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Security in MySQL  /  ...  /  Audit Log Reference

6.5.11 Audit Log Reference

The following sections provide a reference to MySQL Enterprise Audit elements:

To install the audit log tables and functions, use the instructions provided in Section 6.5.2, “Installing or Uninstalling MySQL Enterprise Audit”. Unless those objects are installed, the audit_log plugin operates in legacy mode (deprecated in MySQL 8.0.34). See Section 6.5.10, “Legacy Mode Audit Log Filtering”.

Audit Log Tables

MySQL Enterprise Audit uses tables in the mysql system database for persistent storage of filter and user account data. The tables can be accessed only by users who have privileges for that database. To use a different database, set the audit_log_database system variable at server startup. The tables use the InnoDB storage engine.

If these tables are missing, the audit_log plugin operates in (deprecated) legacy mode. See Section 6.5.10, “Legacy Mode Audit Log Filtering”.

The audit_log_filter table stores filter definitions. The table has these columns:

  • NAME

    The filter name.

  • FILTER

    The filter definition associated with the filter name. Definitions are stored as JSON values.

The audit_log_user table stores user account information. The table has these columns:

  • USER

    The user name part of an account. For an account user1@localhost, the USER part is user1.

  • HOST

    The host name part of an account. For an account user1@localhost, the HOST part is localhost.

  • FILTERNAME

    The name of the filter assigned to the account. The filter name associates the account with a filter defined in the audit_log_filter table.

Audit Log Functions

This section describes, for each audit log function, its purpose, calling sequence, and return value. For information about the conditions under which these functions can be invoked, see Section 6.5.7, “Audit Log Filtering”.

Each audit log function returns a string that indicates whether the operation succeeded. OK indicates success. ERROR: message indicates failure.

As of MySQL 8.0.19, audit log functions convert string arguments to utf8mb4 and string return values are utf8mb4 strings. Prior to MySQL 8.0.19, audit log functions treat string arguments as binary strings (which means they do not distinguish lettercase), and string return values are binary strings.

If an audit log function is invoked from within the mysql client, binary string results display using hexadecimal notation, depending on the value of the --binary-as-hex. For more information about that option, see mysql — The MySQL Command-Line Client.

These audit log functions are available:

  • audit_log_encryption_password_get([keyring_id])

    This function fetches an audit log encryption password from the MySQL keyring, which must be enabled or an error occurs. Any keyring component or plugin can be used; for instructions, see Section 6.4, “The MySQL Keyring”.

    With no argument, the function retrieves the current encryption password as a binary string. An argument may be given to specify which audit log encryption password to retrieve. The argument must be the keyring ID of the current password or an archived password.

    For additional information about audit log encryption, see Encrypting Audit Log Files.

    Arguments:

    keyring_id: As of MySQL 8.0.17, this optional argument indicates the keyring ID of the password to retrieve. The maximum permitted length is 766 bytes. If omitted, the function retrieves the current password.

    Prior to MySQL 8.0.17, no argument is permitted. The function always retrieves the current password.

    Return value:

    The password string for success (up to 766 bytes), or NULL and an error for failure.

    Example:

    Retrieve the current password: 

    mysql> SELECT audit_log_encryption_password_get();
+-------------------------------------+
| audit_log_encryption_password_get() |
+-------------------------------------+
| secret                              |
+-------------------------------------+

    To retrieve a password by ID, you can determine which audit log keyring IDs exist by querying the Performance Schema keyring_keys table: 

    mysql> SELECT KEY_ID FROM performance_schema.keyring_keys
       WHERE KEY_ID LIKE 'audit_log%'
       ORDER BY KEY_ID;
+-----------------------------+
| KEY_ID                      |
+-----------------------------+
| audit_log-20190415T152248-1 |
| audit_log-20190415T153507-1 |
| audit_log-20190416T125122-1 |
| audit_log-20190416T141608-1 |
+-----------------------------+
mysql> SELECT audit_log_encryption_password_get('audit_log-20190416T125122-1');
+------------------------------------------------------------------+
| audit_log_encryption_password_get('audit_log-20190416T125122-1') |
+------------------------------------------------------------------+
| segreto                                                          |
+------------------------------------------------------------------+

  • audit_log_encryption_password_set(password)

    Sets the current audit log encryption password to the argument and stores the password in the MySQL keyring. As of MySQL 8.0.19, the password is stored as a utf8mb4 string. Prior to MySQL 8.0.19, the password is stored in binary form.

    If encryption is enabled, this function performs a log file rotation operation that renames the current log file, and begins a new log file encrypted with the password. The keyring must be enabled or an error occurs. Any keyring component or plugin can be used; for instructions, see Section 6.4, “The MySQL Keyring”.

