MarkLogic 9 Product Documentation

XDBCServer Configuration Help

An XDBC Server is an App Server that accepts requests from an XCC or XDBC client and returns the results to the client.

• server name specifies the name of the XDBC Server.
• root specifies the modules root directory.
• port specifes the socket port for the HTTP server.
• modules specifies the name of the database in which this HTTP server locates XQuery application code. If set to (file system), then any files in the specified root directory are executable (given the proper permissions). If set to a database, then any documents in the database whose URI begins with the specified root directory are executable.
• database specifies the database to which this App Server connects for query execution.
• last login specifies the name of the database in which this HTTP server stores users' last login information.
• display last login specifies if the xdmp:display-last-login API should return true or false in the display-last-login element.
• address specifies the IP address for the App Server.
• backlog specifies the maximum number of pending connections allowed on the HTTP server socket.
• threads specifies the maximum number of App Server threads.
• request timeout specifies the maximum number of seconds before a socket receives a timeout for the first request.
• keep alive timeout specifies the maximum number of seconds before a socket receives a timeout for subsequent requests over the same connection.
• session timeout specifies the maximum number of seconds before a session times out.
• max time limit specifies the upper bound for any request's time limit. No request may set its time limit (for example with xdmp:set-request-time-limit) higher than this number. The time limit, in turn, is the maximum number of seconds allowed for servicing a query request. The App Server gives up on queries which take longer, and returns an error.
• default time limit specifies the default value for any request's time limit, when otherwise unspecified. A request can change its time limit using xdmp:set-request-time-limit. The time limit, in turn, is the maximum number of seconds allowed for servicing a query request. The App Server gives up on queries which take longer, and returns an error.
• pre-commit trigger limit specifies the maximum number of pre-commit triggers a single statement against this App Server can invoke.
• pre-commit trigger depth specifies the maximum depth (how many triggers can cause other triggers to fire, which in turn cause others to fire, and so on) for pre-commit triggers that are executed against this App Server.
• collation specifies the default collation for queries run in this appserver. This will be the collation used for string comparison and sorting if none is specified in the query.
• internal-security specifies whether security database is used for authentication and authorization if the user is found in the security database.
• external authentication specifies an external security config.
• privilege specifies the execute privilege required to access the server.
• concurrent request limit specifies the maximum number of requests any user may have running at a specific time. 0 indicates no maximum.
• log-errors specifes whether to log uncaught errors for this App Server to the ErrorLog.txt file. This is useful to log exceptions that might occur on an App Server for later debugging.
• debug-allow specifies whether to allow requests against this App Server to be stopped for debugging, using the MarkLogic Server debugging APIs.
• profile-allow specifies whether to allow requests against this App Server to be profiled, using the MarkLogic Server profiling APIs.
• default-xquery-version specifies the default XQuery language for this App Server if an XQuery module does explicitly declare its language version.
• multi version concurrency control specifies how the latest timestamp is chosen for lock-free queries. When set to contemporaneous, the server chooses the latest timestamp for which any transaction is known to have committed, even though there still may be other transactions for that timestamp that have not yet fully committed. Queries will see more timely results, but may block waiting for contemporaneous transactions to fully commit. When set to nonblocking, the server chooses the latest timestamp for which all transactions are known to have committed, even though there may be a slightly later timestamp for which another transaction has committed. Queries won't block waiting for transactions, but they may see less timely results.
• distribute timestamps specifies how the latest timestamp is distributed after updates. This affects performance of updates and the timeliness of read-after-write query results from other hosts in the group.
  When set to fast, updates return as quicky as possible. No special timestamp notification messages are broadcasted to other hosts. Instead, timestamps are distributed to other hosts when any other message is sent. The maximum amount of time that could pass before other hosts see the timestamp is one second, because a heartbeat message is sent to other hosts every second.
  When set to strict, updates immediately broadcast timestamp notification messages to every other host in the group. Updates do not return until their timestamp has been distributed. This ensures timeliness of read-after-write query results from other hosts in the group.
• ssl certificate template specifies the certificate template for the App Server. When a certificate template is specified, the App Server uses an SSL encrypted protocol (e.g. https, davs, xccs). The certificate template specifies the common information for the individual SSL certificates needed for each host in the group.
• ssl hostname specifies the hostname for the server's SSL certificate. This is useful when many servers are running behind a load balancer. If not specified, each host will use a certificate for its own hostname.
• ssl ciphers specifies the SSL ciphers that may be used.
• ssl require client certificate specifies whether a client certificate is required when connecting to this application server.
• ssl client certificate authorities enables mutual authentication, where the client also holds a digital certificate that it sends to the server. Select which certificate authority is to be used to sign client certificates for the server.

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Buttons and Tabs:

• The Summary tab displays a list of all of the currently configured App Servers, along with the configuration information for each App Server.
• The Configure tab is where you change App Server settings.
• The Status tab displays current information on all App Servers in the group, including query activity. You can cancel currently running queries on the App Server status page.
• Use the Create HTTP, Create WebDAV, Create XDBC, and Create ODBC tabs to create new App Servers of the appropriate type. HTTP servers service XQuery and HTTP requests over HTTP, WebDAV servers allow access to a database via a WebDAV client, and XDBC servers service requests from XCC or XDBC clients.