FTP Server Structure Markus Heene, DWD

Agenda Structure of FTP Server for Dissemination Phase Basic estimates of directories 24h Cache requirement

Dissemination Phase – Tree 1 Level 1: CCCC Level 2: Alpha / Binary Alpha: T1T2 – Data Type GRIB: A2 – Reference Time GRIB: ii – Level GRID: A1 – Geographical Area, A2 – Reference Time CREX: T1T2A1 YY: Day of the month GG: Hour of observation

Basic estimates of directories Level 1 – CCCC ~ 300 according to http://www.wmo.int/pages/prog/www/ois/Operational_Information/VolumeC1/CCCC_en.html Level 1 – CCCC ~ 1500 according to VolC1 published 17 September 2013 Level 1 – CCCC on FTP Server: 286 Idea: If CCCC ~ 1500, we can create an additional top level directory ISO 2-letter or ISO 3-letter country code to group the CCCCs Level 2 – alpha or binary Level 3 – GRIB – A2: 26 Reference times where 4 currently not assigned Level 3 – T1T2 in case of Alpha: ~ 174 Level 3 – BUFR T1T2A1: ~ 57 Level 3 – GRID: only 4 CCCC’s provide GRID data Level 3 – CREX: only 8 CCCC’s provide GRID data Level 3 – PIC: ~ 25 CCCC’s provide PIC data

Basic estimates of directories – Archive directory Archive: This directory contains 2-minute archives of all data received in this time interval Max archive size (zip): ~ 60.4 MB Max archive size (gz): ~ 58.2 MB Max archive size (bzip2): ~ 55.7 MB Max archive size (xz): ~ 51.8 MB One day (17th Oct. 2013: 5.4 GB [zip]) Suggestion: /RUMS_AMDCN: Directory with 2-minute archives of all data from GISC Moscow’s AMDCN Max archive size (xz): ~ 34 KB One day (17th Oct. 2013: 927 KB [xz]) Compressed archives reduce transfer data volume and we get an additional checksum for free