Patch 8.6.6 #11886
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Patch 8.6.6 #11886
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…11865) Summary: when atomic_flush=false, there are certain cases where we try to install memtable results with already deleted SST files. This can happen when the following sequence events happen: ``` Start Flush0 for memtable M0 to SST0 Start Flush1 for memtable M1 to SST1 Flush 1 returns OK, but don't install to MANIFEST and let whoever flushes M0 to take care of it Flush0 finishes with a retryable IOError, it rollbacks M0, (incorrectly) does not rollback M1, and deletes SST0 and SST1 Starts Flush2 for M0, it does not pick up M1 since it thought M1 is flushed Flush2 writes SST2 and finishes OK, tries to install SST2 and SST1 Error opening SST1 since it's already deleted with an error message like the following: IO error: No such file or directory: While open a file for random read: /tmp/rocksdbtest-501/db_flush_test_3577_4230653031040984171/000011.sst: No such file or directory ``` This happens since: 1. We currently only rollback the memtables that we are flushing in a flush job when atomic_flush=false. 2. Pending output SSTs from previous flushes are deleted since a pending file number is released whenever a flush job is finished no matter of flush status: https://github.com/facebook/rocksdb/blob/f42e70bf561d4be9b6bbe7316d1c2c0c8a3818e6/db/db_impl/db_impl_compaction_flush.cc#L3161 This PR fixes the issue by rollback these pending flushes. There is another issue where if a new flush for new memtable starts and finishes after Flush0 finishes. Its output may also be deleted (see more in unit test). It is fixed by checking bg error status before installing a memtable result, and rollback if there is an error. There is a more efficient fix where we just don't release the pending file output number for flushes that delegate installation. It is more efficient since it does not have to rewrite the flush output file. With the fix in this PR, we can end up with a giant file if a lot of memtables are being flushed together. However, the more efficient fix is a bit more complicated to implement (requires associating such pending file numbers with flush job/memtables) and is more risky since it changes normal flush code path. Pull Request resolved: facebook#11865 Test Plan: * Added repro unit tests. Reviewed By: anand1976 Differential Revision: D49484922 Pulled By: cbi42 fbshipit-source-id: 25b536c08f4e02e7f1d0f86571663737d2b5d53d
…lure (facebook#11872) Summary: With atomic_flush=true, a flush job with younger memtables wait for older memtables to be installed before install its memtables. If the flush for older memtables failed, auto-recovery starts a resume thread which can becomes stuck waiting for all background work to finish (including the flush for younger memtables). If a non-recovery flush starts now and tries to flush, it can make the situation worse since it will fail due to background error but never rollback its memtable: https://github.com/facebook/rocksdb/blob/269478ee4618283cd6d710fdfea9687157a259c1/db/db_impl/db_impl_compaction_flush.cc#L725 This prevents any future flush to pick old memtables. A more detailed repro is in unit test. This PR fixes this issue by 1. Ensure we rollback memtables if an atomic flush fails due to background error 2. When there is a background error, abort atomic flushes that are waiting for older memtables to be installed 3. Do not schedule non-recovery flushes when there is a background error that stops background work There was another issue with atomic_flush=true where DB can hang during DB close, see more in facebook#11867. The fix in this PR, specifically fix 2 above, should be enough to resolve it too. Pull Request resolved: facebook#11872 Test Plan: new unit test. Reviewed By: jowlyzhang Differential Revision: D49556867 Pulled By: cbi42 fbshipit-source-id: 4a0210ff28a8552a99ece7fbb0f574fd24b4da3f
Summary: facebook#11872 causes a unit test to start failing with the error message below. The cause is that the additional call to `FlushAllColumnFamilies()` in `DBImpl::ResumeImpl()` can run while DB is closing. More detailed explanation: there are two places where we call `ResumeImpl()`: 1. in `ErrorHandler::RecoverFromBGError`, for manual resume or recovery from errors like OutOfSpace through sst file manager, and 2. in `Errorhandler::RecoverFromRetryableBGIOError`, for error recovery from errors like flush failure due to retryable IOError. This is tracked by `ErrorHandler::recovery_thread_`. Here is how DB close waits for error recovery: https://github.com/facebook/rocksdb/blob/49da91ec097b4efcd8a8e4dc1b287e9f81eb4093/db/db_impl/db_impl.cc#L540-L543 `CancelErrorRecovery()` waits