What's new in Relay Server version 17.0

Relay Server version 17.0 introduces several new, changed, deprecated, or removed features.

Deprecated features will be removed in future versions. Alter your applications to use recommended feature replacements instead of relying on deprecated features.

Note

Check the readme.txt file for additional information about the software, including feature information that was added after the documentation was completed.

New features

Relay Server performance enhancements
Several enhancements have been made to improve performance:
- The Relay Server now supports the WebSocket protocol for Apache and Microsoft IIS 8 (earlier versions of IIS do not support WebSocket traffic). Applications that support the WebSocket protocol use it automatically. Otherwise, the Relay Server uses HTTP.
- The Outbound Enabler now uses junction pools to send requests to and from the Relay Server and for dedicated backend connections. The rsoe2 utility supports the following options to control the size of the junction pool: -jsl, -jsh, and -jl. See Relay Server Outbound Enabler syntax.
- There is a new setup script for deploying Relay Server to Microsoft Windows (iis7_plus_setup.bat). See Deploying the Relay Server components to Microsoft Windows Server.
Enhancements to Microsoft IIS support
- You can now run Relay Server on Microsoft IIS 8.5.
- The thread pool for the Relay Server on Microsoft IIS is now self governed. You can use the default web garden size of 1 and use the min_thread and max_thread properties in the Options section of the Relay Server configuration file to control the Relay Server thread pool. See Configuring a Relay Server.
Relay Server on Apache supports dual Apache server instances
Relay Server supports configuring and running two Apache server instances. One instance of the Apache server is client facing and only services client requests. The other instance is server facing and only services Outbound Enabler requests. Running Apache Relay Server in this configuration provides better scalability in large deployments.
Relay Server log file size configuration
Limit the size of the Relay Server log file by using the log_size_limit option in the Options section of the Relay Server configuration file. See Configuring a Relay Server.
Configuration file monitoring on Microsoft IIS
On Microsoft IIS, the Relay Server now continuously monitors the configuration file and reports changes in status in the log file.
Automatic configuration of the backend farm and backend server
The new auto_config option instructs the Relay Server to automatically configure the backend farm and backend server. This feature is only available on Windows. See Configuring the Relay Server automatically.

Behavior changes, deprecated features, and features that are no longer supported

Compatibility with previous versions
The version 17 Relay Server does not work with version 16 and earlier of the Outbound Enabler. As well, version 17 of the Outbound Enabler does not work with version 16 and earlier of the Relay Server.
Changes to the rsoe utility
- For HTTPS connections, you must now specify at least one of certificate_name, certificate_company, or certificate_unit to ensure that the Outbound Enabler is connecting to the correct backend server. To prevent checking the certificate, specify the skip_certificate_name_check option.
- The -cs status_url option has been removed.
- The utility has been renamed rsoe2.
- When you connect the Outbound Enabler to the backend server using TLS or HTTPS, specify at least one of the following protocol options: certificate_name, certificate_company, or certificate_unit. The Outbound Enabler checks these values against the backend server certificate to ensure that it is connecting to the correct backend server. To prevent this checking, set the new skip_certificate_name_check protocol option to true.
  
  See Relay Server Outbound Enabler syntax.
AdminChannel tool changes
ianywhere.ml.rs.AdminChannel has been renamed com.sap.relayserver.AdminChannel.

See Remote administration using AdminChannel (Microsoft Windows).
SQL Anywhere Server Monitor support
The SQL Anywhere Server Monitor no longer supports Relay Server. Only the status page is supported

File name changes

Old file name	New file name
rs-setup.bat	iis7_plus_setup.bat
rsoesuppXX	This file has been removed
rsoe.exe	rsoe2.exe
ianywhere.ml.rs Java package qualifier	com.sap.relayserver
rs_admin.dll, rs_client.dll,rs_monitor.dll, and rs_server.dll	rs.dll (all combined into a single DLL)

Change to timeout behavior
The Relay Server and the Outbound Enabler no longer time out client traffic according to the IAS-RS-App-Timeout-Minute header. Instead, the timeout behavior is controlled by the client, other intermediaries, the backend server, and the web server that contains the Relay Server. The default 8 minute timeout for IAS-RS-App-Timeout-Minute no longer applies.

Change to the end of the Relay Server record

The end of the Relay Server record no longer ends with

<processId.threadId.F(BEFarmIdx)B(BEServerIdx)S(BESessionNum)R(RequestIdx)>

It now ends with

<label: J{relayserver-host#backend-farm-name#backend-server-name#junction-index} R{request-number}>

Changes to Microsoft IIS support
- Run Relay Server on Microsoft IIS version 7.0 or later. Support for version 6.0 has been removed.
- The Relay Server now starts on demand when the web service is running. Shutting down the web service also shuts down the Relay Server. As a result of this change, the Relay Server for Microsoft IIS no longer runs on shared memory, and it now uses a single application pool with a web garden size of one.
  
  The rshost service is no longer available to administer Relay Server on Windows, and the dbsvc -t RSHOST option has been removed. On Windows, rshost is only available for internal state management. For Windows, use the AdminChannel class in rstool.jar to administer Relay Server locally and remotely. You can still use rshost on Linux.
  
  As well, the Relay Server logs information to the following locations:
  
  Log file
  
  Location
  
  Configuration file log
  
  Relay-Server-DLL-directory/rs.config
  
  Relay Server log
  
  Relay-Server-DLL-directory/Log/rs.log
Relay Server plug-in removed
The Relay Server plug-in for SQL Central has been removed. Edit the Relay Server configuration file to change your Relay Server configuration.

Log file	Location
Configuration file log	Relay-Server-DLL-directory/rs.config
Relay Server log	Relay-Server-DLL-directory/Log/rs.log

Unsupported properties

Property type	Property	Notes
options section	shared_mem	This property is now ignored for Microsoft IIS. Supported for Apache.
	up_pad_size	Ignored by Microsoft IIS and Apache.
backend_farm section	client_security	The new behavior is the same as the old default (not restricted). Restrict via the web server configuration.
	backend_security	The new behavior is the same as the old default (not restricted). Restrict via the web server configuration.
	active_cookie	The new behavior is the same as the old default (yes to inject a standard cookie). The cookie is now server-level affinity only.
	active_header	Relay Server does not inject a proprietary header for affinity management.
	max_client_buffer	Flow and resource control is now managed via natural congestion on dedicated connections per client.
	renew_overlapped_cookie	This setting is no longer required because socket-level affinity is no longer available.
	socket_level_affinity	Socket-level affinity is no longer available. Relay Server transforms persistent HTTP to non-persistent HTTP downstream towards the back end. Relay Server client persistence over higher latency networks is still preserved. Server-level affinity via standard the cookie mechanism is the only supported behavior.