At Query Manager Start - AFS - Technical Notes

AFS Master-Slave and MiX

Product
AFS
AFS_Version
7.8
Category
Technical Notes
language
English
audience
public

Update Manager actions are willfully ignored. For more information on how Update Manager interact, see dedicated Technical Note - AFS v7.5 - Update Manager Behavior.

Several simplifying assumptions are made in this description:

- The progress is described step by step. In fact, some actions are parallelized.

- Only one afs_search_slave is present in the descriptions. In fact, there may be several.

Find hereafter what happens during the startup of a reply servers cluster in master-slave configuration:

  1. On master server, afs_querymanager binary is started.
  2. On every slave server, afs_querymanager binary is started.
  3. On master server, afs_search_master binary is started.
  4. Using its configuration, afs_search_master request to its afs_querymanager the startup of all its necessary slaves.
  5. afs_querymanager located on master server asks every afs_querymanager located on every slave server to start an afs_search_slave.
  6. Every afs_querymanager located on slaves server starts an afs_search_slave.
  7. Every afs_search_slave registers itself to afs_search_master, and afs_search_master answers by giving the slave its 'position' in the cluster (including the total number of slaves in the cluster).
  8. afs_search_slave can now load the reply databases,knowing it will process 1 out of n part of the databases (where n is the total number of slaves in the cluster).
  9. Once all slaves have registered to afs_search_master, it validates to its afs_querymanager that query processing can start.
  10. Query processing starts.