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* Refactor: Genericise request limit strategies and move to OpenSim.Framework.Communications.Limit

0.6.0-stable
Justin Clarke Casey 2008-03-24 18:21:06 +00:00
parent 56dfa4e6da
commit 8c0955321a
3 changed files with 211 additions and 60 deletions
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68
OpenSim/Framework/Communications/Limit/IRequestLimitStrategy.cs Normal file
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@ -0,0 +1,68 @@
/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the OpenSim Project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
using System;
namespace OpenSim.Framework.Communications.Limit
{
/// <summary>
/// Interface for strategies that can limit requests from the client. Currently only used in the
/// texture modules to deal with repeated requests for certain textures. However, limiting strategies
/// could be used with other requests.
/// </summary>
public interface IRequestLimitStrategy<TId>
{
/// <summary>
/// Should the request be allowed? If the id is not monitored, then the request is always allowed.
/// Otherwise, the strategy criteria will be applied.
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
bool AllowRequest(TId id);
/// <summary>
/// Has the request been refused just once?
/// </summary>
/// <returns>False if the request has not yet been refused, or if the request has been refused more
/// than once.</returns>
bool IsFirstRefusal(TId id);
/// <summary>
/// Start monitoring for future AllowRequest calls. If the id is already monitored, then monitoring
/// continues.
/// </summary>
/// <param name="id"></param>
void MonitorRequests(TId id);
/// <summary>
/// Is the id being monitored?
/// </summary>
/// <param name="uuid"> </param>
/// <returns></returns>
bool IsMonitoringRequests(TId id);
}
}

113
OpenSim/Framework/Communications/Limit/RepeatLimitStrategy.cs Normal file
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@ -0,0 +1,113 @@
/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the OpenSim Project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
using System;
using System.Collections.Generic;
namespace OpenSim.Framework.Communications.Limit
{
/// <summary>
/// Limit requests by discarding them after they've been repeated a certain number of times.
/// </summary>
public class RepeatLimitStrategy<TId> : IRequestLimitStrategy<TId>
{
private static readonly log4net.ILog m_log
= log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
/// <summary>
/// Record each asset request that we're notified about.
/// </summary>
private readonly Dictionary<TId, int> requestCounts = new Dictionary<TId, int>();
/// <summary>
/// The maximum number of requests that can be made before we drop subsequent requests.
/// </summary>
private readonly int m_maxRequests;
public int MaxRequests
{
get { return m_maxRequests; }
}
/// <summary></summary>
/// <param name="maxRequests">The maximum number of requests that may be served before all further
/// requests are dropped.</param>
public RepeatLimitStrategy(int maxRequests)
{
m_maxRequests = maxRequests;
}
/// <summary>
/// <see cref="IRequestLimitStrategy"/>
/// </summary>
public bool AllowRequest(TId id)
{
if (requestCounts.ContainsKey(id))
{
requestCounts[id] += 1;
if (requestCounts[id] > m_maxRequests)
{
return false;
}
}
return true;
}
/// <summary>
/// <see cref="IRequestLimitStrategy"/>
/// </summary>
public bool IsFirstRefusal(TId id)
{
if (m_maxRequests + 1 == requestCounts[id])
{
return true;
}
return false;
}
/// <summary>
/// <see cref="IRequestLimitStrategy"/>
/// </summary>
public void MonitorRequests(TId id)
{
if (!IsMonitoringRequests(id))
{
requestCounts.Add(id, 1);
}
}
/// <summary>
/// <see cref="IRequestLimitStrategy"/>
/// </summary>
public bool IsMonitoringRequests(TId id)
{
return requestCounts.ContainsKey(id);
}
}
}

