of prefixes have very small number of keys
Test Plan: plain_table_db_test
Reviewers: haobo, kailiu, dhruba
Reviewed By: haobo
CC: nkg-, leveldb
Differential Revision: https://reviews.facebook.net/D14343
Summary:
Let's get rid of TransformRep and it's children. We have confirmed that HashSkipListRep works better with multifeed, so there is no benefit to keeping this around.
This diff is mostly just deleting references to obsoleted functions. I also have a diff for fbcode that we'll need to push when we switch to new release.
I had to expose HashSkipListRepFactory in the client header files because db_impl.cc needs access to GetTransform() function for SanitizeOptions.
Test Plan: make check
Reviewers: dhruba, haobo, kailiu, sdong
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14397
Summary: As title. Especially, HashSkipListRepFactory will be able to specify a relatively small height, to reduce the memory overhead of one skiplist per bucket.
Test Plan: make check and test it on leaf4
Reviewers: dhruba, sdong, kailiu
CC: reconnect.grayhat, leveldb
Differential Revision: https://reviews.facebook.net/D14307
Summary: We need access to options for BackupableDB
Test Plan: make check
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb, reconnect.grayhat
Differential Revision: https://reviews.facebook.net/D14331
Summary: This is part of https://reviews.facebook.net/D14295 -- smaller diff that is easier to review
Test Plan: make asan_check
Reviewers: dhruba, haobo, emayanke
Reviewed By: emayanke
CC: leveldb, kailiu, reconnect.grayhat
Differential Revision: https://reviews.facebook.net/D14301
Summary: liveness of the statistics object is already ensured by the shared pointer in DB options. There's no reason to pass again shared pointer among internal functions. Raw pointer is sufficient and efficient.
Test Plan: make check
Reviewers: dhruba, MarkCallaghan, igor
Reviewed By: dhruba
CC: leveldb, reconnect.grayhat
Differential Revision: https://reviews.facebook.net/D14289
Summary:
Provide a framework to profile a query in detail to figure out latency bottleneck. Currently, in Get(), Put() and iterators, 2-3 simple timing is used. We can easily add more profile counters to the framework later.
Test Plan: Enable this profiling in seveal existing tests.
Reviewers: haobo, dhruba, kailiu, emayanke, vamsi, igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14001
Conflicts:
table/merger.cc
Summary:
Provide a framework to profile a query in detail to figure out latency bottleneck. Currently, in Get(), Put() and iterators, 2-3 simple timing is used. We can easily add more profile counters to the framework later.
Test Plan: Enable this profiling in seveal existing tests.
Reviewers: haobo, dhruba, kailiu, emayanke, vamsi, igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14001
Summary:
For prefix mem tables, encoding mem table key may be unnecessary if the prefix doesn't have any key. This patch is a little bit hacky but I want to try out the performance gain of removing this lazy initialization.
In longer term, we might want to revisit the way we abstract mem tables implementations.
Test Plan: make all check
Reviewers: haobo, igor, kailiu
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14265
Summary:
A Simple plain table format. No block structure. When creating the table reader, scanning the full table to create indexes.
Test Plan:Add unit test
Reviewers:haobo,dhruba,kailiu
CC:
Task ID: #
Blame Rev:
Summary:
Previously we introduce a `flush_block_policy_factory` in Options, however, that options is strongly releated to Table based tables.
It will make more sense to move it to block based table's own factory class.
Test Plan: make check to pass existing tests
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14211
Summary:
The primary motivation of the changes is to make it easier to figure out the inside of the tables.
* rename "table stats" to "table properties" since now we have more than "integers" to store in the property block.
* Add filter block size to the basic table properties.
* Whenever a table is built, we'll log the table properties (the sample output is in Test Plan).
* Make an api to expose deleted keys.
Test Plan:
Passed all existing test. and the sample output of table stats:
==================================================================
Basic Properties
------------------------------------------------------------------
# data blocks: 1
# entries: 1
raw key size: 9
raw average key size: 9
raw value size: 9
raw average value size: 0
data block size: 25
index block size: 27
filter block size: 18
(estimated) table size: 70
filter policy: rocksdb.BuiltinBloomFilter
==================================================================
User collected properties: InternalKeyPropertiesCollector
------------------------------------------------------------------
kDeletedKeys: 1
==================================================================
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14187
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:
Created a unittest that verifies that automatic deletion performed by PurgeObsoleteFiles() works correctly.
Also, few small fixes on the logic part -- call version_set_->GetObsoleteFiles() in FindObsoleteFiles() instead of on some arbitrary positions.
Test Plan: Created a unit test
Reviewers: dhruba, haobo, nkg-
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14079
Summary: This diff leverage the existing block cache and extend it to cache index/filter block.
Test Plan:
Added new tests in db_test and table_test
The correctness is checked by:
1. make check
2. make valgrind_check
Performance is test by:
1. 10 times of build_tools/regression_build_test.sh on two versions of rocksdb before/after the code change. Test results suggests no significant difference between them. For the two key operatons `overwrite` and `readrandom`, the average iops are both 20k and ~260k, with very small variance).
2. db_stress.
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb, haobo, xjin
Differential Revision: https://reviews.facebook.net/D13167
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:
@haobo's suggestions from https://reviews.facebook.net/D13827
Renaming some variables, deprecating purge_log_after_flush, changing for loop into auto for loop.
I have not implemented deleting objects outside of mutex yet because it would require a big code change - we would delete object in db_impl, which currently does not know anything about object because it's defined in version_edit.h (FileMetaData). We should do it at some point, though.
