在上一篇文章《使用Memcached提高.NET应用程序的性能》中周公讲述如何在.NET中使用Memcached来提高.NET应用程序的性能。在实际的使用中有可能出现Memcached因为某些不可预知的原因挂掉,一旦出现这样的情况,就会再次给数据库增加巨大的压力,因此需要监控Memcached的运行情况。周公在网上找过,在网上有PHP版的Memcached监控工具,打开那个PHP页面就可以看到各个Memcached的运行情况,一旦不能获取到这些数据,说明Memcached不可访问,不可访问的原因可能是因为网络故障或者Memcached挂掉了,虽然原因不同,但是结果是一样的。参照了Enyim Memcached和PHP版Memcached监控工具的实现,周公实现了一个.NET版的监控工具。
实现思路
上一篇文章《使用Memcached提高.NET应用程序的性能》中周公讲述了可以通过Telnet来获取Memcached的运行状况,通过"stats"命令得到Memcached的数据,如果得不到相应的数据就证明Memcached不可访问。
其中向Memcached发送"stats"命令得到的数据的意义如下:
pid:32u,服务器进程ID。
uptime:32u, 服务器运行时间,单位秒。
time :32u, 服务器当前的UNIX时间。
version :string, 服务器的版本号。
curr_items :32u, 服务器当前存储的内容数量 Current number of items stored by the server
total_items :32u, 服务器启动以来存储过的内容总数。
bytes :64u, 服务器当前存储内容所占用的字节数。
curr_connections :32u, 连接数量。
total_connections :32u, 服务器运行以来接受的连接总数。
connection_structures:32u, 服务器分配的连接结构的数量。
cmd_get :32u, 取回请求总数。
cmd_set :32u, 存储请求总数。
get_hits :32u, 请求成功的总次数。
get_misses :32u, 请求失败的总次数。
bytes_read :64u, 服务器从网络读取到的总字节数。
bytes_written :64u, 服务器向网络发送的总字节数。
limit_maxbytes :32u, 服务器在存储时被允许使用的字节总数。
上面的描述中32u和64u表示32位和64位无符号整数,string表示是string类型数据。
在本篇中我们通过Socket而不是Telnet连接到Memcached,然后解析返回的数据。
程序代码
为了便于管理和维护,在本示例中使用了单页模式,也就是所有的代码都在一个ASPX页面中,没有对应的aspx.cs页面。
程序代码如下:
- <%@ Page Language="C#" %>
- <%@ Import Namespace="System" %>
- <%@ Import Namespace="System.IO" %>
- <%@ Import Namespace="System.Net" %>
- <%@ Import Namespace="System.Net.Sockets" %>
- <%@ Import Namespace="System.Collections.Generic" %>
- <%@ Import Namespace="System.Threading" %>
- <%@ Import Namespace="System.Security" %>
- <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
- <script runat="server">
- /*
- * 作者:周公
- * 日期:2011-03-27
- * 原文出处:http://blog.csdn.net/zhoufoxcn 或http://zhoufoxcn.blog.51cto.com
- * 版权说明:本文可以在保留原文出处的情况下使用于非商业用途,周公对此不作任何担保或承诺。
- * */
- /// <summary>
- /// Memcached服务器监控类
- /// </summary>
- public class MemcachedMonitor
- {
- /// <summary>
- /// 连接Memcached的超时时间
- /// </summary>
- public TimeSpan ConnectionTimeout { get; set; }
- /// <summary>
- /// 接收Memcached返回数据的超时时间
- /// </summary>
- public TimeSpan ReceiveTimeout { get; set; }
- private List<IPEndPoint> serverList;
- public MemcachedMonitor(ICollection<IPEndPoint> list)
- {
- ConnectionTimeout = TimeSpan.FromSeconds(10);
- ReceiveTimeout = TimeSpan.FromSeconds(20);
- serverList = new List<IPEndPoint>();
- serverList.AddRange(list);
- }
- public List<MemcachedServerStats> GetAllServerStats()
- {
- List<MemcachedServerStats> resultList = new List<MemcachedServerStats>();
- foreach (IPEndPoint endPoint in serverList)
- {
- resultList.Add(GetServerStats(endPoint, ConnectionTimeout, ReceiveTimeout));
- }
- return resultList;
- }
- public static MemcachedServerStats GetServerStats(IPEndPoint ip, TimeSpan connectionTimeout, TimeSpan receiveTimeout)
- {
