DPM dev enlarged meeting

Friday 27 Mar 2015, 10:00 → 12:00 Europe/Zurich

28/R-015 (CERN)

Presents:

Fabrizio, Oliver, Andrea, Alessandra Doria, Elena Korolkova, Sam Skipsey,
Lukasz Kreczko

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 - Possible improvements to the puppet setup
   - manual YAIM-ish operation
   - individual templates
 - Avoiding known issues for sites erroneously using YAIM on newer components

 * Sam: what about xlating existing yaim setups to puppet ?
 * Andrea: there is an incomplete tool, yet it's one more component to maintain. advice is to take an existing manifest and put there passwords and the rest of the site-specific things
 * puppet-dpm is a component that is available, though
 * Oliver: why don't we concentrate on simplifying the disk servers first ?
 * Oliver/Andrea/Alessandra: let's explicitely mention the yaim variabs in the comments of the manifest, making them more comfortable for a former Yaim user
 * Alessandra: e.g. we had a missing variable and it was difficult to add it
 *

 - Would a One-click DPM head setup based on Docker be possible and desirable ?
 ** I understand that very few would like that kind of thing at this time

 - How to disseminate the DPM tuning hints (partially or little necessary for puppet)

 * alessandra: maybe the link is not visible enough
  ... when you search with google you are not taken there
  ... put the link also into the installation/config pages!!
 * elena: the instructions for manual config are very useful
   Oliver; we will maintain them, let's do a refresh

 - Reducing rfiod use cases:
  - Towards a brand new dpm-drain
  * andrea: it's a new command in the dmlite shell, actually 3 new commands
    drain server, pool, disk into 3 separated commands
  * Missing things: would like to add checksum verification after replication (which is not done by rfio and the historical dpm-drain) + test + test + test
  * link to the initial docs:

https://svnweb.cern.ch/trac/lcgdm/wiki/Dpm/Dev/Dmlite/Shell#Newfunctionality:Drain

  * volunteers to test ? Thank you Sam!

 - Important: volunteer sites for prod of GridFTP redir
  * Alessandra Forti + Andrea Sartirana (thank you guys!)
  *

 - Progress on the top directory space accounting
   - the command line tool was put with the shell, it's in trunk rel

   - the iopassthrough works, however it won't be executed in all the cases for putdone and delreplica
   - maybe better to replicate that code into the dpm daemon? Seems not
difficult to do, and all the old and new combinations would work, e.g. srm+gridftp (maybe except dmlite hdfs/s3)

  * Sam+ Ale: having a few mysql conns from the disk nodes to the mysql is acceptable
  * and: technically: mysql must be accessed not only from localhost, grant access to the disk nodes + install the mysql plugin in the disk nodes
  * gridftp redir will fail if one has head+disk and individual disk servers


 - AoB