Test new connection configuration in vitess

go/cmd/dolt/commands/sqlserver/command_line_config.go

@@ -19,6 +19,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/dolthub/dolt/go/libraries/doltcore/servercfg"
 	"github.com/dolthub/dolt/go/libraries/utils/filesys"
@@ -42,6 +43,8 @@ type commandLineServerConfig struct {
 	autoCommit              bool
 	doltTransactionCommit   bool
 	maxConnections          uint64
+	maxWaitConnections      uint32
+	maxWaitConnsTimeout     time.Duration
 	tlsKey                  string
 	tlsCert                 string
 	requireSecureTransport  bool
@@ -72,6 +75,8 @@ func DefaultCommandLineServerConfig() *commandLineServerConfig {
 		logFormat:               servercfg.DefaultLogFormat,
 		autoCommit:              servercfg.DefaultAutoCommit,
 		maxConnections:          servercfg.DefaultMaxConnections,
+		maxWaitConnections:      servercfg.DefaultMaxWaitConnections,
+		maxWaitConnsTimeout:     servercfg.DefaultMaxWaitConnectionsTimeout,
 		dataDir:                 servercfg.DefaultDataDir,
 		cfgDir:                  filepath.Join(servercfg.DefaultDataDir, servercfg.DefaultCfgDir),
 		privilegeFilePath:       filepath.Join(servercfg.DefaultDataDir, servercfg.DefaultCfgDir, servercfg.DefaultPrivilegeFilePath),
@@ -169,6 +174,18 @@ func NewCommandLineConfig(creds *cli.UserPassword, apr *argparser.ArgParseResult
 		config.withMaxConnections(uint64(maxConnections))
 	}
 
+	if maxWaitConnections, ok := apr.GetInt(maxWaitConnectionsFlag); ok {
+		config.withMaxWaitConnections(uint32(maxWaitConnections))
+	}
+
+	if maxWaitConnsTimeoutStr, ok := apr.GetValue(maxWaitConsTimeoutFlag); ok {
+		maxWaitConnsTimeout, err := time.ParseDuration(maxWaitConnsTimeoutStr)
+		if err != nil {
+			return nil, fmt.Errorf("invalid duration value for --max-wait-connections-timeout '%s'", maxWaitConnsTimeoutStr)
+		}
+		config.withMaxWaitConnectionsTimeout(maxWaitConnsTimeout)
+	}
+
 	config.autoCommit = !apr.Contains(noAutoCommitFlag)
 	if apr.Contains(noAutoCommitFlag) {
 		config.valuesSet[servercfg.AutoCommitKey] = struct{}{}
@@ -258,6 +275,16 @@ func (cfg *commandLineServerConfig) MaxConnections() uint64 {
 	return cfg.maxConnections
 }
 
+// MaxWaitConnections returns the maximum number of simultaneous connections that the server will allow to block waiting
+// for a connection before new connections result in immediate rejection.
+func (cfg *commandLineServerConfig) MaxWaitConnections() uint32 {
+	return cfg.maxWaitConnections
+}
+
+func (cfg *commandLineServerConfig) MaxWaitConnectionsTimeout() time.Duration {
+	return cfg.maxWaitConnsTimeout
+}
+
 // TLSKey returns a path to the servers PEM-encoded private TLS key. "" if there is none.
 func (cfg *commandLineServerConfig) TLSKey() string {
 	return cfg.tlsKey
@@ -425,6 +452,18 @@ func (cfg *commandLineServerConfig) withMaxConnections(maxConnections uint64) *c
 	return cfg
 }
 
+func (cfg *commandLineServerConfig) withMaxWaitConnections(maxWaitConnections uint32) *commandLineServerConfig {
+	cfg.maxWaitConnections = maxWaitConnections
+	cfg.valuesSet[servercfg.MaxWaitConnectionsKey] = struct{}{}
+	return cfg
+}
+
+func (cfg *commandLineServerConfig) withMaxWaitConnectionsTimeout(maxWaitConnsTimeout time.Duration) *commandLineServerConfig {
+	cfg.maxWaitConnsTimeout = maxWaitConnsTimeout
+	cfg.valuesSet[servercfg.MaxWaitConnectionsTimeoutKey] = struct{}{}
+	return cfg
+}
+
 // withDataDir updates the path to a directory to use as the data dir.
 func (cfg *commandLineServerConfig) withDataDir(dataDir string) *commandLineServerConfig {
 	cfg.dataDir = dataDir

