This driver sends messages into an SQL database. The sql() destination has the following options:
columns()
| Type: |
string list |
| Default: |
"date", "facility", "level", "host", "program", "pid", "message" |
Description: Name of the columns storing the data in fieldname [dbtype] format. The [dbtype] parameter is optional, and specifies the type of the field. By default, syslog-ng OSE creates text columns. Note that not every database engine can index text fields.
|
|
Caution:
The following column types cannot be used in MSSQL destinations: nchar, nvarchar, ntext, and xml. |
create-statement-append()
| Type: |
string |
| Default: |
empty string |
Description: Specifies additional SQL options that are appended to the CREATE statement. That way you can customize what happens when syslog-ng OSE creates a new table in the database. Consult the documentation of your database server for details on the available options. Syntax:
create-statement-append(<options-to-append>)
For example, you can appends the ROW_FORMAT=COMPRESSED option to MySQL create table statements:
create-statement-append(ROW_FORMAT=COMPRESSED)
database()
| Type: |
string |
| Default: |
logs |
Description: Name of the database that stores the logs. Macros cannot be used in database name. Also, when using an Oracle database, you cannot use the same database() settings in more than one destination.
dbd-option()
| Type: |
string |
| Default: |
empty string |
Description: Specify database options that are set whenever syslog-ng OSE connects to the database server. Consult the documentation of your database server for details on the available options. Syntax:
dbd-option(OPTION_NAME VALUE)
OPTION_NAME is always a string, VALUE is a string or a number. For example:
dbd-option("null.sleep.connect" 1)
dbd-option("null.sleep.query" 5)
disk-buffer()
Description: This option enables putting outgoing messages into the disk buffer of the destination to avoid message loss in case of a system failure on the destination side. It has the following options:
| reliable() |
| Type: |
yes|no |
| Default: |
no |
|
Description: If set to yes, syslog-ng OSE cannot lose logs in case of reload/restart, unreachable destination or syslog-ng OSE crash. This solution provides a slower, but reliable disk-buffer option. It is created and initialized at startup and gradually grows as new messages arrive. If set to no, the normal disk-buffer will be used. This provides a faster, but less reliable disk-buffer option.
|
|
Caution:
Hazard of data loss! If you change the value of reliable() option when there are messages in the disk-buffer, the messages stored in the disk-buffer will be lost. | |
| compaction() |
| Type: |
yes|no |
| Default: |
no |
|
Description: If set to yes, syslog-ng OSE prunes the unused space in the LogMessage representation, making the disk queue size smaller at the cost of some CPU time. Setting the compaction() argument to yes is recommended when numerous name-value pairs are unset during processing, or when the same names are set multiple times. |
NOTE: Simply unsetting these name-value pairs by using the unset() rewrite operation is not enough, as due to performance reasons that help when syslog-ng is CPU bound, the internal representation of a LogMessage will not release the memory associated with these name-value pairs. In some cases, however, the size of this overhead becomes significant (the raw message size can grow up to four times its original size), which unnecessarily increases the disk queue file size. For these cases, the compaction will drop "unset" values, making the LogMessage representation smaller at the cost of some CPU time required to perform compaction.
| dir() |
| Type: |
string |
| Default: |
N/A |
|
Description: Defines the folder where the disk-buffer files are stored.
|
|
Caution:
When creating a new dir() option for a disk buffer, or modifying an existing one, make sure you delete the persist file.
syslog-ng OSE creates disk-buffer files based on the path recorded in the persist file. Therefore, if the persist file is not deleted after modifying the dir() option, then following a restart, syslog-ng OSE will look for or create disk-buffer files in their old location. To ensure that syslog-ng OSE uses the new dir() setting, the persist file must not contain any information about the destinations which the disk-buffer file in question belongs to. |
NOTE: If the dir() path provided by the user does not exist, syslog-ng OSE creates the path with the same permission as the running instance. |
| disk-buf-size() |
| Type: |
number (bytes) |
| Default: |
|
| Description: This is a required option. The maximum size of the disk-buffer in bytes. The minimum value is 1048576 bytes. If you set a smaller value, the minimum value will be used automatically. It replaces the old log-disk-fifo-size() option. |
| mem-buf-length() |
| Type: |
number (messages) |
| Default: |
10000 |
| Description: Use this option if the option reliable() is set to no. This option contains the number of messages stored in overflow queue. It replaces the old log-fifo-size() option. It inherits the value of the global log-fifo-size() option if provided. If it is not provided, the default value is 10000 messages. Note that this option will be ignored if the option reliable() is set to yes. |
| mem-buf-size() |
| Type: |
number (bytes) |
| Default: |
163840000 |
| Description: Use this option if the option reliable() is set to yes. This option contains the size of the messages in bytes that is used in the memory part of the disk buffer. It replaces the old log-fifo-size() option. It does not inherit the value of the global log-fifo-size() option, even if it is provided. Note that this option will be ignored if the option reliable() is set to no. |
| qout-size() |
| Type: |
number (messages) |
| Default: |
64 |
| Description: The number of messages stored in the output buffer of the destination. Note that if you change the value of this option and the disk-buffer already exists, the change will take effect when the disk-buffer becomes empty. |
Options reliable() and disk-buf-size() are required options.
