数据库内核月报－ 2017/03 - MySQL · myrocks · myrocks监控信息 - 《数据库内核月报》

SHOW STATUS
INFORMATION_SCHMEA
SHOW ENGINE ROCKSDB STATUS
SHOW ENGING ROKSDB TRANCTION STATUS
总结

rocksdb本身提供了丰富的监控信息，myrocks通过information_schema下的表和show命令等将这些信息展示出来，下面主要以示例的形式来简单介绍下

先创建测试表


1. CREATE TABLE t1 (a INT, b CHAR(8), pk INT AUTO_INCREMENT ,PRIMARY KEY(pk) comment 'cf_1', key idx2(b) comment 'cf_2') engine=rocksdb;

SHOW STATUS

show status 也展示了部分rocksdb引擎的信息


1. show status like '%rock%';
2. +---------------------------------------+------------------------------------------+
3. | Variable_name                         | Value                                    |
4. +---------------------------------------+------------------------------------------+
5. | rocksdb_rows_deleted                  | 0                                        |
6. | rocksdb_rows_inserted                 | 1048579                                  |
7. | rocksdb_rows_read                     | 3145755                                  |
8. | rocksdb_rows_updated                  | 7                                        |
9. | rocksdb_system_rows_deleted           | 0                                        |
10. | rocksdb_system_rows_inserted          | 0                                        |
11. | rocksdb_system_rows_read              | 0                                        |
12. | rocksdb_system_rows_updated           | 0                                        |
13. | rocksdb_block_cache_add               | 16                                       |
14. | rocksdb_block_cache_data_hit          | 76                                       |
15. | rocksdb_block_cache_data_miss         | 6                                        |
16. | rocksdb_block_cache_filter_hit        | 0                                        |
17. | rocksdb_block_cache_filter_miss       | 6                                        |
18. | rocksdb_block_cache_hit               | 76                                       |
19. | rocksdb_block_cache_index_hit         | 0                                        |
20. | rocksdb_block_cache_index_miss        | 6                                        |
21. | rocksdb_block_cache_miss              | 18                                       |
22. | rocksdb_block_cachecompressed_hit     | 0                                        |
23. | rocksdb_block_cachecompressed_miss    | 0                                        |
24. | rocksdb_bloom_filter_prefix_checked   | 0                                        |
25. | rocksdb_bloom_filter_prefix_useful    | 0                                        |
26. | rocksdb_bloom_filter_useful           | 0                                        |
27. | rocksdb_bytes_read                    | 13631762                                 |
28. | rocksdb_bytes_written                 | 108009584                                |
29. | rocksdb_compact_read_bytes            | 142                                      |
30. | rocksdb_compact_write_bytes           | 0                                        |
31. | rocksdb_compaction_key_drop_new       | 0                                        |
32. | rocksdb_compaction_key_drop_obsolete  | 4                                        |
33. | rocksdb_compaction_key_drop_user      | 4                                        |
34. | rocksdb_flush_write_bytes             | 7211                                     |
35. | rocksdb_getupdatessince_calls         | 0                                        |
36. | rocksdb_git_date                      | %cI                                      |
37. | rocksdb_git_hash                      | bc5d7b70299b763127f3714055a63ebe7e04ad47 |
38. | rocksdb_l0_num_files_stall_micros     | 0                                        |
39. | rocksdb_l0_slowdown_micros            | 0                                        |
40. | rocksdb_memtable_compaction_micros    | 0                                        |
41. | rocksdb_memtable_hit                  | 1048593                                  |
42. | rocksdb_memtable_miss                 | 1048609                                  |
43. | rocksdb_no_file_closes                | 0                                        |
44. | rocksdb_no_file_errors                | 0                                        |
45. | rocksdb_no_file_opens                 | 6                                        |
46. | rocksdb_num_iterators                 | 0                                        |
47. | rocksdb_number_block_not_compressed   | 0                                        |
48. | rocksdb_number_deletes_filtered       | 0                                        |
49. | rocksdb_number_keys_read              | 2097202                                  |
50. | rocksdb_number_keys_updated           | 0                                        |
51. | rocksdb_number_keys_written           | 2097220                                  |
52. | rocksdb_number_merge_failures         | 0                                        |
53. | rocksdb_number_multiget_bytes_read    | 0                                        |
54. | rocksdb_number_multiget_get           | 0                                        |
55. | rocksdb_number_multiget_keys_read     | 0                                        |
56. | rocksdb_number_reseeks_iteration      | 0                                        |
57. | rocksdb_number_sst_entry_delete       | 12                                       |
58. | rocksdb_number_sst_entry_merge        | 0                                        |
59. | rocksdb_number_sst_entry_other        | 0                                        |
60. | rocksdb_number_sst_entry_put          | 30                                       |
61. | rocksdb_number_sst_entry_singledelete | 0                                        |
62. | rocksdb_number_stat_computes          | 0                                        |
63. | rocksdb_number_superversion_acquires  | 21                                       |
64. | rocksdb_number_superversion_cleanups  | 1                                        |
65. | rocksdb_number_superversion_releases  | 1                                        |
66. | rocksdb_rate_limit_delay_millis       | 0                                        |
67. | rocksdb_snapshot_conflict_errors      | 0                                        |
68. | rocksdb_wal_bytes                     | 54006676                                 |
69. | rocksdb_wal_group_syncs               | 0                                        |
70. | rocksdb_wal_synced                    | 13                                       |
71. | rocksdb_write_other                   | 0                                        |
72. | rocksdb_write_self                    | 58                                       |
73. | rocksdb_write_timedout                | 0                                        |
74. | rocksdb_write_wal                     | 58                                       |
75. +---------------------------------------+------------------------------------------+

