diff options
Diffstat (limited to 'ctdb/server/ipalloc_nondeterministic.c')
| -rw-r--r-- | ctdb/server/ipalloc_nondeterministic.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/ctdb/server/ipalloc_nondeterministic.c b/ctdb/server/ipalloc_nondeterministic.c new file mode 100644 index 0000000..9da7d6c --- /dev/null +++ b/ctdb/server/ipalloc_nondeterministic.c @@ -0,0 +1,150 @@ +/* + ctdb ip takeover code + + Copyright (C) Ronnie Sahlberg 2007 + Copyright (C) Andrew Tridgell 2007 + Copyright (C) Martin Schwenke 2011 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, see <http://www.gnu.org/licenses/>. +*/ + +#include "replace.h" +#include "system/network.h" + +#include "ctdb_private.h" + +#include "lib/util/debug.h" +#include "common/logging.h" +#include "common/common.h" + +#include "protocol/protocol_util.h" + +#include "server/ipalloc_private.h" + +/* Basic non-deterministic rebalancing algorithm. + */ +static void basic_failback(struct ipalloc_state *ipalloc_state, + int num_ips) +{ + unsigned int i, numnodes, maxnode, minnode; + int maxnum, minnum, num, retries; + struct public_ip_list *t; + + numnodes = ipalloc_state->num; + retries = 0; + +try_again: + maxnum=0; + minnum=0; + + /* for each ip address, loop over all nodes that can serve + this ip and make sure that the difference between the node + serving the most and the node serving the least ip's are + not greater than 1. + */ + for (t = ipalloc_state->all_ips; t != NULL; t = t->next) { + if (t->pnn == CTDB_UNKNOWN_PNN) { + continue; + } + + /* Get the highest and lowest number of ips's served by any + valid node which can serve this ip. + */ + maxnode = CTDB_UNKNOWN_PNN; + minnode = CTDB_UNKNOWN_PNN; + for (i=0; i<numnodes; i++) { + /* only check nodes that can actually serve this ip */ + if (!can_node_takeover_ip(ipalloc_state, i, + t)) { + /* no it couldn't so skip to the next node */ + continue; + } + + num = node_ip_coverage(i, ipalloc_state->all_ips); + if (maxnode == CTDB_UNKNOWN_PNN) { + maxnode = i; + maxnum = num; + } else { + if (num > maxnum) { + maxnode = i; + maxnum = num; + } + } + if (minnode == CTDB_UNKNOWN_PNN) { + minnode = i; + minnum = num; + } else { + if (num < minnum) { + minnode = i; + minnum = num; + } + } + } + if (maxnode == CTDB_UNKNOWN_PNN) { + DEBUG(DEBUG_WARNING, + (__location__ " Could not find maxnode. May not be able to serve ip '%s'\n", + ctdb_sock_addr_to_string(ipalloc_state, + &t->addr, false))); + + continue; + } + + /* if the spread between the smallest and largest coverage by + a node is >=2 we steal one of the ips from the node with + most coverage to even things out a bit. + try to do this a limited number of times since we dont + want to spend too much time balancing the ip coverage. + */ + if ((maxnum > minnum+1) && + (retries < (num_ips + 5))){ + struct public_ip_list *tt; + + /* Reassign one of maxnode's VNNs */ + for (tt = ipalloc_state->all_ips; tt != NULL; tt = tt->next) { + if (tt->pnn == maxnode) { + (void)find_takeover_node(ipalloc_state, + tt); + retries++; + goto try_again;; + } + } + } + } +} + +bool ipalloc_nondeterministic(struct ipalloc_state *ipalloc_state) +{ + /* This should be pushed down into basic_failback. */ + struct public_ip_list *t; + int num_ips = 0; + for (t = ipalloc_state->all_ips; t != NULL; t = t->next) { + num_ips++; + } + + unassign_unsuitable_ips(ipalloc_state); + + basic_allocate_unassigned(ipalloc_state); + + /* If we don't want IPs to fail back then don't rebalance IPs. */ + if (ipalloc_state->no_ip_failback) { + return true; + } + + /* Now, try to make sure the ip addresses are evenly distributed + across the nodes. + */ + basic_failback(ipalloc_state, num_ips); + + return true; +} |