log_tool

Commit logs (clogs) in OceanBase Database are similar to redo logs in a conventional database. They persist the transaction data when transactions are committed. The transaction data is the record of transaction modifications to the database. log_tool parses and prints clog files. This topic describes how to use log_tool.

log_tool is equivalent to clog_tool in earlier versions and is updated for adaptation in OceanBase Database V4.x. Specifically, some command formats are modified and some features are deleted.

log_tool commands

Currently, log_tool is integrated into ob_admin. You can run the ob_admin command to call log_tool.

The following table describes the general commands of log_tool.

dump_log

ob_admin log_tool dump_log <clog_file_name>

Take note of the following considerations:

• You can run the dump_log command to parse and print the specified clog files and archive files. If you want to parse multiple files, separate the file names with spaces.

• You must replace the clog_file_name string with the actual file name. The path of the file can be included in clog_file_name. Here are some examples:

  • To parse and print a single clog file that is named 101 and located in the current directory, run the following command:

    ob_admin log_tool dump_log 101
    

  • To parse and print multiple clog files that are named 101 and 103 and located in the current directory, run the following command:

    ob_admin log_tool dump_log 101 103
    

  • To parse and print multiple clog files that are consecutively named 101, 102, 103, and 104 and located in the current directory, run the following command:

    ob_admin log_tool dump_log {101..104}
    

dump_filter

ob_admin log_tool dump_filter '<filter_name>' <clog_file_name>

Take note of the following considerations:

• You can use dump_filter to print the transaction-related content in clog files based on conditions.

• For more information about <clog_file_name>, see dump_log.

• You can filter log records by specifying filter conditions in the filter_name field. The following table describes the valid values of filter_name.

  Value	Description
  tablet_id	The ID of a data table.
  tx_id	The ID of a transaction.

  You can specify one or more filter conditions in the filter_name field. If you specify multiple filter conditions, separate the conditions with semicolons (;). Here are some examples:

  • Assume that tablet_id is set to 123, and the clog file is named 101 and located in the current directory. Run the following command to parse and print this clog file:

    ob_admin log_tool dump_filter 'tablet_id=123' 101
    

  • Assume that tablet_id is set to 123, tx_id is set to 26058724, and the clog file to be parsed is named 101 and located in the current directory. Run the following command to parse and print this clog file:

    ob_admin log_tool dump_filter 'tablet_id=123;tx_id=26058724' 101
    

stat

ob_admin log_tool stat <clog_file_name>

Take note of the following considerations:

• You can use the stat command to obtain statistics of the specified clog file, including the file size, number of records, and number of transactions.

  Note

  By using the CLOG_TOOL_BREAK_ON_FAIL environment variable, clog_tool can control whether to directly exit or ignore errors and continue. When CLOG_TOOL_BREAK_ON_FAIL is set to true, clog_tool directly exits. When CLOG_TOOL_BREAK_ON_FAIL is set to false, clog_tool ignores errors and continues parsing the specified clog file.

• For more information about <clog_file_name>, see dump_log.