ctdb/server/ipalloc.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 <talloc.h>
  23
  24 #include "replace.h"
  25 #include "system/network.h"
  26
  27 #include "lib/util/debug.h"
  28
  29 #include "common/logging.h"
  30 #include "common/rb_tree.h"
  31
  32 #include "protocol/protocol_util.h"
  33
  34 #include "server/ipalloc_private.h"
  35
  36 /* Initialise main ipalloc state and sub-structures */
  37 struct ipalloc_state *
  38 ipalloc_state_init(TALLOC_CTX *mem_ctx,
  39                    uint32_t num_nodes,
  40                    enum ipalloc_algorithm algorithm,
  41                    bool no_ip_takeover,
  42                    bool no_ip_failback,
  43                    bool no_ip_host_on_all_disabled,
  44                    uint32_t *force_rebalance_nodes)
  45 {
  46         struct ipalloc_state *ipalloc_state =
  47                 talloc_zero(mem_ctx, struct ipalloc_state);
  48         if (ipalloc_state == NULL) {
  49                 DEBUG(DEBUG_ERR, (__location__ " Out of memory\n"));
  50                 return NULL;
  51         }
  52
  53         ipalloc_state->num = num_nodes;
  54
  55         ipalloc_state->noiphost = bitmap_talloc(ipalloc_state,
  56                                                 ipalloc_state->num);
  57         if (ipalloc_state->noiphost == NULL) {
  58                 DEBUG(DEBUG_ERR, (__location__ " Out of memory\n"));
  59                 goto fail;
  60         }
  61
  62         ipalloc_state->algorithm = algorithm;
  63         ipalloc_state->no_ip_takeover = no_ip_takeover;
  64         ipalloc_state->no_ip_failback = no_ip_failback;
  65         ipalloc_state->no_ip_host_on_all_disabled = no_ip_host_on_all_disabled;
  66         ipalloc_state->force_rebalance_nodes = force_rebalance_nodes;
  67
  68         return ipalloc_state;
  69 fail:
  70         talloc_free(ipalloc_state);
  71         return NULL;
  72 }
  73
  74 static void *add_ip_callback(void *parm, void *data)
  75 {
  76         struct public_ip_list *this_ip = parm;
  77         struct public_ip_list *prev_ip = data;
  78
  79         if (prev_ip == NULL) {
  80                 return parm;
  81         }
  82         if (this_ip->pnn == -1) {
  83                 this_ip->pnn = prev_ip->pnn;
  84         }
  85
  86         return parm;
  87 }
  88
  89 static int getips_count_callback(void *param, void *data)
  90 {
  91         struct public_ip_list **ip_list = (struct public_ip_list **)param;
  92         struct public_ip_list *new_ip = (struct public_ip_list *)data;
  93
  94         new_ip->next = *ip_list;
  95         *ip_list     = new_ip;
  96         return 0;
  97 }
  98
  99 /* Nodes only know about those public addresses that they are
 100  * configured to serve and no individual node has a full list of all
 101  * public addresses configured across the cluster.  Therefore, a
 102  * merged list of all public addresses needs to be built so that IP
 103  * allocation can be done. */
 104 static struct public_ip_list *
 105 create_merged_ip_list(struct ipalloc_state *ipalloc_state)
 106 {
 107         int i, j;
 108         struct public_ip_list *ip_list;
 109         struct ctdb_public_ip_list *public_ips;
 110         struct trbt_tree *ip_tree;
 111
 112         ip_tree = trbt_create(ipalloc_state, 0);
 113
 114         if (ipalloc_state->known_public_ips == NULL) {
 115                 DEBUG(DEBUG_ERR, ("Known public IPs not set\n"));
 116                 return NULL;
 117         }
 118
 119         for (i=0; i < ipalloc_state->num; i++) {
 120
 121                 public_ips = &ipalloc_state->known_public_ips[i];
 122
 123                 for (j=0; j < public_ips->num; j++) {
 124                         struct public_ip_list *tmp_ip;
 125
 126                         /* This is returned as part of ip_list */
 127                         tmp_ip = talloc_zero(ipalloc_state, struct public_ip_list);
 128                         if (tmp_ip == NULL) {
 129                                 DEBUG(DEBUG_ERR,
 130                                       (__location__ " out of memory\n"));
 131                                 talloc_free(ip_tree);
