ctdb/server/ipalloc_deterministic.c

   1 /*
   2    ctdb ip takeover code
   3
   4    Copyright (C) Ronnie Sahlberg  2007
   5    Copyright (C) Andrew Tridgell  2007
   6    Copyright (C) Martin Schwenke  2011
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "replace.h"
  23 #include "system/network.h"
  24
  25 #include "lib/util/debug.h"
  26 #include "common/logging.h"
  27
  28 #include "server/ipalloc_private.h"
  29
  30 bool ipalloc_deterministic(struct ipalloc_state *ipalloc_state)
  31 {
  32         struct public_ip_list *t;
  33         int i, numnodes;
  34
  35         numnodes = ipalloc_state->num;
  36
  37         DEBUG(DEBUG_NOTICE,("Deterministic IPs enabled. Resetting all ip allocations\n"));
  38        /* Allocate IPs to nodes in a modulo fashion so that IPs will
  39         *  always be allocated the same way for a specific set of
  40         *  available/unavailable nodes.
  41         */
  42
  43         for (i = 0, t = ipalloc_state->all_ips; t!= NULL; t = t->next, i++) {
  44                 t->pnn = i % numnodes;
  45         }
  46
  47         /* IP failback doesn't make sense with deterministic
  48          * IPs, since the modulo step above implicitly fails
  49          * back IPs to their "home" node.
  50          */
  51         if (ipalloc_state->no_ip_failback) {
  52                 D_WARNING("WARNING: 'NoIPFailback' set but ignored - "
  53                           "incompatible with 'Deterministic IPs\n");
  54         }
  55
  56         unassign_unsuitable_ips(ipalloc_state);
  57
  58         basic_allocate_unassigned(ipalloc_state);
  59
  60         /* No failback here! */
  61
  62         return true;
  63 }