- MemcachedSocket socket = new MemcachedSocket(ip, connectionTimeout, receiveTimeout);
- MemcachedServerStats stats = socket.GetStats();
- return stats;
- }
- public static IPEndPoint Parse(string hostName,int port)
- {
- IPHostEntry host=Dns.GetHostEntry(hostName);
- IPEndPoint endPoint = null;
- foreach (IPAddress ip in host.AddressList)
- {
- if (ip.AddressFamily == AddressFamily.InterNetwork)
- {
- endPoint = new IPEndPoint(ip, port);
- break;
- }
- }
- return endPoint;
- }
- }
- /// <summary>
- /// Memcached服务器运行状态数据类,只有当IsReachable为true时获取的数据才有意义,否则表示不可访问或者Memcached挂了
- /// </summary>
- public class MemcachedServerStats
- {
- private Dictionary<string, string> results;
- /// <summary>
- /// 是否可访问,如果不可访问表示网络故障或者Memcached服务器Down掉了
- /// </summary>
- public bool IsReachable { get; set; }
- /// <summary>
- /// 服务器运行时间,单位秒(32u)
- /// </summary>
- public UInt32 Uptime { get; set; }
- /// <summary>
- /// 服务器当前的UNIX时间(32u)
- /// </summary>
- public UInt32 Time { get; set; }
- /// <summary>
- /// 服务器的版本号(string)
- /// </summary>
- public string Version { get; set; }
- /// <summary>
- /// 服务器当前存储的内容数量(32u)
- /// </summary>
- public UInt32 Curr_Items { get; set; }
- /// <summary>
- /// 服务器启动以来存储过的内容总数(32u)
- /// </summary>
- public UInt32 Total_Items { get; set; }
- /// <summary>
- /// 连接数量(32u)
- /// </summary>
- public UInt32 Curr_Connections { get; set; }
- /// <summary>
- /// 服务器运行以来接受的连接总数(32u)
- /// </summary>
- public UInt32 Total_Connections { get; set; }
- /// <summary>
- /// 服务器分配的连接结构的数量(32u)
- /// </summary>
- public UInt32 Connection_Structures { get; set; }
- /// <summary>
- /// 取回请求总数(32u)
- /// </summary>
- public UInt32 Cmd_Get { get; set; }
- /// <summary>
- /// 存储请求总数(32u)
- /// </summary>
- public UInt32 Cmd_Set { get; set; }
- /// <summary>
- /// 请求成功的总次数(32u)
- /// </summary>
- public UInt32 Get_Hits { get; set; }
- /// <summary>
- /// 请求失败的总次数(32u)
- /// </summary>
- public UInt32 Get_Misses { get; set; }
- /// <summary>
- /// 服务器当前存储内容所占用的字节数(64u)
- /// </summary>
- public UInt64 Bytes { get; set; }
- /// <summary>
- /// 服务器从网络读取到的总字节数(64u)
- /// </summary>
- public UInt64 Bytes_Read { get; set; }
- /// <summary>
- /// 服务器向网络发送的总字节数(64u)
- /// </summary>
- public UInt64 Bytes_Written { get; set; }
- /// <summary>
- /// 服务器在存储时被允许使用的字节总数(32u)
- /// </summary>
- public UInt32 Limit_Maxbytes { get; set; }
- public IPEndPoint IPEndPoint { get; set; }
- public MemcachedServerStats(IPEndPoint endpoint)
- {
- if (endpoint == null)
- {
- throw new ArgumentNullException("endpoint can't be null");
- }
- IPEndPoint = endpoint;
- }
- public MemcachedServerStats(IPEndPoint endpoint, Dictionary<string, string> results)
- {
- if (endpoint == null || results == null)
- {
- throw new ArgumentNullException("point and result can't be null");
- }
- IPEndPoint = endpoint;
