Summary:
**Context:**
Prior to this PR, correctness testing with un-sync data loss [disabled](https://github.com/facebook/rocksdb/pull/10605) transaction (`use_txn=1`) thus all of the `txn_write_policy` . This PR improved that by adding support for one policy - WriteCommit (`txn_write_policy=0`).
**Summary:**
They key to this support is (a) handle Mark{Begin, End}Prepare/MarkCommit/MarkRollback in constructing ExpectedState under WriteCommit policy correctly and (b) monitor CI jobs and solve any test incompatibility issue till jobs are stable. (b) will be part of the test plan.
For (a)
- During prepare (i.e, between `MarkBeginPrepare()` and `MarkEndPrepare(xid)`), `ExpectedStateTraceRecordHandler` will buffer all writes by adding all writes to an internal `WriteBatch`.
- On `MarkEndPrepare()`, that `WriteBatch` will be associated with the transaction's `xid`.
- During the commit (i.e, on `MarkCommit(xid)`), `ExpectedStateTraceRecordHandler` will retrieve and iterate the internal `WriteBatch` and finally apply those writes to `ExpectedState`
- During the rollback (i.e, on `MarkRollback(xid)`), `ExpectedStateTraceRecordHandler` will erase the internal `WriteBatch` from the map.
For (b) - one major issue described below:
- TransactionsDB in db stress recovers prepared-but-not-committed txns from the previous crashed run by randomly committing or rolling back it at the start of the current run, see a historical [PR](6d06be22c0) predated correctness testing.
- And we will verify those processed keys in a recovered db against their expected state.
- However since now we turn on `sync_fault_injection=1` where the expected state is constructed from the trace instead of using the LATEST.state from previous run. The expected state now used to verify those processed keys won't contain UNKNOWN_SENTINEL as they should - see test 1 for a failed case.
- Therefore, we decided to manually update its expected state to be UNKNOWN_SENTINEL as part of the processing.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10624
Test Plan:
1. Test exposed the major issue described above. This test will fail without setting UNKNOWN_SENTINEL in expected state during the processing and pass after
```
db=/dev/shm/rocksdb_crashtest_blackbox
exp=/dev/shm/rocksdb_crashtest_expected
dbt=$db.tmp
expt=$exp.tmp
rm -rf $db $exp
mkdir -p $exp
echo "RUN 1"
./db_stress \
--clear_column_family_one_in=0 --column_families=1 --db=$db --delpercent=10 --delrangepercent=0 --destroy_db_initially=0 --expected_values_dir=$exp --iterpercent=0 --key_len_percent_dist=1,30,69 --max_key=1000000 --max_key_len=3 --prefixpercent=0 --readpercent=0 --reopen=0 --ops_per_thread=100000000 --test_batches_snapshots=0 --value_size_mult=32 --writepercent=90 \
--use_txn=1 --txn_write_policy=0 --sync_fault_injection=1 &
pid=$!
sleep 0.2
sleep 20
kill $pid
sleep 0.2
echo "RUN 2"
./db_stress \
--clear_column_family_one_in=0 --column_families=1 --db=$db --delpercent=10 --delrangepercent=0 --destroy_db_initially=0 --expected_values_dir=$exp --iterpercent=0 --key_len_percent_dist=1,30,69 --max_key=1000000 --max_key_len=3 --prefixpercent=0 --readpercent=0 --reopen=0 --ops_per_thread=100000000 --test_batches_snapshots=0 --value_size_mult=32 --writepercent=90 \
--use_txn=1 --txn_write_policy=0 --sync_fault_injection=1 &
pid=$!
sleep 0.2
sleep 20
kill $pid
sleep 0.2
echo "RUN 3"
./db_stress \
--clear_column_family_one_in=0 --column_families=1 --db=$db --delpercent=10 --delrangepercent=0 --destroy_db_initially=0 --expected_values_dir=$exp --iterpercent=0 --key_len_percent_dist=1,30,69 --max_key=1000000 --max_key_len=3 --prefixpercent=0 --readpercent=0 --reopen=0 --ops_per_thread=100000000 --test_batches_snapshots=0 --value_size_mult=32 --writepercent=90 \
--use_txn=1 --txn_write_policy=0 --sync_fault_injection=1
```
2. Manual testing to ensure ExpectedState is constructed correctly during recovery by verifying it against previously crashed TransactionDB's WAL.
- Run the following command to crash a TransactionDB with WriteCommit policy. Then `./ldb dump_wal` on its WAL file
```
db=/dev/shm/rocksdb_crashtest_blackbox
exp=/dev/shm/rocksdb_crashtest_expected
rm -rf $db $exp
mkdir -p $exp
./db_stress \
--clear_column_family_one_in=0 --column_families=1 --db=$db --delpercent=10 --delrangepercent=0 --destroy_db_initially=0 --expected_values_dir=$exp --iterpercent=0 --key_len_percent_dist=1,30,69 --max_key=1000000 --max_key_len=3 --prefixpercent=0 --readpercent=0 --reopen=0 --ops_per_thread=100000000 --test_batches_snapshots=0 --value_size_mult=32 --writepercent=90 \
--use_txn=1 --txn_write_policy=0 --sync_fault_injection=1 &
pid=$!
sleep 30
kill $pid
sleep 1
```
- Run the following command to verify recovery of the crashed db under debugger. Compare the step-wise result with WAL records (e.g, WriteBatch content, xid, prepare/commit/rollback marker)
```
./db_stress \
--clear_column_family_one_in=0 --column_families=1 --db=$db --delpercent=10 --delrangepercent=0 --destroy_db_initially=0 --expected_values_dir=$exp --iterpercent=0 --key_len_percent_dist=1,30,69 --max_key=1000000 --max_key_len=3 --prefixpercent=0 --readpercent=0 --reopen=0 --ops_per_thread=100000000 --test_batches_snapshots=0 --value_size_mult=32 --writepercent=90 \
--use_txn=1 --txn_write_policy=0 --sync_fault_injection=1
```
3. Automatic testing by triggering all RocksDB stress/crash test jobs for 3 rounds with no failure.
Reviewed By: ajkr, riversand963
Differential Revision: D39199373
Pulled By: hx235
fbshipit-source-id: 7a1dec0e3e2ee6ea86ddf5dd19ceb5543a3d6f0c
Hui Xiao
aed30ddf21