8.18.4. thl list Command

8.18.4. thl list Command
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8.18.4. thl list Command

The list command to the thl command outputs a list of the sequence number information from the THL. By default, the entire THL as stored on disk is output. Command-line options enable you to select individual sequence numbers, sequence number ranges, or all the sequence information from a single file.

thl list
[-seqno # ]
[-low # ] | [-from # ] | [-high # ] | [-to # ]
[-last] [-last #] [-first] [-first #]
[-file filename ] [-no-checksum ] [-sql] [-sizes] [-sizesdetail] [-sizessummary] [-charset] [-headers] [-json] [-specs-] [-charset]

-event eventid

Output THL found that matches the provided eventid. If no exact match found, a message will display details of an approximate match if found. See example below:

An exact match is found:

shell> thl list -event mysql-bin.000015:0000000000030282
SEQ# = 99 / FRAG# = 0 (last frag)
- FILE = thl.data.0000000001
- TIME = 2025-02-21 09:11:28.0
- EPOCH# = 2
- EVENTID = mysql-bin.000015:0000000000030282;44
- SOURCEID = db1
...

No match found:

Event not found : Approximative match found between seqno 915 (mysql-bin.000017:0000000074628153;62) and seqno 916 (mysql-bin.000017:0000000074628349;62)

-file filename
Outputs all of the sequence number fragment information from the specified THL file. If the filename has been determined from the thl index command, or by examining the output of other fragments, the file-based output can be used to identify statements or row data within the THL.
-charset charset
Specify the character set to be used to decode the character-based row data embedded within the THL event. Without this option, data is output as a hex value.
-hex
For SQL that may be in different character sets, the information can be optionally output in hex format to determine the contents and context of the statement, even though the statement itself may be unreadable on the command-line.
-no-checksum
Ignores checksums within the THL. In the event of a checksum failure, use of this option will enable checksums to be ignored when the THL is being read.
-sql
Prints only the SQL for the selected sequence range. Use of this option can be useful if you want to extract the SQL and execute it directly by storing or piping the output.

-headers

Generates only the header information for the selected sequence numbers from the THL. For THL that contains a lot of SQL, obtaining the headers can be used to get basic content and context information without having to manually filter out the SQL in each fragment.

shell> thl list -headers
...
SEQ# = 215 / FRAG# = 0 (last frag)
- FILE = thl.data.0000000001
- TIME = 2025-02-21 09:11:29.0
- EPOCH# = 2
- EVENTID = mysql-bin.000015:0000000000072471;44
- SOURCEID = db1
SEQ# = 216 / FRAG# = 0 (last frag)
- FILE = thl.data.0000000001
- TIME = 2025-02-21 09:12:04.0
- EPOCH# = 2
- EVENTID = mysql-bin.000015:0000000000072872;102
- SOURCEID = db1
...

For more information on the fields displayed, see Section E.1.1, “THL Format”.

-json

Only valid with the -headers option, the header information is output for the selected sequence numbers from the THL in JSON format. The field contents are identical, with each fragment of each THL sequence being contained in a JSON object, with the output consisting of an array of the these sequence objects. For example:

[
...
 {
   "seqno": 215,
   "epoch": 2,
   "frag": 0,
   "lastFrag": true,
   "time": "2025-02-21 09:11:29.0",
   "eventId": "mysql-bin.000015:0000000000072471;44",
   "sourceId": "db1",
   "comments": ""
 },
 {
   "seqno": 216,
   "epoch": 2,
   "frag": 0,
   "lastFrag": true,
   "time": "2025-02-21 09:12:04.0",
   "eventId": "mysql-bin.000015:0000000000072872;102",
   "sourceId": "db1",
   "comments": ""
 },
...
]

-sizes
Shows the size information for a given THL event, describing either the size of the SQL, or the number of rows within the given event. For example:
```
shell> thl list -sizes
SEQ#  Frag# Tstamp
...
10  0 2025-02-21 09:11:27.0   Event total:      1 chunks      24 bytes in SQL statements  0 rows
11  0 2025-02-21 09:11:28.0   Event total:      1 chunks      26 bytes in SQL statements  0 rows
12  0 2025-02-21 09:11:28.0   Event total:      1 chunks      24 bytes in SQL statements  0 rows
13  0 2025-02-21 09:11:28.0   Event total:      1 chunks      19 bytes in SQL statements  0 rows
14  0 2025-02-21 09:11:28.0   Event total:      1 chunks      24 bytes in SQL statements  0 rows
...
```
Summary information is also output identicating an overall count of the changes. For example:
```
Total ROW chunks: 203 with 224 updated rows (93%)
Total STATEMENT chunks: 14 with 1473 bytes (6%)
217 events processed
```
This information can be useful when viewing or monitoring the replication progress as it can help to indicate and identify the size of a specific transaction, particularly if the transaction is large. This can be particularly useful in combination with the -first and/or -last.
For more detailed information on individual fragments within a sequence (and for large transactions there will be multiple fragments), use the thl list -sizesdetail command.