INFORMATION_SCHMEA

information_schema下rocksdb相关的表如下


1. select table_name from INFORMATION_SCHEMA.tables where table_name like '%rock%';
2. +-----------------------------+
3. | table_name                  |
4. +-----------------------------+
5. | ROCKSDB_PERF_CONTEXT        |
6. | ROCKSDB_GLOBAL_INFO         |
7. | ROCKSDB_COMPACTION_STATS    |
8. | ROCKSDB_INDEX_FILE_MAP      |
9. | ROCKSDB_CF_OPTIONS          |
10. | ROCKSDB_PERF_CONTEXT_GLOBAL |
11. | ROCKSDB_CFSTATS             |
12. | ROCKSDB_TRX                 |
13. | ROCKSDB_DBSTATS             |
14. | ROCKSDB_DDL                 |
15. | ROCKSDB_LOCKS               |
16. +-----------------------------+

数据字典相关


1. show create table INFORMATION_SCHEMA.ROCKSDB_INDEX_FILE_MAP\G
2. *************************** 1. row ***************************
3. Table: ROCKSDB_INDEX_FILE_MAP
4. Create Table: CREATE TEMPORARY TABLE `ROCKSDB_INDEX_FILE_MAP` (
5. `COLUMN_FAMILY` int(4) NOT NULL DEFAULT '0',
6. `INDEX_NUMBER` int(4) NOT NULL DEFAULT '0',
7. `SST_NAME` varchar(193) NOT NULL DEFAULT '',
8. `NUM_ROWS` bigint(8) NOT NULL DEFAULT '0',
9. `DATA_SIZE` bigint(8) NOT NULL DEFAULT '0',
10. `ENTRY_DELETES` bigint(8) NOT NULL DEFAULT '0',
11. `ENTRY_SINGLEDELETES` bigint(8) NOT NULL DEFAULT '0',
12. `ENTRY_MERGES` bigint(8) NOT NULL DEFAULT '0',
13. `ENTRY_OTHERS` bigint(8) NOT NULL DEFAULT '0'
14. ) ENGINE=MEMORY DEFAULT CHARSET=utf8
15. 1 row in set (0.00 sec)

17. mysql> show create table INFORMATION_SCHEMA.ROCKSDB_DDL\G
18. *************************** 1. row ***************************
19. Table: ROCKSDB_DDL
20. Create Table: CREATE TEMPORARY TABLE `ROCKSDB_DDL` (
21. `TABLE_SCHEMA` varchar(193) NOT NULL DEFAULT '',
22. `TABLE_NAME` varchar(193) NOT NULL DEFAULT '',
23. `PARTITION_NAME` varchar(193) DEFAULT NULL,
24. `INDEX_NAME` varchar(193) NOT NULL DEFAULT '',
25. `COLUMN_FAMILY` int(4) NOT NULL DEFAULT '0',
26. `INDEX_NUMBER` int(4) NOT NULL DEFAULT '0',
27. `INDEX_TYPE` smallint(2) NOT NULL DEFAULT '0',
28. `KV_FORMAT_VERSION` smallint(2) NOT NULL DEFAULT '0',
29. `CF` varchar(193) NOT NULL DEFAULT ''
30. ) ENGINE=MEMORY DEFAULT CHARSET=utf8

