聊天服務器：什麼是保存對話日誌的最佳（優化）方式

Question

我正在用java構建一個簡單的聊天服務器，用戶之間可以進行私人對話。我想將這些對話保存在服務器級別（不在客戶端），以便我可以將它們作爲對話日誌服務列出給用戶。 我也在我的軟件中使用MySQL作爲數據庫。

我在尋找的是一種優化的方式來保存這些對話，也是一種快速的方式，以便稍後列出它們。 到目前爲止，我想到了2個實現。

1. 使用MySQL數據庫和

   一）保存在一排爲文本交談，但問題是，有些對話是非常巨大的（大量字符的），我可能有保存的問題整個談話

   b）保存在一排談話的每一行，但這樣的速度的問題會出現，當我想列出整個會話

2. 保存在一個分隔的文本文件每次談話，但我恐怕r可能會出現ead/write問題，特別是當用戶（客戶端）非常快地寫入（發送文本）時。

感謝

Answer 1

這是很大的問題的建築，你知道的。像Facebook和Twitter這樣的公司花費了大量的時間和金錢來以可靠的方式解決您的問題。如果你的聊天服務器很簡單（就像你寫的那樣），使用1.b方式，但是創建一個抽象層（類似saveConversation,getConversation）。如果將來的速度不能滿足你，請考慮更有效的表示，比如NoSQL數據庫（LevelDB或類似的東西）。現在不要考慮性能，製作具有良好抽象和可插拔體系結構的原型。

Answer 2

建議的方法都不是最佳的存儲方式。 最好的方法是在會話的基礎上使用動態表格的條形段。

這與範式的原型： -

1. 做一個談話多個參與者。
2. 選項確認聊天。
3. 動作更新選項。
4. 發佈附件的選項。
5. 選項可以分享您當前位置的地圖座標。
6. 離開聊天的選項。

類型

Coordinates(
    lat FLOAT(10, 6) NOT NULL , 
    lng FLOAT(10, 6) NOT NULL 
) 

架構

dbo.User(UserId,<..Details..>) 

dbo.Conversation(ConversationId,Title,CreationDate,LastActivityDate) 

指數：LastActivityDate，的conversationId表

dbo.Participants(ConversationId,UserId) 

收集 - 動態創建

msg.msg_*ConversationId*(MessageId,FromUserId,Message,Attachment,LocationCoordinates,Action,LogDate,AcknowledgeDate) 

抽象

usp_TouchMessage(@Which): 
    if (not exists (select 1 from INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA+'.'+TABLE_NAME = 'msg.msg_'+CAST(@Which as nvarchar(max))) 
    begin 
     @dynamic_sql = 'create table msg.msg_'+CAST(@Which as nvarchar(max))+' (MessageId uniqueidentifier,FromUserId uniqueidentifier,Message nvarchar(max),Attachment BLOB,LocationCoordinates Coordinates,Action nvarchar(max),LogDate DateTime, AcknowledgeDate DateTime);'; 
     exec(@dynamic_sql); 
     @dynamic_sql = 'CREATE TRIGGER msg.trig_msg_'+CAST(@Which as nvarchar(max))+' ON msg.msg_'+CAST(@Which as nvarchar(max))+' AFTER INSERT AS Delete From msg.msg_'+CAST(@Which as nvarchar(max))+' where MessageId in (Select MessageId,ROW_NUMBER() OVER (order by LogDate Desc,AcknowledgeDate Desc,MessageId Desc) RN from msg.msg_'+CAST(@Which as nvarchar(max))+') where RN>=5000'; 
     exec(@dynamic_sql); 

    end 

usp_GetParticipants(@Where) : 
    Select User.UserId,User.FullName 
      from Participants 
       inner join Users on (
         Participants.UserId = Users.UserId 
        And Participants.ConversationId = @Where 
       ); 


usp_AddParticipants(@Who, @Where) : 
    insert into Participants(ConversationId,UserId) values (@Where, @Who); 
    @action = (select User.FullName + ' has joined the chat' from User where User.UserId = @Who); 
    update Conversation set LastActivityDate = GETUTCDATE() where ConversationId = @conversation_id; 
    exec usp_TouchMessage(@Where); 
    @dynamic_sql = 'insert into msg.msg_'+CAST(@Where as nvarchar(max))+' (MessageId,FromUserId,Action,LogDate) values (NewId(),@Who,@Action,GETUTCDATE())'; 
    sp_executesql @dynamic_sql, N'@Who uniqueidentifier,@Action nvarchar(max)', @Who = @Who, @Action = @Action; 


usp_GetConversationList() : 
    With Participation As (
     Select User.UserId,User.FullName,Participants.ConversationId 
      from Participants 
       inner join Users on (Participants.UserId = Users.UserId) 
    ) select Conversation.*, 
      (STUFF((
        SELECT ',' + CAST([FullName] AS nvarchar(max)) 
         FROM Participation 
        WHERE (Participation.ConversationId = Conversation.ConversationId) 
       FOR XML PATH ('') 
      ),1,1,'')) ParticipantList 
     from Conversation 
    order by Conversation.LastActivityDate; 


