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 8.4.5.2, “Installing or Uninstalling MySQL Enterprise Audit”. Unless those objects
are installed, the audit_log
plugin operates
in (deprecated) legacy mode. See
Section 8.4.5.10, “Legacy Mode Audit Log Filtering”.
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 8.4.5.10, “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
, theUSER
part isuser1
.HOST
The host name part of an account. For an account
user1@localhost
, theHOST
part islocalhost
.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.
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 8.4.5.7, “Audit Log Filtering”.
Each audit log function returns a string that indicates
whether the operation succeeded. OK
indicates success. ERROR:
indicates
failure.
message
Audit log functions convert string arguments to
utf8mb4
and string return values are
utf8mb4
strings. Previously, audit log
functions treated string arguments as binary strings (which
means they did not distinguish lettercase), and string return
values were 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 Section 6.5.1, “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 8.4.4, “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
: 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.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. The password is stored as a
utf8mb4
string. Previously, the password was 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 8.4.4, “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 | +---------------------------------------------+
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
, andDELETE
, the changes do not affect filtering immediately. To flush your changes and make them operational, callaudit_log_filter_flush()
.Warningaudit_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 theaudit_log
plugin withUNINSTALL PLUGIN
plusINSTALL 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:
indicates failure.message
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:
indicates failure.message
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
format, oruser_name
@host_name
%
to represent the default account.
Return value:
A string that indicates whether the operation succeeded.
OK
indicates success.ERROR:
indicates failure.message
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
: AJSON
value that specifies the filter definition.
Return value:
A string that indicates whether the operation succeeded.
OK
indicates success.ERROR:
indicates failure.message
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
format, oruser_name
@host_name
%
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:
indicates failure.message
Example:
mysql> SELECT audit_log_filter_set_user('user1@localhost', 'SomeFilter'); +------------------------------------------------------------+ | audit_log_filter_set_user('user1@localhost', 'SomeFilter') | +------------------------------------------------------------+ | OK | +------------------------------------------------------------+
Reads the audit log and returns a
JSON
string result. If the audit log format is notJSON
, an error occurs.With no argument or a
JSON
hash argument,audit_log_read()
reads events from the audit log and returns aJSON
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 aJSON
hash, with the exception that the last element may be aJSON
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 8.4.5.6, “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 aJSON
null
value to close the read sequence, or aJSON
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. Thestart
item has this format, wherevalue
is a literal timestamp value:"start": { "timestamp": "value" }
timestamp
,id
: The position within the audit log of the first event to read. Thetimestamp
andid
items together comprise a bookmark that uniquely identify a particular event. If anaudit_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 astart
item or a bookmark consisting oftimestamp
andid
items. If a hash argument includes both astart
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 aJSON
null
value if that was passed as the argument to close the read sequence. If the call fails, the return value isNULL
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 9.1, string return values could be binary
JSON
strings. For information about converting such values to nonbinary strings, see Section 8.4.5.6, “Reading Audit Log Files”.Returns a
JSON
string representing a bookmark for the most recently written audit log event. If the audit log format is notJSON
, an error occurs.The bookmark is a
JSON
hash withtimestamp
andid
items that uniquely identify the position of an event within the audit log. It is suitable for passing toaudit_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 8.4.5.6, “Reading Audit Log Files”.
Arguments:
None.
Return value:
A
JSON
string containing a bookmark for success, orNULL
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 9.1, string return values could be binary
JSON
strings. For information about converting such values to nonbinary strings, see Section 8.4.5.6, “Reading Audit Log Files”.Arguments:
None.
Return value:
The renamed file name.
Example:
mysql> SELECT audit_log_rotate();
Using
audit_log_rotate()
requires theAUDIT_ADMIN
privilege.
Table 8.44 Audit Log Option and Variable Reference
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:
-
Command-Line Format --audit-log[=value]
Type Enumeration Default Value ON
Valid Values ON
OFF
FORCE
FORCE_PLUS_PERMANENT
This option controls how the server loads the
audit_log
plugin at startup. It is available only if the plugin has been previously registered withINSTALL PLUGIN
or is loaded with--plugin-load
or--plugin-load-add
. See Section 8.4.5.2, “Installing or Uninstalling MySQL Enterprise Audit”.The option value should be one of those available for plugin-loading options, as described in Section 7.6.1, “Installing and Uninstalling Plugins”. For example,
--audit-log=FORCE_PLUS_PERMANENT
tells the server to load the plugin and prevent it from being removed while the server is running.
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.
-
Command-Line Format --audit-log-buffer-size=#
System Variable audit_log_buffer_size
Scope Global Dynamic No SET_VAR
Hint AppliesNo 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.
