// Check whether need to recovery, if yes, reset fseek to the right place.
bool WriteBehindFrontendLogger::NeedRecovery(void) {
// Otherwise, read the last transaction record
fseek(log_file, -TransactionRecord::GetTransactionRecordSize(), SEEK_END);
// Get its type
auto log_record_type = GetNextLogRecordType(log_file, log_file_size);
// Check if the previous transaction run is broken
if (log_record_type == LOGRECORD_TYPE_TRANSACTION_COMMIT) {
TransactionRecord txn_record(LOGRECORD_TYPE_TRANSACTION_COMMIT);
// read the last written out transaction log record
if (ReadTransactionRecordHeader(txn_record, log_file, log_file_size) ==
false) {
return false;
}
// Peloton log records items have fixed size.
// Compute log offset based on txn_id
size_t tuple_log_record_count = txn_record.GetTransactionId();
size_t rollback_offset =
tuple_log_record_count * TupleRecord::GetTupleRecordSize() +
TransactionRecord::GetTransactionRecordSize();
// Rollback to the computed offset
fseek(log_file, -rollback_offset, SEEK_END);
return true;
} else {
return false;
}
}
/**
* @brief Recovery system based on log file
*/
void AriesFrontendLogger::DoRecovery() {
// Set log file size
log_file_size = GetLogFileSize(log_file_fd);
// Go over the log size if needed
if (log_file_size > 0) {
bool reached_end_of_file = false;
// Start the recovery transaction
auto &txn_manager = concurrency::TransactionManager::GetInstance();
// Although we call BeginTransaction here, recovery txn will not be
// recoreded in log file since we are in recovery mode
auto recovery_txn = txn_manager.BeginTransaction();
// Go over each log record in the log file
while (reached_end_of_file == false) {
// Read the first byte to identify log record type
// If that is not possible, then wrap up recovery
auto record_type = GetNextLogRecordType(log_file, log_file_size);
switch (record_type) {
case LOGRECORD_TYPE_TRANSACTION_BEGIN:
AddTransactionToRecoveryTable();
break;
case LOGRECORD_TYPE_TRANSACTION_END:
RemoveTransactionFromRecoveryTable();
break;
case LOGRECORD_TYPE_TRANSACTION_COMMIT:
MoveCommittedTuplesToRecoveryTxn(recovery_txn);
break;
case LOGRECORD_TYPE_TRANSACTION_ABORT:
AbortTuplesFromRecoveryTable();
break;
case LOGRECORD_TYPE_ARIES_TUPLE_INSERT:
InsertTuple(recovery_txn);
break;
case LOGRECORD_TYPE_ARIES_TUPLE_DELETE:
DeleteTuple(recovery_txn);
break;
case LOGRECORD_TYPE_ARIES_TUPLE_UPDATE:
UpdateTuple(recovery_txn);
break;
default:
reached_end_of_file = true;
break;
}
}
// Commit the recovery transaction
txn_manager.CommitTransaction();
// Finally, abort ACTIVE transactions in recovery_txn_table
AbortActiveTransactions();
// After finishing recovery, set the next oid with maximum oid
// observed during the recovery
auto &manager = catalog::Manager::GetInstance();
manager.SetNextOid(max_oid);
}
}
/**
* @brief Recovery system based on log file
*/
void WriteBehindFrontendLogger::DoRecovery() {
// Set log file size
log_file_size = GetLogFileSize(log_file_fd);
// Go over the log size if needed
if (log_file_size > 0) {
bool reached_end_of_file = false;
// check whether first item is LOGRECORD_TYPE_TRANSACTION_COMMIT
// if not, no need to do recovery.
// if yes, need to replay all log records before we hit
// LOGRECORD_TYPE_TRANSACTION_DONE
bool need_recovery = NeedRecovery();
if (need_recovery == true) {
TransactionRecord dummy_transaction_record(LOGRECORD_TYPE_INVALID);
cid_t current_commit_id = INVALID_CID;
// Go over each log record in the log file
while (reached_end_of_file == false) {
// Read the first byte to identify log record type
// If that is not possible, then wrap up recovery
LogRecordType log_type = GetNextLogRecordType(log_file, log_file_size);
switch (log_type) {
case LOGRECORD_TYPE_TRANSACTION_DONE:
case LOGRECORD_TYPE_TRANSACTION_COMMIT: {
// read but do nothing
ReadTransactionRecordHeader(dummy_transaction_record, log_file,
log_file_size);
} break;
case LOGRECORD_TYPE_WBL_TUPLE_INSERT: {
TupleRecord insert_record(LOGRECORD_TYPE_WBL_TUPLE_INSERT);
ReadTupleRecordHeader(insert_record, log_file, log_file_size);
auto insert_location = insert_record.GetInsertLocation();
auto info = SetInsertCommitMark(insert_location);
current_commit_id = info.first;
} break;
case LOGRECORD_TYPE_WBL_TUPLE_DELETE: {
TupleRecord delete_record(LOGRECORD_TYPE_WBL_TUPLE_DELETE);
ReadTupleRecordHeader(delete_record, log_file, log_file_size);
auto delete_location = delete_record.GetDeleteLocation();
auto info = SetDeleteCommitMark(delete_location);
current_commit_id = info.first;
} break;
case LOGRECORD_TYPE_WBL_TUPLE_UPDATE: {
TupleRecord update_record(LOGRECORD_TYPE_WBL_TUPLE_UPDATE);
ReadTupleRecordHeader(update_record, log_file, log_file_size);
auto delete_location = update_record.GetDeleteLocation();
SetDeleteCommitMark(delete_location);
auto insert_location = update_record.GetInsertLocation();
auto info = SetInsertCommitMark(insert_location);
current_commit_id = info.first;
} break;
default:
reached_end_of_file = true;
break;
}
}
// Update latest commit id
if (latest_commit_id < current_commit_id) {
latest_commit_id = current_commit_id;
}
// write out a trasaction done log record to file
// to avoid redo next time during recovery
WriteTransactionLogRecord(
TransactionRecord(LOGRECORD_TYPE_TRANSACTION_DONE));
}
// After finishing recovery, set the next oid with maximum oid
// observed during the recovery
auto &manager = catalog::Manager::GetInstance();
manager.SetNextOid(max_oid);
}
}
