Wait for connections to finish when stopping (#107)

This commit is contained in:
Geoff Bourne 2022-08-05 20:50:32 -05:00 committed by GitHub
parent d15bc9e986
commit f8a65abb61
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 44 additions and 18 deletions

View File

@ -152,7 +152,10 @@ func main() {
// wait for process-stop signal
<-c
logrus.Info("Stopping")
logrus.Info("Stopping. Waiting for connections to complete...")
signal.Stop(c)
connector.WaitForConnections()
logrus.Info("Stopped")
}
func parseMappings(vals []string) map[string]string {

View File

@ -6,6 +6,8 @@ import (
"io"
"net"
"strconv"
"sync"
"sync/atomic"
"time"
"github.com/go-kit/kit/metrics"
@ -21,10 +23,6 @@ const (
var noDeadline time.Time
type Connector interface {
StartAcceptingConnections(ctx context.Context, listenAddress string, connRateLimit int) error
}
type ConnectorMetrics struct {
Errors metrics.Counter
BytesTransmitted metrics.Counter
@ -32,21 +30,25 @@ type ConnectorMetrics struct {
ActiveConnections metrics.Gauge
}
func NewConnector(metrics *ConnectorMetrics, sendProxyProto bool) Connector {
func NewConnector(metrics *ConnectorMetrics, sendProxyProto bool) *Connector {
return &connectorImpl{
return &Connector{
metrics: metrics,
sendProxyProto: sendProxyProto,
connectionsCond: sync.NewCond(&sync.Mutex{}),
}
}
type connectorImpl struct {
type Connector struct {
state mcproto.State
metrics *ConnectorMetrics
sendProxyProto bool
activeConnections int32
connectionsCond *sync.Cond
}
func (c *connectorImpl) StartAcceptingConnections(ctx context.Context, listenAddress string, connRateLimit int) error {
func (c *Connector) StartAcceptingConnections(ctx context.Context, listenAddress string, connRateLimit int) error {
ln, err := net.Listen("tcp", listenAddress)
if err != nil {
@ -60,7 +62,22 @@ func (c *connectorImpl) StartAcceptingConnections(ctx context.Context, listenAdd
return nil
}
func (c *connectorImpl) acceptConnections(ctx context.Context, ln net.Listener, connRateLimit int) {
func (c *Connector) WaitForConnections() {
c.connectionsCond.L.Lock()
defer c.connectionsCond.L.Unlock()
for {
count := atomic.LoadInt32(&c.activeConnections)
if count > 0 {
logrus.Infof("Waiting on %d connection(s)", count)
c.connectionsCond.Wait()
} else {
break
}
}
}
func (c *Connector) acceptConnections(ctx context.Context, ln net.Listener, connRateLimit int) {
//noinspection GoUnhandledErrorResult
defer ln.Close()
@ -82,7 +99,7 @@ func (c *connectorImpl) acceptConnections(ctx context.Context, ln net.Listener,
}
}
func (c *connectorImpl) HandleConnection(ctx context.Context, frontendConn net.Conn) {
func (c *Connector) HandleConnection(ctx context.Context, frontendConn net.Conn) {
c.metrics.Connections.With("side", "frontend").Add(1)
//noinspection GoUnhandledErrorResult
defer frontendConn.Close()
@ -164,7 +181,7 @@ func (c *connectorImpl) HandleConnection(ctx context.Context, frontendConn net.C
}
}
func (c *connectorImpl) findAndConnectBackend(ctx context.Context, frontendConn net.Conn,
func (c *Connector) findAndConnectBackend(ctx context.Context, frontendConn net.Conn,
clientAddr net.Addr, preReadContent io.Reader, serverAddress string) {
backendHostPort, resolvedHost, waker := Routes.FindBackendForServerAddress(ctx, serverAddress)
@ -202,8 +219,14 @@ func (c *connectorImpl) findAndConnectBackend(ctx context.Context, frontendConn
}
c.metrics.Connections.With("side", "backend", "host", resolvedHost).Add(1)
c.metrics.ActiveConnections.Add(1)
defer c.metrics.ActiveConnections.Add(-1)
c.metrics.ActiveConnections.Set(float64(
atomic.AddInt32(&c.activeConnections, 1)))
defer func() {
c.metrics.ActiveConnections.Set(float64(
atomic.AddInt32(&c.activeConnections, -1)))
c.connectionsCond.Signal()
}()
// PROXY protocol implementation
if c.sendProxyProto {
@ -257,7 +280,7 @@ func (c *connectorImpl) findAndConnectBackend(ctx context.Context, frontendConn
c.pumpConnections(ctx, frontendConn, backendConn)
}
func (c *connectorImpl) pumpConnections(ctx context.Context, frontendConn, backendConn net.Conn) {
func (c *Connector) pumpConnections(ctx context.Context, frontendConn, backendConn net.Conn) {
//noinspection GoUnhandledErrorResult
defer backendConn.Close()
@ -283,7 +306,7 @@ func (c *connectorImpl) pumpConnections(ctx context.Context, frontendConn, backe
}
}
func (c *connectorImpl) pumpFrames(incoming io.Reader, outgoing io.Writer, errors chan<- error, from, to string, clientAddr net.Addr) {
func (c *Connector) pumpFrames(incoming io.Reader, outgoing io.Writer, errors chan<- error, from, to string, clientAddr net.Addr) {
amount, err := io.Copy(outgoing, incoming)
logrus.
WithField("client", clientAddr).