    For additional information about audit log encryption, see Encrypting Audit Log Files.

    Arguments:

    password: The password string. The maximum permitted length is 766 bytes.

    Return value:

    1 for success, 0 for failure.

    Example: 

    mysql> SELECT audit_log_encryption_password_set(password);
+---------------------------------------------+
| audit_log_encryption_password_set(password) |
+---------------------------------------------+
| 1                                           |
+---------------------------------------------+

  • audit_log_filter_flush()

    Calling any of the other filtering functions affects operational audit log filtering immediately and updates the audit log tables. If instead you modify the contents of those tables directly using statements such as INSERT, UPDATE, and DELETE, the changes do not affect filtering immediately. To flush your changes and make them operational, call audit_log_filter_flush().

    Warning

    audit_log_filter_flush() should be used only after modifying the audit tables directly, to force reloading all filters. Otherwise, this function should be avoided. It is, in effect, a simplified version of unloading and reloading the audit_log plugin with UNINSTALL PLUGIN plus INSTALL PLUGIN.

    audit_log_filter_flush() affects all current sessions and detaches them from their previous filters. Current sessions are no longer logged unless they disconnect and reconnect, or execute a change-user operation.

    If this function fails, an error message is returned and the audit log is disabled until the next successful call to audit_log_filter_flush().

    Arguments:

    None.

    Return value:

    A string that indicates whether the operation succeeded. OK indicates success. ERROR: message indicates failure.

    Example: 

    mysql> SELECT audit_log_filter_flush();
+--------------------------+
| audit_log_filter_flush() |
+--------------------------+
| OK                       |
+--------------------------+

  • audit_log_filter_remove_filter(filter_name)

    Given a filter name, removes the filter from the current set of filters. It is not an error for the filter not to exist.

    If a removed filter is assigned to any user accounts, those users stop being filtered (they are removed from the audit_log_user table). Termination of filtering includes any current sessions for those users: They are detached from the filter and no longer logged.

    Arguments:

    • filter_name: A string that specifies the filter name.

    Return value:

    A string that indicates whether the operation succeeded. OK indicates success. ERROR: message indicates failure.

    Example: 

    mysql> SELECT audit_log_filter_remove_filter('SomeFilter');
+----------------------------------------------+
| audit_log_filter_remove_filter('SomeFilter') |
+----------------------------------------------+
| OK                                           |
+----------------------------------------------+

  • audit_log_filter_remove_user(user_name)

    Given a user account name, cause the user to be no longer assigned to a filter. It is not an error if the user has no filter assigned. Filtering of current sessions for the user remains unaffected. New connections for the user are filtered using the default account filter if there is one, and are not logged otherwise.

    If the name is %, the function removes the default account filter that is used for any user account that has no explicitly assigned filter.

    Arguments:

    • user_name: The user account name as a string in user_name@host_name format, or % to represent the default account.

    Return value:

    A string that indicates whether the operation succeeded. OK indicates success. ERROR: message indicates failure.

    Example: 

    mysql> SELECT audit_log_filter_remove_user('user1@localhost');
+-------------------------------------------------+
| audit_log_filter_remove_user('user1@localhost') |
+-------------------------------------------------+
| OK                                              |
+-------------------------------------------------+

  • audit_log_filter_set_filter(filter_name, definition)

    Given a filter name and definition, adds the filter to the current set of filters. If the filter already exists and is used by any current sessions, those sessions are detached from the filter and are no longer logged. This occurs because the new filter definition has a new filter ID that differs from its previous ID.

    Arguments:

    • filter_name: A string that specifies the filter name.

    • definition: A JSON value that specifies the filter definition.

    Return value:

    A string that indicates whether the operation succeeded. OK indicates success. ERROR: message indicates failure.

    Example: 

    mysql> SET @f = '{ "filter": { "log": false } }';
mysql> SELECT audit_log_filter_set_filter('SomeFilter', @f);
+-----------------------------------------------+
| audit_log_filter_set_filter('SomeFilter', @f) |
+-----------------------------------------------+
| OK                                            |
+-----------------------------------------------+

  • audit_log_filter_set_user(user_name, filter_name)

    Given a user account name and a filter name, assigns the filter to the user. A user can be assigned only one filter, so if the user was already assigned a filter, the assignment is replaced. Filtering of current sessions for the user remains unaffected. New connections are filtered using the new filter.

    As a special case, the name % represents the default account. The filter is used for connections from any user account that has no explicitly assigned filter.