Test Plan: Ran deletefile_test
Reviewers: haobo
Reviewed By: haobo
CC: leveldb, haobo
Differential Revision: https://reviews.facebook.net/D14025
Summary:
Changed leveldb documentation with rocksdb in doc/index.html. Added some of the important options from options.h to doc.
Also removed benchmark files and impl.h, since this is all replaced by RocksDB wikis.
Test Plan: -
Reviewers: dhruba, haobo, kailiu, emayanke, sdong
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13977
Summary: In our project, when writing to the database, we want to form the value as the concatenation of a small header and a larger payload. It's a shame to have to copy the payload just so we can give RocksDB API a linear view of the value. Since RocksDB makes a copy internally, it's easy to support gather writes.
Test Plan: write_batch_test, new test case
Reviewers: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13947
Summary:
Here's one solution we discussed on speeding up FindObsoleteFiles. Keep a set of all files in DBImpl and update the set every time we create a file. I probably missed few other spots where we create a file.
It might speed things up a bit, but makes code uglier. I don't really like it.
Much better approach would be to abstract all file handling to a separate class. Think of it as layer between DBImpl and Env. Having a separate class deal with file namings and deletion would benefit both code cleanliness (especially with huge DBImpl) and speed things up. It will take a huge effort to do this, though.
Let's discuss offline today.
Test Plan: Ran ./db_stress, verified that files are getting deleted
Reviewers: dhruba, haobo, kailiu, emayanke
Reviewed By: dhruba
Differential Revision: https://reviews.facebook.net/D13827
Summary: What @haobo done with TransformRep, now in TransformRepNoLock. Similar implementation, except that I made DynamicIterator a subclass of Iterator which makes me have less iterator initializations.
Test Plan: ./prefix_test. Seeing huge savings vs. TransformRep again!
Reviewers: dhruba, haobo, sdong, kailiu
Reviewed By: haobo
CC: leveldb, haobo
Differential Revision: https://reviews.facebook.net/D13953
Summary: Allow block based table to configure the way flushing the blocks. This feature will allow us to add support for prefix-aligned block.
Test Plan: make check
Reviewers: dhruba, haobo, sdong, igor
Reviewed By: sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13875
Summary:
Added a new call LogFlush() that flushes the log contents to the OS buffers. We never call it with lock held.
We call it once for every Read/Write and often in compaction/flush process so the frequency should not be a problem.
Test Plan: db_test
Reviewers: dhruba, haobo, kailiu, emayanke
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13935
Summary: Added a prefix_seek flag in ReadOptions to indicate that Seek is prefix aware(might not return data with different prefix), and also not bound to a specific prefix. Multiple Seeks and range scans can be invoked on the same iterator. If a specific prefix is specified, this flag will be ignored. Just a quick prototype that works for PrefixHashRep, the new lockless memtable could be easily extended with this support too.
Test Plan: test it on Leaf
Reviewers: dhruba, kailiu, sdong, igor
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13929
Summary:
Archive cleaning will still happen every WAL_ttl seconds
but archived logs will be deleted only if archive size
is greater then a WAL_size_limit value.
Empty archived logs will be deleted evety WAL_ttl.
Test Plan:
1. Unit tests pass.
2. Benchmark.
Reviewers: emayanke, dhruba, haobo, sdong, kailiu, igor
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13869
Summary:
I'm sending this diff together with https://reviews.facebook.net/D13881 because it didn't allow me to send only the array one.
Here I also replaced unordered_map with just an array of shared_ptrs. This elminated all the locks.
I will run the new benchmark and post the results here.
Test Plan: db_test
Reviewers: dhruba, haobo
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13893
Summary:
strict essentially means that we MUST find the startsequence. Thus we should return if starteSequence is not found in the first file in case strict is set. This will take care of ending the iterator in case of permanent gaps due to corruptions in the log files
Also created NextImpl function that will have internal variable to distinguish whether Next is being called from StartSequence or by application.
Set NotFoudn::gaps status to give an indication of gaps happeneing.
Polished the inline documentation at various places
Test Plan:
* db_repl_stress test
* db_test relating to transaction log iterator
* fbcode/wormhole/rocksdb/rocks_log_iterator
* sigma production machine sigmafio032.prn1
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13689
Summary:
Rocksdb can now support a uncompressed block cache, or a compressed
block cache or both. Lookups first look for a block in the
uncompressed cache, if it is not found only then it is looked up
in the compressed cache. If it is found in the compressed cache,
then it is uncompressed and inserted into the uncompressed cache.
It is possible that the same block resides in the compressed cache
as well as the uncompressed cache at the same time. Both caches
have their own individual LRU policy.
Test Plan: Unit test case attached.
Reviewers: kailiu, sdong, haobo, leveldb
Reviewed By: haobo
CC: xjin, haobo
Differential Revision: https://reviews.facebook.net/D12675
Summary: This is to give application compaction filter a chance to access context information of a specific compaction run. For example, depending on whether a compaction goes through all data files, the application could do things differently.
Test Plan: make check
Reviewers: dhruba, kailiu, sdong
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13683
Summary:
Currently for each put, a fresh memory is allocated, and a new entry is added to the memtable with a new sequence number irrespective of whether the key already exists in the memtable. This diff is an attempt to update the value inplace for existing keys. It currently handles a very simple case:
1. Key already exists in the current memtable. Does not inplace update values in immutable memtable or snapshot
2. Latest value type is a 'put' ie kTypeValue
3. New value size is less than existing value, to avoid reallocating memory
TODO: For a put of an existing key, deallocate memory take by values, for other value types till a kTypeValue is found, ie. remove kTypeMerge.
TODO: Update the transaction log, to allow consistent reload of the memtable.
Test Plan: Added a unit test verifying the inplace update. But some other unit tests broken due to invalid sequence number checks. WIll fix them next.
