The file() driver outputs messages to the specified text file, or to a set of files. The file() destination has the following options:
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Caution:
When creating several thousands separate log files, syslog-ng might not be able to open the required number of files. This might happen for example, when using the ${HOST} macro in the filename while receiving messages from a large number of hosts. To overcome this problem, adjust the --fd-limit command-line parameter of syslog-ng or the global ulimit parameter of your host. For setting the --fd-limit command-line parameter of syslog-ng see the The syslog-ng manual page manual page. For setting the ulimit parameter of the host, see the documentation of your operating system. |
create-dirs()
| Type: | yes or no |
| Default: | no |
Description: Enable creating non-existing directories when creating files or socket files.
dir-group()
| Type: | string |
| Default: | Use the global settings |
Description: The group of the directories created by syslog-ng. To preserve the original properties of an existing directory, use the option without specifying an attribute: dir-group().
dir-owner()
| Type: | string |
| Default: | Use the global settings |
Description: The owner of the directories created by syslog-ng. To preserve the original properties of an existing directory, use the option without specifying an attribute: dir-owner().
Starting with version
dir-perm()
| Type: | number |
| Default: | Use the global settings |
Description: The permission mask of directories created by syslog-ng. Log directories are only created if a file after macro expansion refers to a non-existing directory, and directory creation is enabled (see also the create-dirs() option). For octal numbers prefix the number with 0, for example, use 0755 for rwxr-xr-x.
To preserve the original properties of an existing directory, use the option without specifying an attribute: dir-perm(). Note that when creating a new directory without specifying attributes for dir-perm(), the default permission of the directories is masked with the umask of the parent process (typically 0022).
disk-buffer()
Description: This option enables putting outgoing messages into the disk-buffer file of the destination to avoid message loss in case of a system failure on the destination side. It has the following options:
| disk-buf-size() | |
| Type: | number [bytes] |
| Default: | |
| Description: This is a required option. The maximum size of the disk-buffer file 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 file. 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. | |
| quot-size() | |
| Type: | number [messages] |
| Default: | 1000 |
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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 file already exists, the change will take effect when the disk-buffer file becomes empty. | |
| reliable() | |||
| Type: | yes|no | ||
| Default: | no | ||
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Description: If set to yes, syslog-ng PE cannot lose logs in case of reload/restart, unreachable destination or syslog-ng PE 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 option will be used. This provides a faster, but less reliable disk-buffer option.
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| truncate-size-ratio() | |||
| Type: | number (for percentage) between 0 and 1 | ||
| Default: | 0.1 (10%) | ||
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Description: Limits the truncation of the disk-buffer file. Truncating the disk-buffer file can slow down disk I/O operations, but it saves disk space. As a result, syslog-ng PE only truncates the file if the possible disk gain is more than truncate-size-ratio() times disk-buf-size().
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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")
)
);
};flags()
| Type: | no-multi-line, syslog-protocol, threaded |
| Default: | empty set |
Description: Flags influence the behavior of the destination driver.
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no-multi-line: The no-multi-line flag disables line-breaking in the messages: the entire message is converted to a single line.
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syslog-protocol: The syslog-protocol flag instructs the driver to format the messages according to the new IETF syslog protocol standard (RFC5424), but without the frame header. If this flag is enabled, macros used for the message have effect only for the text of the message, the message header is formatted to the new standard. Note that this flag is not needed for the syslog driver, and that the syslog driver automatically adds the frame header to the messages.
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threaded: The threaded flag enables multithreading for the destination. For details on multithreading, see Multithreading and scaling in syslog-ng PE.
NOTE: The file destination uses multiple threads only if the destination filename contains macros.
flush-lines()
| Type: | number |
| Default: | Use global setting. |
Description: Specifies how many lines are flushed to a destination at a time. The syslog-ng PE 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.
The syslog-ng PE application flushes the messages if it has sent flush-lines() number of messages, or the queue became empty. If you stop or reload syslog-ng PE or in case of network sources, the connection with the client is closed, syslog-ng PE automatically sends the unsent messages to the destination.