    Arguments:

    • user_name: The user account name as a string in user_name@host_name format, or % to represent the default account.

    • filter_name: A string that specifies the filter name.

    Return value:

    A string that indicates whether the operation succeeded. OK indicates success. ERROR: message indicates failure.

    Example: 

    mysql> SELECT audit_log_filter_set_user('user1@localhost', 'SomeFilter');
+------------------------------------------------------------+
| audit_log_filter_set_user('user1@localhost', 'SomeFilter') |
+------------------------------------------------------------+
| OK                                                         |
+------------------------------------------------------------+

  • audit_log_read([arg])

    Reads the audit log and returns a JSON string result. If the audit log format is not JSON, an error occurs.

    With no argument or a JSON hash argument, audit_log_read() reads events from the audit log and returns a JSON string containing an array of audit events. Items in the hash argument influence how reading occurs, as described later. Each element in the returned array is an event represented as a JSON hash, with the exception that the last element may be a JSON null value to indicate no following events are available to read.

    With an argument consisting of a JSON null value, audit_log_read() closes the current read sequence.

    For additional details about the audit log-reading process, see Section 6.5.6, “Reading Audit Log Files”.

    Arguments:

    To obtain a bookmark for the most recently written event, call audit_log_read_bookmark().

    arg: The argument is optional. If omitted, the function reads events from the current position. If present, the argument can be a JSON null value to close the read sequence, or a JSON hash. Within a hash argument, items are optional and control aspects of the read operation such as the position at which to begin reading or how many events to read. The following items are significant (other items are ignored):

    • start: The position within the audit log of the first event to read. The position is given as a timestamp and the read starts from the first event that occurs on or after the timestamp value. The start item has this format, where value is a literal timestamp value: 

      "start": { "timestamp": "value" }

      The start item is permitted as of MySQL 8.0.22.

    • timestamp, id: The position within the audit log of the first event to read. The timestamp and id items together comprise a bookmark that uniquely identify a particular event. If an audit_log_read() argument includes either item, it must include both to completely specify a position or an error occurs.

    • max_array_length: The maximum number of events to read from the log. If this item is omitted, the default is to read to the end of the log or until the read buffer is full, whichever comes first.

    To specify a starting position to audit_log_read(), pass a hash argument that includes either a start item or a bookmark consisting of timestamp and id items. If a hash argument includes both a start item and a bookmark, an error occurs.

    If a hash argument specifies no starting position, reading continues from the current position.

    If a timestamp value includes no time part, a time part of 00:00:00 is assumed.

    Return value:

    If the call succeeds, the return value is a JSON string containing an array of audit events, or a JSON null value if that was passed as the argument to close the read sequence. If the call fails, the return value is NULL and an error occurs.

    Example: 

    mysql> SELECT audit_log_read(audit_log_read_bookmark());
+-----------------------------------------------------------------------+
| audit_log_read(audit_log_read_bookmark())                             |
+-----------------------------------------------------------------------+
| [ {"timestamp":"2020-05-18 22:41:24","id":0,"class":"connection", ... |
+-----------------------------------------------------------------------+
mysql> SELECT audit_log_read('null');
+------------------------+
| audit_log_read('null') |
+------------------------+
| null                   |
+------------------------+

    Notes:

    Prior to MySQL 8.0.19, string return values are binary JSON strings. For information about converting such values to nonbinary strings, see Section 6.5.6, “Reading Audit Log Files”.

  • audit_log_read_bookmark()

    Returns a JSON string representing a bookmark for the most recently written audit log event. If the audit log format is not JSON, an error occurs.

    The bookmark is a JSON hash with timestamp and id items that uniquely identify the position of an event within the audit log. It is suitable for passing to audit_log_read() to indicate to that function the position at which to begin reading.

    For additional details about the audit log-reading process, see Section 6.5.6, “Reading Audit Log Files”.

    Arguments:

    None.

    Return value:

    A JSON string containing a bookmark for success, or NULL and an error for failure.

    Example: 

    mysql> SELECT audit_log_read_bookmark();
+-------------------------------------------------+
| audit_log_read_bookmark()                       |
+-------------------------------------------------+
| { "timestamp": "2019-10-03 21:03:44", "id": 0 } |
+-------------------------------------------------+

    Notes:

    Prior to MySQL 8.0.19, string return values are binary JSON strings. For information about converting such values to nonbinary strings, see Section 6.5.6, “Reading Audit Log Files”.

  • audit_log_rotate()

    Arguments:

    None.

    Return value:

    The renamed file name.

    Example: 

    mysql> SELECT audit_log_rotate();

    Using audit_log_rotate() requires the AUDIT_ADMIN privilege.