Reviewers: xinyaohu, sumeet, haobo, dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12423
Automatic commit by arc
Summary:
This patch is to address @haobo's comments on D13521:
1. rename Table to be TableReader and make its factory function to be GetTableReader
2. move the compression type selection logic out of TableBuilder but to compaction logic
3. more accurate comments
4. Move stat name constants into BlockBasedTable implementation.
5. remove some uncleaned codes in simple_table_db_test
Test Plan: pass test suites.
Reviewers: haobo, dhruba, kailiu
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13785
Summary: This patch makes Table and TableBuilder a abstract class and make all the implementation of the current table into BlockedBasedTable and BlockedBasedTable Builder.
Test Plan: Make db_test.cc to work with block based table. Add a new test simple_table_db_test.cc where a different simple table format is implemented.
Reviewers: dhruba, haobo, kailiu, emayanke, vamsi
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13521
Summary:
1. Added a new option that support user-defined table stats collection.
2. Added a deleted key stats collector in `utilities`
Test Plan:
Added a unit test for newly added code.
Also ran make check to make sure other tests are not broken.
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13491
Summary:
When a Put fails, it can leave database in a messy state. We don't want to pretend that everything is OK when it may not be. We fail every write following the failed one.
I added checks for corruption to DBImpl::Write(). Is there anywhere else I need to add them?
Test Plan: Corruption unit test.
Reviewers: dhruba, haobo, kailiu
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13671
Summary:
This is to simplify rocksdb public APIs and improve the code quality.
Created an additional parameter to ParseFileName for log sub type and improved the code for deleting a wal file.
Wrote exhaustive unit-tests in delete_file_test
Unification of other redundant APIs can be taken up in a separate diff
Test Plan: Expanded delete_file test
Reviewers: dhruba, haobo, kailiu, sdong
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13647
Summary: as title
Test Plan: make check; ./perf_context_test
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13629
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:
This patch adds a option for universal compaction to allow us to only compress output files if the files compacted previously did not yet reach a specified ratio, to save CPU costs in some cases.
Compression is always skipped for flushing. This is because the size information is not easy to evaluate for flushing case. We can improve it later.
Test Plan:
add test
DBTest.UniversalCompactionCompressRatio1 and DBTest.UniversalCompactionCompressRatio12
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13467
Summary: As title.
Test Plan: Updated the unit tests to make sure new statistic is correctly written/read.
Reviewers: dhruba, haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13497
Summary:
* Logstore requests a valid change of reutrning an empty iterator and not an error in case of no log files.
* Changed the code to return the writebatch containing the sequence number requested from GetupdatesSince even if it lies in the middle. Earlier we used to return the next writebatch,. This also allows me oto guarantee that no files played upon by the iterator are redundant. I mean the starting log file has at least a sequence number >= the sequence number requested form GetupdatesSince.
* Cleaned up redundant logic in Iterator::Next and made a new function SeekToStartSequence for greater readability and maintainibilty.
* Modified a test in db_test accordingly
Please check the logic carefully and suggest improvements. I have a separate patch out for more improvements like restricting reader to read till written sequences.
Test Plan:
* transaction log iterator tests in db_test,
* db_repl_stress.
* rocks_log_iterator_test in fbcode/wormhole/rocksdb/test - 2 tests thriving on hacks till now can get simplified
* testing on the shadow setup for sigma with replication
Reviewers: dhruba, haobo, kailiu, sdong
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13437
Summary:
So far we only have key/value pairs as well as bloom filter stored in the
sst file. It will be great if we are able to store more metadata about
this table itself, for example, the entry size, bloom filter name, etc.
This diff is the first step of this effort. It allows table to keep the
basic statistics mentioned in http://fburl.com/14995441, as well as
allowing writing user-collected stats to stats block.
After this diff, we will figure out the interface of how to allow user to collect their interested statistics.
Test Plan:
1. Added several unit tests.
2. Ran `make check` to ensure it doesn't break other tests.
Reviewers: dhruba, haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13419
Summary:
With this patch, when LRUCache.Insert() is called and the cache is full, it will first try to free up entries whose reference counter is 1 (would become 0 after remo\
ving from the cache). We do it in two passes, in the first pass, we only try to release those unreferenced entries. If we cannot free enough space after traversing t\
he first remove_scan_cnt_ entries, we start from the beginning again and remove those entries being used.
Test Plan: add two unit tests to cover the codes
Reviewers: dhruba, haobo, emayanke
Reviewed By: emayanke
CC: leveldb, emayanke, xjin
Differential Revision: https://reviews.facebook.net/D13377
Summary: I have implemented basic simple use case that I need for External Value Store I'm working on. There is a potential for making this prettier by refactoring/combining WritableFile and RandomAccessFile, avoiding some copypasta. However, I decided to implement just the basic functionality, so I can continue working on the other diff.
Test Plan: Added a unittest
Reviewers: dhruba, haobo, kailiu
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13365
Summary:
The previous release 2.4 had a mapping to alias the older
namespace to rocksdb. This mapping is not needed in the new
release.
Test Plan:
make check
make release
Reviewers: emayanke
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13359
Summary: In some cases, you might not want to store the data log (write ahead log) files in the same dir as the sst files. An example use case is leaf, which stores sst files in tmpfs. And would like to save the log files in a separate dir (disk) to save memory.
Test Plan: make all. Ran db_test test. A few test failing. P2785018. If you guys don't see an obvious problem with the code, maybe somebody from the rocksdb team could help me debug the issue here. Running this on leaf worked well. I could see logs stored on disk, and deleted appropriately after compactions. Obviously this is only one set of options. The unit tests cover different options. Seems like I'm missing some edge cases.
