1. 8/21/2015J-PARC1 Data Management Machine / Application State Data

2. Outline  EPICS Archiver  Gathering related datasets  File vs. database storage

3. EPICS Archiver  EPICS toolkit does provide an archiver  > 100,000 different signals are archived at SNS (various rates)  Great for looking for unanticipated correlations between different effects Is beam loss related to cooling temperature?  Great for seeing what failed first Uses the time of arrival to the archiver as the time-stamp Not good for fine-scale time resolution (< 1 sec)  Cumbersome to gather collected sets of large amounts of data What were all the magnets in a beamline set to at 11:23:01 AM on 05/11/2008 ?

4. EPICS Archive Viewer  CSS – Powerful archive -viewer

5. Collected Data Set Storage Why Bother ?  Often applications do not work in the control room when connected to live data for the first time.  It is useful to have a “beam replay” mode for diagnosing application problems after a beam shift (i.e. the next day after you’ve slept some).  When analyzing beam behavior at some moment, it is useful to know the value of all the magnets / BPM readings at that time – difficult to do with the Archiver

6. XAL Services – A Digression  Services are headless executables (no GUI)  Run continuously in the background  Typically on one instance runs  Sometimes more than one instance can run across servers  Provides remote communication with user interfaces XAL defines an API for communication between client and service Uses open standards  XML-RPC for communication  mDNS for dynamic service discovery

7. PV-Logger Service  It will grab a prescribed set of PVs as a collection Can prescribe a collection rate Can trigger on demand a set  e.g. when a beam measurement is done  Can define many independent sets of data to log These definition sets are defined in a database Data sets are stored in a database Allows easy browsing Other tools can access these sets (e.g. Online Model)

8. Machine Save – Compare-Restore (SCORE)  In order to restore the state of a machine, need to capture all settable values in the beamline Magnet fields, RF amplitude/phases, foil poisition, timing setup, …  Need to monitor readback values for these devices A power supply could be tripped  Need convenient restore mechanism  Need convenient browsing of save-sets Viewable comments helpful

9. June 16-27, 2008USPAS9 Data Storage: File vs. Database  File Storage Pros  Easy to implement  Can readily get you hands on the information (editor) Cons  Problem archiving  Not easy to browse contents of many files  Database Pros  Easy management of old data  Wealth of query tools available Cons  More trouble for the initial deployment

10. File Data Storage  Useful for Physics Application Setup Information What sequence is used, what range is being scanned, plot configurations, etc.  Can be used for data storage as well  XML data format is used in XAL See gov.sns.tools.xml.samples Easy to create hierarchal storage  Typically this type configuration is managed in the “document” part of the application (document – view – control architecture model)