例如查询t1表的数据字典信息


1. select d.*,i.* from INFORMATION_SCHEMA.ROCKSDB_INDEX_FILE_MAP i,INFORMATION_SCHEMA.ROCKSDB_DDL d where i.INDEX_NUMBER=d.INDEX_NUMBER\G
2. *************************** 1. row ***************************
3. TABLE_SCHEMA: test
4. TABLE_NAME: t1
5. PARTITION_NAME: NULL
6. INDEX_NAME: PRIMARY
7. COLUMN_FAMILY: 2
8. INDEX_NUMBER: 263
9. INDEX_TYPE: 1
10. KV_FORMAT_VERSION: 11
11. CF: cf_1
12. COLUMN_FAMILY: 2
13. INDEX_NUMBER: 263
14. SST_NAME: 000039.sst
15. NUM_ROWS: 2
16. DATA_SIZE: 42
17. ENTRY_DELETES: 0
18. ENTRY_SINGLEDELETES: 0
19. ENTRY_MERGES: 0
20. ENTRY_OTHERS: 0
21. *************************** 2. row ***************************
22. TABLE_SCHEMA: test
23. TABLE_NAME: t1
24. PARTITION_NAME: NULL
25. INDEX_NAME: idx2
26. COLUMN_FAMILY: 3
27. INDEX_NUMBER: 264
28. INDEX_TYPE: 2
29. KV_FORMAT_VERSION: 11
30. CF: cf_2
31. COLUMN_FAMILY: 3
32. INDEX_NUMBER: 264
33. SST_NAME: 000040.sst
34. NUM_ROWS: 2
35. DATA_SIZE: 45
36. ENTRY_DELETES: 0
37. ENTRY_SINGLEDELETES: 0
38. ENTRY_MERGES: 0
39. ENTRY_OTHERS: 0
40. 2 rows in set (0.00 sec)

事务相关


1. begin;
2. select * from INFORMATION_SCHEMA.ROCKSDB_LOCKS;
3. INSERT INTO t1 (a,b) VALUES (1,'a');
4. select * from INFORMATION_SCHEMA.ROCKSDB_LOCKS;
5. +------------------+----------------+------------------+------+
6. | COLUMN_FAMILY_ID | TRANSACTION_ID | KEY              | MODE |
7. +------------------+----------------+------------------+------+
8. |                2 |             14 | 0000010780000001 | X    |
9. +------------------+----------------+------------------+------+

11. select * from INFORMATION_SCHEMA.ROCKSDB_TRX\G
12. *************************** 1. row ***************************
13. TRANSACTION_ID: 89
14. STATE: STARTED
15. NAME:
16. WRITE_COUNT: 2
17. LOCK_COUNT: 2
18. TIMEOUT_SEC: 2
19. WAITING_KEY:
20. WAITING_COLUMN_FAMILY_ID: 0
21. IS_REPLICATION: 0
22. SKIP_TRX_API: 0
23. READ_ONLY: 0
24. HAS_DEADLOCK_DETECTION: 0
25. NUM_ONGOING_BULKLOAD: 0
26. THREAD_ID: 13
27. QUERY: select * from INFORMATION_SCHEMA.ROCKSDB_TRX

其中KEY 0000010780100002表示indexnum:107(263）pk: 80000001(1) 表示(1,’a’,1)这条记录，具体参考myrocks记录格式分析

统计信息相关


1. select * from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO;
2. +--------------+--------------+-----------------------------------------+
3. | TYPE         | NAME         | VALUE                                   |
4. +--------------+--------------+-----------------------------------------+
5. | BINLOG       | FILE         | mysql-bin.000003                        |
6. | BINLOG       | POS          | 18957545                                |
7. | BINLOG       | GTID         | b89fb268-0b22-11e7-a0ce-2c44fd7a5210:27 |
8. | MAX_INDEX_ID | MAX_INDEX_ID | 264                                     |
9. | CF_FLAGS     | 0            | default [0]                             |
10. | CF_FLAGS     | 1            | __system__ [0]                          |
11. | CF_FLAGS     | 2            | cf_1 [0]                                |
12. | CF_FLAGS     | 3            | cf_2 [0]                                |
13. +--------------+--------------+-----------------------------------------+

