一、information_schema.INNODB_TRX 的trx_state字段

这个字段源码注释如下：

trx_que_t que_state; /*!< valid when trx->state

== TRX_STATE_ACTIVE: TRX_QUE_RUNNING,

TRX_QUE_LOCK_WAIT, ... */

/** Transaction execution states when trx->state == TRX_STATE_ACTIVE */

enum trx_que_t {

TRX_QUE_RUNNING, /*!< transaction is running */

TRX_QUE_LOCK_WAIT, /*!< transaction is waiting for

a lock */

TRX_QUE_ROLLING_BACK, /*!< transaction is rolling back */

TRX_QUE_COMMITTING /*!< transaction is committing */

};

在测试中发现即便是commit下的也会是RUNNING状态，如下： 

因此主要取值有3个

TRX_QUE_RUNNING RUNNING

TRX_QUE_LOCK_WAIT LOCK WAIT

TRX_QUE_ROLLING_BACK ROLLING BACK

但是COMMITTING状态正确commit流程不触发。

二、information_schema.INNODB_TRX 的trx_operation_state字段

这个字段取值很多，标记了事务的各个阶段，主要来自于trx_t::op_info，在commit阶段有如下取值： 

其中preparing 和committing分别由函数trx_prepare_for_mysql和trx_commit_for_mysql进入，做完innodb层的prepare和commit后就会更改为NULL，实际的binlog的flush sync阶段不包含其中，实际也很好测试，可以做一个大事务，会发现 commit期间基本处于NULL状态：

mysql> select * from information_schema.INNODB_TRX \G

*************************** 1. row ***************************

trx_id: 66206

trx_state: RUNNING

trx_started: 2019-08-23 23:44:05

trx_requested_lock_id: NULL

trx_wait_started: NULL

trx_weight: 1046257

trx_mysql_thread_id: 4

trx_query: commit

trx_operation_state: NULL

trx_tables_in_use: 0

trx_tables_locked: 1

trx_lock_structs: 2025

trx_lock_memory_bytes: 319960

trx_rows_locked: 1044232

trx_rows_modified: 1044232

trx_concurrency_tickets: 0

trx_isolation_level: READ COMMITTED

...

三、performance_schema.events_transactions_current 的STATE字段

这个值也只有3个取值：

enum enum_transaction_state

{

TRANS_STATE_ACTIVE= 1,

TRANS_STATE_COMMITTED= 2,

TRANS_STATE_ROLLED_BACK= 3

};

TRANS_STATE_ACTIVE到TRANS_STATE_COMMITTED的转换会出现在innodb层提交完成后，也就是这个时候实际上整个prapare flush sync commit 已经结束了，之前一直除以ACTIVE状态，用处不大。如下：

#0 pfs_end_transaction_v1 (locker=0x7ffee0014ba8, commit=1 '\001') at /mysqldata/percona-server-locks-detail-5.7.22/storage/perfschema/pfs.cc:6116

#1 0x0000000000f7d177 in inline_mysql_commit_transaction (locker=0x7ffee0014ba8)

at /mysqldata/percona-server-locks-detail-5.7.22/include/mysql/psi/mysql_transaction.h:206

#2 0x0000000000f8026c in ha_commit_trans (thd=0x7ffee00129d0, all=true, ignore_global_read_lock=false)

at /mysqldata/percona-server-locks-detail-5.7.22/sql/handler.cc:1843

#3 0x00000000016dcd2f in trans_commit (thd=0x7ffee00129d0) at /mysqldata/percona-server-locks-detail-5.7.22/sql/transaction.cc:239

#4 0x00000000015cf466 in mysql_execute_command (thd=0x7ffee00129d0, first_level=true) at /mysqldata/percona-server-locks-detail-5.7.22/sql/sql_parse.cc:4526

#5 0x00000000015d2fde in mysql_parse (thd=0x7ffee00129d0, parser_state=0x7fffec5ee600) at /mysqldata/percona-server-locks-detail-5.7.22/sql/sql_parse.cc:5901

#6 0x00000000015c6b72 in dispatch_command (thd=0x7ffee00129d0, com_data=0x7fffec5eed70, command=COM_QUERY)

at /mysqldata/percona-server-locks-detail-5.7.22/sql/sql_parse.cc:1490

#7 0x00000000015c58ff in do_command (thd=0x7ffee00129d0) at /mysqldata/percona-server-locks-detail-5.7.22/sql/sql_parse.cc:1021

#8 0x000000000170e578 in handle_connection (arg=0x67d6410) at /mysqldata/percona-server-locks-detail-5.7.22/sql/conn_handler/connection_handler_per_thread.cc:312

#9 0x0000000001945538 in pfs_spawn_thread (arg=0x67be520) at /mysqldata/percona-server-locks-detail-5.7.22/storage/perfschema/pfs.cc:2190

#10 0x00007ffff7bcfaa1 in start_thread () from /lib64/libpthread.so.0

#11 0x00007ffff6b37c4d in clone () from /lib64/libc.so.6

(gdb) n

6117 DBUG_ASSERT(state != NULL);

(gdb) n

6119 ulonglong timer_end= 0;

(gdb) n

6120 ulonglong wait_time= 0;

(gdb) n

6121 uint flags= state->m_flags;

(gdb) n

6123 if (flags & STATE_FLAG_TIMED)

(gdb) n

6125 timer_end= state->m_timer();

(gdb) n

6126 wait_time= timer_end - state->m_timer_start;

(gdb) n

6131 if (flags & STATE_FLAG_THREAD)

(gdb) n

6133 PFS_thread *pfs_thread= reinterpret_cast<PFS_thread *> (state->m_thread);

(gdb) n

6134 DBUG_ASSERT(pfs_thread != NULL);

(gdb) n

6137 stat= &pfs_thread->write_instr_class_transactions_stats()[GLOBAL_TRANSACTION_INDEX];

(gdb) n

6139 if (flags & STATE_FLAG_EVENT)

(gdb) n

6141 PFS_events_transactions *pfs= reinterpret_cast<PFS_events_transactions*> (state->m_transaction);

(gdb) n

6142 DBUG_ASSERT(pfs != NULL);

(gdb) n

6145 if (unlikely(pfs->m_class == NULL))

(gdb) n

6148 pfs->m_timer_end= timer_end;

(gdb) n

6149 pfs->m_end_event_id= pfs_thread->m_event_id;

(gdb) n

6151 pfs->m_state= (commit ? TRANS_STATE_COMMITTED : TRANS_STATE_ROLLED_BACK);

(gdb) p pfs->m_state

$1 = TRANS_STATE_ACTIVE

因此上面3个取值都不是那么有用。