Notes and Limitations for Digital Annealer service are as follows. Refer to the User’s Guide for details of each function.

1. Notes

No. Function Description Remarks

1

Web API

If a QUBO has one or more terms whose coefficient is out of the calculation precision range of Digital Annealer or not an integer, the QUBO is automatically converted into a QUBO that has only terms whose coefficient is integers in the calculation precision range of Digital Annealer by the Scaling and Rounding feature. Therefore, the minimum energy obtained in COMPLETE mode may be lower than the energy obtained in QUICK mode.

If more accurate minimum energy is required, use COMPLETE mode.
Alternatively, change the coefficient of the QUBO to an integer within the range of calculation precision of Digital Annealer beforehand.


2

Web API

If a numerical parameter value that exceeds the maximum value of the double type is set,
the following error message may be displayed.

{"error":"invalid character 'I' looking for beginning of value","message":"invalid character 'I' looking for beginning of value","code":3,"details":[]}

Check the values of the numerical parameters if this error message is displayed.


3

Web API

If the system is under an extremely high load, the following error message may be displayed.

An error occurred. Sorry, the page you are looking for is currently unavailable.
Please try again later.
If you are the system administrator of this resource then you should check the error log for details.
Faithfully yours, nginx.

Retry the API request if this error message is displayed.


4

Web API

When an API request is executed, the following error message may be displayed.

{"error":"transport is closing","message":"transport is closing","code":14,"details":[]}
or
{"error":"all SubConns are in TransientFailure, latest connection error: connection error: desc = \(\backslash\)"transport: Error while dialing dial tcp [::1]:50051: connect: connection refused\(\backslash\)"","message":"all SubConns are in TransientFailure, latest connection error: connection error: desc = \(\backslash\)"transport: Error while dialing dial tcp [::1]:50051: connect: connectionrefused\(\backslash\)"","code":14,"details":[]}

Retry the API request if either of the above error messages is displayed.


2. Limitations

No. Function Description Remarks

1


[Problem] There are no limitations.
                                                                                                                                     
[Workaround]



Note: The above specifications are subject to change without prior notice.