Audit Log Option and Variable Reference

Table 6.29 Audit Log Option and Variable Reference

Name Cmd-Line Option File System Var Status Var Var Scope Dynamic
audit-log Yes Yes
audit_log_buffer_size Yes Yes Yes Global No
audit_log_compression Yes Yes Yes Global No
audit_log_connection_policy Yes Yes Yes Global Yes
audit_log_current_session Yes Both No
Audit_log_current_size Yes Global No
audit_log_database Yes Yes Yes Global No
audit_log_disable Yes Yes Yes Global Yes
audit_log_encryption Yes Yes Yes Global No
Audit_log_event_max_drop_size Yes Global No
Audit_log_events Yes Global No
Audit_log_events_filtered Yes Global No
Audit_log_events_lost Yes Global No
Audit_log_events_written Yes Global No
audit_log_exclude_accounts Yes Yes Yes Global Yes
audit_log_file Yes Yes Yes Global No
audit_log_filter_id Yes Both No
audit_log_flush Yes Global Yes
audit_log_flush_interval_seconds Yes Yes Global No
audit_log_format Yes Yes Yes Global No
audit_log_include_accounts Yes Yes Yes Global Yes
audit_log_max_size Yes Yes Yes Global Yes
audit_log_password_history_keep_days Yes Yes Yes Global Yes
audit_log_policy Yes Yes Yes Global No
audit_log_prune_seconds Yes Yes Yes Global Yes
audit_log_read_buffer_size Yes Yes Yes Varies Varies
audit_log_rotate_on_size Yes Yes Yes Global Yes
audit_log_statement_policy Yes Yes Yes Global Yes
audit_log_strategy Yes Yes Yes Global No
Audit_log_total_size Yes Global No
Audit_log_write_waits Yes Global No

Audit Log Options and Variables

This section describes the command options and system variables that configure operation of MySQL Enterprise Audit. If values specified at startup time are incorrect, the audit_log plugin may fail to initialize properly and the server does not load it. In this case, the server may also produce error messages for other audit log settings because it does not recognize them.

To configure activation of the audit log plugin, use this option:

If the audit log plugin is enabled, it exposes several system variables that permit control over logging: 

mysql> SHOW VARIABLES LIKE 'audit_log%';
+--------------------------------------+--------------+
| Variable_name                        | Value        |
+--------------------------------------+--------------+
| audit_log_buffer_size                | 1048576      |
| audit_log_compression                | NONE         |
| audit_log_connection_policy          | ALL          |
| audit_log_current_session            | OFF          |
| audit_log_database                   | mysql        |
| audit_log_disable                    | OFF          |
| audit_log_encryption                 | NONE         |
| audit_log_exclude_accounts           |              |
| audit_log_file                       | audit.log    |
| audit_log_filter_id                  | 0            |
| audit_log_flush                      | OFF          |
| audit_log_flush_interval_seconds     | 0            |
| audit_log_format                     | NEW          |
| audit_log_format_unix_timestamp      | OFF          |
| audit_log_include_accounts           |              |
| audit_log_max_size                   | 0            |
| audit_log_password_history_keep_days | 0            |
| audit_log_policy                     | ALL          |
| audit_log_prune_seconds              | 0            |
| audit_log_read_buffer_size           | 32768        |
| audit_log_rotate_on_size             | 0            |
| audit_log_statement_policy           | ALL          |
| audit_log_strategy                   | ASYNCHRONOUS |
+--------------------------------------+--------------+

You can set any of these variables at server startup, and some of them at runtime. Those that are available only for legacy mode audit log filtering are so noted.

  • audit_log_buffer_size

    Command-Line Format --audit-log-buffer-size=#
    System Variable audit_log_buffer_size
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type Integer
    Default Value 1048576
    Minimum Value 4096
    Maximum Value (64-bit platforms) 18446744073709547520
    Maximum Value (32-bit platforms) 4294967295
    Unit bytes
    Block Size 4096

    When the audit log plugin writes events to the log asynchronously, it uses a buffer to store event contents prior to writing them. This variable controls the size of that buffer, in bytes. The server adjusts the value to a multiple of 4096. The plugin uses a single buffer, which it allocates when it initializes and removes when it terminates. The plugin allocates this buffer only if logging is asynchronous.

  • audit_log_compression

    Command-Line Format --audit-log-compression=value
    System Variable audit_log_compression
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type Enumeration
    Default Value NONE
    Valid Values

    NONE

    GZIP

    The type of compression for the audit log file. Permitted values are NONE (no compression; the default) and GZIP (GNU Zip compression). For more information, see Compressing Audit Log Files.