- }
- public void InitializeData(Dictionary<string, string> results)
- {
- if (results == null)
- {
- throw new ArgumentNullException("result can't be null");
- }
- this.results = results;
- Uptime = GetUInt32("uptime");
- Time = GetUInt32("time");
- Version = GetRaw("version");
- Curr_Items = GetUInt32("curr_items");
- Total_Items = GetUInt32("total_items");
- Curr_Connections = GetUInt32("curr_connections");
- Total_Connections = GetUInt32("total_connections");
- Connection_Structures = GetUInt32("connection_structures");
- Cmd_Get = GetUInt32("cmd_get");
- Cmd_Set = GetUInt32("cmd_set");
- Get_Hits = GetUInt32("get_hits");
- Get_Misses = GetUInt32("get_misses");
- Bytes = GetUInt64("bytes");
- Bytes_Read = GetUInt64("bytes_read");
- Bytes_Written = GetUInt64("bytes_written");
- Limit_Maxbytes = GetUInt32("limit_maxbytes");
- }
- private string GetRaw(string key)
- {
- string value = string.Empty;
- results.TryGetValue(key, out value);
- return value;
- }
- private UInt32 GetUInt32(string key)
- {
- string value = GetRaw(key);
- UInt32 uptime;
- UInt32.TryParse(value, out uptime);
- return uptime;
- }
- private UInt64 GetUInt64(string key)
- {
- string value = GetRaw(key);
- UInt64 uptime;
- UInt64.TryParse(value, out uptime);
- return uptime;
- }
- }
- /// <summary>
- /// 与Memcached服务器通讯的Socket封装
- /// </summary>
- internal class MemcachedSocket : IDisposable
- {
- private const string CommandString = "stats\r\n";//发送查询Memcached状态的指令,以"\r\n"作为命令的结束
- private const int ErrorResponseLength = 13;
- private const string GenericErrorResponse = "ERROR";
- private const string ClientErrorResponse = "CLIENT_ERROR ";
- private const string ServerErrorResponse = "SERVER_ERROR ";
- private Socket socket;
- private IPEndPoint endpoint;
- private BufferedStream bufferedStream;
- private NetworkStream networkStream;
- public MemcachedSocket(IPEndPoint ip, TimeSpan connectionTimeout, TimeSpan receiveTimeout)
- {
- if (ip == null)
- {
- throw new ArgumentNullException("ip", "不能为空!");
- }
- endpoint = ip;
- socket = new Socket(endpoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
- socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.SendTimeout, connectionTimeout == TimeSpan.MaxValue ? Timeout.Infinite : (int)connectionTimeout.TotalMilliseconds);
- socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, receiveTimeout == TimeSpan.MaxValue ? Timeout.Infinite : (int)receiveTimeout.TotalMilliseconds);
- // all operations are "atomic", we do not send small chunks of data
- socket.NoDelay = true;
- }
- /// <summary>
- /// 获取Memcached的运行状态
- /// </summary>
- /// <returns></returns>
- public MemcachedServerStats GetStats()
- {
- MemcachedServerStats stats = new MemcachedServerStats(endpoint);
- try
- {
- socket.Connect(endpoint);
- networkStream = new NetworkStream(socket);