Reviewers: dhruba, haobo, leveldb
CC: xinyaohu, sumeet
Differential Revision: https://reviews.facebook.net/D13239
Summary:
Change namespace from leveldb to rocksdb. This allows a single
application to link in open-source leveldb code as well as
rocksdb code into the same process.
Test Plan: compile rocksdb
Reviewers: emayanke
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13287
Summary: This is useful to keep track of refreshes in transaction log iterator
Test Plan: make; db_stress --statistics=1 shows it
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13281
Summary:
As explained in comments in GetLiveFiles in db.h, this option will cause flush to be skipped in GetLiveFiles because some use-cases use GetSortedWalFiles after GetLiveFiles to generate more complete snapshots.
Using GetSortedWalFiles after GetLiveFiles allows us to not Flush in GetLiveFiles first because wals have everything.
Note: file deletions will be disabled before calling GLF or GSWF so live logs will not move to archive logs or get delted.
Note: Manifest file is truncated to a proper value in GLF, so it will always reply from the proper wal files on a restart
Test Plan: make
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13257
Summary: As title. This is just a quick hack and not ready for commit. fails a lot of unit test. I will test/debug it directly in ViewState shadow .
Test Plan: Try it in shadow test.
Reviewers: dhruba, xjin
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12933
Summary: as title. unit test not polished. this is for a quick live test
Test Plan: live
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13221
Summary:
I am planning to add more to statistics classes but found current way of using enum is very verbose and unnecessarily increase the
difficulity of adding new statistics.
In this diff I removed the code that explicitly specifies the value of each enum entry. This will help us easily add new statistic
items more conveniently without manually adding the value of other enum entries by one.
Test Plan: make; make check;
Reviewers: haobo, dhruba, xjin, emayanke, vamsi
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13197
Summary: as title
Test Plan: make check
Reviewers: dhruba, emayanke
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13179
Summary:
The constructor for Vector memtable has a parameter called 'count'
that specifies the capacity of the vector to be reserved at allocation
time. It was incorrectly used to initialize the size of the vector.
Test Plan: Enhanced db_test.
Reviewers: haobo, xjin, emayanke
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13083
Summary:
Added a new api to the Environment that allows clearing out not-needed
pages from the OS cache. This will be helpful when the compressed
block cache replaces the OS cache.
Test Plan: EnvPosixTest.InvalidateCache
Reviewers: haobo
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13041
Summary:
Added a new field called max_size_amplification_ratio in the
CompactionOptionsUniversal structure. This determines the maximum
percentage overhead of space amplification.
The size amplification is defined to be the ratio between the size of
the oldest file to the sum of the sizes of all other files. If the
size amplification exceeds the specified value, then min_merge_width
and max_merge_width are ignored and a full compaction of all files is done.
A value of 10 means that the size a database that stores 100 bytes
of user data could occupy 110 bytes of physical storage.
Test Plan: Unit test DBTest.UniversalCompactionSpaceAmplification added.
Reviewers: haobo, emayanke, xjin
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12825
Summary:
this is the ground work for separating memtable flush jobs to their own thread pool.
Both SetBackgroundThreads and Schedule take a third parameter Priority to indicate which thread pool they are working on. The names LOW and HIGH are just identifiers for two different thread pools, and does not indicate real difference in 'priority'. We can set number of threads in the pools independently.
The thread pool implementation is refactored.
Test Plan: make check
Reviewers: dhruba, emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12885
Summary: As title. The DB log file life cycle is tied up with the memtable it backs. Once the memtable is flushed to sst and committed, we should be able to delete the log file, without holding the mutex. This is part of the bigger change to avoid FindObsoleteFiles at runtime. It deals with log files. sst files will be dealt with later.
Test Plan: make check; db_bench
Reviewers: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11709
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:
An iterator invokes reseek if the number of sequential skips over the
same userkey exceeds a configured number. This makes iter->Next()
faster (bacause of fewer key compares) if a large number of
adjacent internal keys in a table (sst or memtable) have the
same userkey.
Test Plan: Unit test DBTest.IterReseek.
Reviewers: emayanke, haobo, xjin
Reviewed By: xjin
CC: leveldb, xjin
Differential Revision: https://reviews.facebook.net/D11865
Summary: LogData doesn't consume sequence numbers and doesn't increase the count of the write-batch. Also it was discussed that GetLiveFiles will have to be followed by GetSortedWalFiles to get a lossless backup
Test Plan: visual
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12753
Summary: So that replication can just download from wherever LogFile.Pathname is pointing them.
Test Plan: make all check;./db_repl_stress
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12609
Summary:
Add new command "change_compaction_style" to ldb tool. For
universal->level, it shows "nothing to do". For level->universal, it
compacts all files into a single one and moves the file to level 0.
Also add check for number of files at level 1+ when opening db with
universal compaction style.
Test Plan:
'make all check'. New unit test for internal convertion function. Also manully test various
cmd like:
./ldb change_compaction_style --old_compaction_style=0
--new_compaction_style=1 --db=/tmp/leveldbtest-3088/db_test
Reviewers: haobo, dhruba
Reviewed By: haobo
CC: vamsi, emayanke
Differential Revision: https://reviews.facebook.net/D12603
Summary:
The way counters/statistics are implemented in rocksdb demands that enum Tickers and TickerNameMap follow the same order, otherwise statistics exposed from fbcode/rocks get out-of-sync. 2 counters for prefix had violated this order and when I built counters for fbcode/mcrocksdb, statistics for sequence number were appearing out-of-sync.