go/cmd/dolt/commands/sqlserver/server.go

@@ -1092,6 +1092,8 @@ func getConfigFromServerConfig(serverConfig servercfg.ServerConfig, plf server.P
 	serverConf.ConnReadTimeout = readTimeout
 	serverConf.ConnWriteTimeout = writeTimeout
 	serverConf.MaxConnections = serverConfig.MaxConnections()
+	serverConf.MaxWaitConnections = serverConfig.MaxWaitConnections()
+	serverConf.MaxWaitConnectionsTimeout = serverConfig.MaxWaitConnectionsTimeout()
 	serverConf.TLSConfig = tlsConfig
 	serverConf.RequireSecureTransport = serverConfig.RequireSecureTransport()
 	serverConf.MaxLoggedQueryLen = serverConfig.MaxLoggedQueryLen()

go/cmd/dolt/commands/sqlserver/server_test.go

@@ -595,6 +595,8 @@ listener:
   # host: localhost
   # port: 3306
   # max_connections: 1000
+  # back_log: 50
+  # max_connections_timeout_millis: 60000
   read_timeout_millis: 11000
   write_timeout_millis: 11000
   # tls_key: key.pem

go/cmd/dolt/commands/sqlserver/sqlserver.go

@@ -48,6 +48,8 @@ const (
 	configFileFlag              = "config"
 	queryParallelismFlag        = "query-parallelism"
 	maxConnectionsFlag          = "max-connections"
+	maxWaitConnectionsFlag      = "back-log"
+	maxWaitConsTimeoutFlag      = "max-connections-timeout"
 	allowCleartextPasswordsFlag = "allow-cleartext-passwords"
 	socketFlag                  = "socket"
 	remotesapiPortFlag          = "remotesapi-port"
@@ -107,6 +109,10 @@ SUPPORTED CONFIG FILE FIELDS:
 
 {{.EmphasisLeft}}listener.max_connections{{.EmphasisRight}}: The number of simultaneous connections that the server will accept
 
+{{.EmphasisLeft}}listener.back_log{{.EmphasisRight}}: The number of simultaneous connections that the server will allow to block waiting for a connection before new connections result in immediate rejection. Default 50.
+
+{{.EmphasisLeft}}listener.max_wait_connections_timeout{{.EmphasisRight}}: The maximum amount of time that a connection will block waiting for a connection before being rejected.
+
 {{.EmphasisLeft}}listener.read_timeout_millis{{.EmphasisRight}}: The number of milliseconds that the server will wait for a read operation
 
 {{.EmphasisLeft}}listener.write_timeout_millis{{.EmphasisRight}}: The number of milliseconds that the server will wait for a write operation
@@ -179,6 +185,8 @@ func (cmd SqlServerCmd) ArgParserWithName(name string) *argparser.ArgParser {
 	ap.SupportsFlag(noAutoCommitFlag, "", "Set @@autocommit = off for the server.")
 	ap.SupportsInt(queryParallelismFlag, "", "num-go-routines", "Deprecated, no effect in current versions of Dolt")
 	ap.SupportsInt(maxConnectionsFlag, "", "max-connections", fmt.Sprintf("Set the number of connections handled by the server. Defaults to `%d`.", serverConfig.MaxConnections()))
+	ap.SupportsInt(maxWaitConnectionsFlag, "", "back-log", fmt.Sprintf("Set the number of connections that can block waiting for a connection before new connections are rejected. Defaults to `%d`.", serverConfig.MaxWaitConnections()))
+	ap.SupportsString(maxWaitConsTimeoutFlag, "", "max-connections-timeout", fmt.Sprintf("Set the maximum duration that a connection will block waiting for a connection before being rejected. Defaults to `%v`.", serverConfig.MaxWaitConnectionsTimeout()))
 	ap.SupportsString(commands.PrivsFilePathFlag, "", "privilege file", "Path to a file to load and store users and grants. Defaults to `$doltcfg-dir/privileges.db`. Will be created as needed.")
 	ap.SupportsString(commands.BranchCtrlPathFlag, "", "branch control file", "Path to a file to load and store branch control permissions. Defaults to `$doltcfg-dir/branch_control.db`. Will be created as needed.")
 	ap.SupportsString(allowCleartextPasswordsFlag, "", "allow-cleartext-passwords", "Allows use of cleartext passwords. Defaults to false.")