  • audit_log_connection_policy

    Command-Line Format --audit-log-connection-policy=value
    Deprecated 8.0.34
    System Variable audit_log_connection_policy
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Enumeration
    Default Value ALL
    Valid Values

    ALL

    ERRORS

    NONE
    Note

    This deprecated variable applies only to legacy mode audit log filtering (see Section 6.5.10, “Legacy Mode Audit Log Filtering”).

    The policy controlling how the audit log plugin writes connection events to its log file. The following table shows the permitted values.

    Value Description
    ALL Log all connection events
    ERRORS Log only failed connection events
    NONE Do not log connection events
    Note

    At server startup, any explicit value given for audit_log_connection_policy may be overridden if audit_log_policy is also specified, as described in Section 6.5.5, “Configuring Audit Logging Characteristics”.

  • audit_log_current_session

    System Variable audit_log_current_session
    Scope Global, Session
    Dynamic No
    SET_VAR Hint Applies No
    Type Boolean
    Default Value depends on filtering policy

    Whether audit logging is enabled for the current session. The session value of this variable is read only. It is set when the session begins based on the values of the audit_log_include_accounts and audit_log_exclude_accounts system variables. The audit log plugin uses the session value to determine whether to audit events for the session. (There is a global value, but the plugin does not use it.)

  • audit_log_database

    Command-Line Format --audit-log-database=value
    Introduced 8.0.33
    System Variable audit_log_database
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type String
    Default Value mysql

    Specifies which database the audit_log plugin uses to find its tables. This variable is read only. For more information, see Section 6.5.2, “Installing or Uninstalling MySQL Enterprise Audit”).

  • audit_log_disable

    Command-Line Format --audit-log-disable[={OFF|ON}]
    Introduced 8.0.28
    System Variable audit_log_disable
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Boolean
    Default Value OFF

    Permits disabling audit logging for all connecting and connected sessions. In addition to the SYSTEM_VARIABLES_ADMIN privilege, disabling audit logging requires the AUDIT_ADMIN privilege. See Section 6.5.9, “Disabling Audit Logging”.

  • audit_log_encryption

    Command-Line Format --audit-log-encryption=value
    System Variable audit_log_encryption
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type Enumeration
    Default Value NONE
    Valid Values

    NONE

    AES

    The type of encryption for the audit log file. Permitted values are NONE (no encryption; the default) and AES (AES-256-CBC cipher encryption). For more information, see Encrypting Audit Log Files.

  • audit_log_exclude_accounts

    Command-Line Format --audit-log-exclude-accounts=value
    Deprecated 8.0.34
    System Variable audit_log_exclude_accounts
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type String
    Default Value NULL
    Note

    This deprecated variable applies only to legacy mode audit log filtering (see Section 6.5.10, “Legacy Mode Audit Log Filtering”).

    The accounts for which events should not be logged. The value should be NULL or a string containing a list of one or more comma-separated account names. For more information, see Section 6.5.7, “Audit Log Filtering”.

    Modifications to audit_log_exclude_accounts affect only connections created subsequent to the modification, not existing connections.

  • audit_log_file

    Command-Line Format --audit-log-file=file_name
    System Variable audit_log_file
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type File name
    Default Value audit.log

    The base name and suffix of the file to which the audit log plugin writes events. The default value is audit.log, regardless of logging format. To have the name suffix correspond to the format, set the name explicitly, choosing a different suffix (for example, audit.xml for XML format, audit.json for JSON format).

    If the value of audit_log_file is a relative path name, the plugin interprets it relative to the data directory. If the value is a full path name, the plugin uses the value as is. A full path name may be useful if it is desirable to locate audit files on a separate file system or directory. For security reasons, write the audit log file to a directory accessible only to the MySQL server and to users with a legitimate reason to view the log.

    For details about how the audit log plugin interprets the audit_log_file value and the rules for file renaming that occurs at plugin initialization and termination, see Naming Conventions for Audit Log Files.

    The audit log plugin uses the directory containing the audit log file (determined from the audit_log_file value) as the location to search for readable audit log files. From these log files and the current file, the plugin constructs a list of the ones that are subject to use with the audit log bookmarking and reading functions. See Section 6.5.6, “Reading Audit Log Files”.

  • audit_log_filter_id

    System Variable audit_log_filter_id
    Scope Global, Session
    Dynamic No
    SET_VAR Hint Applies No
    Type Integer
    Default Value 1
    Minimum Value 0
    Maximum Value 4294967295

    The session value of this variable indicates the internally maintained ID of the audit filter for the current session. A value of 0 means that the session has no filter assigned.

