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MXS-2273 Move code for setting maintenance bit to monitor.cc

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Applies to being-drained as well.

Better that this special handling is handled by Monitor that needs it.
This commit is contained in:
Johan Wikman
2019-01-28 14:00:32 +02:00
parent 05b650ed91
commit 727d3feb3b
3 changed files with 143 additions and 61 deletions
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24
include/maxscale/monitor.hh
View File

@ -193,6 +193,30 @@ public:
void set_interval(int64_t interval); void set_interval(int64_t interval);
/**
* Set status of monitored server.
*
* @param srv Server, must be monitored by this monitor.
* @param bit The server status bit to be sent.
* @errmsg_out If the setting of the bit fails, on return the human readable
* reason why it could not be set.
*
* @return True, if the bit could be set.
*/
bool set_server_status(SERVER* srv, int bit, std::string* errmsg_out);
/**
* Clear status of monitored server.
*
* @param srv Server, must be monitored by this monitor.
* @param bit The server status bit to be cleared.
* @errmsg_out If the clearing of the bit fails, on return the human readable
* reason why it could not be cleared.
*
* @return True, if the bit could be cleared.
*/
bool clear_server_status(SERVER* srv, int bit, std::string* errmsg_out);
void show(DCB* dcb); void show(DCB* dcb);
const char* const m_name; /**< Monitor instance name. TODO: change to string */ const char* const m_name; /**< Monitor instance name. TODO: change to string */

115
server/core/monitor.cc
View File

@ -2336,6 +2336,121 @@ bool Monitor::set_disk_space_threshold(const string& dst_setting)
return rv; return rv;
} }
namespace
{
bool is_monitored_server(MXS_MONITORED_SERVER* pMs, SERVER* pServer)
{
while (pMs && (pMs->server != pServer))
{
pMs = pMs->next;
}
return pMs != nullptr;
}
const char ERR_CANNOT_MODIFY[] =
"The server is monitored, so only the maintenance status can be "
"set/cleared manually. Status was not modified.";
const char WRN_REQUEST_OVERWRITTEN[] =
"Previous maintenance request was not yet read by the monitor and was overwritten.";
}
bool Monitor::set_server_status(SERVER* srv, int bit, string* errmsg_out)
{
mxb_assert(is_monitored_server(this->monitored_servers, srv));
bool written = false;
if (this->state == MONITOR_STATE_RUNNING)
{
/* This server is monitored, in which case modifying any other status bit than Maintenance is
* disallowed. */
if (bit & ~(SERVER_MAINT | SERVER_BEING_DRAINED))
{
MXS_ERROR(ERR_CANNOT_MODIFY);
if (errmsg_out)
{
*errmsg_out = ERR_CANNOT_MODIFY;
}
}
else if (bit & SERVER_MAINT)
{
/* Maintenance is set/cleared using a special variable which the monitor reads when
* starting the next update cycle. */
int previous_request = atomic_exchange_int(&srv->maint_request, SERVER::MAINTENANCE_ON);
written = true;
// Warn if the previous request hasn't been read.
if (previous_request != SERVER::MAINTENANCE_NO_CHANGE)
{
MXS_WARNING(WRN_REQUEST_OVERWRITTEN);
}
// Also set a flag so the next loop happens sooner.
atomic_store_int(&this->check_maintenance_flag, SERVER::MAINTENANCE_FLAG_CHECK);
}
else
{
// TODO: This should be set the same way the maintenance bit is set.
srv->set_status(bit);
written = true;
}
}
else
{
/* The monitor is not running, the bit can be set directly */
srv->set_status(bit);
written = true;
}
return written;
}
bool Monitor::clear_server_status(SERVER* srv, int bit, string* errmsg_out)
{
mxb_assert(is_monitored_server(this->monitored_servers, srv));
bool written = false;
if (this->state == MONITOR_STATE_RUNNING)
{
if (bit & ~(SERVER_MAINT | SERVER_BEING_DRAINED))
{
MXS_ERROR(ERR_CANNOT_MODIFY);
if (errmsg_out)
{
*errmsg_out = ERR_CANNOT_MODIFY;
}
}
else if (bit & SERVER_MAINT)
{
// Warn if the previous request hasn't been read.
int previous_request = atomic_exchange_int(&srv->maint_request, SERVER::MAINTENANCE_OFF);
written = true;
if (previous_request != SERVER::MAINTENANCE_NO_CHANGE)
{
MXS_WARNING(WRN_REQUEST_OVERWRITTEN);
}
atomic_store_int(&this->check_maintenance_flag, SERVER::MAINTENANCE_FLAG_CHECK);
}
else
{
// TODO: This should be set the same way the maintenance bit is set.
srv->clear_status(bit);
written = true;
}
}
else
{
/* The monitor is not running, the bit can be cleared directly */
srv->clear_status(bit);
written = true;
}
return written;
}
void monitor_debug_wait() void monitor_debug_wait()
{ {
using namespace std::chrono; using namespace std::chrono;

