/* Remove a realserver IPVS rule */
static int
clear_service_rs(virtual_server_t * vs, list l)
{
element e;
real_server_t *rs;
long weight_sum;
long down_threshold = vs->quorum - vs->hysteresis;
for (e = LIST_HEAD(l); e; ELEMENT_NEXT(e)) {
rs = ELEMENT_DATA(e);
if (ISALIVE(rs)) {
log_message(LOG_INFO, "Removing service %s from VS %s"
, FMT_RS(rs)
, FMT_VS(vs));
if (!ipvs_cmd(LVS_CMD_DEL_DEST, vs, rs))
return 0;
UNSET_ALIVE(rs);
if (!vs->omega)
continue;
/* In Omega mode we call VS and RS down notifiers
* all the way down the exit, as necessary.
*/
if (rs->notify_down) {
log_message(LOG_INFO, "Executing [%s] for service %s in VS %s"
, rs->notify_down
, FMT_RS(rs)
, FMT_VS(vs));
notify_exec(rs->notify_down);
}
#ifdef _WITH_SNMP_
check_snmp_rs_trap(rs, vs);
#endif
/* Sooner or later VS will lose the quorum (if any). However,
* we don't push in a sorry server then, hence the regression
* is intended.
*/
weight_sum = weigh_live_realservers(vs);
if (vs->quorum_state == UP && (
!weight_sum ||
weight_sum < down_threshold)
) {
vs->quorum_state = DOWN;
if (vs->quorum_down) {
log_message(LOG_INFO, "Executing [%s] for VS %s"
, vs->quorum_down
, FMT_VS(vs));
notify_exec(vs->quorum_down);
}
#ifdef _WITH_SNMP_
check_snmp_quorum_trap(vs);
#endif
}
}
}
return 1;
}
/* Store new weight in real_server struct and then update kernel. */
void
update_svr_wgt(int weight, virtual_server_t * vs, real_server_t * rs
, int update_quorum)
{
if (weight != rs->weight) {
log_message(LOG_INFO, "Changing weight from %d to %d for %s service %s of VS %s"
, rs->weight
, weight
, ISALIVE(rs) ? "active" : "inactive"
, FMT_RS(rs)
, FMT_VS(vs));
rs->weight = weight;
/*
* Have weight change take effect now only if rs is in
* the pool and alive and the quorum is met (or if
* there is no sorry server). If not, it will take
* effect later when it becomes alive.
*/
if (rs->set && ISALIVE(rs) &&
(vs->quorum_state == UP || !vs->s_svr || !ISALIVE(vs->s_svr)))
ipvs_cmd(LVS_CMD_EDIT_DEST, vs, rs);
if (update_quorum)
update_quorum_state(vs);
}
}
/* Set a realserver IPVS rules */
static int
init_service_rs(virtual_server_t * vs)
{
element e;
real_server_t *rs;
if (LIST_ISEMPTY(vs->rs)) {
log_message(LOG_WARNING, "VS [%s] has no configured RS! Skipping RS activation."
, FMT_VS(vs));
return 1;
}
for (e = LIST_HEAD(vs->rs); e; ELEMENT_NEXT(e)) {
rs = ELEMENT_DATA(e);
if (rs->reloaded) {
if (rs->iweight != rs->pweight)
update_svr_wgt(rs->iweight, vs, rs, 0);
/* Do not re-add failed RS instantly on reload */
continue;
}
/* In alpha mode, be pessimistic (or realistic?) and don't
* add real servers into the VS pool. They will get there
* later upon healthchecks recovery (if ever).