  • audit_log_flush

    System Variable audit_log_flush
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Boolean
    Default Value OFF
    Note

    The audit_log_flush variable is deprecated as of MySQL 8.0.31; expect support for it to be removed in a future version of MySQL. It is superseded by the audit_log_rotate() function.

    If audit_log_rotate_on_size is 0, automatic audit log file rotation is disabled and rotation occurs only when performed manually. In that case, enabling audit_log_flush by setting it to 1 or ON causes the audit log plugin to close and reopen its log file to flush it. (The variable value remains OFF so that you need not disable it explicitly before enabling it again to perform another flush.) For more information, see Section 6.5.5, “Configuring Audit Logging Characteristics”.

  • audit_log_flush_interval_seconds

    Command-Line Format --audit-log-flush-interval-seconds[=value]
    Introduced 8.0.34
    System Variable audit_log_flush_interval_seconds
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type Unsigned Long
    Default Value 0
    Maximum Value (Windows) 4294967295
    Maximum Value (Other) 18446744073709551615
    Unit seconds

    This system variable depends on the scheduler component, which must be installed and enabled (see Scheduler Component). To check the status of the component: 

    SHOW VARIABLES LIKE 'component_scheduler%';
+-----------------------------+-------+
| Variable_name               | Value |
+-----------------------------+-------|
| component_scheduler.enabled | On    |
+-----------------------------+-------+

    When audit_log_flush_interval_seconds has a value of zero (the default), no automatic refresh of the privileges occurs, even if the scheduler component is enabled (ON).

    Values of 1 and 59 are not permitted; instead, these values adjusts to 60 automatically and the server emits a warning. Values greater than 60 define the number of seconds the scheduler component waits from startup, or from the beginning of the previous execution, until it attempts to schedule another execution.

    To persist this global system variable to the mysqld-auto.cnf file without setting the global variable runtime value, precede the variable name by the PERSIST_ONLY keyword or the @@PERSIST_ONLY. qualifier.

  • audit_log_format

    Command-Line Format --audit-log-format=value
    System Variable audit_log_format
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type Enumeration
    Default Value NEW
    Valid Values

    OLD

    NEW

    JSON

    The audit log file format. Permitted values are OLD (old-style XML), NEW (new-style XML; the default), and JSON. For details about each format, see Section 6.5.4, “Audit Log File Formats”.

  • audit_log_format_unix_timestamp

    Command-Line Format --audit-log-format-unix-timestamp[={OFF|ON}]
    Introduced 8.0.26
    System Variable audit_log_format_unix_timestamp
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Boolean
    Default Value OFF

    This variable applies only for JSON-format audit log output. When that is true, enabling this variable causes each log file record to include a time field. The field value is an integer that represents the UNIX timestamp value indicating the date and time when the audit event was generated.

    Changing the value of this variable at runtime causes log file rotation so that, for a given JSON-format log file, all records in the file either do or do not include the time field.

    Setting the runtime value of audit_log_format_unix_timestamp requires the AUDIT_ADMIN privilege, in addition to the SYSTEM_VARIABLES_ADMIN privilege (or the deprecated SUPER privilege) normally required to set a global system variable runtime value.

  • audit_log_include_accounts

    Command-Line Format --audit-log-include-accounts=value
    Deprecated 8.0.34
    System Variable audit_log_include_accounts
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type String
    Default Value NULL
    Note

    This deprecated variable applies only to legacy mode audit log filtering (see Section 6.5.10, “Legacy Mode Audit Log Filtering”).

    The accounts for which events should be logged. The value should be NULL or a string containing a list of one or more comma-separated account names. For more information, see Section 6.5.7, “Audit Log Filtering”.

    Modifications to audit_log_include_accounts affect only connections created subsequent to the modification, not existing connections.

  • audit_log_max_size

    Command-Line Format --audit-log-max-size=#
    Introduced 8.0.26
    System Variable audit_log_max_size
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Integer
    Default Value 0
    Minimum Value 0
    Maximum Value (Windows) 4294967295
    Maximum Value (Other) 18446744073709551615
    Unit bytes
    Block Size 4096

    audit_log_max_size pertains to audit log file pruning, which is supported for JSON-format log files only. It controls pruning based on combined log file size:

    • A value of 0 (the default) disables size-based pruning. No size limit is enforced.

    • A value greater than 0 enables size-based pruning. The value is the combined size above which audit log files become subject to pruning.

    If you set audit_log_max_size to a value that is not a multiple of 4096, it is truncated to the nearest multiple. In particular, setting it to a value less than 4096 sets it to 0 and no size-based pruning occurs.

