feat: add grpc connection pool dump

pkg/remote/trans/nphttp2/conn_pool.go

@@ -21,6 +21,7 @@ import (
 	"crypto/tls"
 	"net"
 	"runtime"
+	"runtime/debug"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -227,6 +228,32 @@ func (p *connPool) Close() error {
 	return nil
 }
 
+// Dump dumps the connection pool with the details of the underlying transport.
+func (p *connPool) Dump() interface{} {
+	defer func() {
+		if panicErr := recover(); panicErr != nil {
+			klog.Errorf("KITEX: dump gRPC client connection pool panic, err=%v, stack=%s", panicErr, string(debug.Stack()))
+		}
+	}()
+	res := make(map[string]interface{})
+	p.conns.Range(func(k, v interface{}) bool {
+		addr := k.(string)
+		ts := v.(*transports)
+		var transportsDump = make([]interface{}, 0, len(ts.cliTransports))
+		for _, t := range ts.cliTransports {
+			if t == nil {
+				continue
+			}
+			if dumper, ok := t.(interface{ Dump() interface{} }); ok {
+				transportsDump = append(transportsDump, dumper.Dump())
+			}
+		}
+		res[addr] = transportsDump
+		return true
+	})
+	return res
+}
+
 // newTLSConn constructs a client-side TLS connection and performs handshake.
 func newTLSConn(conn net.Conn, tlsCfg *tls.Config) (net.Conn, error) {
 	tlsConn := tls.Client(conn, tlsCfg)

pkg/remote/trans/nphttp2/grpc/http2_client.go

@@ -1219,3 +1219,38 @@ func (t *http2Client) IsActive() bool {
 	defer t.mu.Unlock()
 	return t.state == reachable
 }
+
+type ClientTransportDump struct {
+	State            transportState `json:"transport_state"`
+	LocalAddress     string         `json:"local_address"`
+	ActiveStreams    []StreamDump   `json:"active_streams"`
+	KeepAliveEnabled bool           `json:"keepalive_enabled"`
+	LastRead         int64          `json:"last_read"`
+}
+
+type StreamDump struct {
+	ID     uint32      `json:"id"`
+	Method string      `json:"method"`
+	State  streamState `json:"stream_state"`
+}
+
+func (t *http2Client) Dump() interface{} {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	var activeStreams = make([]StreamDump, 0, len(t.activeStreams))
+	for _, v := range t.activeStreams {
+		activeStreams = append(activeStreams, StreamDump{
+			ID:     v.id,
+			Method: v.method,
+			State:  v.state,
+		})
+	}
+	return ClientTransportDump{
+		State:            t.state,
+		LocalAddress:     t.LocalAddr().String(),
+		ActiveStreams:    activeStreams,
+		KeepAliveEnabled: t.keepaliveEnabled,
+		LastRead:         atomic.LoadInt64(&t.lastRead),
+	}
+}