C#客户端Redis服务器的分布式缓存
介绍
在这篇文章中,我想介绍我知道的一种最紧凑的安装和配置Redis服务器的方式。另外,我想简短地概述一下在.NET / C#客户端下Redis hash(哈希类型)和list(链表)的使用。
在这篇文章主要讲到:
-
安装Redis服务器(附完整的应用程序文件设置)
-
Redis服务器保护(配置身份验证)
-
配置服务器复制
-
从C#应用程序访问缓存
-
使用Redis ASP.NET会话状态
-
Redis 集合(Set)、列表(List)和事务处理用法示例
-
说明附加的源(Redis Funq LoC MVC项目:举例)
-
缓存的优化思路
背景
Redis是最快也是功能最丰富的内存Key-Value数据存储系统之一。
缺点
-
没有本地数据缓存(如在Azure缓存同步本地数据缓存)
-
没有完全集群化的支持(不过,可能今年年底会实现)
优点
-
易于配置
-
使用简单
-
高性能
-
支持不同的数据类型(如hash(哈希类型)、list(链表)、set(集合)、sorted set(有序集))
-
ASP.NET会话集成
-
Web UI用于浏览缓存内容
下面我将简单说明如何在服务器上安装和配置Redis,并用C#使用它。
Redis的安装
从https://github.com/dmajkic/redis/downloads(win32 win64直接链接)下载二进制文件,解包档案到应用程序目录(如C:\Program Files\Redis)
下载从https://github.com/kcherenkov/redis-windows-service/downloads编译的Redis服务,然后复制到程序文件夹(如C:\Program Files\Redis)。如果配置文件丢失,也可以下载复制到应用程序目录。有效的Redis配置文件的范例在https://raw.github.com/antirez/redis/2.6/redis.conf。
Redis应用程序的完整文件也可以从压缩文件(x64)得到。
当你拥有了全套的应用程序文件(如下图所示),
导航到应用程序目录,然后运行以下命令:
sc create %name% binpath= "\"%binpath%\" %configpath%" start= "auto" DisplayName= "Redis"
其中:
-
%name%——服务实例的名称,例如:redis-instance;
-
%binpath%——到项目exe文件的路径,例如:C:\Program Files\Redis\RedisService_1.1.exe;
-
%configpath%——到Redis配置文件的路径,例如:C:\Program Files\Redis\redis.conf;
举例:
sc create Redis start= auto DisplayName= Redis binpath= "\"C:\Program Files\Redis\RedisService_1.1.exe\
" \"C:\Program Files\Redis\redis.conf\""
即应该是这样的:
请确保有足够的权限启动该服务。安装完毕后,请检查该服务是否创建成功,当前是否正在运行:
或者,你可以使用安装程序(我没试过):https://github.com/rgl/redis/downloads。
Redis服务器保护:密码,IP过滤
保护Redis服务器的主要方式是使用Windows防火墙或活跃的网络连接属性设置IP过滤。此外,还可以使用Redis密码设置额外保护。这需要用下面的方式更新Redis配置文件(redis.conf):
首先,找到这行:
# requirepass foobared
删除开头的#符号,用新密码替换foobared:
requirepass foobared
然后,重新启动Redis Windows服务!
