invalidating query cache entries

[youjie xiang]

hello,

my replication slave server(5.5.19 communication edition) has delayed so much.
i checked processlist, there was a process "invalidating query cache entries (table)" and delayed Time "555234".
i think this process is the cause of delaying.


mysql> show full processlist;
+----+-------------+-----------+------+---------+--------+------------------------------------------+-----------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------------+-----------+------+---------+--------+------------------------------------------+-----------------------+
| 1 | system user | | NULL | Connect | 27920 | Waiting for master to send event | NULL |
| 2 | system user | | NULL | Connect | 555234 | invalidating query cache entries (table) | NULL |
| 31 | [user] | localhost | NULL | Query | 0 | NULL | show full processlist |
+----+-------------+-----------+------+---------+--------+------------------------------------------+-----------------------+



mysql> show variables like '%cache%';
+------------------------------+----------------------+
| Variable_name | Value |
+------------------------------+----------------------+
| binlog_cache_size | 32768 |
| binlog_stmt_cache_size | 32768 |
| have_query_cache | YES |
| key_cache_age_threshold | 300 |
| key_cache_block_size | 1024 |
| key_cache_division_limit | 100 |
| max_binlog_cache_size | 18446744073709547520 |
| max_binlog_stmt_cache_size | 18446744073709547520 |
| metadata_locks_cache_size | 1024 |
| query_cache_limit | 1048576 |
| query_cache_min_res_unit | 4096 |
| query_cache_size | 0 |
| query_cache_type | ON |
| query_cache_wlock_invalidate | OFF |
| table_definition_cache | 400 |
| table_open_cache | 64 |
| thread_cache_size | 1000 |
+------------------------------+----------------------+



mysql> show global variables like '%cache%';
+------------------------------+----------------------+
| Variable_name | Value |
+------------------------------+----------------------+
| binlog_cache_size | 32768 |
| binlog_stmt_cache_size | 32768 |
| have_query_cache | YES |
| key_cache_age_threshold | 300 |
| key_cache_block_size | 1024 |
| key_cache_division_limit | 100 |
| max_binlog_cache_size | 18446744073709547520 |
| max_binlog_stmt_cache_size | 18446744073709547520 |
| metadata_locks_cache_size | 1024 |
| query_cache_limit | 1048576 |
| query_cache_min_res_unit | 4096 |
| query_cache_size | 0 |
| query_cache_type | ON |
| query_cache_wlock_invalidate | OFF |
| table_definition_cache | 400 |
| table_open_cache | 64 |
| thread_cache_size | 1000 |
+------------------------------+----------------------+


mysql> show variables like 'binlog_format';
| binlog_format | MIXED |



i searched informations on the web, but could not solve delaying.
i changed /etc/my.cnf, "query_cache_type" to OFF from ON but
the process is still remained(but the State is changed 'NULL').
the delaying is not solved.

+----+-------------+-----------+------+---------+--------+----------------------------------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------------+-----------+------+---------+--------+----------------------------------+------------------+
| 1 | system user | | NULL | Connect | 55 | Waiting for master to send event | NULL |
| 2 | system user | | NULL | Connect | 556402 | NULL | NULL |
| 31 | [user] | localhost | NULL | Query | 0 | NULL | show processlist |
+----+-------------+-----------+------+---------+--------+------------------------------------------+----------+

can anyone solve this problem ?

thanks for your reading my bad english.