MySQL 9.3 Reference Manual Including MySQL NDB Cluster 9.3
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
, 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.
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(
+---------------------------------------------+ | audit_log_encryption_password_set(password
);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
, and
DELETE
, the changes do not
affect filtering immediately. To flush your changes and
make them operational, call
audit_log_filter_flush()
.
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:
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, or user_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
: A
JSON
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, or user_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 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 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 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
" }
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 9.3, 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 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 8.4.5.6, “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 9.3, 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 the
AUDIT_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 |
|
This option controls how the server loads the
audit_log
plugin at startup. It is
available only if the plugin has been previously
registered with INSTALL
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 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.
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 |
|
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.
Command-Line Format | --audit-log-connection-policy=value |
---|---|
Deprecated | Yes |
System Variable | audit_log_connection_policy |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies |
No |
Type | Enumeration |
Default Value | ALL |
Valid Values |
|
This 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 |
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 8.4.5.5, “Configuring Audit Logging Characteristics”.
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.)
Command-Line Format | --audit-log-database=value |
---|---|
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 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 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 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 Applies |
No |
Type | Enumeration |
Default Value | NONE |
Valid Values |
|
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.
Command-Line Format | --audit-log-exclude-accounts=value |
---|---|
Deprecated | Yes |
System Variable | audit_log_exclude_accounts |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies |
No |
Type | String |
Default Value | NULL |
This 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 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 8.4.5.6, “Reading Audit Log Files”.
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.
System Variable | audit_log_flush |
---|---|
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies |
No |
Type | Boolean |
Default Value | OFF |
The audit_log_flush
variable is deprecated; 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 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 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
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 the
scheduler
component is enabled
(ON
).
Values between 0
and
60
(1 to 59) are not acknowledged;
instead, these values adjust 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.
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 |
|
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 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 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.
Command-Line Format | --audit-log-include-accounts=value |
---|---|
Deprecated | Yes |
System Variable | audit_log_include_accounts |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies |
No |
Type | String |
Default Value | NULL |
This 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 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.
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=# |
---|---|
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.
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.
Command-Line Format | --audit-log-policy=value |
---|---|
Deprecated | Yes |
System Variable | audit_log_policy |
Scope | Global |
Dynamic | No |
SET_VAR Hint Applies |
No |
Type | Enumeration |
Default Value | ALL |
Valid Values |
|
This 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
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 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 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.
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.
Command-Line Format | --audit-log-read-buffer-size=# |
---|---|
System Variable | audit_log_read_buffer_size |
Scope | Global, Session |
Dynamic | Yes |
SET_VAR Hint Applies |
No |
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 of
audit_log_read()
.
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.
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.
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.
Command-Line Format | --audit-log-statement-policy=value |
---|---|
Deprecated | Yes |
System Variable | audit_log_statement_policy |
Scope | Global |
Dynamic | Yes |
SET_VAR Hint Applies |
No |
Type | Enumeration |
Default Value | ALL |
Valid Values |
|
This 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 |
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 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 Applies |
No |
Type | Enumeration |
Default Value | ASYNCHRONOUS |
Valid Values |
|
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.
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 of
Audit_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”.