go/go.mod

@@ -14,7 +14,7 @@ require (
 	github.com/dolthub/fslock v0.0.3
 	github.com/dolthub/ishell v0.0.0-20240701202509-2b217167d718
 	github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81
-	github.com/dolthub/vitess v0.0.0-20250320231804-0e77d549294c
+	github.com/dolthub/vitess v0.0.0-20250325024605-8131be3ca6d3
 	github.com/dustin/go-humanize v1.0.1
 	github.com/fatih/color v1.13.0
 	github.com/flynn-archive/go-shlex v0.0.0-20150515145356-3f9db97f8568
@@ -60,7 +60,7 @@ require (
 	github.com/creasty/defaults v1.6.0
 	github.com/dolthub/aws-sdk-go-ini-parser v0.0.0-20250305001723-2821c37f6c12
 	github.com/dolthub/flatbuffers/v23 v23.3.3-dh.2
-	github.com/dolthub/go-mysql-server v0.19.1-0.20250321183729-47285a54773c
+	github.com/dolthub/go-mysql-server v0.19.1-0.20250325031739-45c4c4ce0449
 	github.com/dolthub/gozstd v0.0.0-20240423170813-23a2903bca63
 	github.com/esote/minmaxheap v1.0.0
 	github.com/goccy/go-json v0.10.2

go/go.sum

@@ -221,8 +221,8 @@ github.com/dolthub/fslock v0.0.3 h1:iLMpUIvJKMKm92+N1fmHVdxJP5NdyDK5bK7z7Ba2s2U=
 github.com/dolthub/fslock v0.0.3/go.mod h1:QWql+P17oAAMLnL4HGB5tiovtDuAjdDTPbuqx7bYfa0=
 github.com/dolthub/go-icu-regex v0.0.0-20250319212010-451ea8d003fa h1:NFbzJ4wjWRz32nz2EimbrHpRx1Xt6k+IaR8N+j4x62k=
 github.com/dolthub/go-icu-regex v0.0.0-20250319212010-451ea8d003fa/go.mod h1:ylU4XjUpsMcvl/BKeRRMXSH7e7WBrPXdSLvnRJYrxEA=
-github.com/dolthub/go-mysql-server v0.19.1-0.20250321183729-47285a54773c h1:bCPelFSgt6aOPUqvrKV3OY8S9tjcBxQTgFNGARsrcSU=
-github.com/dolthub/go-mysql-server v0.19.1-0.20250321183729-47285a54773c/go.mod h1:WyimbJzsrNiYsQ7nfnXYLIoFAfNX0I7rHH1WaDt7faM=
+github.com/dolthub/go-mysql-server v0.19.1-0.20250325031739-45c4c4ce0449 h1:pW0XNR2cdUTGmLXyvFux5hZQRFJlHK12fWeC5vdmWNo=
+github.com/dolthub/go-mysql-server v0.19.1-0.20250325031739-45c4c4ce0449/go.mod h1:vKBT9NZQDwG0Db6CT4D92Mw6kaJpWbIDy1hBX7XWUCA=
 github.com/dolthub/gozstd v0.0.0-20240423170813-23a2903bca63 h1:OAsXLAPL4du6tfbBgK0xXHZkOlos63RdKYS3Sgw/dfI=
 github.com/dolthub/gozstd v0.0.0-20240423170813-23a2903bca63/go.mod h1:lV7lUeuDhH5thVGDCKXbatwKy2KW80L4rMT46n+Y2/Q=
 github.com/dolthub/ishell v0.0.0-20240701202509-2b217167d718 h1:lT7hE5k+0nkBdj/1UOSFwjWpNxf+LCApbRHgnCA17XE=
@@ -231,8 +231,8 @@ github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71 h1:bMGS25NWAGTE
 github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71/go.mod h1:2/2zjLQ/JOOSbbSboojeg+cAwcRV0fDLzIiWch/lhqI=
 github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81 h1:7/v8q9XGFa6q5Ap4Z/OhNkAMBaK5YeuEzwJt+NZdhiE=
 github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81/go.mod h1:siLfyv2c92W1eN/R4QqG/+RjjX5W2+gCTRjZxBjI3TY=
-github.com/dolthub/vitess v0.0.0-20250320231804-0e77d549294c h1:Dv2DfEGb8WRBi8I5KF5Sy39TuZi/FI692mpobKWcv4g=
-github.com/dolthub/vitess v0.0.0-20250320231804-0e77d549294c/go.mod h1:1gQZs/byeHLMSul3Lvl3MzioMtOW1je79QYGyi2fd70=
+github.com/dolthub/vitess v0.0.0-20250325024605-8131be3ca6d3 h1:euU+adNAYw46Zcp1HnoaSDWhqjfaL8s/1SPU+i16gYM=
+github.com/dolthub/vitess v0.0.0-20250325024605-8131be3ca6d3/go.mod h1:1gQZs/byeHLMSul3Lvl3MzioMtOW1je79QYGyi2fd70=
 github.com/dustin/go-humanize v0.0.0-20171111073723-bb3d318650d4/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=

