zen hub port reuse (#850)

- Feature: Added `--allow-port-probing` option to control whether zenserver searches for a free port on startup (default: true, automatically false when --dedicated is set)
- Feature: Added new hub options for controlling provisioned storage server instances:
  - `--hub-instance-http` - HTTP server implementation for instances (asio/httpsys)
  - `--hub-instance-http-threads` - Number of HTTP connection threads per instance
  - `--hub-instance-corelimit` - Limit CPU concurrency per instance
- Improvement: Hub now manages a deterministic port pool for provisioned instances allowing reuse of unused ports

4 files changed, 5 insertions, 3 deletions

diff --git a/src/zenhttp/servers/httpasio.cpp b/src/zenhttp/servers/httpasio.cpp
index 9f4875eaf..a2cae8762 100644
--- a/src/zenhttp/servers/httpasio.cpp
+++ b/src/zenhttp/servers/httpasio.cpp
@@ -2182,7 +2182,7 @@ HttpAsioServerImpl::Start(uint16_t Port, const AsioConfig& Config)
 	if (!Config.NoNetwork)
 	{
 		m_Acceptor.reset(
-			new asio_http::HttpAcceptor(*this, m_IoService, Port, Config.ForceLoopback, /*AllowPortProbing */ !Config.IsDedicatedServer));
+			new asio_http::HttpAcceptor(*this, m_IoService, Port, Config.ForceLoopback, /*AllowPortProbing */ Config.AllowPortProbing));
 
 		if (!m_Acceptor->IsValid())
 		{
@@ -2224,7 +2224,7 @@ HttpAsioServerImpl::Start(uint16_t Port, const AsioConfig& Config)
 														   *m_SslContext,
 														   gsl::narrow<uint16_t>(Config.HttpsPort),
 														   Config.ForceLoopback,
-														   /*AllowPortProbing*/ !Config.IsDedicatedServer));
+														   /*AllowPortProbing*/ Config.AllowPortProbing));
 
 		if (m_HttpsAcceptor->IsValid())
 		{
diff --git a/src/zenhttp/servers/httpasio.h b/src/zenhttp/servers/httpasio.h
index 21d10170e..154c87d9c 100644
--- a/src/zenhttp/servers/httpasio.h
+++ b/src/zenhttp/servers/httpasio.h
@@ -12,6 +12,7 @@ struct AsioConfig
 	bool		 ForceLoopback	   = false;
 	bool		 IsDedicatedServer = false;
 	bool		 NoNetwork		   = false;
+	bool		 AllowPortProbing  = true;
 	std::string	 UnixSocketPath;
 #if ZEN_USE_OPENSSL
 	int			HttpsPort = 0;	// 0 = auto-assign; set CertFile/KeyFile to enable HTTPS
diff --git a/src/zenhttp/servers/httpsys.cpp b/src/zenhttp/servers/httpsys.cpp
index f8fb1c9be..9fe9a2254 100644
--- a/src/zenhttp/servers/httpsys.cpp
+++ b/src/zenhttp/servers/httpsys.cpp
@@ -1153,7 +1153,7 @@ HttpSysServer::RegisterHttpUrls(int BasePort)
 
 	m_BaseUris.clear();
 
-	const bool AllowPortProbing = !m_InitialConfig.IsDedicatedServer;
+	const bool AllowPortProbing = m_InitialConfig.AllowPortProbing;
 	const bool AllowLocalOnly	= !m_InitialConfig.IsDedicatedServer;
 
 	int EffectivePort = BasePort;
diff --git a/src/zenhttp/servers/httpsys.h b/src/zenhttp/servers/httpsys.h
index ca465ad00..88ec13834 100644
--- a/src/zenhttp/servers/httpsys.h
+++ b/src/zenhttp/servers/httpsys.h
@@ -22,6 +22,7 @@ struct HttpSysConfig
 	bool		 IsRequestLoggingEnabled = false;
 	bool		 IsDedicatedServer		 = false;
 	bool		 ForceLoopback			 = false;
+	bool		 AllowPortProbing		 = true;
 	int			 HttpsPort				 = 0;  // 0 = HTTPS disabled
 	std::string	 CertThumbprint;			   // Hex SHA-1 (40 chars) for auto SSL binding
 	std::string	 CertStoreName = "MY";		   // Windows certificate store name