    If both audit_log_max_size and audit_log_rotate_on_size are greater than 0, audit_log_max_size should be more than 7 times the value of audit_log_rotate_on_size. Otherwise, a warning is written to the server error log because in this case the “granularity” of size-based pruning may be insufficient to prevent removal of all or most rotated log files each time it occurs.

    Note

    Setting audit_log_max_size by itself is not sufficient to cause log file pruning to occur because the pruning algorithm uses audit_log_rotate_on_size, audit_log_max_size, and audit_log_prune_seconds in conjunction. For details, see Space Management of Audit Log Files.

  • audit_log_password_history_keep_days

    Command-Line Format --audit-log-password-history-keep-days=#
    Introduced 8.0.17
    System Variable audit_log_password_history_keep_days
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Integer
    Default Value 0
    Minimum Value 0
    Maximum Value 4294967295
    Unit days

    The audit log plugin implements log file encryption using encryption passwords stored in the MySQL keyring (see Encrypting Audit Log Files). The plugin also implements password history, which includes password archiving and expiration (removal).

    When the audit log plugin creates a new encryption password, it archives the previous password, if one exists, for later use. The audit_log_password_history_keep_days variable controls automatic removal of expired archived passwords. Its value indicates the number of days after which archived audit log encryption passwords are removed. The default of 0 disables password expiration: the password retention period is forever.

    New audit log encryption passwords are created under these circumstances:

    • During plugin initialization, if the plugin finds that log file encryption is enabled, it checks whether the keyring contains an audit log encryption password. If not, the plugin automatically generates a random initial encryption password.

    • When the audit_log_encryption_password_set() function is called to set a specific password.

    In each case, the plugin stores the new password in the key ring and uses it to encrypt new log files.

    Removal of expired audit log encryption passwords occurs under these circumstances:

    • During plugin initialization.

    • When the audit_log_encryption_password_set() function is called.

    • When the runtime value of audit_log_password_history_keep_days is changed from its current value to a value greater than 0. Runtime value changes occur for SET statements that use the GLOBAL or PERSIST keyword, but not the PERSIST_ONLY keyword. PERSIST_ONLY writes the variable setting to mysqld-auto.cnf, but has no effect on the runtime value.

    When password removal occurs, the current value of audit_log_password_history_keep_days determines which passwords to remove:

    • If the value is 0, the plugin removes no passwords.

    • If the value is N > 0, the plugin removes passwords more than N days old.

    Note

    Take care not to expire old passwords that are still needed to read archived encrypted log files.

    If you normally leave password expiration disabled (that is, audit_log_password_history_keep_days has a value of 0), it is possible to perform an on-demand cleanup operation by temporarily assigning the variable a value greater than zero. For example, to expire passwords older than 365 days, do this: 

    SET GLOBAL audit_log_password_history_keep_days = 365;
SET GLOBAL audit_log_password_history_keep_days = 0;

    Setting the runtime value of audit_log_password_history_keep_days requires the AUDIT_ADMIN privilege, in addition to the SYSTEM_VARIABLES_ADMIN privilege (or the deprecated SUPER privilege) normally required to set a global system variable runtime value.

  • audit_log_policy

    Command-Line Format --audit-log-policy=value
    Deprecated 8.0.34
    System Variable audit_log_policy
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type Enumeration
    Default Value ALL
    Valid Values

    ALL

    LOGINS

    QUERIES

    NONE
    Note

    This deprecated variable applies only to legacy mode audit log filtering (see Section 6.5.10, “Legacy Mode Audit Log Filtering”).

    The policy controlling how the audit log plugin writes events to its log file. The following table shows the permitted values.

    Value Description
    ALL Log all events
    LOGINS Log only login events
    QUERIES Log only query events
    NONE Log nothing (disable the audit stream)

    audit_log_policy can be set only at server startup. At runtime, it is a read-only variable. Two other system variables, audit_log_connection_policy and audit_log_statement_policy, provide finer control over logging policy and can be set either at startup or at runtime. If you use audit_log_policy at startup instead of the other two variables, the server uses its value to set those variables. For more information about the policy variables and their interaction, see Section 6.5.5, “Configuring Audit Logging Characteristics”.

  • audit_log_prune_seconds

    Command-Line Format --audit-log-prune-seconds=#
    Introduced 8.0.24
    System Variable audit_log_prune_seconds
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Integer
    Default Value 0
    Minimum Value 0
    Maximum Value (Windows) 4294967295
    Maximum Value (Other) 18446744073709551615
    Unit bytes

    audit_log_prune_seconds pertains to audit log file pruning, which is supported for JSON-format log files only. It controls pruning based on log file age:

    • A value of 0 (the default) disables age-based pruning. No age limit is enforced.