The other change is to record sequence-number using setTickerCount only and not recordTick. This is because of difference in statistics as understood by rocks/utils which uses ServiceData::statistics function and rocksdb statistics. In rocksdb there is just 1 counter for a countername. But in ServiceData there are 4 independent buckets for every countername-Count, Sum, Average and Rate. SetTickerCount and RecordTick update the same variable in rocksdb but different buckets in ServiceData. Therefore, I had to choose one consistent function from RecordTick or SetTickerCount for sequence number in rocksdb. I chose SetTickerCount because the statistics object in options passed during rocksdb-open is user-dependent and SetTickerCount makes sense there.
There will be a corresponding diff to mcorcksdb in fbcode shortly.
Test Plan: make all check; check ticker value using fprintfs
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12669
Summary: WouldBlock was an internediate statue but was changed to Incomplete
Test Plan: visual
Reviewers: dhruba
Differential Revision: https://reviews.facebook.net/D12651
Summary:
The DeleteFile API was removing files inside the db-lock. This
is now changed to remove files outside the db-lock.
The GetLiveFilesMetadata() returns the smallest and largest
seqnuence number of each file as well.
Test Plan: deletefile_test
Reviewers: emayanke, haobo
Reviewed By: haobo
CC: leveldb
Maniphest Tasks: T63
Differential Revision: https://reviews.facebook.net/D12567
Summary: Let TransformRepFactory own the passed in transform. Also make it better encapsulated.
Test Plan: make valgrind_check;
Reviewers: dhruba, emayanke
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12591
Summary:
If ReadOptions.non_blocking_io is set to true, then KeyMayExists
and Iterators will return data that is cached in RAM.
If the Iterator needs to do IO from storage to serve the data,
then the Iterator.status() will return Status::IsRetry().
Test Plan:
Enhanced unit test DBTest.KeyMayExist to detect if there were are IOs
issues from storage. Added DBTest.NonBlockingIteration to verify
nonblocking Iterations.
Reviewers: emayanke, haobo
Reviewed By: haobo
CC: leveldb
Maniphest Tasks: T63
Differential Revision: https://reviews.facebook.net/D12531
Summary: There is a memory leak because TransformRepFactory does not delete its SliceTransform pointer. This patch adds a delete to the destructor.
Test Plan:
make check
make valgrind_check
Reviewers: dhruba, emayanke, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12513
Summary: Fix code so that the filter_block layer only assumes keys are internal when prefix_extractor is set.
Test Plan: ./filter_block_test
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12501
Summary: Replace include/leveldb with include/rocksdb.
Test Plan:
make clean; make check
make clean; make release
Differential Revision: https://reviews.facebook.net/D12489
Summary:
This patch adds three new MemTableRep's: UnsortedRep, PrefixHashRep, and VectorRep.
UnsortedRep stores keys in an std::unordered_map of std::sets. When an iterator is requested, it dumps the keys into an std::set and iterates over that.
VectorRep stores keys in an std::vector. When an iterator is requested, it creates a copy of the vector and sorts it using std::sort. The iterator accesses that new vector.
PrefixHashRep stores keys in an unordered_map mapping prefixes to ordered sets.
I also added one API change. I added a function MemTableRep::MarkImmutable. This function is called when the rep is added to the immutable list. It doesn't do anything yet, but it seems like that could be useful. In particular, for the vectorrep, it means we could elide the extra copy and just sort in place. The only reason I haven't done that yet is because the use of the ArenaAllocator complicates things (I can elaborate on this if needed).
Test Plan:
make -j32 check
./db_stress --memtablerep=vector
./db_stress --memtablerep=unsorted
./db_stress --memtablerep=prefixhash --prefix_size=10
Reviewers: dhruba, haobo, emayanke
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12117
Summary: If use_prefix_filters is set and read_range>1, then the random seeks will set a the prefix filter to be the prefix of the key which was randomly selected as the target. Still need to add statistics (perhaps in a separate diff).
Test Plan: ./db_bench --benchmarks=fillseq,prefixscanrandom --num=10000000 --statistics=1 --use_prefix_blooms=1 --use_prefix_api=1 --bloom_bits=10
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb, haobo
Differential Revision: https://reviews.facebook.net/D12273
Summary: An api to query the level, key ranges, size etc for each SST file and an api to delete a specific file from the db and all associated state in the bookkeeping datastructures.
Notes: Editing the manifest version does not release the obsolete files right away. However deleting the file directly will mess up the iterator. We may need a more aggressive/timely file deletion api.
I have used std::unique_ptr - will switch to boost:: since this is external. thoughts?
Unit test is fragile right now as it expects the compaction at certain levels.
Test Plan: unittest
Reviewers: dhruba, vamsi, emayanke
CC: zshao, leveldb, haobo
Task ID: #
Blame Rev:
Summary:
Sometimes you don't need to iterate through the whole WriteBatch. This diff makes the Handler member functions return a bool that indicates whether to abort or not. If they return true, the iteration stops.
One thing I just thought of is that this will break backwards-compability. Maybe it would be better to add a virtual member function WriteBatch::Handler::ShouldAbort() that returns false by default. Comments requested.
I still have to add a new unit test for the abort code, but let's finalize the API first.
Test Plan: make -j32 check
Reviewers: dhruba, haobo, vamsi, emayanke
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12339
Test Plan:
- make all check;
- make release;
- make stringappend_test; ./stringappend_test
Reviewers: haobo, emayanke
Reviewed By: haobo
CC: leveldb, kailiu
Differential Revision: https://reviews.facebook.net/D12381
Summary: Also expanded class LogFile to have startSequene and FileSize and exposed it publicly
Test Plan: make all check
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12087
Summary:
-Added null checks and revisions to DBIter::MergeValuesNewToOld()
-Added DBIter test to stringappend_test
-Major fix with Merge and TTL
More plans for fixes later.