- bufferedStream = new BufferedStream(networkStream);
- byte[] buffer = Encoding.ASCII.GetBytes(CommandString);
- SocketError socketError;
- socket.Send(buffer, 0, buffer.Length, SocketFlags.None, out socketError);
- if (socketError != SocketError.Success)
- {
- stats.IsReachable = false;
- }
- else
- {
- stats.IsReachable = true;
- string result = ReadLine();
- Dictionary<string, string> serverData = new Dictionary<string, string>(StringComparer.Ordinal);
- while (!string.IsNullOrEmpty(result))
- {
- // 返回的数据信息以"END"作为结束标记
- if (String.Compare(result, "END", StringComparison.Ordinal) == 0)
- break;
- //期望的响应格式是:"STAT 名称 值"(注意"STAT 名称 值"之间有空格)
- if (result.Length < 6 || String.Compare(result, 0, "STAT ", 0, 5, StringComparison.Ordinal) != 0)
- {
- continue;
- }
- //获取以空格作为分隔符的键值对
- string[] parts = result.Remove(0, 5).Split(' ');
- if (parts.Length != 2)
- {
- continue;
- }
- serverData[parts[0]] = parts[1];
- result = ReadLine();
- }
- stats.InitializeData(serverData);
- }
- }
- catch (Exception exception)
- {
- stats.IsReachable = false;
- //Debug.WriteLine("Exception Message:" + exception.Message);
- }
- finally
- {
- }
- return stats;
- }
- /// <summary>
- /// 从远程主机的响应流中读取一行数据
- /// </summary>
- /// <returns></returns>
- private string ReadLine()
- {
- MemoryStream ms = new MemoryStream(50);
- bool gotR = false;
- byte[] buffer = new byte[1];
- int data;
- try
- {
- while (true)
- {
- data = bufferedStream.ReadByte();
- if (data == 13)
- {
- gotR = true;
- continue;
- }
- if (gotR)
- {
- if (data == 10)
- break;
- ms.WriteByte(13);
- gotR = false;
- }
- ms.WriteByte((byte)data);
- }
- }
- catch (IOException)
- {
- throw;
- }
- string retureValue = Encoding.ASCII.GetString(ms.GetBuffer(), 0, (int)ms.Length);
- if (String.IsNullOrEmpty(retureValue))
- throw new Exception("接收到空响应。");
- if (String.Compare(retureValue, GenericErrorResponse, StringComparison.Ordinal) == 0)
- throw new NotSupportedException("无效的指令。");
- if (retureValue.Length >= ErrorResponseLength)
- {
- if (String.Compare(retureValue, 0, ClientErrorResponse, 0, ErrorResponseLength, StringComparison.Ordinal) == 0)
- {
- throw new Exception(retureValue.Remove(0, ErrorResponseLength));
- }
- else if (String.Compare(retureValue, 0, ServerErrorResponse, 0, ErrorResponseLength, StringComparison.Ordinal) == 0)
- {
- throw new Exception(retureValue.Remove(0, ErrorResponseLength));
- }
- }
- return retureValue;
- }
- public void Dispose()
- {
- if (socket != null)
- {
- socket.Shutdown(SocketShutdown.Both);
- }
- socket = null;
- networkStream.Dispose();
- networkStream = null;
- bufferedStream.Dispose();
- bufferedStream = null;
- }
- }
- </script>
- <html xmlns="http://www.w3.org/1999/xhtml">
- <head>
- <title>ASP.NET版Memcached监控工具</title>
- <style>
- a {
- color:#000000;
