负载均衡时，在State_Server模式中的Session共享问题（不讨论负载均衡的问题）

前言：

配置Session的mode为State_Server模式，不说明，请按照如下配置

<sessionState mode="StateServer" stateConnectionString="tcpip=192.168.224.1:42424"cookieless="true" cookieName="APSNET_SessionId" timeout="6000" ></sessionState>

红色部分是关键部分，上面的ip是我的虚拟机的ip地址。

通过services.msc找到ASP.Net状态服务，并且开启，然后到注册表中打开AllowRemoteConnection值，设置成1.注册表地址：自己去网上搜吧，太长了不写了。

以上内容是网上大部分的内容，然后你都做好了，也未必就能Session共享。不信你去试试。（不要给我拿两个浏览器去查询，然后问我为啥不共享，我要咬人的）

补充：关于负载均衡的配置我是使用nginx做的测试，刚刚使用这个工具，还不是很熟练，你可以在网上找到。至于webFrame嘛，装起来真TMD麻烦。

正文

废话说了一大堆，上正文吧。

以上的配置都做好了之后需要检查你的iis配置，网站的应用程序池和网站的id是否相同，一定要保证相同。

那么还有一个很重要的就是要修改你的global.asax文件，添加如下代码

public override void Init()
{
base.Init();
foreach (string moduleName in this.Modules)
{
string appName = "APPNAME";
IHttpModule module = this.Modules[moduleName];
SessionStateModule ssm = module as SessionStateModule;
if (ssm != null)
{
System.Reflection.FieldInfo storeInfo = typeof(SessionStateModule).GetField("_store", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
SessionStateStoreProviderBase store = (SessionStateStoreProviderBase)storeInfo.GetValue(ssm);
if (store == null)//In IIS7 Integrated mode, module.Init() is called later
{
System.Reflection.FieldInfo runtimeInfo = typeof(HttpRuntime).GetField("_theRuntime", System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic);
HttpRuntime theRuntime = (HttpRuntime)runtimeInfo.GetValue(null);
System.Reflection.FieldInfo appNameInfo = typeof(HttpRuntime).GetField("_appDomainAppId", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
appNameInfo.SetValue(theRuntime, appName);
}
else
{
Type storeType = store.GetType();
if (storeType.Name.Equals("OutOfProcSessionStateStore"))
{
System.Reflection.FieldInfo uribaseInfo = storeType.GetField("s_uribase", System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic);
uribaseInfo.SetValue(storeType, appName);
}
}
}
}
}

一切就绪，然后就嗨起来吧，真的可以了。我再这里不上截图了，附件将源码带上（其中包括网站项目、mvc项目和网站应用，都需要配置global文件）。

如果一切到这里就结束了，好像也能接受，但是我告诉你，我们还没完呢

通过上面的代码我们可以看到主要思路就是 HttpRuntime的_appDomainAppId属性赋值或者是给OutOfProcSessionStateStore的s_uribase赋值。

我们通过查看.net源码发现这两个属性都是私有属性,在我的源码附件中的mvc项目中可以看到，在不同的机器和iis版本下，输出的内容不一致，这个内容就是存储session库的一个关键值。

以下是我查看到的部分源码，抛出来给大家打打牙祭。

void OneTimeInit() {
SessionStateSection config = RuntimeConfig.GetAppConfig().SessionState;

s_configPartitionResolverType = config.PartitionResolverType;
s_configStateConnectionString = config.StateConnectionString;
s_configStateConnectionStringFileName = config.ElementInformation.Properties["stateConnectionString"].Source;
s_configStateConnectionStringLineNumber = config.ElementInformation.Properties["stateConnectionString"].LineNumber;
s_configCompressionEnabled = config.CompressionEnabled;

if (_partitionResolver == null) {
String stateConnectionString = config.StateConnectionString;

SessionStateModule.ReadConnectionString(config, ref stateConnectionString, "stateConnectionString");

s_singlePartitionInfo = (StateServerPartitionInfo)CreatePartitionInfo(stateConnectionString);
}
else {
s_usePartition = true;
s_partitionManager = new PartitionManager(new CreatePartitionInfo(CreatePartitionInfo));
}

s_networkTimeout = (int)config.StateNetworkTimeout.TotalSeconds;

string appId = HttpRuntime.AppDomainAppId;
string idHash = Convert.ToBase64String(CryptoUtil.ComputeSHA256Hash(Encoding.UTF8.GetBytes(appId)));