65
server/core/server.cc
View File

@ -108,10 +108,6 @@ private:
ThisUnit this_unit; ThisUnit this_unit;
const char ERR_CANNOT_MODIFY[] = "The server is monitored, so only the maintenance status can be "
"set/cleared manually. Status was not modified.";
const char WRN_REQUEST_OVERWRITTEN[] = "Previous maintenance request was not yet read by the monitor "
"and was overwritten.";
const char ERR_TOO_LONG_CONFIG_VALUE[] = "The new value for %s is too long. Maximum length is %i characters."; const char ERR_TOO_LONG_CONFIG_VALUE[] = "The new value for %s is too long. Maximum length is %i characters.";
// Converts Server::ConfigParam to MXS_CONFIG_PARAM and keeps them in the same order. Required for some // Converts Server::ConfigParam to MXS_CONFIG_PARAM and keeps them in the same order. Required for some
@ -968,38 +964,9 @@ bool mxs::server_set_status(SERVER* srv, int bit, string* errmsg_out)
* but the race condition cannot cause significant harm. Monitors are never * but the race condition cannot cause significant harm. Monitors are never
* freed so the pointer stays valid. */ * freed so the pointer stays valid. */
Monitor* mon = monitor_server_in_use(srv); Monitor* mon = monitor_server_in_use(srv);
if (mon && mon->m_state == MONITOR_STATE_RUNNING) if (mon)
{ {
/* This server is monitored, in which case modifying any other status bit than Maintenance is written = mon->set_server_status(srv, bit, errmsg_out);
* disallowed. */
if (bit & ~(SERVER_MAINT | SERVER_BEING_DRAINED))
{
MXS_ERROR(ERR_CANNOT_MODIFY);
if (errmsg_out)
{
*errmsg_out = ERR_CANNOT_MODIFY;
}
}
else if (bit & SERVER_MAINT)
{
/* Maintenance is set/cleared using a special variable which the monitor reads when
* starting the next update cycle. */
int previous_request = atomic_exchange_int(&srv->maint_request, SERVER::MAINTENANCE_ON);
written = true;
// Warn if the previous request hasn't been read.
if (previous_request != SERVER::MAINTENANCE_NO_CHANGE)
{
MXS_WARNING(WRN_REQUEST_OVERWRITTEN);
}
// Also set a flag so the next loop happens sooner.
atomic_store_int(&mon->m_check_maintenance_flag, SERVER::MAINTENANCE_FLAG_CHECK);
}
else
{
// TODO: This should be set the same way the maintenance bit is set.
srv->set_status(bit);
written = true;
}
} }
else else
{ {
@ -1016,33 +983,9 @@ bool mxs::server_clear_status(SERVER* srv, int bit, string* errmsg_out)
// See server_set_status(). // See server_set_status().
bool written = false; bool written = false;
Monitor* mon = monitor_server_in_use(srv); Monitor* mon = monitor_server_in_use(srv);
if (mon && mon->m_state == MONITOR_STATE_RUNNING) if (mon)
{ {
if (bit & ~(SERVER_MAINT | SERVER_BEING_DRAINED)) written = mon->clear_server_status(srv, bit, errmsg_out);
{
MXS_ERROR(ERR_CANNOT_MODIFY);
if (errmsg_out)
{
*errmsg_out = ERR_CANNOT_MODIFY;
}
}
else if (bit & SERVER_MAINT)
{
// Warn if the previous request hasn't been read.
int previous_request = atomic_exchange_int(&srv->maint_request, SERVER::MAINTENANCE_OFF);
written = true;
if (previous_request != SERVER::MAINTENANCE_NO_CHANGE)
{
MXS_WARNING(WRN_REQUEST_OVERWRITTEN);
}
atomic_store_int(&mon->m_check_maintenance_flag, SERVER::MAINTENANCE_FLAG_CHECK);
}
else
{
// TODO: This should be set the same way the maintenance bit is set.
srv->clear_status(bit);
written = true;
}
} }
else else
{ {