Welcome to the JSOC Users Guide
Contents
This guide contains information of interest to all users of the JSOC software. Information for making new software is in the Developers Guide.
Getting Started
Welcome to the Solar Dynamics Observatory Helioseismic and Magnetic Imager and Atmospheric Imaging Array Joint Science Operations Center Data Record Management System and Storage Unit Management System online document tools.
I.e. SDO HMI/AIA JSOC DRMS/SUMS online document tools.
If you only want to use some JSOC programs you will need to do the steps described in 'Initial Steps' and be familiar with the topics below down through the 'JSOC Man Pages (man 1)' sections below. Basic unix/linux familiarity is assumed. The following is intended for persons who will be working on JSOC and with its data regularly. If you have a user account at SDO, you may find you need to use JSOC programs such as "show_keys" and "create_series". To set up your user environment, please follow the instructions below. If you are a JSOC software developer, you may have some different needs from regular users, as noted below.
Initial Steps
These steps are to setup access to run or create programs in the JSOC-SDP environment.
Setup Your JSOC Account JSOC New User Setup -- Initial steps for a new user
OK, now that you are a JSOC user or developer, try these Sample Commands.
General Information
DRMS Data Series
DataAccessPolicy -- SDO Data Use Policy
Overview -- What is a Data Series and how do DRMS and SUMS work (and what are they)
Names -- DRMS Dataset Names and Queries
SUMS Data Storage -- SUMS Basic Data Storage Concepts
JSOC Programs
- JSOC Sessions, Pipelines, and Modules ("Oh my!")
JSOC programs that use DRMS to operate on Data Series are called "modules". Modules are run in "sessions". HMI and AIA major processing tasks are accomplished in "pipelines" consisting of one or more sessions. Pipelines are started by "PUI" (Pipeline User Interface) usually by the JSOC production team. Pipelines may also be initiated by users requesting DataSets via the web or by team members running locally or remotely. A DataSet is a collection of records selected by a query. In essence a dataset name is simply the query that describes it.
All DRMS & SUMS connections and transactions occur inside a session. A DRMS Session is the basic unit of computing for interacting with DRMS and SUMS. At the start of a session the user connects to the DRMS database. During the session the user runs one or more modules which read or create DataRecords in one or more DataSeries. Access to the actual data stored in SUMS is accomplished within a module via the DRMS API. At the end of a session, SUMS is notified to save any new records online and/or on tape, or to delete records marked temporary to the session.
- Actually using the JSOC DRMS requires running a program or module. By "program" we mean a normal shell command and by "module" we mean a program built to run within a DRMS session and communication to a drms_server. There are four types of programs/modules:
Modules - Most programs that do the work of a JSOC user are what we call "modules". On the outside modules look like programs. They must run in a DRMS session. If they are built with the normal jsoc_main program they will use an existing session if they are run from a Session Provider. Or modules will start their own use-once session if they are called stand-alone from the shell.
Utility programs like create_series and describe_series which are usually used to manage the existence of DataSeries; they are not intended to pick up and use DataSeries. These programs talk directly to the database.
Session Providers like drms_run or later the Pipeline User Interface start DRMS sessions and execute a script file. They can also be used to execute a single instance of a module.
drms_server which connects to the database and serves sessions. Most users will not need to start drms_server explicitly.
- The benefit of running programs as "modules" will hopefully become apparent when we start running complex pipelines using hundreds of processors.
DRMS Man Pages
All programs and modules should have unix-style man pages at man1. Note that all modules built with jsoc_main share a basic set of flags and command line keywords. See module.1. For specific programming information about a module, such as input and output parameters, formats, etc, the man page is expected to be the primary user resource.
- Data series utilities to be run from a user's shell
create_series -- Create entries and tables for a new series in the DRMS database
describe_series -- Prints a verbose description of the named series and its current highest record number on stdout.
delete_series -- Removes a series and all its associated entries from DRMS.