-sizesdetail

Shows detailed size information for a given THL event, describing either the size of the SQL, or the number of rows within the given event per fragment within each event, and with a summary for each event total. For very large THL event sizes this provide more detailed information about the size and makeup of the event. For example:

shell> thl list -sizesdetail -last
SEQ#  Frag# Tstamp      Chunks    SQL Data        Row Data
1604  0 2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  1 2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  2 2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  3 2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  4 2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  5 2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  6 2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  7 2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  8 2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  9 2025-02-21-29 11:04:53.0  123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  10  2025-02-21 11:04:53.0 123 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 45633 (371 avg rows per chunk)
1604  11  2025-02-21 11:04:53.0 7 chunks  SQL 0 bytes (0 avg bytes per chunk) Rows 2535 (362 avg rows per chunk)
     Event total: 1360 chunks  0 bytes in SQL statements 504498 rows

Summary information is also output identicating an overall count of the changes. For example:

Total ROW chunks: 69487 with 18257671 updated rows (100%)
Total STATEMENT chunks: 0 with 0 bytes (0%)
628 events processed

This information can be useful when viewing or monitoring the replication progress as it can help to indicate and identify the size of a specific transaction, particularly if the transaction is large. This can be particularly useful in combination with the -first and/or -last.

-sizessummary

Outputs only the size summary information for the requested THL:

shell> thl list -sizessummary
Total ROW chunks: 69487 with 18257671 updated rows (100%)
Total STATEMENT chunks: 0 with 0 bytes (0%)
628 events processed

-specs

Shows the column specifications, such as identified type, length, and additional settings, when viewing events within row-based replication. This can be helpful when examining THL data in heterogeneous replication deployments.

For example:

shell> thl list -seqno 216 -specs
SEQ# = 216 / FRAG# = 0 (last frag)
- FILE = thl.data.0000000001
- TIME = 2025-02-21 09:12:04.0
- EPOCH# = 2
- EVENTID = mysql-bin.000015:0000000000072872;102
- SOURCEID = db1
- METADATA = [mysql_server_id=10;mysql_thread_id=102;dbms_type=mysql;tz_aware=true;is_metadata=true;service=alpha;shard=tungsten_alpha;heartbeat=MASTER_ONLINE]
- GLOBAL OPTIONS = [autocommit=1;sql_auto_is_null=0;foreign_key_checks=1;unique_checks=1;sql_mode='NO_ENGINE_SUBSTITUTION,ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,IGNORE_SPACE,NO_ZERO_DATE,NO_ZERO_IN_DATE';character_set_client=33;collation_connection=33;collation_server=255]
- TYPE = com.continuent.tungsten.replicator.event.ReplDBMSEvent
- OPTIONS = [foreign_key_checks = 1, unique_checks = 1, time_zone = '+00:00', ##charset = UTF-8]
- SQL(0) =
- ACTION = UPDATE
- SCHEMA = tungsten_alpha
- TABLE = heartbeat
- ROW# = 0
 - COL(index=1 name= type=4 [INTEGER] length=8 unsigned=false blob=false desc=) (size = 1) = 1
 - COL(index=2 name= type=0 [NULL] length=0 unsigned=false blob=false desc=) (size = 0) = NULL
 - COL(index=3 name= type=0 [NULL] length=0 unsigned=false blob=false desc=) (size = 0) = NULL
 - COL(index=4 name= type=93 [TIMESTAMP] length=0 unsigned=false blob=false desc=) (size = 21) = 2025-02-21 09:12:04.0
 - COL(index=5 name= type=0 [NULL] length=0 unsigned=false blob=false desc=) (size = 0) = NULL
 - COL(index=6 name= type=0 [NULL] length=0 unsigned=false blob=false desc=) (size = 0) = NULL
 - COL(index=7 name= type=4 [INTEGER] length=8 unsigned=false blob=false desc=) (size = 1) = 0
 - COL(index=8 name= type=12 [VARCHAR] length=0 unsigned=false blob=false desc=) (size = 13) = MASTER_ONLINE
 - KEY(index=1 name= type=4 [INTEGER] length=8 unsigned=false blob=false desc=) (size = 1) = 1

When identifying the different data types, the following effects should be noted:

CHAR and VARCHAR are identified as type 12, VARCHAR
SET is identified as an INTEGER
When the value is either NULL or 0 (Zero), date and time fields are shown as type 0, NULL
ENUM is identified as an OTHER
BLOB and TEXT are identified as type 2004, BLOB

-timezone
Specify the timezone to use when display date or time values. When not specified, times are displayed using UTC.

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8.18.4. thl list Command