Example: Examples for using disk-buffer()
In the following case reliable disk-buffer() is used.
destination d_demo {
network(
"127.0.0.1"
port(3333)
disk-buffer(
mem-buf-size(10000)
disk-buf-size(2000000)
reliable(yes)
dir("/tmp/disk-buffer")
)
);
};
In the following case normal disk-buffer() is used.
destination d_demo {
network(
"127.0.0.1"
port(3333)
disk-buffer(
mem-buf-length(10000)
disk-buf-size(2000000)
reliable(no)
dir("/tmp/disk-buffer")
)
);
};
|
truncate-size-ratio() |
| Type: |
number (between 0 and 1) |
| Default: |
0.1 (10%) |
|
Description: Limits the truncation of the disk-buffer file. Truncating the disk-buffer file can slow down the disk IO operations, but it saves disk space, so syslog-ng only truncates the file, if the possible disk gain is more than truncate-size-ratio() times disk-buf-size().
|
|
Caution:
One Identity does not recommend you to change truncate-size-ratio(). Only change its value if you know the performance implications of doing so. | |
flags()
| Type: |
list of flags |
| Default: |
empty string |
Description: Flags related to the sql() destination.
-
dont-create-tables: Enable this flag to prevent syslog-ng OSE from creating non-existing database tables automatically. The syslog-ng OSE application typically has to create tables if you use macros in the table names. Available in syslog-ng OSE version 3.2 and later.
-
explicit-commits: By default, syslog-ng OSE commits every log message to the target database individually. When the explicit-commits option is enabled, messages are committed in batches. This improves the performance, but results in some latency, as the messages are not immediately sent to the database. The size and frequency of batched commits can be set using the batch-lines() parameter. The explicit-commits option is available in syslog-ng OSE version 3.2 and later.
Example: Setting flags for SQL destinations
The following example sets the dont-create-tables and explicit-commits flags for an sql() destination.
flags(dont-create-tables,explicit-commits)
batch-bytes()
| Accepted values: |
number [bytes] |
| Default: |
none |
Description: Sets the maximum size of payload in a batch. If the size of the messages reaches this value, syslog-ng OSE sends the batch to the destination even if the number of messages is less than the value of the batch-lines() option.
Note that if the batch-timeout() option is enabled and the queue becomes empty, syslog-ng OSE flushes the messages only if batch-timeout() expires, or the batch reaches the limit set in batch-bytes().
Available in syslog-ng OSE version 3.19 and later.
batch-lines()
Description: Specifies how many lines are flushed to a destination in one batch. The syslog-ng OSE application waits for this number of lines to accumulate and sends them off in a single batch. Increasing this number increases throughput as more messages are sent in a single batch, but also increases message latency.
For example, if you set batch-lines() to 100, syslog-ng OSE waits for 100 messages.
If the batch-timeout() option is disabled, the syslog-ng OSE application flushes the messages if it has sent batch-lines() number of messages, or the queue became empty. If you stop or reload syslog-ng OSE or in case of network sources, the connection with the client is closed, syslog-ng OSE automatically sends the unsent messages to the destination.
Note that if the batch-timeout() option is enabled and the queue becomes empty, syslog-ng OSE flushes the messages only if batch-timeout() expires, or the batch reaches the limit set in batch-lines().
For optimal performance, make sure that the syslog-ng OSE source that feeds messages to this destination is configured properly: the value of the log-iw-size() option of the source must be higher than the batch-lines()*workers() of the destination. Otherwise, the size of the batches cannot reach the batch-lines() limit.
batch-timeout()
| Type: |
time in milliseconds |
| Default: |
-1 (disabled) |
Description: Specifies the time syslog-ng OSE waits for lines to accumulate in the output buffer. The syslog-ng OSE application sends batches to the destinations evenly. The timer starts when the first message arrives to the buffer, so if only few messages arrive, syslog-ng OSE sends messages to the destination at most once every batch-timeout() milliseconds.
frac-digits()
Description: The syslog-ng application can store fractions of a second in the timestamps according to the ISO8601 format. The frac-digits() parameter specifies the number of digits stored. The digits storing the fractions are padded by zeros if the original timestamp of the message specifies only seconds. Fractions can always be stored for the time the message was received.
