Code of good conduct - suggestions to the users of the OTL service

Göteborg, January 5, 2022

• a heavy OTL request comprising 100 stations and an ocean model with 1/8 × 1/8 degrees resolution (e,g, FES2004) requires between 1.5 and 2.5 hours for processing;_{__}
• a row of submissions from a user issued in a short period of time will place jobs in the queue in front of later and less heavy requests issued by a range of clients._{__} 
• Users of our service have requested a more balanced queue management.

1. The managing script includes a reshuffling of jobs an the basis of the time needed for computation and the time of waiting in the queue. Thus, recently submitted heavy jobs will be disadvantaged for some period._{__}
2. When many requests are building up in the normal ("fast track") queue, the system resorts to side-tracking. It opens a directory folder where jobs from a few clients are placed in waiting, to be switched back into processing when the fast track is empty.

Side-tracking can be avoided if clients with heavy requests (50 to100 stations and high-resolution ocean models) submit their requests at two to three hours intervals.

Since Dec. 26, 2021 the system rejects jobs with identical request parameters that are submitted within a short time interval (details here).
The system also rejects jobs with duplicated station names. This is a coarse criterion to avoid calculations when stations are located close together. The measure attempts to stifle carelessness in composing the station lists. Users can help to reduce the load on the computer by considering

1. Computation of displacement at a station that only differ in the height coordinate with respect to another station is redundant (in gravity and coastal settings, it is not of course).
   
2. In general, the loading parameters for displacement will not differ significantly if stations are closely collocated and sit far inland. As a rule of thumb: take the distance of the nearest coast to the centre of a station array, D, and the distance between array stations, d_ij. If  20 × d_ij <  D, the loading parameters will be identical at the sub 1-mm level. (Concerning gravity, the low number of such stations in the world makes us tolerate the extra computational load not withstanding its insignificance.)   If in doubt, you can bracket your cases and submit the a set of three sites with the shortest and farthest mutual distances, and submit consecutive requests as long as the parameters are different measured by your own criteria.
   

Before feeling tempted to announce a shame prize for the user (part of the email address) with the most redundant requests of the year, you can make a voluntary effort to the benefit of the user community.

Take the two items above as a guideline and, in addition,
visit the job queue web page and utilise time segments when the system is idle or the queue is only occupied with requests for a low number of stations, one to 10.    

If you notice that your jobs have never entered the queue and are not in ongoing processing, don't resubmit them. Other hurdles can cause delays. e.g. email routing; or spam filtering in our central mail system at chalmers.se; or your institution's mail server has blacklisted the chalmers.se domain.

Requests are rejected due to missing keywords; results won't arrive if you misspell the email address  (direct mailers, please revisit the guidelines).

Tampering with the web page is to no avail - that transport system of requests, occurring locally on the computer named holt, has its own spam detector; it's very picky at the verification of a form filled in with the required information. For example, missing to select an ocean model in the drop-down manu reverts to a decoy DFLT model, used an indicator that a spammer has used a tampered page to send us ads (the OTL programs won't ever think of buying Rayban sunglasses or click on any hyperlink with a mouse it doesn't have). Sorry if you, decent user, have forgotten to select the model. For good reason you will not receive a notice.

The system does reply with an automatic message concerning a request denied
if

• a direct mail was sent with a content type other than text/plain,    
• repeated station names were found,
  
• identical jobs have been submitted.
  

If you think your request should have been accepted but is not shown in the queue (granting a reasonable time margin),

1. Using the web page http://holt.oso.chalmers.se/loading/ : send us a copy / screen clip of the "Thank you" page
2. Sending direct mail to loading_kanelbulle_holt.oso.chalmers.se  : send us a copy of the mail

to hgs_kanelbulle_chalmers.se

If you must repeat a request because the results have been lost, just swap two lines of the station list or add a nuisance station, and the jobs will be admitted as they look formally different. The correction of a typo in e.g. the email address will also make the job different with respect to the lost one.

• all stations located further than four degrees from the nearest coast: 60 s wall time per station,
• add 20 to 60 seconds for each station located closer to a coast.