hcq/MaxScale
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

MXS-1845 Add demotion code

Browse Source 
The master demotion in switchover now uses query retrying with
the switchover time limit.
This commit is contained in:
Esa Korhonen
2018-10-02 11:08:12 +03:00
parent a438a6df34
commit 49e85d9a28
3 changed files with 125 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
server/modules/monitor/mariadbmon/cluster_manipulation.cc
View File

@ -727,8 +727,6 @@ bool MariaDBMonitor::switchover_perform(ClusterOperation& op)
json_t** const error_out = op.error_out;
mxb_assert(promotion_target && demotion_target);
maxbase::StopWatch timer;
// Step 1: Save all slaves except promotion target to an array.
// Try to redirect even disconnected slaves.
// TODO: 'switchover_wait_slaves_catchup' needs to be smarter and not bother with such slaves.
@ -736,12 +734,11 @@ bool MariaDBMonitor::switchover_perform(ClusterOperation& op)
bool rval = false;
// Step 2: Set read-only to on, flush logs, update master gtid:s
if (switchover_demote_master(demotion_target, error_out))
if (demotion_target->demote(op))
{
m_cluster_modified = true;
bool catchup_and_promote_success = false;
op.time_remaining -= timer.restart();
maxbase::StopWatch timer;
// Step 3: Wait for the slaves (including promotion target) to catch up with master.
ServerArray catchup_slaves = redirectable_slaves;
catchup_slaves.push_back(promotion_target);
@ -750,7 +747,7 @@ bool MariaDBMonitor::switchover_perform(ClusterOperation& op)
op.time_remaining.secs(),
error_out))
{
auto step3_duration = timer.restart();
auto step3_duration = timer.lap();
MXS_DEBUG("Switchover: slave catchup took %.1f seconds.", step3_duration.secs());
op.time_remaining -= step3_duration;
@ -759,7 +756,7 @@ bool MariaDBMonitor::switchover_perform(ClusterOperation& op)
{
catchup_and_promote_success = true;
m_next_master = promotion_target;
timer.restart();
// Step 5: Redirect slaves and start replication on old master.
ServerArray redirected_slaves;
bool start_ok = switchover_start_slave(demotion_target, promotion_target);
@ -772,6 +769,7 @@ bool MariaDBMonitor::switchover_perform(ClusterOperation& op)
bool success = redirectable_slaves.empty() ? start_ok : start_ok || redirects > 0;
if (success)
{
op.time_remaining -= timer.lap();
// Step 6: Finally, add an event to the new master to advance gtid and wait for the slaves
// to receive it. If using external replication, skip this step. Come up with an
// alternative later.
@ -785,7 +783,7 @@ bool MariaDBMonitor::switchover_perform(ClusterOperation& op)
op.time_remaining.secs()))
{
rval = true;
auto step6_duration = timer.restart();
auto step6_duration = timer.lap();
op.time_remaining -= step6_duration;
MXS_DEBUG("Switchover: slave replication confirmation took %.1f seconds with "
"%.1f seconds to spare.",