当具体使用客户端的时候,使用带密码的构造函数:
RedisClient client = new RedisClient(serverHost, port, redisPassword);
Redis服务器复制(主—从配置)
Redis支持主从同步,即,每次主服务器修改,从服务器得到通知,并自动同步。大多复制用于读取(但不能写)扩展和数据冗余和服务器故障转移。设 置两个Redis实例(在相同或不同服务器上的两个服务),然后配置其中之一作为从站。为了让Redis服务器实例是另一台服务器的从属,可以这样更改配 置文件:
找到以下代码:
# slaveof <masterip> <masterport>
替换为:
slaveof 192.168.1.1 6379
(可以自定义指定主服务器的真实IP和端口)。如果主服务器配置为需要密码(验证),可以如下所示改变redis.conf,找到这一行代码:
# masterauth <master-password>
删除开头的#符号,用主服务器的密码替换<master-password>,即:
masterauth mastpassword
现在这个Redis实例可以被用来作为主服务器的只读同步副本。
用C#代码使用Redis缓存
用C#代码使用Redis运行Manage NuGet包插件,找到ServiceStack.Redis包,并进行安装。
直接从实例化客户端使用Set
/Get
方法示例:
- string host = "localhost";
- string elementKey = "testKeyRedis";
- using (RedisClient redisClient = new RedisClient(host))
- {
- if (redisClient.Get<string>(elementKey) == null)
- {
- // adding delay to see the difference
- Thread.Sleep(5000);
- // save value in cache
- redisClient.Set(elementKey, "some cached value");
- }
- // get value from the cache by key
- message = "Item value is: " + redisClient.Get<string>("some cached value");
- }
类型化实体集更有意思和更实用,这是因为它们操作的是确切类型的对象。在下面的代码示例中,有两个类分别定义为Phone和Person——phone的主人。每个phone实例引用它的主人。下面的代码演示我们如何通过标准添加、删除和发现缓存项:
- public class Phone
- {
- public int Id { get; set; }
- public string Model { get; set; }
- public string Manufacturer { get; set; }
- public Person Owner { get; set; }
- }
- public class Person
- {
- public int Id { get; set; }
- public string Name { get; set; }
- public string Surname { get; set; }
- public int Age { get; set; }
- public string Profession { get; set; }
- }
- using (RedisClient redisClient = new RedisClient(host))
- {
- IRedisTypedClient<phone> phones = redisClient.As<phone>();
- Phone phoneFive = phones.GetValue("5");
- if (phoneFive == null)
- {
- // make a small delay
- Thread.Sleep(5000);
- // creating a new Phone entry
- phoneFive = new Phone
- {
- Id = 5,
- Manufacturer = "Motorolla",
- Model = "xxxxx",
- Owner = new Person
- {
- Id = 1,
- Age = 90,
- Name = "OldOne",
- Profession = "sportsmen",
- Surname = "OldManSurname"
- }
- };
- // adding Entry to the typed entity set
- phones.SetEntry(phoneFive.Id.ToString(), phoneFive);
- }
- message = "Phone model is " + phoneFive.Manufacturer;
- message += "Phone Owner Name is: " + phoneFive.Owner.Name;
- }
在上面的例子中,我们实例化了输入端IRedisTypedClient,它与缓存对象的特定类型——Phone类型一起工作。
Redis ASP.NET会话状态
要用Redis提供商配置ASP.NET会话状态,添加新文件到你的Web项目,命名为RedisSessionStateProvider.cs,可以从https://github.com/chadman/redis-service-provider/raw/master/RedisProvider/SessionProvider/RedisSessionProvider.cs复制代码,然后添加或更改配置文件中的以下部分(sessionState标签已经内置于system.web标签),或者你也可以下载附加来源和复制代码。
- <sessionstate timeout="1" mode="Custom"
- customprovider="RedisSessionStateProvider" cookieless="false">
- <providers>
- <add name="RedisSessionStateProvider" writeexceptionstoeventlog="false"
- type="RedisProvider.SessionProvider.CustomServiceProvider"
- server="localhost" port="6379" password="pasword">
- </add> </providers>
- </sessionstate>
注意,此密码是可以选择的,看服务器是否需要认证。它必须被真实的值替换或删除,如果Redis服务器不需要身份验证,那么服务器属性和端口得由具体的数值代替(默认端口为6379)。然后在项目中,你才可以使用会话状态:
- // in the Global.asax
- public class MvcApplication1 : System.Web.HttpApplication
- {
- protected void Application_Start()
- {
- //....
- }
- protected void Session_Start()
- {
- Session["testRedisSession"] = "Message from the redis ression";
- }
- }
- 在Home controller(主控制器):
- public class HomeController : Controller
- {
- public ActionResult Index()
- {
- //...
- ViewBag.Message = Session["testRedisSession"];
- return View();
- }
- //...
