fix #124: expose configuration for connection pool parameters

src/config/iisnode_schema.xml

@@ -34,6 +34,8 @@ Details at http://learn.iis.net/page.aspx/241/configuration-extensibility/
     <attribute name="maxConcurrentRequestsPerProcess" type="uint" allowInfitnite="true" defaultValue="1024"/>
     <attribute name="maxNamedPipeConnectionRetry" type="uint" defaultValue="3"/>
     <attribute name="namedPipeConnectionRetryDelay" type="uint" defaultValue="2000"/>
+    <attribute name="maxNamedPipeConnectionPoolSize" type="uint" defaultValue="512"/>
+    <attribute name="maxNamedPipePooledConnectionAge" type="uint" defaultValue="30000"/>    
     <attribute name="initialRequestBufferSize" type="uint" defaultValue="4096"/>
     <attribute name="maxRequestBufferSize" type="uint" defaultValue="65536"/>
     <attribute name="uncFileChangesPollingInterval" type="uint" defaultValue="5000"/>

src/config/iisnode_schema_x64.xml

@@ -34,6 +34,8 @@ Details at http://learn.iis.net/page.aspx/241/configuration-extensibility/
     <attribute name="maxConcurrentRequestsPerProcess" type="uint" allowInfitnite="true" defaultValue="1024"/>
     <attribute name="maxNamedPipeConnectionRetry" type="uint" defaultValue="3"/>
     <attribute name="namedPipeConnectionRetryDelay" type="uint" defaultValue="2000"/>
+    <attribute name="maxNamedPipeConnectionPoolSize" type="uint" defaultValue="512"/>
+    <attribute name="maxNamedPipePooledConnectionAge" type="uint" defaultValue="30000"/>
     <attribute name="initialRequestBufferSize" type="uint" defaultValue="4096"/>
     <attribute name="maxRequestBufferSize" type="uint" defaultValue="65536"/>
     <attribute name="uncFileChangesPollingInterval" type="uint" defaultValue="5000"/>

src/iisnode/cconnectionpool.cpp

@@ -10,8 +10,8 @@ HRESULT CConnectionPool::Initialize(IHttpContext* ctx)
 	HRESULT hr;
 
 	ErrorIf(NULL == (this->list = (PSLIST_HEADER)_aligned_malloc(sizeof(SLIST_HEADER), MEMORY_ALLOCATION_ALIGNMENT)), ERROR_NOT_ENOUGH_MEMORY);
-	this->maxPoolSize = 512; // TODO, expose configuration for this
-	this->maxAge = 30000; // TODO, expose configuration for this
+	this->maxPoolSize = CModuleConfiguration::GetMaxNamedPipeConnectionPoolSize(ctx);
+	this->maxAge = CModuleConfiguration::GetMaxNamedPipePooledConnectionAge(ctx);
 
 	InitializeSListHead(this->list);
 

src/iisnode/cmoduleconfiguration.cpp

@@ -444,6 +444,8 @@ HRESULT CModuleConfiguration::GetConfig(IHttpContext* context, CModuleConfigurat
 		CheckError(GetDWORD(section, L"maxConcurrentRequestsPerProcess", &c->maxConcurrentRequestsPerProcess));
 		CheckError(GetDWORD(section, L"maxNamedPipeConnectionRetry", &c->maxNamedPipeConnectionRetry));
 		CheckError(GetDWORD(section, L"namedPipeConnectionRetryDelay", &c->namedPipeConnectionRetryDelay));
+		CheckError(GetDWORD(section, L"maxNamedPipeConnectionPoolSize", &c->maxNamedPipeConnectionPoolSize));
+		CheckError(GetDWORD(section, L"maxNamedPipePooledConnectionAge", &c->maxNamedPipePooledConnectionAge));
 		CheckError(GetDWORD(section, L"initialRequestBufferSize", &c->initialRequestBufferSize));
 		CheckError(GetDWORD(section, L"maxRequestBufferSize", &c->maxRequestBufferSize));
 		CheckError(GetDWORD(section, L"uncFileChangesPollingInterval", &c->uncFileChangesPollingInterval));
@@ -643,6 +645,16 @@ LPWSTR CModuleConfiguration::GetWatchedFiles(IHttpContext* ctx)
 	GETCONFIG(watchedFiles)
 }
 
