Communication Methods


Introduction

Tamino offers three communication methods:

  • via direct HTTP rsp. HTTPS,

  • via a web server, or

  • WSL (webserverless)

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The desired communication methods are specified via the database property communication method (see the table "Server properties" in the Tamino Manager documentation, section Database Handling).

Communication is stateless: a client issues a request and receives a reply. A physical connection between client and X-Machine lasts only for the duration of a request.

HTTP/HTTPS based communication

Tamino XML Server is able to act as an HTTP server of its own rights. Clients can communicate with Tamino using a native HTTP and/or HTTPS protocol.

The communication via HTTP is the default in that a newly created database specifies 'HTTP' as the communication method database property (see the table "Server properties" in the Tamino Manager documentation, section Database Handling). HTTPS accessibility is achieved by setting the server property communication method to e.g. "HTTPS" or "HTTP and HTTPS".

A valid port number has to be assigned to the server property HTTP port. Via this port, messages based on either HTTP or HTTPS protocol are communicated.

The contents of the HTTP requests and responses with respect to Tamino server request protocol are not affected by this method of communication.

The Tamino Mass Loader (inoload) communicates via XTS or alternatively via TCP/IP. Thus when the communication method does not involve either of the two, the loader can't operate.

For HTTPS the following properties are relevant.

Property Name Meaning
SSL certificate file

The absolute path to a file containing an SSL certificate.

SSL key file

The absolute path to a file containing an SSL key.

SSL password

Optionally, an SSL password.

SSL verify depth

Optionally, the maximum depth for the certificate chain verification.

SSL CA file

Optionally, the absolute path to a CA (Certificate Authority) file.

SSL cipher list

Optionally, a user defined cipher list for OpenSSL communication. Per default the server uses the cipher list "ALL:!ADH:RC4+RSA:!SSLv2:!LOW:!EXPORT:@STRENGTH".

SSL verify client

Optionally, yes or no.

The Tamino installation provides a self-signed certificate in the directory $INODIR/$INOVERS/files/certs that can be used to test HTTPS communication.

Communication via a Web Server

To communicate with Tamino via web server a web server must be configured to redirect the user's HTTP (or HTTPS) calls towards Tamino as described in the section "Configuring the Web Server" in the chapter, Before You Start Using Tamino. Whether the communication between the user and the web server is HTTP or HTTPS depends solely on the configuration of the server and has nothing to do with Tamino communication. Communication from the server towards Tamino is either via TCP/IP or via XTS. XTS-based communication can further be secured using SSL for encryption. The default communication here is XTS. XTS uses TCP/IP also.

In case of TCP/IP communication Tamino listens for incoming requests on the port that is specified via the database property XML port (see table "Port properties" in the Tamino Manager documentation, section Database Handling). The port number is assigned when the database is created.

In case of XTS communication Tamino listens for incoming requests on the port that is specified via the database property XML XTS port (see table "Port properties" in the Tamino Manager documentation, section Database Handling). If the property is not specified, the server picks a port when it is started. A typical use case where a port needs to be specified is when client and database are on opposite sides of a firewall, so that a port must be opened there.

A database name is resolved to an IP address and port number via a directory server. The database registers itself with the directory server at startup and deregisters at shutdown. A web server an and a database have to use the same directory server to be able to communicate.

Related Properties

The following database server properties are also relevant for working with XTS (see the table "Server properties" in the Tamino Manager documentation, section Database Handling):

Property Name Meaning
overwrite XTS registration

If a database with the given name is already registered in the directory server, its registry entry is overwritten.

server host name

The hostname that can be optionally entered into the directory server at server startup.

The SSL communication method is identical to XTS, but the communication between the web server and the Tamino database is encrypted. For SSL the following properties are relevant.

Property Name Meaning
SSL certificate file

The absolute path to a file containing an SSL certificate.

SSL key file

The absolute path to a file containing an SSL key.

SSL password

Optionally, an SSL password.

The "webserverless" option of the Java or C API

The Tamino APIs for Java and for C offer a webserverless option. Clients can communicate with Tamino without using HTTP. The communication method XTS must be configured in this case. Client and database have to use the same directory server to be able to communicate.