NOTE: The syslog-ng OSE application can add the fractions to non-ISO8601 timestamps as well.
NOTE: As syslog-ng OSE is precise up to the microsecond, when the frac-digits() option is set to a value higher than 6, syslog-ng OSE will truncate the fraction seconds in the timestamps after 6 digits.
hook-commands()
Description: This option makes it possible to execute external programs when the relevant driver is initialized or torn down. The hook-commands() can be used with all source and destination drivers with the exception of the usertty() and internal() drivers.
NOTE: The syslog-ng OSE application must be able to start and restart the external program, and have the necessary permissions to do so. For example, if your host is running AppArmor or SELinux, you might have to modify your AppArmor or SELinux configuration to enable syslog-ng OSE to execute external applications.
Using the hook-commands() when syslog-ng OSE starts or stops
To execute an external program when syslog-ng OSE starts or stops, use the following options:
| startup() |
| Type: |
string |
| Default: |
N/A |
|
Description: Defines the external program that is executed as syslog-ng OSE starts. |
| shutdown() |
| Type: |
string |
| Default: |
N/A |
|
Description: Defines the external program that is executed as syslog-ng OSE stops. |
Using the hook-commands() when syslog-ng OSE reloads
To execute an external program when the syslog-ng OSE configuration is initiated or torn down, for example, on startup/shutdown or during a syslog-ng OSE reload, use the following options:
| setup() |
| Type: |
string |
| Default: |
N/A |
|
Description: Defines an external program that is executed when the syslog-ng OSE configuration is initiated, for example, on startup or during a syslog-ng OSE reload. |
| teardown() |
| Type: |
string |
| Default: |
N/A |
|
Description: Defines an external program that is executed when the syslog-ng OSE configuration is stopped or torn down, for example, on shutdown or during a syslog-ng OSE reload. |
Example: Using the hook-commands() with a network source
In the following example, the hook-commands() is used with the network() driver and it opens an iptables port automatically as syslog-ng OSE is started/stopped.
The assumption in this example is that the LOGCHAIN chain is part of a larger ruleset that routes traffic to it. Whenever the syslog-ng OSE created rule is there, packets can flow, otherwise the port is closed.
source {
network(transport(udp)
hook-commands(
startup("iptables -I LOGCHAIN 1 -p udp --dport 514 -j ACCEPT")
shutdown("iptables -D LOGCHAIN 1")
)
);
};
host()
| Type: |
hostname or IP address |
| Default: |
n/a |
Description: Hostname of the database server. Note that Oracle destinations do not use this parameter, but retrieve the hostname from the /etc/tnsnames.ora file.
NOTE: If you specify host="localhost", syslog-ng will use a socket to connect to the local database server. Use host="127.0.0.1" to force TCP communication between syslog-ng and the local database server.
To specify the socket to use, set and export the MYSQL_UNIX_PORT environment variable, for example, MYSQL_UNIX_PORT=/var/lib/mysql/mysql.sock; export MYSQL_UNIX_PORT.
indexes()
| Type: |
string list |
| Default: |
"date", "facility", "host", "program" |
Description: The list of columns that are indexed by the database to speed up searching. To disable indexing for the destination, include the empty indexes() parameter in the destination, simply omitting the indexes parameter will cause syslog-ng to request indexing on the default columns.
The syslog-ng OSE application will create the name of indexes automaticaly with the following method:
-
In case of MsSQL, PostgreSQL, MySQL or SQLite or (Oracle but tablename < 30 characters): {table}_{column}_idx.
-
In case of Oracle and tablename > 30 characters: md5sum of {table}_{column}-1 and the first character will be replaced by "i" character and the md5sum will be truncated to 30 characters.
local-time-zone()
| Type: |
name of the timezone, or the timezone offset |
| Default: |
The local timezone. |
Description: Sets the timezone used when expanding filename and tablename templates.
The timezone can be specified by using the name, for example, time-zone("Europe/Budapest")), or as the timezone offset in +/-HH:MM format, for example, +01:00). On Linux and UNIX platforms, the valid timezone names are listed under the /usr/share/zoneinfo directory.
log-fifo-size()
| Type: |
number |
| Default: |
Use global setting. |
Description: The number of messages that the output queue can store.
null()
Description: If the content of a column matches the string specified in the null() parameter, the contents of the column will be replaced with an SQL NULL value. If unset (by default), the option does not match on any string. For details, see the Example: Using SQL NULL values.