// Make sure that we have a absolute URI, some hosts(Cassini) don't provide this.
if (appId.StartsWith("/", StringComparison.Ordinal)) {
s_uribase = appId + "(" + idHash + ")/";
}
else {
s_uribase = "/" + appId + "(" + idHash + ")/";
}

// We only need to do this in one instance
s_onAppDomainUnload = new EventHandler(OnAppDomainUnload);
Thread.GetDomain().DomainUnload += s_onAppDomainUnload;

s_oneTimeInited = true;
}

 通过上面红色的代码，我们可以看到，不管是在global中赋值给哪个变量，最后都汇集到s_uribase这个变量中。那我们继续找，看一下是在哪里使用到了这个变量吧

void MakeRequest(
UnsafeNativeMethods.StateProtocolVerb   verb,
String                                  id,
UnsafeNativeMethods.StateProtocolExclusive    exclusiveAccess,
int                                     extraFlags,
int                                     timeout,
int                                     lockCookie,
byte[]                                  buf,
int                                     cb,
int                                     networkTimeout,
out UnsafeNativeMethods.SessionNDMakeRequestResults results) {//笔者注：这是一个很重要的out参数

int                         hr;
string                      uri;
OutOfProcConnection         conn = null;
HandleRef                   socketHandle;
bool                        checkVersion = false;

Debug.Assert(timeout <= SessionStateModule.MAX_CACHE_BASED_TIMEOUT_MINUTES, "item.Timeout <= SessionStateModule.MAX_CACHE_BASED_TIMEOUT_MINUTES");

SessionIDManager.CheckIdLength(id, true /* throwOnFail */);

if (_partitionInfo == null) {
Debug.Assert(s_partitionManager != null);
Debug.Assert(_partitionResolver != null);

_partitionInfo = (StateServerPartitionInfo)s_partitionManager.GetPartition(_partitionResolver, id);

// If its still null, we give up
if (_partitionInfo == null) {
throw new HttpException(SR.GetString(SR.Bad_partition_resolver_connection_string, "PartitionManager"));
}
}

// Need to make sure we dispose the connection if anything goes wrong
try {
conn = (OutOfProcConnection)_partitionInfo.RetrieveResource();
if (conn != null) {
socketHandle = new HandleRef(this, conn._socketHandle.Handle);
}
else {
socketHandle = new HandleRef(this, INVALID_SOCKET);
}

if (_partitionInfo.StateServerVersion == -1) {
// We don't need locking here because it's okay to have two
// requests initializing s_stateServerVersion.
checkVersion = true;
}

Debug.Trace("OutOfProcSessionStateStoreMakeRequest",
"Calling MakeRequest, " +
"socket=" + (IntPtr)socketHandle.Handle +
"verb=" + verb +
" id=" + id +
" exclusiveAccess=" + exclusiveAccess +
" timeout=" + timeout +
" buf=" + ((buf != null) ? "non-null" : "null") +

c8ef
" cb=" + cb +
" checkVersion=" + checkVersion +
" extraFlags=" + extraFlags);

// Have to UrlEncode id because it may contain non-URL-safe characters
uri = HttpUtility.UrlEncode(s_uribase + id);//笔者注：在这里使用到了s_uribase
//笔者注：在这里使用uri和主方法的out参数作为参数调用了另外一个方法，并且返回了一个int类型，到此可以看到 hr 对我们的价值已经没有了，我们进入到这个方法看看吧。
hr = UnsafeNativeMethods.SessionNDMakeRequest(
socketHandle, _partitionInfo.Server, _partitionInfo.Port, _partitionInfo.ServerIsIPv6NumericAddress /* forceIPv6 */, networkTimeout, verb, uri,
exclusiveAccess, extraFlags, timeout, lockCookie,
buf, cb, checkVersion, out results);