- }
结果:
ASP.NET输出缓存提供者,并且Redis可以用类似的方式进行配置。
Redis Set(集合)和List(列表)
主要要注意的是,Redis列表实现IList<T>,而Redis集合实现ICollection<T>
。下面来说说如何使用它们。
当需要区分相同类型的不同分类对象时,使用列表。例如,我们有“mostSelling(热销手机)”和“oldCollection(回收手机)”两个列表:
- string host = "localhost";
- using (var redisClient = new RedisClient(host))
- {
- //Create a 'strongly-typed' API that makes all Redis Value operations to apply against Phones
- IRedisTypedClient<phone> redis = redisClient.As<phone>();
- IRedisList<phone> mostSelling = redis.Lists["urn:phones:mostselling"];
- IRedisList<phone> oldCollection = redis.Lists["urn:phones:oldcollection"];
- Person phonesOwner = new Person
- {
- Id = 7,
- Age = 90,
- Name = "OldOne",
- Profession = "sportsmen",
- Surname = "OldManSurname"
- };
- // adding new items to the list
- mostSelling.Add(new Phone
- {
- Id = 5,
- Manufacturer = "Sony",
- Model = "768564564566",
- Owner = phonesOwner
- });
- oldCollection.Add(new Phone
- {
- Id = 8,
- Manufacturer = "Motorolla",
- Model = "324557546754",
- Owner = phonesOwner
- });
- var upgradedPhone = new Phone
- {
- Id = 3,
- Manufacturer = "LG",
- Model = "634563456",
- Owner = phonesOwner
- };
- mostSelling.Add(upgradedPhone);
- // remove item from the list
- oldCollection.Remove(upgradedPhone);
- // find objects in the cache
- IEnumerable<phone> LGPhones = mostSelling.Where(ph => ph.Manufacturer == "LG");
- // find specific
- Phone singleElement = mostSelling.FirstOrDefault(ph => ph.Id == 8);
- //reset sequence and delete all lists
- redis.SetSequence(0);
- redisClient.Remove("urn:phones:mostselling");
- redisClient.Remove("urn:phones:oldcollection");
- }
当需要存储相关的数据集和收集统计信息,例如answer -> queustion给答案或问题投票时,Redis集合就非常好使。假设我们有很多的问题(queustion)和答案(answer ),需要将它们存储在缓存中。使用Redis,我们可以这么做:
- /// <summary>
- /// Gets or sets the Redis Manager. The built-in IoC used with ServiceStack autowires this property.
- /// </summary>
- IRedisClientsManager RedisManager { get; set; }
- /// <summary>
- /// Delete question by performing compensating actions to
- /// StoreQuestion() to keep the datastore in a consistent state
- /// </summary>
- /// <param name="questionId">
- public void DeleteQuestion(long questionId)
- {
- using (var redis = RedisManager.GetClient())
- {
- var redisQuestions = redis.As<question>();
- var question = redisQuestions.GetById(questionId);
- if (question == null) return;
- //decrement score in tags list
- question.Tags.ForEach(tag => redis.IncrementItemInSortedSet("urn:tags", tag, -1));
- //remove all related answers
- redisQuestions.DeleteRelatedEntities<answer>(questionId);
- //remove this question from user index
- redis.RemoveItemFromSet("urn:user>q:" + question.UserId, questionId.ToString());
- //remove tag => questions index for each tag
- question.Tags.ForEach("urn:tags>q:" + tag.ToLower(), questionId.ToString()));
- redisQuestions.DeleteById(questionId);
- }
- }
- public void StoreQuestion(Question question)
- {
- using (var redis = RedisManager.GetClient())
- {
- var redisQuestions = redis.As<question>();
- if (question.Tags == null) question.Tags = new List<string>();
- if (question.Id == default(long))
- {
- question.Id = redisQuestions.GetNextSequence();
- question.CreatedDate = DateTime.UtcNow;
- //Increment the popularity for each new question tag
- question.Tags.ForEach(tag => redis.IncrementItemInSortedSet("urn:tags", tag, 1));
- }
- redisQuestions.Store(question);
- redisQuestions.AddToRecentsList(question);
- redis.AddItemToSet("urn:user>q:" + question.UserId, question.Id.ToString());
- //Usage of tags - Populate tag => questions index for each tag
- question.Tags.ForEach(tag => redis.AddItemToSet
- ("urn:tags>q:" + tag.ToLower(), question.Id.ToString()));
- }
- }
- /// <summary>