go/libraries/doltcore/servercfg/serverconfig.go

@@ -22,6 +22,7 @@ import (
 	"path/filepath"
 	"runtime"
 	"strings"
+	"time"
 )
 
 var DefaultUnixSocketFilePath = DefaultMySQLUnixSocketFilePath
@@ -47,28 +48,30 @@ const (
 )
 
 const (
-	DefaultHost                    = "localhost"
-	DefaultPort                    = 3306
-	DefaultUser                    = "root"
-	DefaultPass                    = ""
-	DefaultTimeout                 = 8 * 60 * 60 * 1000 // 8 hours, same as MySQL
-	DefaultReadOnly                = false
-	DefaultLogLevel                = LogLevel_Info
-	DefaultLogFormat               = LogFormat_Text
-	DefaultAutoCommit              = true
-	DefaultAutoGCBehaviorEnable    = false
-	DefaultDoltTransactionCommit   = false
-	DefaultMaxConnections          = 1000
-	DefaultDataDir                 = "."
-	DefaultCfgDir                  = ".doltcfg"
-	DefaultPrivilegeFilePath       = "privileges.db"
-	DefaultBranchControlFilePath   = "branch_control.db"
-	DefaultMetricsHost             = ""
-	DefaultMetricsPort             = -1
-	DefaultAllowCleartextPasswords = false
-	DefaultMySQLUnixSocketFilePath = "/tmp/mysql.sock"
-	DefaultMaxLoggedQueryLen       = 0
-	DefaultEncodeLoggedQuery       = false
+	DefaultHost                      = "localhost"
+	DefaultPort                      = 3306
+	DefaultUser                      = "root"
+	DefaultPass                      = ""
+	DefaultTimeout                   = 8 * 60 * 60 * 1000 // 8 hours, same as MySQL
+	DefaultReadOnly                  = false
+	DefaultLogLevel                  = LogLevel_Info
+	DefaultLogFormat                 = LogFormat_Text
+	DefaultAutoCommit                = true
+	DefaultAutoGCBehaviorEnable      = false
+	DefaultDoltTransactionCommit     = false
+	DefaultMaxConnections            = 1000
+	DefaultMaxWaitConnections        = 50
+	DefaultMaxWaitConnectionsTimeout = 60 * time.Second
+	DefaultDataDir                   = "."
+	DefaultCfgDir                    = ".doltcfg"
+	DefaultPrivilegeFilePath         = "privileges.db"
+	DefaultBranchControlFilePath     = "branch_control.db"
+	DefaultMetricsHost               = ""
+	DefaultMetricsPort               = -1
+	DefaultAllowCleartextPasswords   = false
+	DefaultMySQLUnixSocketFilePath   = "/tmp/mysql.sock"
+	DefaultMaxLoggedQueryLen         = 0
+	DefaultEncodeLoggedQuery         = false
 )
 
 func ptr[T any](t T) *T {
@@ -159,6 +162,11 @@ type ServerConfig interface {
 	CfgDir() string
 	// MaxConnections returns the maximum number of simultaneous connections the server will allow.  The default is 1
 	MaxConnections() uint64
+	// MaxWaitConnections returns the maximum number of simultaneous connections that the server will allow to block waiting
+	// for a connection before new connections result in immediate rejection
+	MaxWaitConnections() uint32
+	// MaxWaitConnectionsTimeout returns the maximum amount of time that a connection will block waiting for a connection
+	MaxWaitConnectionsTimeout() time.Duration
 	// TLSKey returns a path to the servers PEM-encoded private TLS key. "" if there is none.
 	TLSKey() string
 	// TLSCert returns a path to the servers PEM-encoded TLS certificate chain. "" if there is none.
@@ -240,6 +248,8 @@ func defaultServerConfigYAML() *YAMLConfig {
 			HostStr:                 ptr(DefaultHost),
 			PortNumber:              ptr(DefaultPort),
 			MaxConnections:          ptr(uint64(DefaultMaxConnections)),
+			BackLog:                 ptr(uint32(DefaultMaxWaitConnections)),
+			MaxConnectionsTimeoutMs: ptr(uint64(DefaultMaxWaitConnectionsTimeout.Milliseconds())),
 			ReadTimeoutMillis:       ptr(uint64(DefaultTimeout)),
 			WriteTimeoutMillis:      ptr(uint64(DefaultTimeout)),
 			AllowCleartextPasswords: ptr(DefaultAllowCleartextPasswords),
@@ -306,6 +316,8 @@ const (
 	DataDirKey                      = "data_dir"
 	CfgDirKey                       = "cfg_dir"
 	MaxConnectionsKey               = "max_connections"
+	MaxWaitConnectionsKey           = "back_log"
+	MaxWaitConnectionsTimeoutKey    = "max_connections_timeout"
 	TLSKeyKey                       = "tls_key"
 	TLSCertKey                      = "tls_cert"
 	RequireSecureTransportKey       = "require_secure_transport"