    • A value greater than 0 enables age-based pruning. The value is the number of seconds after which audit log files become subject to pruning.

    Note

    Setting audit_log_prune_seconds by itself is not sufficient to cause log file pruning to occur because the pruning algorithm uses audit_log_rotate_on_size, audit_log_max_size, and audit_log_prune_seconds in conjunction. For details, see Space Management of Audit Log Files.

  • audit_log_read_buffer_size

    Command-Line Format --audit-log-read-buffer-size=#
    System Variable audit_log_read_buffer_size
    Scope (≥ 8.0.12) Global, Session
    Scope (8.0.11) Global
    Dynamic (≥ 8.0.12) Yes
    Dynamic (8.0.11) No
    SET_VAR Hint Applies No
    Type Integer
    Default Value (≥ 8.0.12) 32768
    Default Value (8.0.11) 1048576
    Minimum Value (≥ 8.0.12) 32768
    Minimum Value (8.0.11) 1024
    Maximum Value 4194304
    Unit bytes

    The buffer size for reading from the audit log file, in bytes. The audit_log_read() function reads no more than this many bytes. Log file reading is supported only for JSON log format. For more information, see Section 6.5.6, “Reading Audit Log Files”.

    As of MySQL 8.0.12, this variable has a default of 32KB and can be set at runtime. Each client should set its session value of audit_log_read_buffer_size appropriately for its use of audit_log_read(). Prior to MySQL 8.0.12, audit_log_read_buffer_size has a default of 1MB, affects all clients, and can be changed only at server startup.

  • audit_log_rotate_on_size

    Command-Line Format --audit-log-rotate-on-size=#
    System Variable audit_log_rotate_on_size
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Integer
    Default Value 0
    Minimum Value 0
    Maximum Value 18446744073709551615
    Unit bytes
    Block Size 4096

    If audit_log_rotate_on_size is 0, the audit log plugin does not perform automatic size-based log file rotation. If rotation is to occur, you must perform it manually; see Manual Audit Log File Rotation (Before MySQL 8.0.31).

    If audit_log_rotate_on_size is greater than 0, automatic size-based log file rotation occurs. Whenever a write to the log file causes its size to exceed the audit_log_rotate_on_size value, the audit log plugin renames the current log file and opens a new current log file using the original name.

    If you set audit_log_rotate_on_size to a value that is not a multiple of 4096, it is truncated to the nearest multiple. In particular, setting it to a value less than 4096 sets it to 0 and no rotation occurs, except manually.

    Note

    audit_log_rotate_on_size controls whether audit log file rotation occurs. It can also be used in conjunction with audit_log_max_size and audit_log_prune_seconds to configure pruning of rotated JSON-format log files. For details, see Space Management of Audit Log Files.

  • audit_log_statement_policy

    Command-Line Format --audit-log-statement-policy=value
    Deprecated 8.0.34
    System Variable audit_log_statement_policy
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Enumeration
    Default Value ALL
    Valid Values

    ALL

    ERRORS

    NONE
    Note

    This deprecated variable applies only to legacy mode audit log filtering (see Section 6.5.10, “Legacy Mode Audit Log Filtering”).

    The policy controlling how the audit log plugin writes statement events to its log file. The following table shows the permitted values.

    Value Description
    ALL Log all statement events
    ERRORS Log only failed statement events
    NONE Do not log statement events
    Note

    At server startup, any explicit value given for audit_log_statement_policy may be overridden if audit_log_policy is also specified, as described in Section 6.5.5, “Configuring Audit Logging Characteristics”.

  • audit_log_strategy

    Command-Line Format --audit-log-strategy=value
    System Variable audit_log_strategy
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type Enumeration
    Default Value ASYNCHRONOUS
    Valid Values

    ASYNCHRONOUS

    PERFORMANCE

    SEMISYNCHRONOUS

    SYNCHRONOUS

    The logging method used by the audit log plugin. These strategy values are permitted:

    • ASYNCHRONOUS: Log asynchronously. Wait for space in the output buffer.

    • PERFORMANCE: Log asynchronously. Drop requests for which there is insufficient space in the output buffer.

    • SEMISYNCHRONOUS: Log synchronously. Permit caching by the operating system.

    • SYNCHRONOUS: Log synchronously. Call sync() after each request.

Audit Log Status Variables

If the audit log plugin is enabled, it exposes several status variables that provide operational information. These variables are available for legacy mode audit filtering (deprecated in MySQL 8.0.34) and JSON mode audit filtering.


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