Example: Using SQL NULL values
The null() parameter of the SQL driver can be used to replace the contents of a column with a special SQL NULL value. To replace every column that contains an empty string with NULL, use the null("") option, for example
destination d_sql {
sql(type(pgsql)
host("logserver") username("syslog-ng") password("password")
database("logs")
table("messages_${HOST}_${R_YEAR}${R_MONTH}${R_DAY}")
columns("datetime", "host", "program", "pid", "message")
values("${R_DATE}", "${HOST}", "${PROGRAM}", "${PID}", "${MSGONLY}")
indexes("datetime", "host", "program", "pid", "message")
null(""));
};
To replace only a specific column (for example, pid) if it is empty, assign a default value to the column, and use this default value in the null() parameter:
destination d_sql {
sql(type(pgsql)
host("logserver") username("syslog-ng") password("password")
database("logs")
table("messages_${HOST}_${R_YEAR}${R_MONTH}${R_DAY}")
columns("datetime", "host", "program", "pid", "message")
values("${R_DATE}", "${HOST}", "${PROGRAM}", "${PID:-@@NULL@@}", "${MSGONLY}")
indexes("datetime", "host", "program", "pid", "message")
null("@@NULL@@"));
};
Ensure that the default value you use does not appear in the actual log messages, because other occurrences of this string will be replaced with NULL as well.
password()
| Type: |
string |
| Default: |
n/a |
Description: Password of the database user.
port()
| Type: |
number |
| Default: |
1433 TCP for MSSQL, 3306 TCP for MySQL, 1521 for Oracle, and 5432 TCP for PostgreSQL |
Description: The port number to connect to.
retries()
| Type: |
number (insertion attempts) |
| Default: |
3 |
Description: The number of insertion attempts. If syslog-ng OSE could not insert a message into the database, it will repeat the attempt until the number of attempts reaches retries, then drops the connection to the database. For example, syslog-ng OSE will try to insert a message maximum three times by default (once for first insertion and twice if the first insertion was failed).
session-statements()
| Type: |
comma-separated list of SQL statements |
| Default: |
empty string |
Description: Specifies one or more SQL-like statement which is executed after syslog-ng OSE has successfully connected to the database. For example:
session-statements("SET COLLATION_CONNECTION='utf8_general_ci'")
|
|
Caution:
The syslog-ng OSE application does not validate or limit the contents of customized queries. Consequently, queries performed with a user with write-access can potentially modify or even harm the database. Use customized queries with care, and only for your own responsibility. |
table()
| Type: |
string |
| Default: |
messages |
Description: Name of the database table to use (can include macros). When using macros, note that some databases limit the length of table names.
time-reopen()
| Accepted values: |
number [seconds] |
| Default: |
60 |
Description: The time to wait in seconds before a dead connection is reestablished.
time-zone()
| Type: |
name of the timezone, or the timezone offset |
| Default: |
unspecified |
Description: Convert timestamps to the timezone specified by this option. If this option is not set, then the original timezone information in the message is used. Converting the timezone changes the values of all date-related macros derived from the timestamp, for example, HOUR. For the complete list of such macros, see Date-related macros.
The timezone can be specified by using the name, for example, time-zone("Europe/Budapest")), or as the timezone offset in +/-HH:MM format, for example, +01:00). On Linux and UNIX platforms, the valid timezone names are listed under the /usr/share/zoneinfo directory.
type()
| Type: |
mssql, mysql, oracle, pgsql, or sqlite3 |
| Default: |
mysql |
Description: Specifies the type of the database, that is, the DBI database driver to use. Use the mssql option to send logs to an MSSQL database. For details, see the examples of the databases on the following sections.
username()
| Type: |
string |
| Default: |
n/a |
Description: Name of the database user.
values()
| Type: |
string list |
| Default: |
"${R_YEAR}-${R_MONTH}-${R_DAY}, ${R_HOUR}:${R_MIN}:${R_SEC}", "${FACILITY}", "${LEVEL}", "${HOST}", "${PROGRAM}", "${PID}", "${MSGONLY}" |
Description: The parts of the message to store in the fields specified in the columns() parameter.
It is possible to give a special value calling: default (without quotation marks).It means that the value will be used that is the default of the column type of this value.
Example: Value: default
columns("date datetime", "host varchar(32)", "row_id serial")
values("${R_DATE}", "${HOST}", default)
