Changes to the postage stamp server interface and implementation to be made on 2015-April-27

While the collection of data for the PS1 Science Consortium has ended PS1 continues to take data. For now, this new data is only available to members of the new Pan-Starrs Consortium PSNC.

Some changes to the operation of the postage stamp system are required to support the new consortium. This page describes the changes. For users who use the Pan-Starrs Science Interface (PSI) to submit requests these changes will be mostly transparent. Users who "roll their own" request files will need to insure that they conform to some new requirements.

Beginning 2015-May-05 Postage stamp request files that use version 1 of the request format will no longer be accepted. A version 2 file with a valid email address in the request header will be required

The email header word was added in version 2. The system needs the value to determine the submitting user's access rights. The email address is required to be of the form user@domain. By default, access rights will be determined from the domain. Members whose email contains the domain of a member of the new consortium will have access level 2. The system has a provision to extend access rights for individual users whose PSI accounts use email that does not contain the instition's domain. For support purposes use of this feature is discouraged.

At this time no checks are made that an email address in a request submitted outside of PSI actually works. It is treated as a token for determining access rights and for directing the results to the correct data store product (see next section). The IPP portion of the postage stamp system does not automatically send any email.

If the email address' domain is unknown to the system. Postage stamp results will be given the default access level 1 unless the specific user has been provided with a higher access level.

A user with level 1 access will be limited to single frame observations made prior to 2015-03-01. Access to stacks will be handled on a release by release basis using the release tables in the IPP databases.

pstamp_version_2_conversion provides some hints for converting software that creates version 1 request files to version 2.

Requests from version 1 files received between April 21 and May 5 will only be given level 1 access. Beginning May 5 version 1 files will be rejected.

The postage stamp images and other results may be directed to a different data store location based on the email address

Currently most postage stamp results are posted to filesets in a single data store product "pstampresults". This product is accessible through HTTP requests from a set list of all the identified PS1SC institutions. In the new implementation each PSNC institution will get it's own data store product. For example requests from users will go to an ifa specific data store product. Results for users from QUB will go to a directory specific to that institution. Each product will have it's own list of allowable IP addresses. Certain users (for example MOPS) will have their own data store products.

If the system can't figure out a specific product for the user the results will continue to go to pstampresults.

The data store links that PSI presents will automatically resolve to the new locations. Users who summit their own files will need to learn where to look.

If a PS1SC institution would like to have their own data store product let Bill Sweeney know.

Other implementation changes

There are also some minor changes to the postage stamp implementation that are being made at this time. These primarily apply to requests submitted outside of PSI and are being made to improve parsing performance.

  • Currently if requests do not supply a survey or release the system for look ups by coordinate or skycell fall back to a list of "default data_groups". Over time this list has fallen woefully out of date. (For example, for an embarassingly long time PV3 was not included in the list). This concept is removed. If no release parameters are included in the request SURVEY will be set to 3PI. The DATA_GROUP column in the request specification is still respected if supplied.

This parameter has been somewhat obsolete since SURVEY and IPP_RELEASE were added.

  • For skycell images if a tess_id is not supplied with the request, it defaults to the most appropriate tessellation based on the survey. For 3PI the tess_id is set to RINGS.V3. For the medium deep fields, tess_id is set to the V3 version. For example MD01.V3.