SERVER-72984 send bulk write commands from mongos to mongod

2 files changed, 63 insertions, 6 deletions

diff --git a/src/mongo/s/write_ops/bulk_write_exec.cpp b/src/mongo/s/write_ops/bulk_write_exec.cpp
index 89303c51a49..719cf6e8086 100644
--- a/src/mongo/s/write_ops/bulk_write_exec.cpp
+++ b/src/mongo/s/write_ops/bulk_write_exec.cpp
@@ -30,26 +30,75 @@
 #include "mongo/s/write_ops/bulk_write_exec.h"
 
 #include "mongo/base/error_codes.h"
+#include "mongo/client/read_preference.h"
 #include "mongo/client/remote_command_targeter.h"
 #include "mongo/db/commands/bulk_write_gen.h"
+#include "mongo/db/database_name.h"
+#include "mongo/db/write_concern_options.h"
 #include "mongo/executor/task_executor_pool.h"
 #include "mongo/logv2/log.h"
+#include "mongo/s/async_requests_sender.h"
 #include "mongo/s/client/shard_registry.h"
 #include "mongo/s/grid.h"
+#include "mongo/s/multi_statement_transaction_requests_sender.h"
 #include "mongo/s/transaction_router.h"
+#include "mongo/s/write_ops/batch_write_op.h"
+#include "mongo/s/write_ops/write_op.h"
 #include "mongo/s/write_ops/write_without_shard_key_util.h"
 
 #define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kSharding
 
 namespace mongo {
+namespace bulk_write_exec {
 namespace {
 
 // The number of times we'll try to continue a batch op if no progress is being made. This only
 // applies when no writes are occurring and metadata is not changing on reload.
 const int kMaxRoundsWithoutProgress(5);
 
+// Send and process the child batches. Each child batch is targeted at a unique shard: therefore
+// one shard will have only one batch incoming.
+void executeChildBatches(OperationContext* opCtx,
+                         const TargetedBatchMap& childBatches,
+                         const BulkWriteOp& bulkWriteOp) {
+    std::vector<AsyncRequestsSender::Request> requests;
+    for (auto& childBatch : childBatches) {
+        auto request = [&]() {
+            auto bulkReq = bulkWriteOp.buildBulkCommandRequest(*childBatch.second);
+
+            // Transform the request into a sendable BSON.
+            BSONObjBuilder builder;
+            bulkReq.serialize(BSONObj(), &builder);
+
+            logical_session_id_helpers::serializeLsidAndTxnNumber(opCtx, &builder);
+            builder.append(WriteConcernOptions::kWriteConcernField,
+                           opCtx->getWriteConcern().toBSON());
+
+            return builder.obj();
+        }();
+
+        requests.emplace_back(childBatch.first, request);
+    }
+
+    bool isRetryableWrite = opCtx->getTxnNumber() && !TransactionRouter::get(opCtx);
+
+    // Use MultiStatementTransactionRequestsSender to send any ready sub-batches to targeted
+    // shard endpoints. Requests are sent on construction.
+    MultiStatementTransactionRequestsSender ars(
+        opCtx,
+        Grid::get(opCtx)->getExecutorPool()->getArbitraryExecutor(),
+        DatabaseName("admin"),
+        requests,
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        isRetryableWrite ? Shard::RetryPolicy::kIdempotent : Shard::RetryPolicy::kNoRetry);
+
+    while (!ars.done()) {
+        // Block until a response is available.
+        auto response = ars.next();
+    }
+}
+
 }  // namespace
-namespace bulk_write_exec {
 
 std::vector<BulkWriteReplyItem> execute(OperationContext* opCtx,
                                         const std::vector<std::unique_ptr<NSTargeter>>& targeters,
@@ -72,6 +121,10 @@ std::vector<BulkWriteReplyItem> execute(OperationContext* opCtx,
         // re-batch ops based on their targeted shard id.
         TargetedBatchMap childBatches;
 
+        // Divide and group ("target") the operations in the bulk write command. Some operations may
+        // be split up (such as an update that needs to go to more than one shard), while others may
+        // be grouped together if they need to go to the same shard.
+        // These operations are grouped by shardId in the TargetedBatchMap childBatches.
         bool recordTargetErrors = refreshedTargeter;
         auto targetStatus = bulkWriteOp.target(targeters, recordTargetErrors, childBatches);
         if (!targetStatus.isOK()) {
@@ -86,12 +139,10 @@ std::vector<BulkWriteReplyItem> execute(OperationContext* opCtx,
             refreshedTargeter = true;
         }
 
-        // 2: Use MultiStatementTransactionRequestsSender to send any ready sub-batches to targeted
-        // shard endpoints.
+        // Send the child batches and wait for responses.
+        executeChildBatches(opCtx, childBatches, bulkWriteOp);
 
-        // 3: Wait for responses for all those sub-batches and keep track of the responses from
-        // sub-batches based on the op index in the original bulkWrite command. Abort the batch upon
-        // errors for ordered writes or transactions.
+        // 3: Abort the batch upon errors for ordered writes or transactions.
         // TODO(SERVER-72792): Remove the logic below that mimics ok responses and process real
         // batch responses.
         for (const auto& childBatch : childBatches) {
@@ -157,6 +208,7 @@ BulkWriteOp::BulkWriteOp(OperationContext* opCtx, const BulkWriteCommandRequest&
     : _opCtx(opCtx),
       _clientRequest(clientRequest),
       _txnNum(_opCtx->getTxnNumber()),
+      _writeConcern(opCtx->getWriteConcern()),
       _inTransaction(static_cast<bool>(TransactionRouter::get(opCtx))),
       _isRetryableWrite(opCtx->isRetryableWrite()) {
     _writeOps.reserve(_clientRequest.getOps().size());
@@ -238,6 +290,8 @@ BulkWriteCommandRequest BulkWriteOp::buildBulkCommandRequest(
     // TODO (SERVER-72989): Attach stmtIds etc. when building support for retryable
     // writes on mongos
 
+    request.setDbName(DatabaseName("admin"));
+
     return request;
 }
 
diff --git a/src/mongo/s/write_ops/bulk_write_exec.h b/src/mongo/s/write_ops/bulk_write_exec.h
index 41d6ebf9c4d..51d862ad3f9 100644
--- a/src/mongo/s/write_ops/bulk_write_exec.h
+++ b/src/mongo/s/write_ops/bulk_write_exec.h
@@ -149,6 +149,9 @@ private:
     // Cached transaction number (if one is present on the operation contex).
     boost::optional<TxnNumber> _txnNum;
 
+    // The write concern that the bulk write command was issued with.
+    WriteConcernOptions _writeConcern;
+
     // Set to true if this write is part of a transaction.
     const bool _inTransaction{false};
     const bool _isRetryableWrite{false};