Test Plan:
-make clean; make stringappend_test -j 32; ./stringappend_test
-make all check;
Reviewers: haobo, emayanke, vamsi, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12315
Summary: statistic for sequence number is needed by wormhole. setTickerCount is demanded for this statistic. I can't simply recordTick(max_sequence) when db recovers because the statistic iobject is owned by client and may/may not be reset during reopen. Eg. statistic is reset in mcrocksdb whereas it is not in db_stress. Therefore it is best to go with setTickerCount
Test Plan: ./db_stress ... --statistics=1 and observed expected sequence number
Reviewers: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12327
Summary:
This patch adds the ability for the user to add sequences of arbitrary data (blobs) to write batches. These blobs are saved to the log along with everything else in the write batch. You can add multiple blobs per WriteBatch and the ordering of blobs, puts, merges, and deletes are preserved.
Blobs are not saves to SST files. RocksDB ignores blobs in every way except for writing them to the log.
Before committing this patch, I need to add some test code. But I'm submitting it now so people can comment on the API.
Test Plan: make -j32 check
Reviewers: dhruba, haobo, vamsi
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12195
Summary:
As title. No locking/atomic is needed due to thread local. There is also no need to modify the existing client interface, in order to expose related counters.
perf_context_test shows a simple example of retrieving the number of user key comparison done for each put and get call. More counters could be added later.
Sample output
./perf_context_test 1000000
==== Test PerfContextTest.KeyComparisonCount
Inserting 1000000 key/value pairs
...
total user key comparison get: 43446523
total user key comparison put: 8017877
max user key comparison get: 88939
avg user key comparison get:43
Basically, the current skiplist does well on average, but could perform poorly in extreme cases.
Test Plan: run perf_context_test <total number of entries to put/get>
Reviewers: dhruba
Differential Revision: https://reviews.facebook.net/D12225
Summary:
With Merge returning bool, it can keep failing silently(eg. While faling to fetch timestamp in TTL). We need to detect this through a rocksdb counter which can get bumped whenever Merge returns false. This will also be super-useful for the mcrocksdb-counter service where Merge may fail.
Added a counter NUMBER_MERGE_FAILURES and appropriately updated db/merge_helper.cc
I felt that it would be better to directly add counter-bumping in Merge as a default function of MergeOperator class but user should not be aware of this, so this approach seems better to me.
Test Plan: make all check
Reviewers: dnicholas, haobo, dhruba, vamsi
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12129
Summary: Similar to v2 (db and table code understands prefixes), but use ReadOptions as in v3. Also, make the CreateFilter code faster and cleaner.
Test Plan: make db_test; export LEVELDB_TESTS=PrefixScan; ./db_test
Reviewers: dhruba
Reviewed By: dhruba
CC: haobo, emayanke
Differential Revision: https://reviews.facebook.net/D12027
Summary:
If we have same compaction filter for each compaction,
application cannot know about the different compaction processes.
Later on, we can put in more details in compaction filter for the
application to consume and use it according to its needs. For e.g. In
the universal compaction, we have a compaction process involving all the
files while others don't involve all the files. Applications may want to
collect some stats only when during full compaction.
Test Plan: run existing unit tests
Reviewers: haobo, dhruba
Reviewed By: dhruba
CC: xinyaohu, leveldb
Differential Revision: https://reviews.facebook.net/D12057
Summary:
Here are the major changes to the Merge Interface. It has been expanded
to handle cases where the MergeOperator is not associative. It does so by stacking
up merge operations while scanning through the key history (i.e.: during Get() or
Compaction), until a valid Put/Delete/end-of-history is encountered; it then
applies all of the merge operations in the correct sequence starting with the
base/sentinel value.
I have also introduced an "AssociativeMerge" function which allows the user to
take advantage of associative merge operations (such as in the case of counters).
The implementation will always attempt to merge the operations/operands themselves
together when they are encountered, and will resort to the "stacking" method if
and only if the "associative-merge" fails.
This implementation is conjectured to allow MergeOperator to handle the general
case, while still providing the user with the ability to take advantage of certain
efficiencies in their own merge-operator / data-structure.
NOTE: This is a preliminary diff. This must still go through a lot of review,
revision, and testing. Feedback welcome!
Test Plan:
-This is a preliminary diff. I have only just begun testing/debugging it.
-I will be testing this with the existing MergeOperator use-cases and unit-tests
(counters, string-append, and redis-lists)
-I will be "desk-checking" and walking through the code with the help gdb.
-I will find a way of stress-testing the new interface / implementation using
db_bench, db_test, merge_test, and/or db_stress.
-I will ensure that my tests cover all cases: Get-Memtable,
Get-Immutable-Memtable, Get-from-Disk, Iterator-Range-Scan, Flush-Memtable-to-L0,
Compaction-L0-L1, Compaction-Ln-L(n+1), Put/Delete found, Put/Delete not-found,
end-of-history, end-of-file, etc.
-A lot of feedback from the reviewers.
Reviewers: haobo, dhruba, zshao, emayanke
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11499
Summary: This diff adds histogram stats for soft_rate_limit stalls. It also renames the old rate_limit stats to hard_rate_limit.
Test Plan: make -j32 check
Reviewers: dhruba, haobo, MarkCallaghan
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12021
Summary: rocksdb replicaiton will need this when writing value+TS from master to slave 'as is'
Test Plan: make
Reviewers: dhruba, vamsi, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11919
Summary:
This diff adds support for both soft and hard rate limiting. The following changes are included:
1) Options.rate_limit is renamed to Options.hard_rate_limit.