- text-decoration:none;
- }
- a.current {
- color:#0000FF;
- }
- a:hover {
- text-decoration: none;
- }
- body {
- font-family: verdana, geneva,tahoma, helvetica, arial, sans-serif;
- font-size: 100%;
- background-color:#FFFFFF;
- margin: 0em;
- }
- ul {
- font-size:80%;
- color:#666666;
- line-height: 1.5em;
- list-style: none;
- }
- </style>
- </head>
- <body>
- <table border="0">
- <tr><th>IP</th><th>Version</th><th>IsReachable</th><th>Bytes</th><th>Bytes_Read</th><th>Bytes_Written</th><th>Cmd_Get</th><th>Cmd_Set</th><th>Curr_Connections</th><th>Curr_Items</th><th>Get_Hits</th><th>Get_Misses</th><th>Limit_Maxbytes</th><th>Total_Items</th></tr>
- <%
- String format = "<tr><td>{0}</td><td>{1}</th><th>{2}</th><th>{3}</th><th>{4}</th><th>{5}</th><th>{6}</th><th>{7}</th><th>{8}</th><th>{9}</th><th>{10}</th><th>{11}</th><th>{12}</th><th>{13}</th></tr>";
- List<IPEndPoint> list = new List<IPEndPoint> { new IPEndPoint(IPAddress.Parse("127.0.0.1"), 11121), MemcachedMonitor.Parse("localhost",11131) };
- MemcachedMonitor monitor = new MemcachedMonitor(list);
- List<MemcachedServerStats> resultList = monitor.GetAllServerStats();
- string result=string.Empty;
- foreach (MemcachedServerStats stats in resultList)
- {
- result = string.Format(format, stats.IPEndPoint, stats.Version,stats.IsReachable, stats.Bytes, stats.Bytes_Read, stats.Bytes_Written, stats.Cmd_Get, stats.Cmd_Set, stats.Curr_Connections, stats.Curr_Items, stats.Get_Hits, stats.Get_Misses, stats.Limit_Maxbytes, stats.Total_Items);
- Response.Write(result);
- }
- %>
- </table>
- 这些数据所代表的意义如下:
- <ul>
- <li>pid:32u,服务器进程ID。</li>
- <li>uptime:32u, 服务器运行时间,单位秒。</li>
- <li>time :32u, 服务器当前的UNIX时间。</li>
- <li>version :string, 服务器的版本号。 </li>
- <li>curr_items :32u, 服务器当前存储的内容数量</li>
- <li>total_items :32u, 服务器启动以来存储过的内容总数。</li>
- <li>bytes :64u, 服务器当前存储内容所占用的字节数。</li>
- <li>curr_connections :32u, 连接数量。 </li>
- <li>total_connections :32u, 服务器运行以来接受的连接总数。</li>
- <li>connection_structures:32u, 服务器分配的连接结构的数量。</li>
- <li>cmd_get :32u, 取回请求总数。 </li>
- <li>cmd_set :32u, 存储请求总数。 </li>
- <li>get_hits :32u, 请求成功的总次数。</li>
- <li>get_misses :32u, 请求失败的总次数。</li>
- <li>bytes_read :64u, 服务器从网络读取到的总字节数。</li>
- <li>bytes_written :64u, 服务器向网络发送的总字节数。</li>
- <li>limit_maxbytes :32u, 服务器在存储时被允许使用的字节总数。</li>
- </ul>
- 上面的描述中32u和64u表示32位和64位无符号整数,string表示是string类型数据。<br />
- 作者博客:<a href="http://blog.csdn.net/zhoufoxcn" target="_blank">CSDN博客</a>|<a href="http://zhoufoxcn.blog.51cto.com" target="_blank">51CTO博客</a>
- </body>
- </html>
说明:周公对CSS不太熟悉,所以没有好好设计页面的显示效果,以能显示各Memcached的运行状态为准。
总结:Memcached作为一个非常不错的分布式缓存确实能很大程度上提高程序的性能。在上面的例子中有关检测Memcached运行状态数据的代码可以提取出来应用于WinForm或者Windows Service,一旦检测出Memcached不可访问可以采取更灵活的方式,比如发送邮件到指定的邮箱,关于这一部分的功能相信大家都能轻易实现,所以在这里就不再赘述了。
本文转自周金桥51CTO博客,原文链接: http://blog.51cto.com/zhoufoxcn/530247,如需转载请自行联系原作者