 132                                 return NULL;
 133                         }
 134
 135                         /* Do not use information about IP addresses hosted
 136                          * on other nodes, it may not be accurate */
 137                         if (public_ips->ip[j].pnn == i) {
 138                                 tmp_ip->pnn = public_ips->ip[j].pnn;
 139                         } else {
 140                                 tmp_ip->pnn = -1;
 141                         }
 142                         tmp_ip->addr = public_ips->ip[j].addr;
 143                         tmp_ip->next = NULL;
 144
 145                         trbt_insertarray32_callback(ip_tree,
 146                                 IP_KEYLEN, ip_key(&public_ips->ip[j].addr),
 147                                 add_ip_callback,
 148                                 tmp_ip);
 149                 }
 150         }
 151
 152         ip_list = NULL;
 153         trbt_traversearray32(ip_tree, IP_KEYLEN, getips_count_callback, &ip_list);
 154         talloc_free(ip_tree);
 155
 156         return ip_list;
 157 }
 158
 159 static bool populate_bitmap(struct ipalloc_state *ipalloc_state)
 160 {
 161         struct public_ip_list *ip = NULL;
 162         int i, j;
 163
 164         for (ip = ipalloc_state->all_ips; ip != NULL; ip = ip->next) {
 165
 166                 ip->known_on = bitmap_talloc(ip, ipalloc_state->num);
 167                 if (ip->known_on == NULL) {
 168                         return false;
 169                 }
 170
 171                 ip->available_on = bitmap_talloc(ip, ipalloc_state->num);
 172                 if (ip->available_on == NULL) {
 173                         return false;
 174                 }
 175
 176                 for (i = 0; i < ipalloc_state->num; i++) {
 177                         struct ctdb_public_ip_list *known =
 178                                 &ipalloc_state->known_public_ips[i];
 179                         struct ctdb_public_ip_list *avail =
 180                                 &ipalloc_state->available_public_ips[i];
 181
 182                         /* Check to see if "ip" is available on node "i" */
 183                         for (j = 0; j < avail->num; j++) {
 184                                 if (ctdb_sock_addr_same_ip(
 185                                             &ip->addr, &avail->ip[j].addr)) {
 186                                         bitmap_set(ip->available_on, i);
 187                                         break;
 188                                 }
 189                         }
 190
 191                         /* Optimisation: available => known */
 192                         if (bitmap_query(ip->available_on, i)) {
 193                                 bitmap_set(ip->known_on, i);
 194                                 continue;
 195                         }
 196
 197                         /* Check to see if "ip" is known on node "i" */
 198                         for (j = 0; j < known->num; j++) {
 199                                 if (ctdb_sock_addr_same_ip(
 200                                             &ip->addr, &known->ip[j].addr)) {
 201                                         bitmap_set(ip->known_on, i);
 202                                         break;
 203                                 }
 204                         }
 205                 }
 206         }
 207
 208         return true;
 209 }
 210
 211 static bool all_nodes_are_disabled(struct ctdb_node_map *nodemap)
 212 {
 213         int i;
 214
 215         for (i=0;i<nodemap->num;i++) {
 216                 if (!(nodemap->node[i].flags &
 217                       (NODE_FLAGS_INACTIVE|NODE_FLAGS_DISABLED))) {
 218                         /* Found one completely healthy node */
 219                         return false;
 220                 }
 221         }
 222
 223         return true;
 224 }
 225
 226 /* Set internal flags for IP allocation:
 227  *   Clear ip flags
 228  *   Set NOIPHOST ip flag for each INACTIVE node
 229  *   if all nodes are disabled:
 230  *     Set NOIPHOST ip flags from per-node NoIPHostOnAllDisabled tunable
 231  *   else
 232  *     Set NOIPHOST ip flags for disabled nodes
