From: "Fabio M. Di Nitto" <fdinitto@xxxxxxxxxx>
this flag (0|1) can be configured via quorum.last_man_standing and when
enabled, it allows expected_votes to be dynamically recalculated.
Assuming an 8 nodes cluster, every node votes 1 (mandatory requirement for
this feature).
In the first event, 3 nodes are lost.
The remaining partition of 5 is barely quorate.
After a configurable timeout (quorum.last_man_standing_window, default 10sec)
the quorate partition is allow to recalculate expected_votes based on
the remaining nodes.
This operation will bring expected_votes to 5 and quorum to 3.
Repeating the above loop, in the next event, 2 more nodes are allowed to
die. etc. etc.
Signed-off-by: Fabio M. Di Nitto <fdinitto@xxxxxxxxxx>
---
:100644 100644 0099cd7... 7a2078b... M exec/coroparse.c
:100644 100644 9d46269... e56654a... M services/votequorum.c
exec/coroparse.c | 2 ++
services/votequorum.c | 39 +++++++++++++++++++++++++++++++++++++++
2 files changed, 41 insertions(+), 0 deletions(-)
diff --git a/exec/coroparse.c b/exec/coroparse.c
index 0099cd7..7a2078b 100644
--- a/exec/coroparse.c
+++ b/exec/coroparse.c
@@ -360,6 +360,7 @@ static int main_config_parser_cb(const char *path,
if ((strcmp(path, "quorum.expected_votes") == 0) ||
(strcmp(path, "quorum.votes") == 0) ||
(strcmp(path, "quorum.quorumdev_poll") == 0) ||
+ (strcmp(path, "quorum.last_man_standing_window") == 0) ||
(strcmp(path, "quorum.leaving_timeout") == 0)) {
i = atoi(value);
icmap_set_uint32(path, i);
@@ -369,6 +370,7 @@ static int main_config_parser_cb(const char *path,
if ((strcmp(path, "quorum.two_node") == 0) ||
(strcmp(path, "quorum.wait_for_all") == 0) ||
(strcmp(path, "quorum.auto_tie_breaker") == 0) ||
+ (strcmp(path, "quorum.last_man_standing") == 0) ||
(strcmp(path, "quorum.quorate") == 0)) {
i = atoi(value);
icmap_set_uint8(path, i);
diff --git a/services/votequorum.c b/services/votequorum.c
index 9d46269..e56654a 100644
--- a/services/votequorum.c
+++ b/services/votequorum.c
@@ -79,6 +79,7 @@
#define DEFAULT_EXPECTED 1024
#define DEFAULT_QDEV_POLL 10000
#define DEFAULT_LEAVE_TMO 10000
+#define DEFAULT_LMS_WIN 10000
LOGSYS_DECLARE_SUBSYS ("VOTEQ");
@@ -121,9 +122,14 @@ static int cluster_is_quorate;
static int first_trans = 1;
static unsigned int quorumdev_poll = DEFAULT_QDEV_POLL;
static unsigned int leaving_timeout = DEFAULT_LEAVE_TMO;
+
static uint8_t wait_for_all = 0;
static uint8_t auto_tie_breaker = 0;
static int lowest_node_id = -1;
+static uint8_t last_man_standing = 0;
+static uint32_t last_man_standing_window = DEFAULT_LMS_WIN;
+static int last_man_standing_timer_set = 0;
+static corosync_timer_handle_t last_man_standing_timer;
static struct cluster_node *us;
static struct cluster_node *quorum_device = NULL;
@@ -375,6 +381,8 @@ static void votequorum_init(struct corosync_api_v1 *api,
icmap_get_uint8("quorum.wait_for_all", &wait_for_all);
icmap_get_uint8("quorum.auto_tie_breaker", &auto_tie_breaker);
+ icmap_get_uint8("quorum.last_man_standing", &last_man_standing);
+ icmap_get_uint32("quorum.last_man_standing_window", &last_man_standing_window);
/*
* TODO: we need to know the lowest node-id in the cluster
@@ -875,6 +883,16 @@ static int quorum_exec_send_reconfigure(int param, int nodeid, int value)
return ret;
}
+static void lms_timer_fn(void *arg)
+{
+ ENTER();
+ last_man_standing_timer_set = 0;
+ if (cluster_is_quorate) {
+ recalculate_quorum(1,1);
+ }
+ LEAVE();
+}
+
static void quorum_confchg_fn (
enum totem_configuration_type configuration_type,
const unsigned int *member_list, size_t member_list_entries,
@@ -902,6 +920,17 @@ static void quorum_confchg_fn (
}
}
+ if (last_man_standing) {
+ if ((member_list_entries >= quorum) && (left_list_entries)) {
+ if (last_man_standing_timer_set) {
+ corosync_api->timer_delete(last_man_standing_timer);
+ last_man_standing_timer_set = 0;
+ }
+ corosync_api->timer_add_duration((unsigned long long)last_man_standing_window*1000000, NULL, lms_timer_fn, &last_man_standing_timer);
+ last_man_standing_timer_set = 1;
+ }
+ }
+
if (member_list_entries) {
memcpy(quorum_members, member_list, sizeof(unsigned int) * member_list_entries);
quorum_members_entries = member_list_entries;
@@ -975,6 +1004,16 @@ static void message_handler_req_exec_votequorum_nodeinfo (
log_printf(LOGSYS_LEVEL_DEBUG, "nodeinfo message: votes: %d, expected: %d wfa: %d\n", req_exec_quorum_nodeinfo->votes, req_exec_quorum_nodeinfo->expected_votes, req_exec_quorum_nodeinfo->wait_for_all);
+ if ((last_man_standing) && (req_exec_quorum_nodeinfo->votes > 1)) {
+ log_printf(LOGSYS_LEVEL_WARNING, "Last Man Standing feature is supported only when all"
+ "cluster nodes votes are set to 1. Disabling LMS.");
+ last_man_standing = 0;
+ if (last_man_standing_timer_set) {
+ corosync_api->timer_delete(last_man_standing_timer);
+ last_man_standing_timer_set = 0;
+ }
+ }
+
node->flags &= ~NODE_FLAGS_BEENDOWN;
if (new_node || req_exec_quorum_nodeinfo->first_trans ||
--
1.7.7.5
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