+DWORD CModuleConfiguration::GetMaxNamedPipeConnectionPoolSize(IHttpContext* ctx)
+{
+	GETCONFIG(maxNamedPipeConnectionPoolSize)
+}
+
+DWORD CModuleConfiguration::GetMaxNamedPipePooledConnectionAge(IHttpContext* ctx)
+{
+	GETCONFIG(maxNamedPipePooledConnectionAge)
+}
+
 HRESULT CModuleConfiguration::GetDebugPortRange(IHttpContext* ctx, DWORD* start, DWORD* end)
 {
 	HRESULT hr;

src/iisnode/cmoduleconfiguration.h

@@ -32,6 +32,8 @@ class CModuleConfiguration : public IHttpStoredContext
 	BOOL devErrorsEnabled;
 	BOOL flushResponse;
 	LPWSTR watchedFiles;
+	DWORD maxNamedPipeConnectionPoolSize;
+	DWORD maxNamedPipePooledConnectionAge;
 
 	static IHttpServer* server;
 	static HTTP_MODULE_ID moduleId;
@@ -72,6 +74,8 @@ class CModuleConfiguration : public IHttpStoredContext
 	static BOOL GetDevErrorsEnabled(IHttpContext* ctx);
 	static BOOL GetFlushResponse(IHttpContext* ctx);
 	static LPWSTR GetWatchedFiles(IHttpContext* ctx);
+	static DWORD GetMaxNamedPipeConnectionPoolSize(IHttpContext* ctx);
+	static DWORD GetMaxNamedPipePooledConnectionAge(IHttpContext* ctx);
 
 	static HRESULT CreateNodeEnvironment(IHttpContext* ctx, DWORD debugPort, PCH namedPipe, PCH* env);
 

src/samples/configuration/readme.htm

@@ -64,6 +64,12 @@ <h2>
       node process in order to send a new HTTP request
 
     * namedPipeConnectionRetryDelay - delay in milliseconds between connection retries
+
+    * maxNamedPipeConnectionPoolSize - maximum number of named pipe connections that will be kept in a connection pool; 
+      connection pooling helps improve the performance of applications that process a large number of short lived HTTP requests
+
+    * maxNamedPipePooledConnectionAge - age of a pooled connection in milliseconds after which the connection is not reused for
+      subsequent requests
 
     * asyncCompletionThreadCount - size of the IO thread pool maintained by the IIS module to process asynchronous IO; setting it
       to 0 (default) results in creating one thread per each processor on the machine
@@ -126,6 +132,8 @@ <h2>
       maxConcurrentRequestsPerProcess="1024"
       maxNamedPipeConnectionRetry="3"
       namedPipeConnectionRetryDelay="2000"      
+      maxNamedPipeConnectionPoolSize="512"
+      maxNamedPipePooledConnectionAge="30000"
       asyncCompletionThreadCount="0"
       initialRequestBufferSize="4096"
       maxRequestBufferSize="65536"

src/samples/configuration/web.config

@@ -31,6 +31,12 @@
 
     * namedPipeConnectionRetryDelay - delay in milliseconds between connection retries
 
+    * maxNamedPipeConnectionPoolSize - maximum number of named pipe connections that will be kept in a connection pool; 
+      connection pooling helps improve the performance of applications that process a large number of short lived HTTP requests
+
+    * maxNamedPipePooledConnectionAge - age of a pooled connection in milliseconds after which the connection is not reused for
+      subsequent requests
+
     * asyncCompletionThreadCount - size of the IO thread pool maintained by the IIS module to process asynchronous IO; setting it
       to 0 (default) results in creating one thread per each processor on the machine
 
@@ -92,6 +98,8 @@
       maxConcurrentRequestsPerProcess="1024"
       maxNamedPipeConnectionRetry="3"
       namedPipeConnectionRetryDelay="2000"      
+      maxNamedPipeConnectionPoolSize="512"
+      maxNamedPipePooledConnectionAge="30000"
       asyncCompletionThreadCount="0"
       initialRequestBufferSize="4096"
       maxRequestBufferSize="65536"