- /// Delete Answer by performing compensating actions to
- /// StoreAnswer() to keep the datastore in a consistent state
- /// </summary>
- /// <param name="questionId">
- /// <param name="answerId">
- public void DeleteAnswer(long questionId, long answerId)
- {
- using (var redis = RedisManager.GetClient())
- {
- var answer = redis.As<question>().GetRelatedEntities<answer>
- (questionId).FirstOrDefault(x => x.Id == answerId);
- if (answer == null) return;
- redis.As<question>().DeleteRelatedEntity<answer>(questionId, answerId);
- //remove user => answer index
- redis.RemoveItemFromSet("urn:user>a:" + answer.UserId, answerId.ToString());
- }
- }
- public void StoreAnswer(Answer answer)
- {
- using (var redis = RedisManager.GetClient())
- {
- if (answer.Id == default(long))
- {
- answer.Id = redis.As<answer>().GetNextSequence();
- answer.CreatedDate = DateTime.UtcNow;
- }
- //Store as a 'Related Answer' to the parent Question
- redis.As<question>().StoreRelatedEntities(answer.QuestionId, answer);
- //Populate user => answer index
- redis.AddItemToSet("urn:user>a:" + answer.UserId, answer.Id.ToString());
- }
- }
- public List<answer> GetAnswersForQuestion(long questionId)
- {
- using (var redis = RedisManager.GetClient())
- {
- return redis.As<question>().GetRelatedEntities<answer>(questionId);
- }
- }
- public void VoteQuestionUp(long userId, long questionId)
- {
- //Populate Question => User and User => Question set indexes in a single transaction
- RedisManager.ExecTrans(trans =>
- {
- //Register upvote against question and remove any downvotes if any
- trans.QueueCommand(redis =>
- redis.AddItemToSet("urn:q>user+:" + questionId, userId.ToString()));
- trans.QueueCommand(redis =>
- redis.RemoveItemFromSet("urn:q>user-:" + questionId, userId.ToString()));
- //Register upvote against user and remove any downvotes if any
- trans.QueueCommand(redis =>
- redis.AddItemToSet("urn:user>q+:" + userId, questionId.ToString()));
- trans.QueueCommand(redis =>
- redis.RemoveItemFromSet("urn:user>q-:" + userId, questionId.ToString()));
- });
- }
- public void VoteQuestionDown(long userId, long questionId)
- {
- //Populate Question => User and User => Question set indexes in a single transaction
- RedisManager.ExecTrans(trans =>
- {
- //Register downvote against question and remove any upvotes if any
- trans.QueueCommand(redis =>
- redis.AddItemToSet("urn:q>user-:" + questionId, userId.ToString()));
- trans.QueueCommand(redis =>
- redis.RemoveItemFromSet("urn:q>user+:" + questionId, userId.ToString()));
- //Register downvote against user and remove any upvotes if any
- trans.QueueCommand(redis =>
- redis.AddItemToSet"urn:user>q-:" + userId, questionId.ToString()));
- trans.QueueCommand(redis =>
- redis.RemoveItemFromSet("urn:user>q+:" + userId, questionId.ToString()));
- });
- }
- public void VoteAnswerUp(long userId, long answerId)
- {
- //Populate Question => User and User => Question set indexes in a single transaction
- RedisManager.ExecTrans(trans =>
- {
- //Register upvote against answer and remove any downvotes if any
- trans.QueueCommand(redis =>
- redis.AddItemToSet("urn:a>user+:" + answerId, userId.ToString()));
- trans.QueueCommand(redis =>
- redis.RemoveItemFromSet("urn:a>user-:" + answerId, userId.ToString()));
- //Register upvote against user and remove any downvotes if any
- trans.QueueCommand(redis =>
- redis.AddItemToSet("urn:user>a+:" + userId, answerId.ToString()));
- trans.QueueCommand(redis =>
- redis.RemoveItemFromSet("urn:user>a-:" + userId, answerId.ToString()));
- });
- }
- public void VoteAnswerDown(long userId, long answerId)
- {
- //Populate Question => User and User => Question set indexes in a single transaction
