What is the purpose of the Virtuoso MaxClientConnections parameter?
The Virtuoso MaxClientConnections parameter is set in both the [Parameters] and [HTTPServer] sections of the configuration file (virtuoso.ini by default), and is used to control thread allocations when starting a Virtuoso server instance.
SQL Connectivity
In the [Parameters] section, the MaxClientConnections sets the maximum number of threads that can be allocated for SQL Connectivity used by internal database management, iSQL, ODBC, JDBC, and ADO.Net clients. It’s important to note that, in this context, allocation occurs on-demand, consuming a database session connection unit with regards to commercial edition licensing. A setting of at least 100 is recommended.
HTTP Connectivity
In the [HTTPServer] section, the MaxClientConnections sets the number of threads that can be allocated for use by the native HTTP server thread pool, which are preallocated at server startup, each consuming a license point with regards to the commercial edition. This value should not be set to or more than the number of license connections, as otherwise there will be no license points available for SQL connections.
Note:
This INI setting used to be called ServerThreads (in prior releases), and as such, an alias is available so that this setting continues working should this old name still be in use with current binaries."