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Code Activity

MDEV-11153 - Introduce status variables for table cache monitoring and tuning

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Status variables added: Table_open_cache_hits, Table_open_cache_misses,
Table_open_cache_overflows, Table_open_cache_active_instances.
This commit is contained in:
Sergey Vojtovich
2017-08-10 15:45:03 +04:00
parent 5d3ed9acdd
commit 613dd62a76
7 changed files with 99 additions and 9 deletions
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35
sql/table_cache.cc
View File

@ -56,7 +56,7 @@
ulong tdc_size; /**< Table definition cache threshold for LRU eviction. */
ulong tc_size; /**< Table cache threshold for LRU eviction. */
uint32 tc_instances;
static uint32 tc_active_instances= 1;
uint32 tc_active_instances= 1;
static uint32 tc_contention_warning_reported;
/** Data collections. */
@ -369,18 +369,30 @@ void tc_add_table(THD *thd, TABLE *table)
mysql_mutex_unlock(&element->LOCK_table_share);
mysql_mutex_lock(&tc[i].LOCK_table_cache);
if (tc[i].records == tc_size && (LRU_table= tc[i].free_tables.pop_front()))
if (tc[i].records == tc_size)
{
LRU_table->s->tdc->free_tables[i].list.remove(LRU_table);
/* Needed if MDL deadlock detector chimes in before tc_remove_table() */
LRU_table->in_use= thd;
if ((LRU_table= tc[i].free_tables.pop_front()))
{
LRU_table->s->tdc->free_tables[i].list.remove(LRU_table);
/* Needed if MDL deadlock detector chimes in before tc_remove_table() */
LRU_table->in_use= thd;
mysql_mutex_unlock(&tc[i].LOCK_table_cache);
/* Keep out of locked LOCK_table_cache */
tc_remove_table(LRU_table);
}
else
{
tc[i].records++;
mysql_mutex_unlock(&tc[i].LOCK_table_cache);
}
/* Keep out of locked LOCK_table_cache */
status_var_increment(thd->status_var.table_open_cache_overflows);
}
else
{
tc[i].records++;
mysql_mutex_unlock(&tc[i].LOCK_table_cache);
if (LRU_table)
tc_remove_table(LRU_table);
mysql_mutex_unlock(&tc[i].LOCK_table_cache);
}
}
@ -841,7 +853,10 @@ retry:
tdc_purge(false);
if (out_table)
{
status_var_increment(thd->status_var.table_open_cache_misses);
*out_table= 0;
}
share->m_psi= PSI_CALL_get_table_share(false, share);
goto end;
}
@ -858,8 +873,10 @@ retry:
DBUG_ASSERT(element->share);
DBUG_ASSERT(!element->share->error);
DBUG_ASSERT(!element->share->is_view);
status_var_increment(thd->status_var.table_open_cache_hits);
DBUG_RETURN(element->share);
}
status_var_increment(thd->status_var.table_open_cache_misses);
}
mysql_mutex_lock(&element->LOCK_table_share);