go/libraries/doltcore/servercfg/testdata/minver_validation.txt

@@ -21,6 +21,8 @@ ListenerConfig servercfg.ListenerYAMLConfig 0.0.0 listener,omitempty
 -HostStr *string 0.0.0 host,omitempty
 -PortNumber *int 0.0.0 port,omitempty
 -MaxConnections *uint64 0.0.0 max_connections,omitempty
+-BackLog *uint32 0.0.0 back_log,omitempty
+-MaxConnectionsTimeoutMs *uint64 0.0.0 max_connections_timeout_millis,omitempty
 -ReadTimeoutMillis *uint64 0.0.0 read_timeout_millis,omitempty
 -WriteTimeoutMillis *uint64 0.0.0 write_timeout_millis,omitempty
 -TLSKey *string 0.0.0 tls_key,omitempty
@@ -64,4 +66,4 @@ ClusterCfg *servercfg.ClusterYAMLConfig 0.0.0 cluster,omitempty
 --TLSCert_ string 0.0.0 tls_cert
 --TLSCA_ string 0.0.0 tls_ca
 --URLMatches []string 0.0.0 server_name_urls
---DNSMatches []string 0.0.0 server_name_dns
+--DNSMatches []string 0.0.0 server_name_dns

go/libraries/doltcore/servercfg/yaml_config.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"path/filepath"
 	"strings"
+	"time"
 	"unicode"
 	"unicode/utf8"
 
