Known Problems with the MELTS/pMELTS/Calc APPLET interface and server:

The phase assemblage appears to be metastable.

(to be completed)

Server drops communication with client.

If a connection between the APPLET and the server is abruptly terminated with the display of a message box indicating "Contact with MELTS server lost.  Restart APPLET." it means that either the network or the the server is down.  If other network applications are functioning, then most likely the server has crashed.  If you were in the middle of a calculation it's possible that some sequence of commands you sent the server caused the crash.  It's also possible that some other user crashed the server and you became an innocent victim of circumstance.  And, of course it is possible that the server administrator deliberately took the server off-line for maintenance, updates, or a host of other reasons.  Be patience, and try to reconnect in two or three minutes.  An independent background process runs on the server, waking up every two minutes to check to make sure that the server is active.  If this process detects a problem, it will restart the server and bring it back online.  If the server is off-line for more than 5 minutes, consult the MELTS/pMELTS/Calc gateway web page.  If the server administrator has purposefully brought the server down, a message will be posted there to indicate the problem and the length of the downtime.  If no explanation is available at the site and no connection is possible for more than one hour email the server administrator at ghiorso@u.washington.edu with a request to fix the problem.

Server enters an infinite loop and refuses to respond to client.

The server maintains a number of loop counters, timers and other measures to try to insure that a user request does not result in a calculation that enters an infinite processing loop.  Despite these measures, this will occasionally happen and the only recourse is to manually restart the server.  Simply terminating the client APPLET is insufficient, and unfortunately for very sound server algorithmic reasons, all other calculation requests sent to the server will be held in a queue until the active process terminates.  Two indicators are diagnostic that the server is in an infinite loop state: (1) The message "Server request in progress" is displayed for longer than 30 seconds and will not pop down, and (2) A a new APPLET instance will not return a result from the server when the equilibrate button is pressed.  If  the server response problem is not corrected within an hour, contact the server administrator at ghiorso@u.washington.edu with a request to fix the problem.  An infinite loop condition in the server must be manually fixed.  If you think some sequence of calculations you requested precipitation the infinite loop in the server, it is very important that you report this sequence of events to the server administrator.  This is the only way software errors of this nature may be found and corrected.

Server refuses connection with client.

This condition occurs when a user attempts to contact the MELTS server when the latter is down or in an infinite loop state.  The symptom will either manifest itself in an error message and a blank APPLET display or refusal to respond to a request and persistence of the "Server request in progress" message box.  If the server is off-line for more than 5 minutes, consult the MELTS/pMELTS/Calc gateway web page.  If the server administrator has purposefully brought the server down, a message will be posted there to indicate the problem and the length of the downtime.  If no explanation is available at the site and no connection is possible for more than one hour email the server administrator at ghiorso@u.washington.edu with a request to fix the problem.


Last Modified Fri, Jan 3, 2003| Back to Top

Known Problems