Debug.Trace("OutOfProcSessionStateStoreMakeRequest", "MakeRequest returned: " +
"hr=" + hr +
" socket=" + (IntPtr)results.socket +
" httpstatus=" + results.httpStatus +
" timeout=" + results.timeout +
" contentlength=" + results.contentLength +
" uri=" + (IntPtr)results.content +
" lockCookie=" + results.lockCookie +
" lockDate=" + string.Format("{0:x}", results.lockDate) +
" lockAge=" + results.lockAge +
" stateServerMajVer=" + results.stateServerMajVer +
" actionFlags=" + results.actionFlags);

if (conn != null) {
if (results.socket == INVALID_SOCKET) {
conn.Detach();
conn = null;
}
else if (results.socket != socketHandle.Handle) {
// The original socket is no good.  We've got a new one.
// Pleae note that EnsureConnected has closed the bad
// one already.
conn._socketHandle = new HandleRef(this, results.socket);
}
}
else if (results.socket != INVALID_SOCKET) {
conn = new OutOfProcConnection(results.socket);
}

if (conn != null) {
_partitionInfo.StoreResource(conn);
}
}
catch {
// We just need to dispose the connection if anything bad happened
if (conn != null) {
conn.Dispose();
}

throw;
}

if (hr != 0) {
HttpException e = CreateConnectionException(_partitionInfo.Server, _partitionInfo.Port, hr);

string phase = null;

switch (results.lastPhase) {
case (int)UnsafeNativeMethods.SessionNDMakeRequestPhase.Initialization:
phase = SR.GetString(SR.State_Server_detailed_error_phase0);
break;

case (int)UnsafeNativeMethods.SessionNDMakeRequestPhase.Connecting:
phase = SR.GetString(SR.State_Server_detailed_error_phase1);
break;

case (int)UnsafeNativeMethods.SessionNDMakeRequestPhase.SendingRequest:
phase = SR.GetString(SR.State_Server_detailed_error_phase2);
break;

case (int)UnsafeNativeMethods.SessionNDMakeRequestPhase.ReadingResponse:
phase = SR.GetString(SR.State_Server_detailed_error_phase3);
break;

default:
Debug.Assert(false, "Unknown results.lastPhase: " + results.lastPhase);
break;
}

WebBaseEvent.RaiseSystemEvent(SR.GetString(SR.State_Server_detailed_error,
phase,
"0x" + hr.ToString("X08", CultureInfo.InvariantCulture),
cb.ToString(CultureInfo.InvariantCulture)),
this, WebEventCodes.WebErrorOtherError, WebEventCodes.StateServerConnectionError, e);

throw e;
}

if (results.httpStatus == 400) {
if (s_usePartition) {
throw new HttpException(
SR.GetString(SR.Bad_state_server_request_partition_resolver,
s_configPartitionResolverType, _partitionInfo.Server, _partitionInfo.Port.ToString(CultureInfo.InvariantCulture)));
}
else {
throw new HttpException(
SR.GetString(SR.Bad_state_server_request));
}
}

if (checkVersion) {
_partitionInfo.StateServerVersion = results.stateServerMajVer;
if (_partitionInfo.StateServerVersion < WHIDBEY_MAJOR_VERSION) {
// We won't work with versions lower than Whidbey
if (s_usePartition) {
throw new HttpException(
SR.GetString(SR.Need_v2_State_Server_partition_resolver,
s_configPartitionResolverType, _partitionInfo.Server, _partitionInfo.Port.ToString(CultureInfo.InvariantCulture)));
}
else {
throw new HttpException(
SR.GetString(SR.Need_v2_State_Server));
}
}
}
}

     下面是SessionNDMakeRequest方法的源代码，很明显在上面使用了这个方法，

[DllImport(ModName.ENGINE_FULL_NAME, CharSet=CharSet.Ansi, BestFitMapping=false, ThrowOnUnmappableChar=true)]
internal static extern int SessionNDMakeRequest(
HandleRef               socket,
string                  server,
int                     port,
bool                    forceIPv6,
int                     networkTimeout,
StateProtocolVerb       verb,
string                  uri,
StateProtocolExclusive  exclusive,
int                     extraFlags,
int                     timeout,
int                     lockCookie,
byte[]                  body,
int                     cb,
bool                    checkVersion,
out SessionNDMakeRequestResults results);

真的要到此为止，往下也找不到了，也看不懂了，等到高手来指导，说的就是你，不要走，告诉我这是为什么  ^_^!!!

源码在这里点击下崽哟