usp_GetConversationById(@Which,@Lite = 0,@Page = 1) : 
    Select User.UserId,User.FullName 
      from Participants 
      inner join Users on (Participants.UserId = Users.UserId and Participants.ConversationId = @Which); 
    @dynamic_sql = 'select * from 
         (select u.UserId,u.FullName,m.MessageId,' 
           +(case when @Lite=1 then 'm.Message,m.LocationCoordinates,m.Attachment,m.Action,' else '' end) 
           +'m.LogDate,m.AcknowledgeDate, ROW_NUMBER() Over (order by m.LogDate Desc,m.AcknowledgeDate Desc,m.MessageId Desc) RN 
          From msg.msg_'+CAST(@Which AS nvarchar(max))+' m 
          inner join User u on (m.FromUserId = u.UserId) 
         ) tmp 
        where RN Between ((@Page-1)*20+1) AND (@Page*20+1) 
       '; 
    sp_executesql @dynamic_sql, N'@Page bigint', @Page = @Page; 
    If @Page = 1 And @Lite=0 
    begin 
     @dynamic_sql = 'update msg.msg_'+CAST(@Which as nvarchar(max))+' Set AcknowledgeDate = GETUTCDATE() where AcknowledgeDate is null and FromUserId <> @Who'; 
     sp_executesql @dynamic_sql, N'@Who uniqueidentifier', @Who = @Who; 
    end 

usp_GetConversation(@Who,@WithWhome,@Lite = 0,@Page = 1) : 
    @conversation_id = (
     Select top 1 ConversationId 
      from Participants self 
      inner join Participants partner 
       on (self.ConversationId = partner.ConversationId and self.UserId = @Who and partner.UserId = @WithWhome) 
      where (Select count(1) from Participants where ConversationId = self.ConversationId) = 2 
    ); 
    if(@conversation_id is not null) 
    then 
     exec usp_GetConversationById(@conversation_id, @Lite, @Page); 
    end 


usp_PostConversationById(@Who,@Which,@WhatMessage,@WhichLocation,@WhatAttachment) : 
    update Conversation set LastActivityDate = GETUTCDATE() where ConversationId = @Which; 
    exec usp_TouchMessage(@Which); 
    @dynamic_sql = 'insert into msg.msg_'+CAST(@Which as nvarchar(max))+' (MessageId,FromUserId,Message,Attachment,LocationCoordinates,LogDate) values (NewId(),@Who,@WhatMessage,@WhichLocation,@WhatAttachment,GETUTCDATE())'; 
    sp_executesql @dynamic_sql, N'@Who uniqueidentifier,@WithWhome uniqueidentifier,@WhatMessage nvarchar(max),@WhichLocation Coordinates,@WhatAttachment BLOB', @Who = @Who, @WhatMessage = @WhatMessage, @WhichLocation = @WhichLocation, @WhatAttachment = @WhatAttachment; 


usp_PostConversation(@Who,@WithWhome,@WhatMessage,@WhichLocation,@WhatAttachment) : 
    @conversation_id = (
     Select top 1 ConversationId 
      from Participants self 
      inner join Participants partner 
       on (self.ConversationId = partner.ConversationId and self.UserId = @Who and partner.UserId = @WithWhome) 
      where (Select count(1) from Participants where ConversationId = self.ConversationId) = 2 
    ); 
    if(@conversation_id is not null) 
    then 
     @conversation_id = newid() 
     insert into Conversation(ConversationId,CreationDate) values (@conversation_id,GETUTCDATE()); 
     exec usp_AddParticipants(@Who,@conversation_id); 
     exec usp_AddParticipants(@WithWhome,@conversation_id); 
    end 
    exec usp_PostConversationById(@Who,@conversation_id,@WhatMessage,@WhichLocation,@WhatAttachment); 


usp_UpdateConversationAlias(@Who,@Which,@WithWhat) : 
    @action = (select User.FullName + ' has changed title'+isnull(' from <b>'+Conversation.Title+'</b>','')+isnull(' to <b>'+@WithWhat+'</b>','') from User inner join Conversation on (Conversation.ConversationId = @Which and User.UserId = @Who)); 
    update Conversation set LastActivityDate = GETUTCDATE(), Title = @WithWhat where ConversationId = @conversation_id; 
    if (not exists (select 1 from INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA+'.'+TABLE_NAME = 'msg.msg_'+CAST(@Which as nvarchar(max))) 
    exec usp_TouchMessage(@Which); 
    @dynamic_sql = 'insert into msg.msg_'+CAST(@Which as nvarchar(max))+' (MessageId,FromUserId,Action,LogDate) values (NewId(),@Who,@Action,GETUTCDATE())'; 
    sp_executesql @dynamic_sql, N'@Who uniqueidentifier,@Action nvarchar(max)', @Who = @Who, @Action = @Action; 


usp_LeaveConversation(@Who,@Which) : 
    delete from Participants where ConversationId = @Where and UserId = @Who; 
    if(not exists (Select 1 From Participants Where ConversationId = @Which)) 
    begin 
     @dynamic_sql = 'drop table msg.msg_'+CAST(@Which as nvarchar(max))+'; 
     exec @dynamic_sql; 
     delete from Conversation where ConversationId = @Which; 
    end 
    else 
    begin 
     @action = (select User.FullName + ' has left the chat' from User where User.UserId = @Who); 
     update Conversation set LastActivityDate = GETUTCDATE() where ConversationId = @conversation_id; 
     exec usp_TouchMessage(@Which); 
     @dynamic_sql = 'insert into msg.msg_'+CAST(@Which as nvarchar(max))+' (MessageId,FromUserId,Action,LogDate) values (NewId(),@Who,@Action,GETUTCDATE())'; 
     sp_executesql @dynamic_sql, N'@Who uniqueidentifier,@Action nvarchar(max)', @Who = @Who, @Action = @Action; 
    end