YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

// Copyright (c) YugaByte, Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except

// in compliance with the License.  You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software distributed under the License

// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

// or implied.  See the License for the specific language governing permissions and limitations

// under the License.

//

#include "yb/master/ysql_transaction_ddl.h"

#include "yb/client/transaction_rpc.h"

#include "yb/common/ql_expr.h"

#include "yb/common/wire_protocol.h"

#include "yb/docdb/doc_rowwise_iterator.h"

#include "yb/gutil/casts.h"

#include "yb/master/sys_catalog.h"

#include "yb/tablet/tablet.h"

#include "yb/tablet/tablet_metadata.h"

#include "yb/tablet/tablet_peer.h"

#include "yb/tserver/tserver_service.pb.h"

#include "yb/util/logging.h"

#include "yb/util/monotime.h"

#include "yb/util/net/net_fwd.h"

#include "yb/util/status_log.h"

DEFINE_int32(ysql_transaction_bg_task_wait_ms, 200,

  "Amount of time the catalog manager background task thread waits "

  "between runs");

namespace yb {

namespace master {

YsqlTransactionDdl::~YsqlTransactionDdl() {

  // Shutdown any outstanding RPCs.

  rpcs_.Shutdown();

}

void YsqlTransactionDdl::VerifyTransaction(

    const TransactionMetadata& transaction_metadata,

    std::function<Status(bool)> complete_callback) {

  SleepFor(MonoDelta::FromMilliseconds(FLAGS_ysql_transaction_bg_task_wait_ms));

  YB_LOG_EVERY_N_SECS(INFO, 1) << "Verifying Transaction " << transaction_metadata;

  tserver::GetTransactionStatusRequestPB req;

  req.set_tablet_id(transaction_metadata.status_tablet);

  req.add_transaction_id()->assign(

      pointer_cast<const char*>(transaction_metadata.transaction_id.data()),

      transaction_metadata.transaction_id.size());

  auto rpc_handle = rpcs_.Prepare();

  if (rpc_handle == rpcs_.InvalidHandle()) {

    LOG(WARNING) << "Shutting down. Cannot send GetTransactionStatus: " << transaction_metadata;

    return;

  }

  auto client = client_future_.get();

  if (!client) {

    LOG(WARNING) << "Shutting down. Cannot get GetTransactionStatus: " << transaction_metadata;

    return;

  }

  // We need to query the TransactionCoordinator here.  Can't use TransactionStatusResolver in

  // TransactionParticipant since this TransactionMetadata may not have any actual data flushed yet.

  *rpc_handle = client::GetTransactionStatus(

      TransactionRpcDeadline(),

      nullptr /* tablet */,

      client,

      &req,

      [this, rpc_handle, transaction_metadata, complete_callback]

          (Status status, const tserver::GetTransactionStatusResponsePB& resp) {

        auto retained = rpcs_.Unregister(rpc_handle);

        TransactionReceived(transaction_metadata, complete_callback, std::move(status), resp);

      });

  (**rpc_handle).SendRpc();

}

void YsqlTransactionDdl::TransactionReceived(

    const TransactionMetadata& transaction,

    std::function<Status(bool)> complete_callback,

    Status txn_status, const tserver::GetTransactionStatusResponsePB& resp) {

  if (!txn_status.ok()) {

    LOG(WARNING) << "Transaction Status attempt (" << transaction.ToString()

                 << ") failed with status " << txn_status;

    WARN_NOT_OK(thread_pool_->SubmitFunc([complete_callback] () {

      WARN_NOT_OK(complete_callback(false /* txn_rpc_success */), "Callback failure");

    }), "Failed to enqueue callback");

    // #5981: Improve failure handling to retry transient errors or recognize transaction complete.

