Summary:
Add a new CF immutable option `paranoid_memory_check_key_checksum_on_seek` that allows additional data integrity validations during seek on SkipList Memtable. When this option is enabled and memtable_protection_bytes_per_key is non zero, skiplist-based memtable will validate the checksum of each key visited during seek operation. The option is opt-in due to performance overhead. This is an enhancement on top of paranoid_memory_checks option.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13902
Test Plan:
* new unit test added for paranoid_memory_check_key_checksum_on_seek=true.
* existing unit test for paranoid_memory_check_key_checksum_on_seek=false.
* enable in stress test.
Performance Benchmark: we check for performance regression in read path where data is in memtable only. For each benchmark, the script was run at the same time for main and this PR:
### Memtable-only randomread ops/sec:
* Value size = 100 Bytes
```
for B in 0 1 2 4 8; do (for I in $(seq 1 50);do ./db_bench --benchmarks=fillseq,readrandom --write_buffer_size=268435456 --writes=250000 --value_size=100 --num=250000 --reads=500000 --seed=1723056275 --paranoid_memory_check_key_checksum_on_seek=true --memtable_protection_bytes_per_key=$B 2>&1 | grep "readrandom"; done;) | awk '{ t += $5; c++; print } END { print 1.0 * t / c }'; done;
```
1. Main: 928999
2. PR with paranoid_memory_check_key_checksum_on_seek=false: 930993 (+0.2%)
3. PR with paranoid_memory_check_key_checksum_on_seek=true:
3.1 memtable_protection_bytes_per_key=1: 464577 (-50%)
3.2 memtable_protection_bytes_per_key=2: 470319 (-49%)
3.3 memtable_protection_bytes_per_key=4: 468457 (-50%)
3.4 memtable_protection_bytes_per_key=8: 465061 (-50%)
* Value size = 1000 Bytes
```
for B in 0 1 2 4 8; do (for I in $(seq 1 50);do ./db_bench --benchmarks=fillseq,readrandom --write_buffer_size=268435456 --writes=250000 --value_size=1000 --num=250000 --reads=500000 --seed=1723056275 --paranoid_memory_check_key_checksum_on_seek=true --memtable_protection_bytes_per_key=$B 2>&1 | grep "readrandom"; done;) | awk '{ t += $5; c++; print } END { print 1.0 * t / c }'; done;
```
1. Main: 601321
2. PR with paranoid_memory_check_key_checksum_on_seek=false: 607885 (+1.1%)
3. PR with paranoid_memory_check_key_checksum_on_seek=true:
3.1 memtable_protection_bytes_per_key=1: 185742 (-69%)
3.2 memtable_protection_bytes_per_key=2: 177167 (-71%)
3.3 memtable_protection_bytes_per_key=4: 185908 (-69%)
3.4 memtable_protection_bytes_per_key=8: 183639 (-69%)
Reviewed By: pdillinger
Differential Revision: D81199245
Pulled By: xingbowang
fbshipit-source-id: e3c29552ab92f2c5f360361366a293fa26934913
94e65a2e0b