Support transactions from write queue

cmd/rqlited/flags.go

@@ -173,6 +173,9 @@ type Config struct {
 	// Execute queues, if a batch size has not been reached.
 	WriteQueueTimeout time.Duration
 
+	// WriteQueueTx controls whether writes from the queue are done within a transaction.
+	WriteQueueTx bool
+
 	// CompressionSize sets request query size for compression attempt
 	CompressionSize int
 
@@ -364,6 +367,7 @@ func ParseFlags(name, desc string, build *BuildInfo) (*Config, error) {
 	flag.StringVar(&config.RaftLogLevel, "raft-log-level", "INFO", "Minimum log level for Raft module")
 	flag.IntVar(&config.WriteQueueCap, "write-queue-capacity", 1024, "Write queue capacity")
 	flag.IntVar(&config.WriteQueueBatchSz, "write-queue-batch-size", 64, "Write queue batch size")
+	flag.BoolVar(&config.WriteQueueTx, "write-queue-tx", false, "Use a transaction when writing from queue")
 	flag.DurationVar(&config.WriteQueueTimeout, "write-queue-timeout", 100*time.Millisecond, "Write queue timeout")
 	flag.IntVar(&config.CompressionSize, "compression-size", 150, "Request query size for compression attempt")
 	flag.IntVar(&config.CompressionBatch, "compression-batch", 5, "Request batch threshold for compression attempt")

cmd/rqlited/main.go

@@ -258,6 +258,7 @@ func startHTTPService(cfg *Config, str *store.Store, cltr *cluster.Client, credS
 	s.DefaultQueueCap = cfg.WriteQueueCap
 	s.DefaultQueueBatchSz = cfg.WriteQueueBatchSz
 	s.DefaultQueueTimeout = cfg.WriteQueueTimeout
+	s.DefaultQueueTx = cfg.WriteQueueTx
 	s.BuildInfo = map[string]interface{}{
 		"commit":     cmd.Commit,
 		"branch":     cmd.Branch,

http/service.go

@@ -253,6 +253,7 @@ type Service struct {
 	DefaultQueueCap     int
 	DefaultQueueBatchSz int
 	DefaultQueueTimeout time.Duration
+	DefaultQueueTx      bool
 
 	credentialStore CredentialStore
 
@@ -1282,7 +1283,8 @@ func (s *Service) runQueue() {
 		case stmts := <-s.stmtQueue.C:
 			er := &command.ExecuteRequest{
 				Request: &command.Request{
-					Statements: stmts,
+					Statements:  stmts,
+					Transaction: s.DefaultQueueTx,
 				},
 			}
 			for {