2) Options.rate_limit_delay_milliseconds is renamed to Options.rate_limit_delay_max_milliseconds.
3) Options.soft_rate_limit is added.
4) If the maximum compaction score is > hard_rate_limit and rate_limit_delay_max_milliseconds == 0, then writes are delayed by 1 ms at a time until the max compaction score falls below hard_rate_limit.
5) If the max compaction score is > soft_rate_limit but <= hard_rate_limit, then writes are delayed by 0-1 ms depending on how close we are to hard_rate_limit.
6) Users can disable 4 by setting hard_rate_limit = 0. They can add a limit to the maximum amount of time waited by setting rate_limit_delay_max_milliseconds > 0. Thus, the old behavior can be preserved by setting soft_rate_limit = 0, which is the default.
Test Plan:
make -j32 check
./db_stress
Reviewers: dhruba, haobo, MarkCallaghan
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12003
Summary: TTL uses compaction filter to purge key-values and required the user to not pass one. This diff makes it accommodating of user's compaciton filter. Added test to ttl_test
Test Plan: make; ./ttl_test
Reviewers: dhruba, haobo, vamsi
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11973
Summary: Removed KeyMayExistImpl because KeyMayExist demanded Get like semantics now. Removed no_io from memtable and imm because we need the proper value now and shouldn't just stop when we see Merge in memtable. Added checks to block_cache. Updated documentation and unit-test
Test Plan: make all check;db_stress for 1 hour
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11853
Summary:
Currently, when a certain number of level0 files (level0_slowdown_writes_trigger) are present, RocksDB will slow down each write by 1ms. There is a second limit of level0 files at which RocksDB will stop writes altogether (level0_stop_writes_trigger).
This patch enables the user to supply a third parameter specifying the number of files at which Rocks will start slowing down writes (level0_start_slowdown_writes). When this number is reached, Rocks will slow down writes as a quadratic function of level0_slowdown_writes_trigger - num_level0_files.
For some workloads, this improves latency and throughput. I will post some stats momentarily in https://our.intern.facebook.com/intern/tasks/?t=2613384.
Test Plan:
make -j32 check
./db_stress
./db_bench
Reviewers: dhruba, haobo, MarkCallaghan, xjin
Reviewed By: xjin
CC: leveldb, xjin, zshao
Differential Revision: https://reviews.facebook.net/D11859
Summary:
Add an option for arena block size, default value 4096 bytes. Arena will allocate blocks with such size.
I am not sure about passing parameter to skiplist in the new virtualized framework, though I talked to Jim a bit. So add Jim as reviewer.
Test Plan:
new unit test, I am running db_test.
For passing paramter from configured option to Arena, I tried tests like:
TEST(DBTest, Arena_Option) {
std::string dbname = test::TmpDir() + "/db_arena_option_test";
DestroyDB(dbname, Options());
DB* db = nullptr;
Options opts;
opts.create_if_missing = true;
opts.arena_block_size = 1000000; // tested 99, 999999
Status s = DB::Open(opts, dbname, &db);
db->Put(WriteOptions(), "a", "123");
}
and printed some debug info. The results look good. Any suggestion for such a unit-test?
Reviewers: haobo, dhruba, emayanke, jpaton
Reviewed By: dhruba
CC: leveldb, zshao
Differential Revision: https://reviews.facebook.net/D11799
Summary: Previously, statistics are kept on how much time is spent on stalls of different types. This patch adds support for keeping number of stalls of each type. For example, instead of just reporting how many microseconds are spent waiting for memtables to be compacted, it will also report how many times a write stalled for that to occur.
Test Plan:
make -j32 check
./db_stress
# Not really sure what else should be done...
Reviewers: dhruba, MarkCallaghan, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11841
Summary: This diff virtualizes the skiplist interface so that users can provide their own implementation of a backing store for MemTables. Eventually, the backing store will be responsible for its own synchronization, allowing users (and us) to experiment with different lockless implementations.
Test Plan:
make clean
make -j32 check
./db_stress
Reviewers: dhruba, emayanke, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11739
Summary:
Introduced KeyMayExist checking during writebatch-delete and removed from Outer Delete API because it uses writebatch-delete.
Added code to skip getting Table from disk if not already present in table_cache.
Some renaming of variables.
Introduced KeyMayExistImpl which allows checking since specified sequence number in GetImpl useful to check partially written writebatch.
Changed KeyMayExist to not be pure virtual and provided a default implementation.
Expanded unit-tests in db_test to check appropriately.
Ran db_stress for 1 hour with ./db_stress --max_key=100000 --ops_per_thread=10000000 --delpercent=50 --filter_deletes=1 --statistics=1.
Test Plan: db_stress;make check
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb, xjin
Differential Revision: https://reviews.facebook.net/D11745
Summary: As title. This diff added an option reduce_level to CompactRange. When set to true, it will try to move the files back to the minimum level sufficient to hold the data set. Note that the default is set to true now, just to excerise it in all existing tests. Will set the default to false before check-in, for backward compatibility.
Test Plan: make check;
Reviewers: dhruba, emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11553
Summary:
Wrote a new function in db_impl.c-CheckKeyMayExist that calls Get but with a new parameter turned on which makes Get return false only if bloom filters can guarantee that key is not in database. Delete calls this function and if the option- deletes_use_filter is turned on and CheckKeyMayExist returns false, the delete will be dropped saving:
1. Put of delete type
2. Space in the db,and
3. Compaction time
Test Plan:
make all check;
will run db_stress and db_bench and enhance unit-test once the basic design gets approved
Reviewers: dhruba, haobo, vamsi
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11607
Summary:
Rename PickCompactionHybrid to PickCompactionUniversal.
Changed a few LOG message from "Hybrid:" to "Universal:".