15. select * from INFORMATION_SCHEMA.ROCKSDB_DBSTATS;
16. +-------------------------+-------+
17. | STAT_TYPE               | VALUE |
18. +-------------------------+-------+
19. | DB_BACKGROUND_ERRORS    |     0 |
20. | DB_NUM_SNAPSHOTS        |     0 |
21. | DB_OLDEST_SNAPSHOT_TIME |     0 |
22. | DB_BLOCK_CACHE_USAGE    |  1119 |
23. +-------------------------+-------+

25. select * from INFORMATION_SCHEMA.ROCKSDB_CFSTATS where CF_NAME='cf_1';
26. +---------+-------------------------------+----------+
27. | CF_NAME | STAT_TYPE                     | VALUE    |
28. +---------+-------------------------------+----------+
29. | cf_1    | NUM_IMMUTABLE_MEM_TABLE       |        0 |
30. | cf_1    | MEM_TABLE_FLUSH_PENDING       |        0 |
31. | cf_1    | COMPACTION_PENDING            |        0 |
32. | cf_1    | CUR_SIZE_ACTIVE_MEM_TABLE     | 44739520 |
33. | cf_1    | CUR_SIZE_ALL_MEM_TABLES       | 44739520 |
34. | cf_1    | NUM_ENTRIES_ACTIVE_MEM_TABLE  |  1048574 |
35. | cf_1    | NUM_ENTRIES_IMM_MEM_TABLES    |        0 |
36. | cf_1    | NON_BLOCK_CACHE_SST_MEM_USAGE |        0 |
37. | cf_1    | NUM_LIVE_VERSIONS             |        1 |
38. +---------+-------------------------------+----------+

性能相关

INFORMATION_SCHEMA.ROCKSDB_PERF_CONTEXT_GLOBAL 是全局的性能信息，而INFORMATION_SCHEMA.ROCKSDB_PERF_CONTEXT是以表为单位的性能信息。

性能统计由参数rocksdb_perf_context_level控制，取值范围如下


1. enum PerfLevel : unsigned char {
2. kUninitialized = 0,             // unknown setting
3. kDisable = 1,                   // disable perf stats
4. kEnableCount = 2,               // enable only count stats
5. kEnableTimeExceptForMutex = 3,  // Other than count stats, also enable time
6. // stats except for mutexes
7. kEnableTime = 4,                // enable count and time stats
8. kOutOfBounds = 5                // N.B. Must always be the last value!
9. };

示例如下：


2. select * from INFORMATION_SCHEMA.ROCKSDB_PERF_CONTEXT_GLOBAL;
3. +---------------------------------+-------------+
4. | STAT_TYPE                       | VALUE       |
5. +---------------------------------+-------------+
6. | USER_KEY_COMPARISON_COUNT       |   565061179 |
7. | BLOCK_CACHE_HIT_COUNT           |          26 |
8. | BLOCK_READ_COUNT                |           2 |
9. | BLOCK_READ_BYTE                 |         145 |
10. | BLOCK_READ_TIME                 |      684522 |
11. | BLOCK_CHECKSUM_TIME             |        8380 |
12. | BLOCK_DECOMPRESS_TIME           |       10825 |
13. | INTERNAL_KEY_SKIPPED_COUNT      |     3371079 |
14. | INTERNAL_DELETE_SKIPPED_COUNT   |           0 |
15. | GET_SNAPSHOT_TIME               |  2409821566 |
16. | GET_FROM_MEMTABLE_TIME          | 68354733245 |
17. | GET_FROM_MEMTABLE_COUNT         |     4194309 |
18. | GET_POST_PROCESS_TIME           |  3421224444 |
19. | GET_FROM_OUTPUT_FILES_TIME      |  8016972510 |
20. | SEEK_ON_MEMTABLE_TIME           |      277621 |
21. | SEEK_ON_MEMTABLE_COUNT          |          33 |
22. | SEEK_CHILD_SEEK_TIME            |     1700582 |
23. | SEEK_CHILD_SEEK_COUNT           |          54 |
24. | SEEK_IN_HEAP_TIME               |      101201 |
25. | SEEK_INTERNAL_SEEK_TIME         |     2019275 |
26. | FIND_NEXT_USER_ENTRY_TIME       |  3997301676 |
27. | WRITE_WAL_TIME                  |   410899041 |
28. | WRITE_MEMTABLE_TIME             | 23580852751 |
29. | WRITE_DELAY_TIME                |           0 |
30. | WRITE_PRE_AND_POST_PROCESS_TIME |     1117611 |
31. | DB_MUTEX_LOCK_NANOS             |      237804 |
32. | DB_CONDITION_WAIT_NANOS         |           0 |
33. | MERGE_OPERATOR_TIME_NANOS       |           0 |
34. | READ_INDEX_BLOCK_NANOS          |           0 |
35. | READ_FILTER_BLOCK_NANOS         |           0 |
36. | NEW_TABLE_BLOCK_ITER_NANOS      |     1109437 |
37. | NEW_TABLE_ITERATOR_NANOS        |      308214 |
38. | BLOCK_SEEK_NANOS                |  1290004508 |
39. | FIND_TABLE_NANOS                |           0 |
40. | IO_THREAD_POOL_ID               |         102 |
41. | IO_BYTES_WRITTEN                |    54016973 |
42. | IO_BYTES_READ                   |         145 |
43. | IO_OPEN_NANOS                   |           0 |
44. | IO_ALLOCATE_NANOS               |           0 |
45. | IO_WRITE_NANOS                  |   116163102 |
46. | IO_READ_NANOS                   |      664547 |
47. | IO_RANGE_SYNC_NANOS             |           0 |
48. | IO_LOGGER_NANOS                 |           0 |
49. +---------------------------------+-------------+