*/
if (!vs->alpha && !ISALIVE(rs)) {
ipvs_cmd(LVS_CMD_ADD_DEST, vs, rs);
SET_ALIVE(rs);
}
}
return 1;
}
/* add or remove _alive_ real servers from a virtual server */
static void
perform_quorum_state(virtual_server_t *vs, int add)
{
element e;
real_server_t *rs;
if (LIST_ISEMPTY(vs->rs))
return;
log_message(LOG_INFO, "%s the pool for VS %s"
, add?"Adding alive servers to":"Removing alive servers from"
, FMT_VS(vs));
for (e = LIST_HEAD(vs->rs); e; ELEMENT_NEXT(e)) {
rs = ELEMENT_DATA(e);
if (!ISALIVE(rs)) /* We only handle alive servers */
continue;
if (add)
rs->alive = 0;
ipvs_cmd(add?LVS_CMD_ADD_DEST:LVS_CMD_DEL_DEST, vs, rs);
rs->alive = 1;
}
}
/* manipulate add/remove rs according to alive state */
static int
perform_svr_state(int alive, virtual_server_t * vs, real_server_t * rs)
{
/*
* | ISALIVE(rs) | alive | context
* | 0 | 0 | first check failed under alpha mode, unreachable here
* | 0 | 1 | RS went up, add it to the pool
* | 1 | 0 | RS went down, remove it from the pool
* | 1 | 1 | first check succeeded w/o alpha mode, unreachable here
*/
if (!ISALIVE(rs) && alive) {
log_message(LOG_INFO, "%s service %s to VS %s"
, (rs->inhibit) ? "Enabling" : "Adding"
, FMT_RS(rs)
, FMT_VS(vs));
/* Add only if we have quorum or no sorry server */
if (vs->quorum_state == UP || !vs->s_svr || !ISALIVE(vs->s_svr)) {
if (ipvs_cmd(LVS_CMD_ADD_DEST, vs, rs))
return -1;
}
rs->alive = alive;
if (rs->notify_up) {
log_message(LOG_INFO, "Executing [%s] for service %s in VS %s"
, rs->notify_up
, FMT_RS(rs)
, FMT_VS(vs));
notify_exec(rs->notify_up);
}
#ifdef _WITH_SNMP_CHECKER_
check_snmp_rs_trap(rs, vs);
#endif
/* We may have gained quorum */
update_quorum_state(vs);
}
if (ISALIVE(rs) && !alive) {
log_message(LOG_INFO, "%s service %s from VS %s"
, (rs->inhibit) ? "Disabling" : "Removing"
, FMT_RS(rs)
, FMT_VS(vs));
/* server is down, it is removed from the LVS realserver pool
* Remove only if we have quorum or no sorry server
*/
if (vs->quorum_state == UP || !vs->s_svr || !ISALIVE(vs->s_svr)) {
if (ipvs_cmd(LVS_CMD_DEL_DEST, vs, rs))
return -1;
}
rs->alive = alive;
if (rs->notify_down) {
log_message(LOG_INFO, "Executing [%s] for service %s in VS %s"
, rs->notify_down
, FMT_RS(rs)
, FMT_VS(vs));
notify_exec(rs->notify_down);
}
#ifdef _WITH_SNMP_CHECKER_
check_snmp_rs_trap(rs, vs);
#endif
/* We may have lost quorum */
update_quorum_state(vs);
}
return 0;
}
/* set quorum state depending on current weight of real servers */
static void
update_quorum_state(virtual_server_t * vs)
{
long weight_sum = weigh_live_realservers(vs);
long up_threshold = vs->quorum + vs->hysteresis;
long down_threshold = vs->quorum - vs->hysteresis;
/* If we have just gained quorum, it's time to consider notify_up. */
if (vs->quorum_state == DOWN &&
weight_sum >= up_threshold) {
vs->quorum_state = UP;
log_message(LOG_INFO, "Gained quorum %lu+%lu=%li <= %li for VS %s"
, vs->quorum
, vs->hysteresis
, up_threshold
, weight_sum
, FMT_VS(vs));
if (vs->s_svr && ISALIVE(vs->s_svr)) {
log_message(LOG_INFO, "%s sorry server %s from VS %s"
, (vs->s_svr->inhibit ? "Disabling" : "Removing")
, FMT_RS(vs->s_svr)
, FMT_VS(vs));
ipvs_cmd(LVS_CMD_DEL_DEST, vs, vs->s_svr);
vs->s_svr->alive = 0;
/* Adding back alive real servers */
perform_quorum_state(vs, 1);
}
if (vs->quorum_up) {
log_message(LOG_INFO, "Executing [%s] for VS %s"
, vs->quorum_up
, FMT_VS(vs));
notify_exec(vs->quorum_up);
}
#ifdef _WITH_SNMP_CHECKER_
check_snmp_quorum_trap(vs);
#endif
return;
}
/* If we have just lost quorum for the VS, we need to consider
* VS notify_down and sorry_server cases
*/
if (vs->quorum_state == UP &&
(!weight_sum || weight_sum < down_threshold)
) {
vs->quorum_state = DOWN;
log_message(LOG_INFO, "Lost quorum %lu-%lu=%li > %li for VS %s"
, vs->quorum
, vs->hysteresis
, down_threshold
, weight_sum
, FMT_VS(vs));
if (vs->quorum_down) {
log_message(LOG_INFO, "Executing [%s] for VS %s"
, vs->quorum_down
, FMT_VS(vs));
notify_exec(vs->quorum_down);
}
if (vs->s_svr) {
log_message(LOG_INFO, "%s sorry server %s to VS %s"
, (vs->s_svr->inhibit ? "Enabling" : "Adding")
, FMT_RS(vs->s_svr)
, FMT_VS(vs));
/* the sorry server is now up in the pool, we flag it alive */
ipvs_cmd(LVS_CMD_ADD_DEST, vs, vs->s_svr);
vs->s_svr->alive = 1;
/* Remove remaining alive real servers */
perform_quorum_state(vs, 0);
}
#ifdef _WITH_SNMP_CHECKER_
check_snmp_quorum_trap(vs);
#endif
return;
}
}