- RedisManager.ExecTrans(trans =>
- {
- //Register downvote against answer and remove any upvotes if any
- trans.QueueCommand(redis =>
- redis.AddItemToSet("urn:a>user-:" + answerId, userId.ToString()));
- trans.QueueCommand(redis =>
- redis.RemoveItemFromSet("urn:a>user+:" + answerId, userId.ToString()));
- //Register downvote against user and remove any upvotes if any
- trans.QueueCommand(redis =>
- redis.AddItemToSet("urn:user>a-:" + userId, answerId.ToString()));
- trans.QueueCommand(redis =>
- redis.RemoveItemFromSet("urn:user>a+:" + userId, answerId.ToString()));
- });
- }
- public QuestionResult GetQuestion(long questionId)
- {
- var question = RedisManager.ExecAs<question>
- (redisQuestions => redisQuestions.GetById(questionId));
- if (question == null) return null;
- var result = ToQuestionResults(new[] { question })[0];
- var answers = GetAnswersForQuestion(questionId);
- var uniqueUserIds = answers.ConvertAll(x => x.UserId).ToHashSet();
- var usersMap = GetUsersByIds(uniqueUserIds).ToDictionary(x => x.Id);
- result.Answers = answers.ConvertAll(answer =>
- new AnswerResult { Answer = answer, User = usersMap[answer.UserId] });
- return result;
- }
- public List<user> GetUsersByIds(IEnumerable<long> userIds)
- {
- return RedisManager.ExecAs<user>(redisUsers => redisUsers.GetByIds(userIds)).ToList();
- }
- public QuestionStat GetQuestionStats(long questionId)
- {
- using (var redis = RedisManager.GetReadOnlyClient())
- {
- var result = new QuestionStat
- {
- VotesUpCount = redis.GetSetCount("urn:q>user+:" +questionId),
- VotesDownCount = redis.GetSetCount("urn:q>user-:" + questionId)
- };
- result.VotesTotal = result.VotesUpCount - result.VotesDownCount;
- return result;
- }
- }
- public List<tag> GetTagsByPopularity(int skip, int take)
- {
- using (var redis = RedisManager.GetReadOnlyClient())
- {
- var tagEntries = redis.GetRangeWithScoresFromSortedSetDesc("urn:tags", skip, take);
- var tags = tagEntries.ConvertAll(kvp => new Tag { Name = kvp.Key, Score = (int)kvp.Value });
- return tags;
- }
- }
- public SiteStats GetSiteStats()
- {
- using (var redis = RedisManager.GetClient())
- {
- return new SiteStats
- {
- QuestionsCount = redis.As<question>().TypeIdsSet.Count,
- AnswersCount = redis.As<answer>().TypeIdsSet.Count,
- TopTags = GetTagsByPopularity(0, 10)
- };
- }
- }
附加资源说明
项目中引用的一些包在packages.config文件中配置。
Funq IoC的相关配置,以及注册类型和当前控制器目录,在Global.asax文件中配置。
基于IoC的缓存使用以及Global.asax可以打开以下URL:http://localhost:37447/Question/GetQuestions?tag=test 查看。
你可以将tag字段设置成test3,test1,test2等。
Redis缓存配置——在web config文件(<system.web><sessionState>节点)以及RedisSessionStateProvider.cs文件中。
在MVC项目中有很多待办事项,因此,如果你想改进/继续,请更新,并上传。
如果有人能提供使用Redis(以及Funq IOC)缓存的MVC应用程序示例,本人将不胜感激。Funq IOC已经配置,使用示例已经在Question controller中。
注:部分取样于“ServiceStack.Examples-master”解决方案。
结论。优化应用程序缓存以及快速本地缓存
由于Redis并不在本地存储(也不在本地复制)数据,那么通过在本地缓存区存储一些轻量级或用户依赖的对象(跳过序列化字符串和客户端—服务端数据转换)来优化性能是有意义的。例如,在Web应用中,对于轻量级的对象使用’System.Runtime.Caching.ObjectCache
‘ 会更好——用户依赖,并且应用程序时常要用。否则,当经常性地需要使用该对象时,就必须在分布式Redis缓存中存储大量容积的内容。用户依赖的对象举例——个人资料信息,个性化信息 。常用对象——本地化数据,不同用户之间的共享信息,等等。
链接
如何运行Redis服务:
https://github.com/kcherenkov/redis-windows-service
文档:
.NET / C#示例:
https://github.com/ServiceStack/ServiceStack.Examples
关于如何用C#在Windows上使用Redis的好建议:
http://maxivak.com/getting-started-with-redis-and-asp-net-mvc-under-windows/:
http://www.piotrwalat.net/using-redis-with-asp-net-web-api/
关于Redis:
https://github.com/ServiceStack/ServiceStack.Redis
Azure缓存
http://kotugoroshko.blogspot.ae/2013/07/windows-azure-caching-integration.html
许可证
这篇文章,以及任何相关的源代码和文件,依据The Code Project Open License (CPOL)。
译文链接:http://www.codeceo.com/article/distributed-caching-redis-server.html
英文原文:Distributed Caching using Redis Server with .NET/C# Client