51. select * from INFORMATION_SCHEMA.ROCKSDB_PERF_CONTEXT where table_name='t1' limit 1;
52. +--------------+------------+----------------+---------------------------+-----------+
53. | TABLE_SCHEMA | TABLE_NAME | PARTITION_NAME | STAT_TYPE                 | VALUE     |
54. +--------------+------------+----------------+---------------------------+-----------+
55. | test         | t1         | NULL           | USER_KEY_COMPARISON_COUNT | 565060904 |
56. +--------------+------------+----------------+---------------------------+-----------+

COMPACTION相关


1. select * from INFORMATION_SCHEMA.ROCKSDB_COMPACTION_STATS where CF_NAME='cf_1' limit 3;
2. +---------+-------+-----------+-------+
3. | CF_NAME | LEVEL | TYPE      | VALUE |
4. +---------+-------+-----------+-------+
5. | cf_1    | L0    | AvgSec    |     0 |
6. | cf_1    | L0    | CompCount |     2 |
7. | cf_1    | L0    | CompSec   |     0 |
8. +---------+-------+-----------+-------+

具体可以参考下节SHOW ENGINE ROCKSDB STATUS。

参数配置

每个column family 都是独立的配置信息


1. select * from INFORMATION_SCHEMA.ROCKSDB_CF_OPTIONS where CF_NAME='cf_1' limit 3;
2. +---------+-------------------+------------------+
3. | CF_NAME | OPTION_TYPE       | VALUE            |
4. +---------+-------------------+------------------+
5. | cf_1    | COMPARATOR        | RocksDB_SE_v3.10 |
6. | cf_1    | MERGE_OPERATOR    | NULL             |
7. | cf_1    | COMPACTION_FILTER | NULL             |
8. +---------+-------------------+------------------+

SHOW ENGINE ROCKSDB STATUS

show engine rocksdb status.结果主要分为三部分
1）DB Stats
2）Compaction Stats
3）Memory_Stats

show engine rocksdb status\G结果节选


1. show engine rocksdb status\G
2. *************************** 1. row ***************************
3. Type: DBSTATS
4. Name: rocksdb
5. Status:
6. ** DB Stats **
7. Uptime(secs): 211548.0 total, 8140.1 interval
8. Cumulative writes: 58 writes, 2097K keys, 58 commit groups, 1.0 writes per commit group, ingest: 0.10 GB, 0.00 MB/s
9. Cumulative WAL: 58 writes, 13 syncs, 4.14 writes per sync, written: 0.05 GB, 0.00 MB/s
10. Cumulative stall: 00:00:0.000 H:M:S, 0.0 percent
11. Interval writes: 0 writes, 0 keys, 0 commit groups, 0.0 writes per commit group, ingest: 0.00 MB, 0.00 MB/s
12. Interval WAL: 0 writes, 0 syncs, 0.00 writes per sync, written: 0.00 MB, 0.00 MB/s
13. Interval stall: 00:00:0.000 H:M:S, 0.0 percent

15. ......(省略)

