/
server_connections.go
91 lines (76 loc) · 2.36 KB
/
server_connections.go
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// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
package grpc
import (
"net"
"sync"
"github.com/apache/skywalking-satellite/internal/pkg/log"
)
type ConnectionManager struct {
net.Listener
acceptLimiter *AcceptLimiter
}
func NewConnectionManager(network, address string, acceptConnectionConfig AcceptConnectionConfig) (*ConnectionManager, error) {
listen, err := net.Listen(network, address)
if err != nil {
return nil, err
}
limiter, err := NewAcceptLimiter(acceptConnectionConfig)
if err != nil {
return nil, err
}
return &ConnectionManager{listen, limiter}, nil
}
func (c *ConnectionManager) Accept() (net.Conn, error) {
conn, err := c.Listener.Accept()
if err != nil {
return nil, err
}
if !c.acceptLimiter.CouldHandleConnection() {
conn.Close()
log.Logger.Warnf("out of accept limit, drop the connection: %v->%v, environment: cpuUtilization: %f, connectionCount: %d",
conn.RemoteAddr(), conn.LocalAddr(), c.acceptLimiter.CurrentCPU, c.acceptLimiter.ActiveConnection)
return nil, &outOfLimit{}
}
return &ConnectionWrapper{Conn: conn, manager: c}, nil
}
func (c *ConnectionManager) notifyCloseConnection() {
c.acceptLimiter.CloseConnection()
}
type ConnectionWrapper struct {
net.Conn
manager *ConnectionManager
closeOnce sync.Once
}
func (c *ConnectionWrapper) Close() error {
defer c.CloseNotify()
return c.Conn.Close()
}
func (c *ConnectionWrapper) CloseNotify() {
c.closeOnce.Do(func() {
c.manager.notifyCloseConnection()
})
}
type outOfLimit struct {
error
}
func (o *outOfLimit) Temporary() bool {
return true
}
func (o *outOfLimit) Error() string {
return "out of limit"
}