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Run manual commands without stopping the monitor

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The command is saved in a function object which is read by the monitor
thread. This way, manual and automatic cluster modification commands are
ran in the same step of a monitor cycle.

This update required several modifications in related code.
This commit is contained in:
Esa Korhonen
2018-06-21 18:34:27 +03:00
parent 6bf10904d7
commit 9525d3507b
5 changed files with 231 additions and 132 deletions
Download Patch File Download Diff File Expand all files Collapse all files

70
server/modules/monitor/mariadbmon/cluster_manipulation.cc
View File

@ -25,17 +25,6 @@ static void print_redirect_errors(MariaDBServer* first_server, const ServerArray
bool MariaDBMonitor::manual_switchover(SERVER* new_master, SERVER* current_master, json_t** error_out)
{
bool running = is_running();
if (running)
{
stop();
MXS_NOTICE("Stopped the monitor %s for the duration of switchover.", m_monitor->name);
}
else
{
MXS_NOTICE("Monitor %s already stopped, switchover can proceed.", m_monitor->name);
}
/* It's possible for either current_master, or both new_master & current_master to be NULL, which means
* autoselect. Only autoselecting new_master is not possible. Autoselection will happen at the actual
* switchover function. */
@ -70,27 +59,11 @@ bool MariaDBMonitor::manual_switchover(SERVER* new_master, SERVER* current_maste
}
}
if (running)
{
// TODO: What if this fails?
start(m_monitor->parameters);
}
return rval;
}
bool MariaDBMonitor::manual_failover(json_t** output)
{
bool running = is_running();
if (running)
{
stop();
MXS_NOTICE("Stopped monitor %s for the duration of failover.", m_monitor->name);
}
else
{
MXS_NOTICE("Monitor %s already stopped, failover can proceed.", m_monitor->name);
}
bool rv = true;
string failover_error;
rv = failover_check(&failover_error);
@ -112,27 +85,11 @@ bool MariaDBMonitor::manual_failover(json_t** output)
failover_error.c_str());
}
if (running)
{
// TODO: What if this fails?
start(m_monitor->parameters);
}
return rv;
}
bool MariaDBMonitor::manual_rejoin(SERVER* rejoin_server, json_t** output)
{
bool running = is_running();
if (running)
{
stop();
MXS_NOTICE("Stopped monitor %s for the duration of rejoin.", m_monitor->name);
}
else
{
MXS_NOTICE("Monitor %s already stopped, rejoin can proceed.", m_monitor->name);
}
bool rval = false;
if (cluster_can_be_joined())
{
@ -188,11 +145,6 @@ bool MariaDBMonitor::manual_rejoin(SERVER* rejoin_server, json_t** output)
PRINT_MXS_JSON_ERROR(output, BAD_CLUSTER, m_monitor->name);
}
if (running)
{
// TODO: What if this fails?
start(m_monitor->parameters);
}
return rval;
}
@ -351,6 +303,7 @@ uint32_t MariaDBMonitor::do_rejoin(const ServerArray& joinable_servers, json_t**
if (op_success)
{
servers_joined++;
m_cluster_modified = true;
}
}
}
@ -587,6 +540,7 @@ bool MariaDBMonitor::do_switchover(MariaDBServer** current_master, MariaDBServer
// Step 2: Set read-only to on, flush logs, update master gtid:s
if (switchover_demote_master(demotion_target, err_out))
{
m_cluster_modified = true;
bool catchup_and_promote_success = false;
time_t step2_time = time(NULL);
seconds_remaining -= difftime(step2_time, start_time);
@ -606,6 +560,8 @@ bool MariaDBMonitor::do_switchover(MariaDBServer** current_master, MariaDBServer
if (promote_new_master(promotion_target, err_out))
{
catchup_and_promote_success = true;
m_next_master = promotion_target;
// Step 5: Redirect slaves and start replication on old master.
ServerArray redirected_slaves;
bool start_ok = switchover_start_slave(demotion_target, promotion_target);
@ -706,6 +662,8 @@ bool MariaDBMonitor::do_failover(json_t** err_out)
// Step 3: Stop and reset slave, set read-only to 0.
if (promote_new_master(new_master, err_out))
{
m_next_master = new_master;
m_cluster_modified = true;
// Step 4: Redirect slaves.
ServerArray redirected_slaves;
int redirects = redirect_slaves(new_master, redirectable_slaves, &redirected_slaves);
@ -1378,17 +1336,14 @@ bool MariaDBMonitor::failover_check(string* error_out)
* If a master failure has occurred and MaxScale is configured with failover functionality, this fuction
* executes failover to select and promote a new master server. This function should be called immediately
* after @c mon_process_state_changes. If an error occurs, this method disables automatic failover.
*
* @return True if failover was performed, or at least attempted
*/
bool MariaDBMonitor::handle_auto_failover()
void MariaDBMonitor::handle_auto_failover()
{
const char RE_ENABLE_FMT[] = "%s To re-enable failover, manually set '%s' to 'true' for monitor "
"'%s' via MaxAdmin or the REST API, or restart MaxScale.";
bool cluster_modified = false;
if (config_get_global_options()->passive || (m_master && m_master->is_master()))
if (m_master && m_master->is_master())
{
return cluster_modified;
return;
}
if (failover_not_possible())
@ -1400,14 +1355,14 @@ bool MariaDBMonitor::handle_auto_failover()
MXS_ERROR(RE_ENABLE_FMT, PROBLEMS, CN_AUTO_FAILOVER, m_monitor->name);
m_auto_failover = false;
disable_setting(CN_AUTO_FAILOVER);
return cluster_modified;
return;
}
// If master seems to be down, check if slaves are receiving events.
if (m_verify_master_failure && m_master && m_master->is_down() && slave_receiving_events())
{
MXS_INFO("Master failure not yet confirmed by slaves, delaying failover.");
return cluster_modified;
return;
}
MariaDBServer* failed_master = NULL;
@ -1463,7 +1418,6 @@ bool MariaDBMonitor::handle_auto_failover()
m_auto_failover = false;
disable_setting(CN_AUTO_FAILOVER);
}
cluster_modified = true;
}
else
{
@ -1482,8 +1436,6 @@ bool MariaDBMonitor::handle_auto_failover()
{
m_warn_failover_precond = true;
}
return cluster_modified;
}
bool MariaDBMonitor::failover_not_possible()