MySQL buffer pool在 resize后，导致了crash。 看下日志
2023-06-26T03:10:12.510862Z 0 [Warning] InnoDB: A long semaphore wait: --Thread 140516243474176 has waited at i_s.cc line 2117 for 265 seconds the semaphore: Mutex at 0x7ff2c1f4cfb8, Mutex BUF_POOL_ZIP_FREE created buf0buf.cc:1720, lock var 1 processlist输出 FROM information_schema.innodb_cmpmem | 0 | 0 | | 276841 | xx | 127.0.0.1:34252 | NULL | Query | 508 | executing | SELECT page_size, buffer_pool_instance, pages_used, pages_free, relocation_ops, relocation_time FROM information_schema.innodb_cmpmem | 0 | 0 | InnoDB: ###### Diagnostic info printed to the standard error stream 2023-06-26T03:10:42.512788Z 0 [ERROR] [FATAL] InnoDB: Semaphore wait has lasted > 600 seconds. We intentionally crash the server because it appears to be hung. 2023-06-26 11:10:42 0x7fcc825ff700 InnoDB: Assertion failure in thread 140516337383168 in file ut0ut.cc line 922 InnoDB: We intentionally generate a memory trap. InnoDB: Submit a detailed bug report to InnoDB: If you get repeated assertion failures or crashes, even InnoDB: immediately after the mysqld startup, there may be InnoDB: corruption in the InnoDB tablespace. Please refer to InnoDB: http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html InnoDB: about forcing recovery. 03:10:42 UTC - mysqld got signal 6 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. Attempting to collect some information that could help diagnose the problem. As this is a crash and something is definitely wrong, the information collection process might fail.
可以看到是信号量等待超时，导致了crash，process list中的sql是监控的sql,这个sql执行过程中会获取buf_pool_zip_free, resize期间也会持有，这样如果buffer pool比较大，导致等待时间太长，会出现crash，将监控停止，resize正常。这里停监控也是使用了非常规的操作。 sql执行堆栈
i_s_cmpmem_fill_low(THD*, TABLE_LIST*, Item*, unsigned long) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/storage/innobase/handler/i_s.cc:2109) i_s_cmpmem_fill(THD*, TABLE_LIST*, Item*) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/storage/innobase/handler/i_s.cc:2162) do_fill_table(THD*, TABLE_LIST*, QEP_TAB*) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_show.cc:8188) get_schema_tables_result(JOIN*, enum_schema_table_state) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_show.cc:8319) JOIN::prepare_result() (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_select.cc:916) JOIN::exec() (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_executor.cc:131) handle_query(THD*, LEX*, Query_result*, unsigned long long, unsigned long long) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_select.cc:191) execute_sqlcom_select(THD*, TABLE_LIST*) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_parse.cc:5155) mysql_execute_command(THD*, bool) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_parse.cc:2826) mysql_parse(THD*, Parser_state*) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_parse.cc:5584) dispatch_command(THD*, COM_DATA const*, enum_server_command) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_parse.cc:1491) do_command(THD*) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/sql_parse.cc:1032) ::handle_connection(void *) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/sql/conn_handler/connection_handler_per_thread.cc:313) ::pfs_spawn_thread(void *) (/Users/xiaoyu.bai/Downloads/mysql-5.7.29/storage/perfschema/pfs.cc:2197) _pthread_start (@_pthread_start:54) thread_start (@thread_start:8)