Test Plan:
Reviewers:
CC:
Task ID: #
Blame Rev:
Summary: rocksdb-2.0 released to third party
Test Plan: visual inspection
Reviewers: dhruba, haobo, sheki
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11559
Summary:
There is a new option called hybrid_mode which, when switched on,
causes HBase style compactions. Files from L0 are
compacted back into L0. This meat of this compaction algorithm
is in PickCompactionHybrid().
All files reside in L0. That means all files have overlapping
keys. Each file has a time-bound, i.e. each file contains a
range of keys that were inserted around the same time. The
start-seqno and the end-seqno refers to the timeframe when
these keys were inserted. Files that have contiguous seqno
are compacted together into a larger file. All files are
ordered from most recent to the oldest.
The current compaction algorithm starts to look for
candidate files starting from the most recent file. It continues to
add more files to the same compaction run as long as the
sum of the files chosen till now is smaller than the next
candidate file size. This logic needs to be debated
and validated.
The above logic should reduce write amplification to a
large extent... will publish numbers shortly.
Test Plan: dbstress runs for 6 hours with no data corruption (tested so far).
Differential Revision: https://reviews.facebook.net/D11289
Summary: As title. Exposed a Count function that returns the number of updates in a batch. Could be handy for replication sequence number check.
Test Plan: make check;
Reviewers: emayanke, sheki, dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11523
Summary: as title, use initialize list so that lines fit in 80 chars.
Test Plan: make check;
Reviewers: sheki, dhruba
Differential Revision: https://reviews.facebook.net/D11385
Summary: as title, also removed an incorrect assertion
Test Plan: make check; db_stress --mmap_read=1; db_stress --mmap_read=0
Reviewers: dhruba, emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11367
Summary: This diff added an option to control the incremenal sync frequency. db_bench has a new flag bytes_per_sync for easy tuning exercise.
Test Plan: make check; db_bench
Reviewers: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11295
Summary:
Merge multiple multiple memtables in memory before writing it
out to a file in L0.
There is a new config parameter min_write_buffer_number_to_merge
that specifies the number of write buffers that should be merged
together to a single file in storage. The system will not flush
wrte buffers to storage unless at least these many buffers have
accumulated in memory.
The default value of this new parameter is 1, which means that
a write buffer will be immediately flushed to disk as soon it is
ready.
Test Plan: make check
Differential Revision: https://reviews.facebook.net/D11241
Summary: Add a histogram to track WriteBlock times
Test Plan: db_bench and print
Reviewers: haobo, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11319
Summary: Table is setup for compaction using Table::SetupForCompaction. So read block calls can be differentiated b/w Gets/Compaction. Use this and measure times.
Test Plan: db_bench --statistics=1
Reviewers: dhruba, haobo
Reviewed By: haobo
CC: leveldb, MarkCallaghan
Differential Revision: https://reviews.facebook.net/D11217
Summary:
During compaction, we sync the output files after they are fully written out. This causes unnecessary blocking of the compaction thread and burstiness of the write traffic.
This diff simply asks the OS to sync data incrementally as they are written, on the background. The hope is that, at the final sync, most of the data are already on disk and we would block less on the sync call. Thus, each compaction runs faster and we could use fewer number of compaction threads to saturate IO.
In addition, the write traffic will be smoothed out, hopefully reducing the IO P99 latency too.
Some quick tests show 10~20% improvement in per thread compaction throughput. Combined with posix advice on compaction read, just 5 threads are enough to almost saturate the udb flash bandwidth for 800 bytes write only benchmark.
What's more promising is that, with saturated IO, iostat shows average wait time is actually smoother and much smaller.
For the write only test 800bytes test:
Before the change: await occillate between 10ms and 3ms
After the change: await ranges 1-3ms
Will test against read-modify-write workload too, see if high read latency P99 could be resolved.
Will introduce a parameter to control the sync interval in a follow up diff after cleaning up EnvOptions.
Test Plan: make check; db_bench; db_stress
Reviewers: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11115
Summary:
This diff simplifies EnvOptions by treating it as POD, similar to Options.
- virtual functions are removed and member fields are accessed directly.
- StorageOptions is removed.
- Options.allow_readahead and Options.allow_readahead_compactions are deprecated.
- Unused global variables are removed: useOsBuffer, useFsReadAhead, useMmapRead, useMmapWrite
Test Plan: make check; db_stress
Reviewers: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11175
Summary: the assert was wrong in D11145. Broke build
Test Plan: make db_bench run it
Reviewers: dhruba, haobo, emayanke
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11187
Summary: Provide a map of histograms and ticker vs strings. Fb303 libraries can use this to provide the mapping. We will not have to duplicate the code during release.
Test Plan: db_bench with statistics=1
Reviewers: dhruba, haobo
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11145
Summary:
Implemented the MultiGet operator which takes in a list of keys
and returns their associated values. Currently uses std::vector as its
container data structure. Otherwise, it works identically to "Get".
Test Plan:
1. make db_test ; compile it
2. ./db_test ; test it
3. make all check ; regress / run all tests
4. make release ; (optional) compile with release settings
Reviewers: haobo, MarkCallaghan, dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10875
Summary:
This diff adds an option to specify whether PTHREAD_MUTEX_ADAPTIVE_NP will be enabled for the rocksdb single big kernel lock. db_bench also have this option now.
Quickly tested 8 thread cpu bound 100 byte random read.
No fast mutex: ~750k/s ops
With fast mutex: ~880k/s ops
Test Plan: make check; db_bench; db_stress
Reviewers: dhruba
CC: MarkCallaghan, leveldb
Differential Revision: https://reviews.facebook.net/D11031
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
