Commit Graph

14 Commits

Author SHA1 Message Date
Igor Canadi
3c75cc15a9 Fix HashSkipList and HashLinkedList SIGSEGV
Summary:
Original Summary:
Yesterday, @ljin and I were debugging various db_stress issues. We suspected one of them happens when we concurrently call NewIterator without prefix_seek on HashSkipList. This test demonstrates it.

Update:
Arena is not thread-safe!! When creating a new full iterator, we *have* to create a new arena, otherwise we're doomed.

Test Plan: SIGSEGV and assertion-throwing test now works!

Reviewers: ljin, haobo, sdong

Reviewed By: sdong

CC: leveldb, ljin

Differential Revision: https://reviews.facebook.net/D16857
2014-03-14 10:02:04 -07:00
Lei Jin
8d007b4aaf Consolidate SliceTransform object ownership
Summary:
(1) Fix SanitizeOptions() to also check HashLinkList. The current
dynamic case just happens to work because the 2 classes have the same
layout.
(2) Do not delete SliceTransform object in HashSkipListFactory and
HashLinkListFactory destructor. Reason: SanitizeOptions() enforces
prefix_extractor and SliceTransform to be the same object when
Hash**Factory is used. This makes the behavior strange: when
Hash**Factory is used, prefix_extractor will be released by RocksDB. If
other memtable factory is used, prefix_extractor should be released by
user.

Test Plan: db_bench && make asan_check

Reviewers: haobo, igor, sdong

Reviewed By: igor

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D16587
2014-03-10 12:56:46 -07:00
sdong
b2d29675c8 Add a test in prefix_test to verify correctness of results
Summary:
Add a test to verify HashLinkList and HashSkipList (mainly for the former one) returns the correct results when inserting the same bucket in the different orders.

Some other changes:
(1) add the test to test list
(2) fix compile error
(3) add header

Test Plan: ./prefix_test

Reviewers: haobo, kailiu

Reviewed By: haobo

CC: igor, yhchiang, i.am.jin.lei, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D16143
2014-02-19 17:00:34 -08:00
Siying Dong
5b5ab0c1a8 [Performance Branch] Fix memory leak in HashLinkListRep.GetIterator()
Summary: Full list constructed for full iterator can be leaked. This was a bug introduced when I copy the full iterator codes from hash skip list to hash link list. This patch fixes it.

Test Plan: Run valgrind test against db_test and make sure the memory leak is fixed

Reviewers: kailiu, haobo

Reviewed By: kailiu

CC: igor, leveldb

Differential Revision: https://reviews.facebook.net/D15093
2014-01-10 12:12:28 -08:00
Siying Dong
424a524ac9 [Performance Branch] A Hashed Linked List Based Mem Table
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
2014-01-09 16:19:11 -08:00
Haobo Xu
3c02c363b3 [RocksDB] [Performance Branch] Added dynamic bloom, to be used for memable non-existing key filtering
Summary: as title

Test Plan: dynamic_bloom_test

Reviewers: dhruba, sdong, kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14385
2013-12-11 00:15:14 -08:00
kailiu
551e9428ce Merge branch 'master' into performance 2013-12-06 14:15:42 -08:00
Igor Canadi
eb12e47e0e Killing Transform Rep
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
2013-12-03 12:42:15 -08:00
Haobo Xu
4e6463ea44 [RocksDB][Performance Branch] Make height and branching factor configurable for skiplist implementation
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
2013-11-26 21:59:36 -08:00
Haobo Xu
a617227a36 [RocksDB] fix prefix_test
Summary: user comparator needs to work if either input is prefix only.

Test Plan: ./prefix_test --write_buffer_size=100000 --total_prefixes=10000 --items_per_prefix=10

Reviewers: dhruba, igor

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14241
2013-11-20 09:16:23 -08:00
Igor Canadi
8b3379dc0a Implementing DynamicIterator for TransformRepNoLock
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
2013-11-08 00:31:09 -08:00
Haobo Xu
fd2044883a [RocksDB] Generalize prefix-aware iterator to be used for more than one Seek
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
2013-11-06 20:45:49 -08:00
Igor Canadi
be96f2498e TransformRep - use array instead of unordered_map
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
2013-11-06 11:55:43 -08:00
Haobo Xu
fe4a449472 [RocksDB] prefixhash memtable test
Summary: as title, half baked test for prefixhash memtable. Also contains deadlock test option

Test Plan: run it

Reviewers: igor, dhruba

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13887
2013-11-05 23:20:10 -08:00