-
Command-Line Format --audit-log-compression=value
System Variable audit_log_compression
Scope Global Dynamic No SET_VAR
Hint AppliesNo 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) andGZIP
(GNU Zip compression). For more information, see Compressing Audit Log Files. -
Command-Line Format --audit-log-connection-policy=value
Deprecated Yes System Variable audit_log_connection_policy
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo Type Enumeration Default Value ALL
Valid Values ALL
ERRORS
NONE
NoteThis deprecated variable applies only to legacy mode audit log filtering (see Section 8.4.5.10, “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 NoteAt server startup, any explicit value given for
audit_log_connection_policy
may be overridden ifaudit_log_policy
is also specified, as described in Section 8.4.5.5, “Configuring Audit Logging Characteristics”. -
System Variable audit_log_current_session
Scope Global, Session Dynamic No SET_VAR
Hint AppliesNo 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
andaudit_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.) -
Command-Line Format --audit-log-database=value
System Variable audit_log_database
Scope Global Dynamic No SET_VAR
Hint AppliesNo 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 8.4.5.2, “Installing or Uninstalling MySQL Enterprise Audit”). -
Command-Line Format --audit-log-disable[={OFF|ON}]
System Variable audit_log_disable
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo 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 theAUDIT_ADMIN
privilege. See Section 8.4.5.9, “Disabling Audit Logging”. -
Command-Line Format --audit-log-encryption=value
System Variable audit_log_encryption
Scope Global Dynamic No SET_VAR
Hint AppliesNo 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) andAES
(AES-256-CBC cipher encryption). For more information, see Encrypting Audit Log Files. -
Command-Line Format --audit-log-exclude-accounts=value
Deprecated Yes System Variable audit_log_exclude_accounts
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo Type String Default Value NULL
NoteThis deprecated variable applies only to legacy mode audit log filtering (see Section 8.4.5.10, “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 8.4.5.7, “Audit Log Filtering”.Modifications to
audit_log_exclude_accounts
affect only connections created subsequent to the modification, not existing connections. -
Command-Line Format --audit-log-file=file_name
System Variable audit_log_file
Scope Global Dynamic No SET_VAR
Hint AppliesNo 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 8.4.5.6, “Reading Audit Log Files”. -
System Variable audit_log_filter_id
Scope Global, Session Dynamic No SET_VAR
Hint AppliesNo 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.
-
System Variable audit_log_flush
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo Type Boolean Default Value OFF
NoteThe
audit_log_flush
variable is deprecated; expect support for it to be removed in a future version of MySQL. It is superseded by theaudit_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, enablingaudit_log_flush
by setting it to 1 orON
causes the audit log plugin to close and reopen its log file to flush it. (The variable value remainsOFF
so that you need not disable it explicitly before enabling it again to perform another flush.) For more information, see Section 8.4.5.5, “Configuring Audit Logging Characteristics”. audit_log_flush_interval_seconds
Command-Line Format --audit-log-flush-interval-seconds[=value]
System Variable audit_log_flush_interval_seconds
Scope Global Dynamic No SET_VAR
Hint AppliesNo 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 Section 7.5.5, “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 thescheduler
component is enabled (ON
).Values between
0
and60
(1 to 59) are not acknowledged; instead, these values adjust to60
automatically and the server emits a warning. Values greater than60
define the number of seconds thescheduler
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 thePERSIST_ONLY
keyword or the@@PERSIST_ONLY.
qualifier.-
Command-Line Format --audit-log-format=value
System Variable audit_log_format
Scope Global Dynamic No SET_VAR
Hint AppliesNo 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), andJSON
. For details about each format, see Section 8.4.5.4, “Audit Log File Formats”. audit_log_format_unix_timestamp
Command-Line Format --audit-log-format-unix-timestamp[={OFF|ON}]
System Variable audit_log_format_unix_timestamp
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo 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 theAUDIT_ADMIN
privilege, in addition to theSYSTEM_VARIABLES_ADMIN
privilege (or the deprecatedSUPER
privilege) normally required to set a global system variable runtime value.-
Command-Line Format --audit-log-include-accounts=value
Deprecated Yes System Variable audit_log_include_accounts
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo Type String Default Value NULL
NoteThis deprecated variable applies only to legacy mode audit log filtering (see Section 8.4.5.10, “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 8.4.5.7, “Audit Log Filtering”.Modifications to
audit_log_include_accounts
affect only connections created subsequent to the modification, not existing connections. -
Command-Line Format --audit-log-max-size=#
System Variable audit_log_max_size
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo 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
andaudit_log_rotate_on_size
are greater than 0,audit_log_max_size
should be more than 7 times the value ofaudit_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.NoteSetting
audit_log_max_size
by itself is not sufficient to cause log file pruning to occur because the pruning algorithm usesaudit_log_rotate_on_size
,audit_log_max_size
, andaudit_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=#
System Variable audit_log_password_history_keep_days
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo 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 forSET
statements that use theGLOBAL
orPERSIST
keyword, but not thePERSIST_ONLY
keyword.PERSIST_ONLY
writes the variable setting tomysqld-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 thanN
days old.
