Adding velocity columns to FT2 Files

Note: This procedure assumes that a change has already been approved by C&A, and that a JIRA has been entered documenting the desired change. Please document JIRAs in the comments, and note when they are closed.

6/17/19 - TS - I'll be updating this page to reflect what has been done and any outstanding questions on how to proceed.  Feel free to answer any questions (marked in red) that come up if you know the answer.  Also, please add in any steps or sub-steps.   Items with by them are completed.

STGEN-165 - Getting issue details... STATUS

Implementation Process:

1. Define the name of the columns
2. Update File Format Document & Interface Control Document.
3. Implement the new columns in fitsGen, which means adding them to the template FT2 file: https://github.com/fermi-lat/fitsGen/blob/master/data/ft2.tpl  Note: If things have been implemented as they should, no change to the actual code should be necessary.
4. Change the ft2 code. to get the velocities from the magic7 and save them in the new columns
   1. Create pipeline tasks to reprocess the FT2 data
   2. Create pipeline tasks to properly apply the Bad Time interval data.
5. Test everything end-to-end with a sample of the new ft2 files. (by this I mean the pulsar software)
   1. Use the code to reprocess 1-2 weeks of data for testing.
      
      1. we reprocessed a two-week chunk of data from runs 545208791 to 546407418.  This included several files with BTI data in the database
      2. more files were reprocessed with the P310 task(s). This includes a variety of cases for BTIs and a selection of different DATA_QUALs.
   2. Check to make sure the velocities are being copied correctly from the magic7 packets and that they make sense based on the change in coordinates - Don/Tom.
   3. Ingest files at FSSC - Don/Alex
   4. Verify that the BTI data is correct - ME/Tom/Simone
   5. Test with Pulsar Tools - Dave Smith 
   6. Non-pulsar tests - Joe Eggen.
   7. Check with the C& A group. Don brought it up at the 6/24 C&A group meeting.  No one raised any issues (or volunteered to do any testing).
   8. Check with other mission elements. Don checked with Michelle Hui at the GIOC that the change won't affect them.
6. Fix all the runs that need repiping (Runs to be rePiped and reprocessed)
   
7. Reprocess the FT2 files (Usually done in two steps. Initial reprocess & backfill)
   1. Create a list of runs for reprocessing and BTI flagging from the datacatalog. Validate against the list at the FSSC server.
   2. Install the reprocessing tasks in the PROD pipeline
   3. The reprocessing step will be putting them into /Data/Flight/Reprocess/P310, how do we move them to /Data/Flight/Level1/LPA (where the current version is) when we are ready to go? MEM: we absolutely don't move the files from one place to the other. They will stay in the reprocessing folder. The only place where they are merged is at the FSSC photon database. TS: That makes things easier   Good to know.
   4. Tom estimates that the reprocessing may take ~1 week.
      
8. Transfer the files to the FSSC and ingest them into the FSSC's data server.
   1. Wilko has setup a proxy server so Don can copy the files directly from xroot.
   2. Alex estimates the ingest may take ~1 week.
   3. This may be able to take place in parallel with the reprocessing by transferring batches as they are reprocessed.
9. Obtain a new GlastRelease
   
   1. What is the process for doing this? MEM will ask Heather
   2. Do we need a completely new GlastRelease or just the updated L1PROC codebase? MEM: Yes, we need a new version of GR because of the updated fitsGen. But we only need this for the new version of L1Proc, not for the reprocessing.
10. Create a new version of the L1Proc, rePipeL1 and Flag FT2 tasks
    
    1. Test them meaningfully on DEV
    2. Get CCB approval to make the change operational.
    3. I've never done this before so I don't know the process here either - T.S. -> MEM: I'll prepare the CCB request once validation is completed 
11. Coordinate a switchover date between ISOC and FSSC.
12. Switch L1 to use the new GlastRelease.  Note: backfill and switch must be coordinated and timed together.
13. Switch the data server to use the new files.  The FSSC has an internal wiki page on the steps for this