17. *************************** 3. row ***************************
18. Type: CF_COMPACTION
19. Name: cf_1
20. Status:
21. ** Compaction Stats [cf_1] **
22. Level    Files   Size(MB} Score Read(GB}  Rn(GB} Rnp1(GB} Write(GB} Wnew(GB} Moved(GB} W-Amp Rd(MB/s} Wr(MB/s} Comp(sec} Comp(cnt} Avg(sec} KeyIn KeyDrop
23. ----------------------------------------------------------------------------------------------------------------------------------------------------------
24. L0      1/0       0.00   0.2      0.0     0.0      0.0       0.0      0.0       0.0   0.0      0.0      0.3         0         2    0.004       0      0
25. Sum      1/0       0.00   0.0      0.0     0.0      0.0       0.0      0.0       0.0   1.0      0.1      0.2         0         3    0.004       2      2
26. Int      0/0       0.00   0.0      0.0     0.0      0.0       0.0      0.0       0.0   0.0      0.0      0.0         0         0    0.000       0      0
27. Uptime(secs): 210665.0 total, 210665.0 interval
28. Flush(GB): cumulative 0.000, interval 0.000
29. AddFile(GB): cumulative 0.000, interval 0.000
30. AddFile(Total Files): cumulative 0, interval 0
31. AddFile(L0 Files): cumulative 0, interval 0
32. AddFile(Keys): cumulative 0, interval 0
33. Cumulative compaction: 0.00 GB write, 0.00 MB/s write, 0.00 GB read, 0.00 MB/s read, 0.0 seconds
34. Interval compaction: 0.00 GB write, 0.00 MB/s write, 0.00 GB read, 0.00 MB/s read, 0.0 seconds
35. Stalls(count): 0 level0_slowdown, 0 level0_slowdown_with_compaction, 0 level0_numfiles, 0 level0_numfiles_with_compaction, 0 stop for pending_compaction_bytes, 0 slowdown for pending_compaction_bytes, 0 memtable_compaction, 0 memtable_slowdown, interval 0 total count

37. ......(省略)

39. *************************** 6. row ***************************
40. Type: Memory_Stats
41. Name: rocksdb
42. Status:
43. MemTable Total: 93675232
44. MemTable Unflushed: 93673184
45. Table Readers Total: 0
46. Cache Total: 1119
47. Default Cache Capacity: 0
48. 6 rows in set (0.00 sec)

DB Stats

其中： Interval stall: 此值受max_write_buffer_number，level0_slowdown_writes_trigger、soft_pending_compaction_bytes_limit等参数的影响，具体参考（SetupDelay）

Compaction Stats

其中 Rn(GB} = bytes_read_non_output_levels / kGB Rnp1(GB} = bytes_read_output_level / kGB W-Amp = bytes_written/bytes_read_non_output_levels

此部分内容与 INFORMATION_SCHEMA.ROCKSDB_COMPACTION_STATS有部分重合。

Memory_Stats

MemTable Total: 对应DB::Properties::kSizeAllMemTables MemTable Unflushed：对应DB::Properties::kCurSizeAllMemTables Table Readers Total: 对应DB::Properties::kEstimateTableReadersMem Cache Total: 表示已使用的内存 Default Cache Capacity: 使用默认blockcache的总量(basetable没有指定blockcache时使用默认的8M的blockcache)

SHOW ENGING ROKSDB TRANCTION STATUS

显示当前正在运行的事务语句


1. show engine rocksdb transaction status\G
2. *************************** 1. row ***************************
3. Type: SNAPSHOTS
4. Name: rocksdb
5. Status:
6. ============================================================
7. 2017-03-20 07:49:22 ROCKSDB TRANSACTION MONITOR OUTPUT
8. ============================================================
9. ---------
10. SNAPSHOTS
11. ---------
12. LIST OF SNAPSHOTS FOR EACH SESSION:
13. ---SNAPSHOT, ACTIVE 5 sec
14. MySQL thread id 12, OS thread handle 0x7fd23a1d0700, query id 187 127.0.0.1 root Searching rows for update
15. update t1 set b='cc' where a=2
16. lock count 72822, write count 2
17. -----------------------------------------
18. END OF ROCKSDB TRANSACTION MONITOR OUTPUT
19. =========================================

总结

以上粗略介绍了myrocks的监控信息，具体还需要在实践中灵活运用。myrocks的监控信息也在不断完善中。

原文：http://mysql.taobao.org/monthly/2017/03/10/