mirror of https://github.com/facebook/rocksdb.git
ed46981bea
Summary: FilePrefetchBuffer makes an unchecked assumption about the behavior of RandomAccessFileReader::Read: that it will write to the provided buffer rather than returning the data in an alternate buffer. FilePrefetchBuffer has been quietly incompatible with mmap reads (e.g. allow_mmap_reads / use_mmap_reads) because in that case an alternate buffer is returned (mmapped memory). This incompatibility currently leads to quiet data corruption, as seen in amplified crash test failure in https://github.com/facebook/rocksdb/issues/12200. In this change, * Check whether RandomAccessFileReader::Read has the expected behavior, and fail if not. (Assertion failure in debug build, return Corruption in release build.) This will detect future regressions synchronously and precisely, rather than relying on debugging downstream data corruption. * Why not recover? My understanding is that FilePrefetchBuffer is not intended for use when RandomAccessFileReader::Read uses an alternate buffer, so quietly recovering could lead to undesirable (inefficient) behavior. * Mention incompatibility with mmap-based readers in the internal API comments for FilePrefetchBuffer * Fix two cases where FilePrefetchBuffer could be used with mmap, both stemming from SstFileDumper, though one fix is in BlockBasedTableReader. There is currently no way to ask a RandomAccessFileReader whether it's using mmap, so we currently have to rely on other options as clues. Keeping separate from https://github.com/facebook/rocksdb/issues/12200 in part because this change is more appropriate for backport than that one. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12206 Test Plan: * Manually verified that the new check aids in debugging. * Unit test added, that fails if either fix is missed. * Ran blackbox_crash_test for hours, with and without https://github.com/facebook/rocksdb/issues/12200 Reviewed By: akankshamahajan15 Differential Revision: D52551701 Pulled By: pdillinger fbshipit-source-id: dea87c5782b7c484a6c6e424585c8832dfc580dc |
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| .. | ||
| advisor | ||
| block_cache_analyzer | ||
| dump | ||
| CMakeLists.txt | ||
| Dockerfile | ||
| analyze_txn_stress_test.sh | ||
| auto_sanity_test.sh | ||
| backup_db.sh | ||
| benchmark.sh | ||
| benchmark_ci.py | ||
| benchmark_compare.sh | ||
| benchmark_leveldb.sh | ||
| blob_dump.cc | ||
| check_all_python.py | ||
| check_format_compatible.sh | ||
| db_bench.cc | ||
| db_bench_tool.cc | ||
| db_bench_tool_test.cc | ||
| db_crashtest.py | ||
| db_repl_stress.cc | ||
| db_sanity_test.cc | ||
| dbench_monitor | ||
| generate_random_db.sh | ||
| ingest_external_sst.sh | ||
| io_tracer_parser.cc | ||
| io_tracer_parser_test.cc | ||
| io_tracer_parser_tool.cc | ||
| io_tracer_parser_tool.h | ||
| ldb.cc | ||
| ldb_cmd.cc | ||
| ldb_cmd_impl.h | ||
| ldb_cmd_test.cc | ||
| ldb_test.py | ||
| ldb_tool.cc | ||
| pflag | ||
| reduce_levels_test.cc | ||
| regression_test.sh | ||
| restore_db.sh | ||
| rocksdb_dump_test.sh | ||
| run_blob_bench.sh | ||
| run_flash_bench.sh | ||
| run_leveldb.sh | ||
| sample-dump.dmp | ||
| simulated_hybrid_file_system.cc | ||
| simulated_hybrid_file_system.h | ||
| sst_dump.cc | ||
| sst_dump_test.cc | ||
| sst_dump_tool.cc | ||
| trace_analyzer.cc | ||
| trace_analyzer_test.cc | ||
| trace_analyzer_tool.cc | ||
| trace_analyzer_tool.h | ||
| verify_random_db.sh | ||
| write_external_sst.sh | ||
| write_stress.cc | ||
| write_stress_runner.py | ||