90
OpenSim/Region/Environment/Modules/UserTextureDownloadService.cs
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@ -32,6 +32,7 @@ using libsecondlife;
using libsecondlife.Packets; using libsecondlife.Packets;
using OpenSim.Framework; using OpenSim.Framework;
using OpenSim.Framework.Communications.Limit;
using OpenSim.Framework.Console; using OpenSim.Framework.Console;
using OpenSim.Region.Environment.Interfaces; using OpenSim.Region.Environment.Interfaces;
using OpenSim.Region.Environment.Scenes; using OpenSim.Region.Environment.Scenes;
@ -53,6 +54,20 @@ namespace OpenSim.Region.Environment.Modules
/// </summary> /// </summary>
private static readonly int MAX_ALLOWED_TEXTURE_REQUESTS = 5; private static readonly int MAX_ALLOWED_TEXTURE_REQUESTS = 5;
/// <summary>
/// We're going to limit repeated requests for the same missing texture.
/// XXX This is really a temporary solution to deal with the situation where a client continually requests
/// the same missing textures
/// </summary>
private readonly IRequestLimitStrategy<LLUUID> missingTextureLimitStrategy
= new RepeatLimitStrategy<LLUUID>(MAX_ALLOWED_TEXTURE_REQUESTS);
/// <summary>
/// XXX Also going to limit repeated requests for found textures.
/// </summary>
private readonly IRequestLimitStrategy<LLUUID> foundTextureLimitStrategy
= new RepeatLimitStrategy<LLUUID>(MAX_ALLOWED_TEXTURE_REQUESTS);
/// <summary> /// <summary>
/// Holds texture senders before they have received the appropriate texture from the asset cache. /// Holds texture senders before they have received the appropriate texture from the asset cache.
/// </summary> /// </summary>
@ -64,18 +79,6 @@ namespace OpenSim.Region.Environment.Modules
/// </summary> /// </summary>
private readonly BlockingQueue<ITextureSender> m_sharedSendersQueue; private readonly BlockingQueue<ITextureSender> m_sharedSendersQueue;
/// <summary>
/// We're going to record when we get a request for a particular missing texture for each client
/// XXX This is really a temporary solution to deal with the situation where a client continually requests
/// the same missing textures
/// </summary>
private readonly Dictionary<LLUUID, int> missingTextureRequestCounts = new Dictionary<LLUUID, int>();
/// <summary>
/// XXX Also going to record all the textures found and dispatched
/// </summary>
private readonly Dictionary<LLUUID, int> dispatchedTextureRequestCounts = new Dictionary<LLUUID, int>();
private readonly Scene m_scene; private readonly Scene m_scene;
private readonly IClientAPI m_client; private readonly IClientAPI m_client;
@ -109,50 +112,21 @@ namespace OpenSim.Region.Environment.Modules
textureSender.UpdateRequest(e.DiscardLevel, e.PacketNumber); textureSender.UpdateRequest(e.DiscardLevel, e.PacketNumber);
} }
else else
{ {
// If we've already told the client we're missing the texture, then don't ask the if (!foundTextureLimitStrategy.AllowRequest(e.RequestedAssetID))
// asset server for it again - record the fact that it's missing instead.
// XXX This is to reduce (but not resolve) a current problem where some clients keep
// requesting the same textures
if (missingTextureRequestCounts.ContainsKey(e.RequestedAssetID))
{ {
missingTextureRequestCounts[e.RequestedAssetID] += 1; return;
if (missingTextureRequestCounts[e.RequestedAssetID] > MAX_ALLOWED_TEXTURE_REQUESTS)
{
if (MAX_ALLOWED_TEXTURE_REQUESTS + 1 == missingTextureRequestCounts[e.RequestedAssetID])
{
m_log.DebugFormat(
"[USER TEXTURE DOWNLOAD SERVICE]: Dropping requests for notified missing texture {0} for {1} since we have received more than {2} requests",
e.RequestedAssetID, m_client.AgentId, MAX_ALLOWED_TEXTURE_REQUESTS);
}
return;
}
} }
else else if (!missingTextureLimitStrategy.AllowRequest(e.RequestedAssetID))
{ {
// If we keep receiving requests for textures we've already served to the client, if (missingTextureLimitStrategy.IsFirstRefusal(e.RequestedAssetID))
// then stop sending them. This is a short term approach approach to the problem
// of clients which keep requesting the same texture - the long term approach
// will be to treat the cause (and possibly more generally cap the request
// queues as well/instead)
if (dispatchedTextureRequestCounts.ContainsKey(e.RequestedAssetID))
{ {
dispatchedTextureRequestCounts[e.RequestedAssetID] += 1; m_log.DebugFormat(
"[USER TEXTURE DOWNLOAD SERVICE]: Dropping requests for notified missing texture {0} for client {1} since we have received more than {1} requests",
if (dispatchedTextureRequestCounts[e.RequestedAssetID] > MAX_ALLOWED_TEXTURE_REQUESTS) e.RequestedAssetID, m_client.AgentId, MAX_ALLOWED_TEXTURE_REQUESTS);
{ }
// if (MAX_ALLOWED_TEXTURE_REQUESTS + 1 == dispatchedTextureRequestCounts[e.RequestedAssetID])
// { return;
// m_log.DebugFormat(
// "[USER TEXTURE DOWNLOAD SERVICE]: Dropping further requests for dispatched/queued texture {0} for {1} since we have received more than {2} requests",
// e.RequestedAssetID, m_client.AgentId, MAX_ALLOWED_TEXTURE_REQUESTS);
// }
return;
}
}
} }
m_scene.AddPendingDownloads(1); m_scene.AddPendingDownloads(1);
@ -197,9 +171,9 @@ namespace OpenSim.Region.Environment.Modules
// Needs investigation. // Needs investigation.
if (texture == null || texture.Data == null) if (texture == null || texture.Data == null)
{ {
if (!missingTextureRequestCounts.ContainsKey(textureID)) if (!missingTextureLimitStrategy.IsMonitoringRequests(textureID))
{ {
missingTextureRequestCounts.Add(textureID, 1); missingTextureLimitStrategy.MonitorRequests(textureID);
m_log.DebugFormat( m_log.DebugFormat(
"[USER TEXTURE DOWNLOAD SERVICE]: Queueing first TextureNotFoundSender for {0}, client {1}", "[USER TEXTURE DOWNLOAD SERVICE]: Queueing first TextureNotFoundSender for {0}, client {1}",
@ -216,11 +190,7 @@ namespace OpenSim.Region.Environment.Modules
textureSender.TextureReceived(texture); textureSender.TextureReceived(texture);
EnqueueTextureSender(textureSender); EnqueueTextureSender(textureSender);
// Record the fact that we've put this texture in for dispatch foundTextureLimitStrategy.MonitorRequests(textureID);
if (!dispatchedTextureRequestCounts.ContainsKey(textureID))
{
dispatchedTextureRequestCounts.Add(textureID, 1);
}
} }
} }