NoteTake 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 theAUDIT_ADMIN
privilege, in addition to theSYSTEM_VARIABLES_ADMIN
privilege (or the deprecatedSUPER
privilege) normally required to set a global system variable runtime value.-
Command-Line Format --audit-log-policy=value
Deprecated Yes System Variable audit_log_policy
Scope Global Dynamic No SET_VAR
Hint AppliesNo Type Enumeration Default Value ALL
Valid Values ALL
LOGINS
QUERIES
NONE
NoteThis deprecated variable applies only to legacy mode audit log filtering (see Section 8.4.5.10, “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
andaudit_log_statement_policy
, provide finer control over logging policy and can be set either at startup or at runtime. If you useaudit_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 8.4.5.5, “Configuring Audit Logging Characteristics”. -
Command-Line Format --audit-log-prune-seconds=#
System Variable audit_log_prune_seconds
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo 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.
NoteSetting
audit_log_prune_seconds
by itself is not sufficient to cause log file pruning to occur because the pruning algorithm usesaudit_log_rotate_on_size
,audit_log_max_size
, andaudit_log_prune_seconds
in conjunction. For details, see Space Management of Audit Log Files. -
Command-Line Format --audit-log-read-buffer-size=#
System Variable audit_log_read_buffer_size
Scope Global, Session Dynamic Yes SET_VAR
Hint AppliesNo Type Integer Default Value 32768
Minimum Value 32768
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 8.4.5.6, “Reading Audit Log Files”.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 ofaudit_log_read()
. -
Command-Line Format --audit-log-rotate-on-size=#
System Variable audit_log_rotate_on_size
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo 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.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 theaudit_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.Noteaudit_log_rotate_on_size
controls whether audit log file rotation occurs. It can also be used in conjunction withaudit_log_max_size
andaudit_log_prune_seconds
to configure pruning of rotated JSON-format log files. For details, see Space Management of Audit Log Files. -
Command-Line Format --audit-log-statement-policy=value
Deprecated Yes System Variable audit_log_statement_policy
Scope Global Dynamic Yes SET_VAR
Hint AppliesNo Type Enumeration Default Value ALL
Valid Values ALL
ERRORS
NONE
NoteThis deprecated variable applies only to legacy mode audit log filtering (see Section 8.4.5.10, “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 NoteAt server startup, any explicit value given for
audit_log_statement_policy
may be overridden ifaudit_log_policy
is also specified, as described in Section 8.4.5.5, “Configuring Audit Logging Characteristics”. -
Command-Line Format --audit-log-strategy=value
System Variable audit_log_strategy
Scope Global Dynamic No SET_VAR
Hint AppliesNo 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. Callsync()
after each request.
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) and JSON mode audit filtering.
The size of the current audit log file. The value increases when an event is written to the log and is reset to 0 when the log is rotated.
When the audit log plugin writes events to the JSON-format audit log, it uses a buffer to store event contents prior to writing them. If the query length is greater than the size of the buffer, then the plugin writes the event directly to the log, bypassing the buffer. This variable shows the number of direct writes. The plugin determines the count based on the current write strategy in use (see
audit_log_strategy
).Table 8.45 Write-Strategy Effect on the Direct Write Count
Write Strategy Description ASYNCHRONOUS
Incremented if the event size does not fit into the internal buffer ( audit_log_buffer_size
server system variable).PERFORMANCE
Not incremented. The plugin discards events larger than internal buffer. SEMISYNCHRONOUS
Always incremented. SYNCHRONOUS
Always incremented. The size of the largest dropped event in performance logging mode. For a description of logging modes, see Section 8.4.5.5, “Configuring Audit Logging Characteristics”.
The number of events handled by the audit log plugin, whether or not they were written to the log based on filtering policy (see Section 8.4.5.5, “Configuring Audit Logging Characteristics”).
The number of events handled by the audit log plugin that were filtered (not written to the log) based on filtering policy (see Section 8.4.5.5, “Configuring Audit Logging Characteristics”).
The number of events lost in performance logging mode because an event was larger than the available audit log buffer space. This value may be useful for assessing how to set
audit_log_buffer_size
to size the buffer for performance mode. For a description of logging modes, see Section 8.4.5.5, “Configuring Audit Logging Characteristics”.The number of events written to the audit log.
The total size of events written to all audit log files. Unlike
Audit_log_current_size
, the value ofAudit_log_total_size
increases even when the log is rotated.The number of times an event had to wait for space in the audit log buffer in asynchronous logging mode. For a description of logging modes, see Section 8.4.5.5, “Configuring Audit Logging Characteristics”.