@@ -77,11 +78,13 @@ type UserYAMLConfig struct {
 
 // ListenerYAMLConfig contains information on the network connection that the server will open
 type ListenerYAMLConfig struct {
-	HostStr            *string `yaml:"host,omitempty"`
-	PortNumber         *int    `yaml:"port,omitempty"`
-	MaxConnections     *uint64 `yaml:"max_connections,omitempty"`
-	ReadTimeoutMillis  *uint64 `yaml:"read_timeout_millis,omitempty"`
-	WriteTimeoutMillis *uint64 `yaml:"write_timeout_millis,omitempty"`
+	HostStr                 *string `yaml:"host,omitempty"`
+	PortNumber              *int    `yaml:"port,omitempty"`
+	MaxConnections          *uint64 `yaml:"max_connections,omitempty"`
+	BackLog                 *uint32 `yaml:"back_log,omitempty"`
+	MaxConnectionsTimeoutMs *uint64 `yaml:"max_connections_timeout_millis,omitempty"`
+	ReadTimeoutMillis       *uint64 `yaml:"read_timeout_millis,omitempty"`
+	WriteTimeoutMillis      *uint64 `yaml:"write_timeout_millis,omitempty"`
 	// TLSKey is a file system path to an unencrypted private TLS key in PEM format.
 	TLSKey *string `yaml:"tls_key,omitempty"`
 	// TLSCert is a file system path to a TLS certificate chain in PEM format.
@@ -197,6 +200,8 @@ func ServerConfigAsYAMLConfig(cfg ServerConfig) *YAMLConfig {
 			HostStr:                 ptr(cfg.Host()),
 			PortNumber:              ptr(cfg.Port()),
 			MaxConnections:          ptr(cfg.MaxConnections()),
+			BackLog:                 ptr(cfg.MaxWaitConnections()),
+			MaxConnectionsTimeoutMs: ptr(uint64(cfg.MaxWaitConnectionsTimeout().Milliseconds())),
 			ReadTimeoutMillis:       ptr(cfg.ReadTimeout()),
 			WriteTimeoutMillis:      ptr(cfg.WriteTimeout()),
 			TLSKey:                  nillableStrPtr(cfg.TLSKey()),
@@ -267,6 +272,8 @@ func ServerConfigSetValuesAsYAMLConfig(cfg ServerConfig) *YAMLConfig {
 			HostStr:                 zeroIf(ptr(cfg.Host()), !cfg.ValueSet(HostKey)),
 			PortNumber:              zeroIf(ptr(cfg.Port()), !cfg.ValueSet(PortKey)),
 			MaxConnections:          zeroIf(ptr(cfg.MaxConnections()), !cfg.ValueSet(MaxConnectionsKey)),
+			BackLog:                 zeroIf(ptr(cfg.MaxWaitConnections()), !cfg.ValueSet(MaxWaitConnectionsKey)),
+			MaxConnectionsTimeoutMs: zeroIf(ptr(uint64(cfg.MaxWaitConnectionsTimeout().Milliseconds())), !cfg.ValueSet(MaxWaitConnectionsTimeoutKey)),
 			ReadTimeoutMillis:       zeroIf(ptr(cfg.ReadTimeout()), !cfg.ValueSet(ReadTimeoutKey)),
 			WriteTimeoutMillis:      zeroIf(ptr(cfg.WriteTimeout()), !cfg.ValueSet(WriteTimeoutKey)),
 			TLSKey:                  zeroIf(ptr(cfg.TLSKey()), !cfg.ValueSet(TLSKeyKey)),
@@ -487,6 +494,12 @@ func (cfg YAMLConfig) withDefaultsFilledIn() YAMLConfig {
 	if withDefaults.ListenerConfig.MaxConnections == nil {
 		withDefaults.ListenerConfig.MaxConnections = defaults.ListenerConfig.MaxConnections
 	}
+	if withDefaults.ListenerConfig.BackLog == nil {
+		withDefaults.ListenerConfig.BackLog = defaults.ListenerConfig.BackLog
+	}
+	if withDefaults.ListenerConfig.MaxConnectionsTimeoutMs == nil {
+		withDefaults.ListenerConfig.MaxConnectionsTimeoutMs = defaults.ListenerConfig.MaxConnectionsTimeoutMs
+	}
 	if withDefaults.ListenerConfig.ReadTimeoutMillis == nil {
 		withDefaults.ListenerConfig.ReadTimeoutMillis = defaults.ListenerConfig.ReadTimeoutMillis
 	}
@@ -659,6 +672,22 @@ func (cfg YAMLConfig) MaxConnections() uint64 {
 	return *cfg.ListenerConfig.MaxConnections
 }
 
+func (cfg YAMLConfig) MaxWaitConnections() uint32 {
+	if cfg.ListenerConfig.BackLog == nil {
+		return DefaultMaxWaitConnections
+	}
+
+	return *cfg.ListenerConfig.BackLog
+}
+
+func (cfg YAMLConfig) MaxWaitConnectionsTimeout() time.Duration {
+	if cfg.ListenerConfig.MaxConnectionsTimeoutMs == nil {
+		return DefaultMaxWaitConnectionsTimeout
+	}
+
+	return time.Duration(*cfg.ListenerConfig.MaxConnectionsTimeoutMs) * time.Millisecond
+}
+
 // DisableClientMultiStatements returns true if the server should run in a mode
 // where the CLIENT_MULTI_STATEMENTS option are ignored and every incoming
 // ComQuery packet is assumed to be a standalone query.
@@ -946,6 +975,10 @@ func (cfg YAMLConfig) ValueSet(value string) bool {
 		return cfg.ListenerConfig.WriteTimeoutMillis != nil
 	case MaxConnectionsKey:
 		return cfg.ListenerConfig.MaxConnections != nil
+	case MaxWaitConnectionsKey:
+		return cfg.ListenerConfig.BackLog != nil
+	case MaxWaitConnectionsTimeoutKey:
+		return cfg.ListenerConfig.MaxConnectionsTimeoutMs != nil
 	case EventSchedulerKey:
 		return cfg.BehaviorConfig.EventSchedulerStatus != nil
 	}

go/libraries/doltcore/servercfg/yaml_config_test.go

@@ -41,6 +41,8 @@ listener:
     host: localhost
     port: 3306
     max_connections: 1000
+    back_log: 50
+    max_connections_timeout_millis: 60000
     read_timeout_millis: 28800000
     write_timeout_millis: 28800000