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MXS-2219 Check that monitored server is part of quorum

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When the monitor connects to a Clustrix node, it checks that
the node is part of the quorum, before taking it into use.
This commit is contained in:
Johan Wikman
2019-01-18 11:41:43 +02:00
parent 6b556859ce
commit 01c3da9e0f
1 changed files with 92 additions and 3 deletions
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95
server/modules/monitor/clustrixmon/clustrixmonitor.cc
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@ -97,6 +97,76 @@ void ClustrixMonitor::tick()
}
}
namespace
{
bool is_part_of_the_quorum(const MXS_MONITORED_SERVER& ms)
{
bool rv = false;
const char ZQUERY_TEMPLATE[] =
"SELECT ms.status FROM system.membership AS ms INNER JOIN system.nodeinfo AS ni "
"ON ni.nodeid = ms.nid WHERE ni.iface_ip = '%s'";
const char* zAddress = ms.server->address;
char zQuery[sizeof(ZQUERY_TEMPLATE) + strlen(zAddress)];
sprintf(zQuery, ZQUERY_TEMPLATE, zAddress);
if (mysql_query(ms.con, zQuery) == 0)
{
MYSQL_RES* pResult = mysql_store_result(ms.con);
if (pResult)
{
mxb_assert(mysql_field_count(ms.con) == 1);
MYSQL_ROW row;
while ((row = mysql_fetch_row(pResult)) != nullptr)
{
if (row[0])
{
Clustrix::Status status = Clustrix::status_from_string(row[0]);
switch (status)
{
case Clustrix::Status::QUORUM:
rv = true;
break;
case Clustrix::Status::STATIC:
MXS_NOTICE("Node %s is not part of the quorum, switching to "
"other node for monitoring.", zAddress);
break;
case Clustrix::Status::UNKNOWN:
MXS_WARNING("Do not know how to interpret '%s'. Assuming node %s "
"is not part of the quorum.", row[0], zAddress);
}
}
else
{
MXS_WARNING("No status returned for '%s' on %s.", zQuery, zAddress);
}
}
mysql_free_result(pResult);
}
else
{
MXS_WARNING("No result returned for '%s' on %s.", zQuery, zAddress);
}
}
else
{
MXS_ERROR("Could not execute '%s' on %s: %s", zQuery, zAddress, mysql_error(ms.con));
}
return rv;
}
}
void ClustrixMonitor::update_cluster_nodes()
{
auto b = begin(*(m_monitor->monitored_servers));
@ -106,15 +176,34 @@ void ClustrixMonitor::update_cluster_nodes()
[this](MXS_MONITORED_SERVER& ms) -> bool {
mxs_connect_result_t rv = mon_ping_or_connect_to_db(m_monitor, &ms);
return mon_connection_is_ok(rv) ? true : false;
bool usable = false;
if (mon_connection_is_ok(rv) && is_part_of_the_quorum(ms))
{
usable = true;
}
return usable;
});
if (it != e)
{
MXS_MONITORED_SERVER& ms = *it;
update_cluster_nodes(ms);
if (!m_pMonitored_server)
{
MXS_NOTICE("Monitoring Clustrix cluster state using node %s.", ms.server->address);
}
else if (m_pMonitored_server != &ms)
{
MXS_NOTICE("Monitoring Clustrix cluster state using %s (used to be %s).",
ms.server->address, m_pMonitored_server->server->address);
}
m_pMonitored_server = &ms;
update_cluster_nodes(*m_pMonitored_server);
}
else
{
@ -256,7 +345,7 @@ void ClustrixMonitor::update_cluster_nodes(MXS_MONITORED_SERVER& ms)
}
else
{
MXS_WARNING("No result returned for '%s'.", ZQUERY);
MXS_WARNING("No result returned for '%s' on %s.", ZQUERY, ms.server->address);
}
}
else