 233  */
 234 void ipalloc_set_node_flags(struct ipalloc_state *ipalloc_state,
 235                             struct ctdb_node_map *nodemap)
 236 {
 237         int i;
 238         bool all_disabled = all_nodes_are_disabled(nodemap);
 239
 240         for (i=0;i<nodemap->num;i++) {
 241                 /* Can not host IPs on INACTIVE node */
 242                 if (nodemap->node[i].flags & NODE_FLAGS_INACTIVE) {
 243                         bitmap_set(ipalloc_state->noiphost, i);
 244                 }
 245
 246                 /* If node is disabled then it can only host IPs if
 247                  * all nodes are disabled and NoIPHostOnAllDisabled is
 248                  * unset
 249                  */
 250                 if (nodemap->node[i].flags & NODE_FLAGS_DISABLED) {
 251                         if (!(all_disabled &&
 252                               ipalloc_state->no_ip_host_on_all_disabled == 0)) {
 253
 254                                 bitmap_set(ipalloc_state->noiphost, i);
 255                         }
 256                 }
 257         }
 258 }
 259
 260 void ipalloc_set_public_ips(struct ipalloc_state *ipalloc_state,
 261                             struct ctdb_public_ip_list *known_ips,
 262                             struct ctdb_public_ip_list *available_ips)
 263 {
 264         ipalloc_state->available_public_ips = available_ips;
 265         ipalloc_state->known_public_ips = known_ips;
 266 }
 267
 268 /* This can only return false if there are no available IPs *and*
 269  * there are no IP addresses currently allocated.  If the latter is
 270  * true then the cluster can clearly host IPs... just not necessarily
 271  * right now... */
 272 bool ipalloc_can_host_ips(struct ipalloc_state *ipalloc_state)
 273 {
 274         int i;
 275         bool have_ips = false;
 276
 277         for (i=0; i < ipalloc_state->num; i++) {
 278                 struct ctdb_public_ip_list *ips =
 279                         ipalloc_state->known_public_ips;
 280                 if (ips[i].num != 0) {
 281                         int j;
 282                         have_ips = true;
 283                         /* Succeed if an address is hosted on node i */
 284                         for (j=0; j < ips[i].num; j++) {
 285                                 if (ips[i].ip[j].pnn == i) {
 286                                         return true;
 287                                 }
 288                         }
 289                 }
 290         }
 291
 292         if (! have_ips) {
 293                 return false;
 294         }
 295
 296         /* At this point there are known addresses but none are
 297          * hosted.  Need to check if cluster can now host some
 298          * addresses.
 299          */
 300         for (i=0; i < ipalloc_state->num; i++) {
 301                 if (ipalloc_state->available_public_ips[i].num != 0) {
 302                         return true;
 303                 }
 304         }
 305
 306         return false;
 307 }
 308
 309 /* The calculation part of the IP allocation algorithm. */
 310 struct public_ip_list *ipalloc(struct ipalloc_state *ipalloc_state)
 311 {
 312         bool ret = false;
 313
 314         ipalloc_state->all_ips = create_merged_ip_list(ipalloc_state);
 315         if (ipalloc_state->all_ips == NULL) {
 316                 return NULL;
 317         }
 318
 319         if (!populate_bitmap(ipalloc_state)) {
 320                 return NULL;
 321         }
 322
 323         switch (ipalloc_state->algorithm) {
 324         case IPALLOC_LCP2:
 325                 ret = ipalloc_lcp2(ipalloc_state);
 326                 break;
 327         case IPALLOC_DETERMINISTIC:
 328                 ret = ipalloc_deterministic(ipalloc_state);
 329                 break;
 330         case IPALLOC_NONDETERMINISTIC:
 331                 ret = ipalloc_nondeterministic(ipalloc_state);
 332                break;
 333         }
 334
 335         /* at this point ->pnn is the node which will own each IP
 336            or -1 if there is no node that can cover this ip
 337         */
 338
 339         return (ret ? ipalloc_state->all_ips : NULL);
 340 }