  } else if (resp.has_error()) {

    const Status s = StatusFromPB(resp.error().status());

    const tserver::TabletServerErrorPB::Code code = resp.error().code();

    LOG(WARNING) << "Transaction Status attempt (" << transaction.ToString()

                 << ") failed with error code " << tserver::TabletServerErrorPB::Code_Name(code)

                 << ": " << s;

    WARN_NOT_OK(thread_pool_->SubmitFunc([complete_callback] () {

      WARN_NOT_OK(complete_callback(false /* txn_rpc_success */), "Callback failure");

    }), "Failed to enqueue callback");

    // #5981: Maybe have the same heuristic as above?

  } else {

    YB_LOG_EVERY_N_SECS(INFO, 1) << "Got Response for " << transaction.ToString()

                                 << ", resp: " << resp.ShortDebugString();

    bool is_pending = (resp.status_size() == 0);

    for (int i = 0; i < resp.status_size() && !is_pending; ++i) {

      // NOTE: COMMITTED state is also "pending" because we need APPLIED.

      is_pending = resp.status(i) == TransactionStatus::PENDING ||

                   resp.status(i) == TransactionStatus::COMMITTED;

    }

    if (is_pending) {

      // Re-enqueue if transaction is still pending.

      WARN_NOT_OK(thread_pool_->SubmitFunc(

          std::bind(&YsqlTransactionDdl::VerifyTransaction, this, transaction, complete_callback)),

          "Could not submit VerifyTransaction to thread pool");

    } else {

      // If this transaction isn't pending, then the transaction is in a terminal state.

      // Note: We ignore the resp.status() now, because it could be ABORT'd but actually a SUCCESS.

      WARN_NOT_OK(thread_pool_->SubmitFunc([complete_callback] () {

        WARN_NOT_OK(complete_callback(true /* txn_rpc_success */), "Callback failure");

      }), "Failed to enqueue callback");

    }

  }

}

Result<bool> YsqlTransactionDdl::PgEntryExists(TableId pg_table_id, Result<uint32_t> entry_oid) {

  auto tablet_peer = sys_catalog_->tablet_peer();

  if (!tablet_peer || !tablet_peer->tablet()) {

    return STATUS(ServiceUnavailable, "SysCatalog unavailable");

  }

  const tablet::Tablet* catalog_tablet = tablet_peer->tablet();

  const Schema& pg_database_schema =

      *VERIFY_RESULT(catalog_tablet->metadata()->GetTableInfo(pg_table_id))->schema;

  // Use Scan to query the 'pg_database' table, filtering by our 'oid'.

  Schema projection;

  RETURN_NOT_OK(pg_database_schema.CreateProjectionByNames({"oid"}, &projection,

                pg_database_schema.num_key_columns()));

  const auto oid_col_id = VERIFY_RESULT(projection.ColumnIdByName("oid")).rep();

  auto iter = VERIFY_RESULT(catalog_tablet->NewRowIterator(

      projection.CopyWithoutColumnIds(), {} /* read_hybrid_time */, pg_table_id));

  auto e_oid_val = VERIFY_RESULT(std::move(entry_oid));

  {

    auto doc_iter = down_cast<docdb::DocRowwiseIterator*>(iter.get());

    PgsqlConditionPB cond;

    cond.add_operands()->set_column_id(oid_col_id);

    cond.set_op(QL_OP_EQUAL);

    cond.add_operands()->mutable_value()->set_uint32_value(e_oid_val);

    const std::vector<docdb::PrimitiveValue> empty_key_components;

    docdb::DocPgsqlScanSpec spec(

        projection, rocksdb::kDefaultQueryId, empty_key_components, empty_key_components,

        &cond, boost::none /* hash_code */, boost::none /* max_hash_code */, nullptr /* where */);

    RETURN_NOT_OK(doc_iter->Init(spec));

  }

  // Expect exactly one row, which means the transaction was a success.

  QLTableRow row;

  if (VERIFY_RESULT(iter->HasNext())) {

    RETURN_NOT_OK(iter->NextRow(&row));

    return true;

  }

  return false;

}

}  // namespace master

}  // namespace yb