until `recovery_thread_` finishes and `IsRecoveryInProgress()` checks the `recovery_in_prog_` flag. The additional call to `FlushAllColumnFamilies()` in `ResumeImpl()` happens after it clears bg error and the `recovery_in_prog_` flag: https://github.com/facebook/rocksdb/blob/49da91ec097b4efcd8a8e4dc1b287e9f81eb4093/db/db_impl/db_impl.cc#L436-L463. So if `ResumeImpl()` is called in `RecoverFromBGError()`, we can have a thread running `FlushAllColumnFamilies()` while DB is closing and thought that recovery is done. The fix is to only do the additional call to `FlushAllColumnFamilies()` when doing error recovery through `Errorhandler::RecoverFromRetryableBGIOError` by setting flags in `DBRecoverContext`. Pull Request resolved: facebook#11880 Test Plan: `gtest-parallel --repeat=100 --workers=4 ./error_handler_fs_test --gtest_filter="*AutoRecoverFlushError*"` reproduces the error pretty reliably. ```[==========] Running 1 test from 1 test case. [----------] Global test environment set-up. [----------] 1 test from DBErrorHandlingFSTest [ RUN ] DBErrorHandlingFSTest.AutoRecoverFlushError error_handler_fs_test: db/column_family.cc:1618: rocksdb::ColumnFamilySet::~ColumnFamilySet(): Assertion `last_ref' failed. Received signal 6 (Aborted) ... facebook#10 0x00007fac4409efd6 in __GI___assert_fail (assertion=0x7fac452c0afa "last_ref", file=0x7fac452c9fb5 "db/column_family.cc", line=1618, function=0x7fac452cb950 "rocksdb::ColumnFamilySet::~ColumnFamilySet()") at assert.c:101 101 in assert.c facebook#11 0x00007fac44b5324f in rocksdb::ColumnFamilySet::~ColumnFamilySet (this=0x7b5400000000) at db/column_family.cc:1618 1618 assert(last_ref); facebook#12 0x00007fac44e0f047 in std::default_delete<rocksdb::ColumnFamilySet>::operator() (this=0x7b5800000940, __ptr=0x7b5400000000) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:85 85 delete __ptr; facebook#13 std::__uniq_ptr_impl<rocksdb::ColumnFamilySet, std::default_delete<rocksdb::ColumnFamilySet> >::reset (this=0x7b5800000940, __p=0x0) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:182 182 _M_deleter()(__old_p); facebook#14 std::unique_ptr<rocksdb::ColumnFamilySet, std::default_delete<rocksdb::ColumnFamilySet> >::reset (this=0x7b5800000940, __p=0x0) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:456 456 _M_t.reset(std::move(__p)); facebook#15 rocksdb::VersionSet::~VersionSet (this=this@entry=0x7b5800000900) at db/version_set.cc:5081 5081 column_family_set_.reset(); facebook#16 0x00007fac44e0f97a in rocksdb::VersionSet::~VersionSet (this=0x7b5800000900) at db/version_set.cc:5078 5078 VersionSet::~VersionSet() { facebook#17 0x00007fac44bf0b2f in std::default_delete<rocksdb::VersionSet>::operator() (this=0x7b8c00000068, __ptr=0x7b5800000900) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:85 85 delete __ptr; facebook#18 std::__uniq_ptr_impl<rocksdb::VersionSet, std::default_delete<rocksdb::VersionSet> >::reset (this=0x7b8c00000068, __p=0x0) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:182 182 _M_deleter()(__old_p); facebook#19 std::unique_ptr<rocksdb::VersionSet, std::default_delete<rocksdb::VersionSet> >::reset (this=0x7b8c00000068, __p=0x0) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:456 456 _M_t.reset(std::move(__p)); facebook#20 rocksdb::DBImpl::CloseHelper (this=this@entry=0x7b8c00000000) at db/db_impl/db_impl.cc:676 676 versions_.reset(); facebook#21 0x00007fac44bf1346 in rocksdb::DBImpl::CloseImpl (this=0x7b8c00000000) at db/db_impl/db_impl.cc:720 720 Status DBImpl::CloseImpl() { return CloseHelper(); } facebook#22 rocksdb::DBImpl::~DBImpl (this=this@entry=0x7b8c00000000) at db/db_impl/db_impl.cc:738 738 closing_status_ = CloseImpl(); facebook#23 0x00007fac44bf2bba in rocksdb::DBImpl::~DBImpl (this=0x7b8c00000000) at db/db_impl/db_impl.cc:722 722 DBImpl::~DBImpl() { facebook#24 0x00007fac455444d4 in rocksdb::DBTestBase::Close (this=this@entry=0x7b6c00000000) at db/db_test_util.cc:678 678 delete db_; facebook#25 0x00007fac455455fb in rocksdb::DBTestBase::TryReopen (this=this@entry=0x7b6c00000000, options=...) at db/db_test_util.cc:707 707 Close(); facebook#26 0x00007fac45543459 in rocksdb::DBTestBase::Reopen (this=0x7ffed74b79a0, options=...) at db/db_test_util.cc:670 670 ASSERT_OK(TryReopen(options)); facebook#27 0x00000000004f2522 in rocksdb::DBErrorHandlingFSTest_AutoRecoverFlushError_Test::TestBody (this=this@entry=0x7b6c00000000) at db/error_handler_fs_test.cc:1224 1224 Reopen(options); ``` Reviewed By: jowlyzhang Differential Revision: D49579701 Pulled By: cbi42 fbshipit-source-id: 3fc8325e6dde7e7faa8bcad95060cb4e26eda638
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Include #11865, #11872 and #11880. Updates version.h and HISTORY.md.
Test plan: CI