For optimal performance when sending messages to a syslog-ng PE server, make sure that the flush-lines() is smaller than the window size set using the log-iw-size() option in the source of your server.
flush-timeout() (DEPRECATED)
| Type: | time in milliseconds |
| Default: | Use global setting. |
Description: This is a deprecated option. Specifies the time syslog-ng waits for lines to accumulate in its output buffer. For details, see the flush-lines() option.
frac-digits()
| Type: | number |
| Default: | 0 |
Description: The syslog-ng PE 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 PE application can add the fractions to non-ISO8601 timestamps as well.
NOTE: As syslog-ng PE is precise up to the microsecond, when the frac-digits() option is set to a value higher than 6, syslog-ng PE will truncate the fraction seconds in the timestamps after 6 digits.
fsync()
| Type: | yes or no |
| Default: | no |
Description: Forces an fsync() call on the destination fd after each write.
NOTE: Enabling this option may seriously degrade performance.
group()
| Type: | string |
| Default: | Use the global settings |
Description: Set the group of the created file to the one specified. To preserve the original properties of an existing file, use the option without specifying an attribute: group().
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 as using the name of the (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.
mark-freq()
| Accepted values: | number [seconds] |
| Default: | 1200 |
Description: An alias for the obsolete mark() option, retained for compatibility with syslog-ng version 1.6.x.
The number of seconds between two MARK messages. MARK messages are generated when there was no message traffic to inform the receiver that the connection is still alive. If set to zero (0), no MARK messages are sent. The mark-freq() can be set for global option and/or every MARK capable destination driver if mark-mode() is periodical or dst-idle or host-idle. If mark-freq() is not defined in the destination, then the mark-freq() will be inherited from the global options. If the destination uses internal mark-mode(), then the global mark-freq() will be valid (does not matter what mark-freq() set in the destination side).
mark-mode()
| Accepted values: | internal | dst-idle | host-idle | periodical | none | global |
| Default: |
internal for pipe, program drivers none for file, unix-dgram, unix-stream drivers global for syslog, tcp, udp destinations host-idle for global option |
Description: The mark-mode() option can be set for the following destination drivers: file(), program(), unix-dgram(), unix-stream(), network(), pipe(), syslog() and in global option.
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internal: When internal mark mode is selected, internal source should be placed in the log path as this mode does not generate mark by itself at the destination. This mode only yields the mark messages from internal source. This is the mode as
file(), pipe(), unix-stream(), unix-dgram(), program()
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dst-idle: Sends MARK signal if there was NO traffic on destination drivers. MARK signal from internal source will be dropped.
MARK signal can be sent by the following destination drivers: network(), syslog(), program(), file(), pipe(), unix-stream(), unix-dgram().
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host-idle: Sends MARK signal if there was NO local message on destination drivers. For example, MARK is generated even if messages were received from tcp. MARK signal from internal source will be dropped.
MARK signal can be sent by the following destination drivers: network(), syslog(), program(), file(), pipe(), unix-stream(), unix-dgram().
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periodical: Sends MARK signal perodically, regardless of traffic on destination driver. MARK signal from internal source will be dropped.
MARK signal can be sent by the following destination drivers: network(), syslog(), program(), file(), pipe(), unix-stream(), unix-dgram().
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none: Destination driver drops all MARK messages. If an explicit mark-mode() is not given to the drivers where none is the default value, then none will be used.
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global: Destination driver uses the global mark-mode() setting. Note that setting the global mark-mode() to global causes a syntax error in syslog-ng PE.
NOTE: In case of dst-idle, host-idle and periodical, the MARK message will not be written in the destination, if it is not open yet.
Available in
overwrite-if-older()
| Type: | number (seconds) |
| Default: | 0 |
Description: If set to a value higher than 0, syslog-ng PE checks when the file was last modified before starting to write into the file. If the file is older than the specified amount of time (in seconds), then syslog-ng removes the existing file and opens a new file with the same name. In combination with for example, the ${WEEKDAY} macro, this can be used for simple log rotation, in case not all history has to be kept. (Note that in this weekly log rotation example if its Monday 00:01, then the file from last Monday is not seven days old, because it was probably last modified shortly before 23:59 last Monday, so it is actually not even six days old. So in this case, set the overwrite-if-older() parameter to a-bit-less-than-six-days, for example, to 518000 seconds.
owner()
| Type: | string |
| Default: | Use the global settings |
Description: Set the owner of the created file to the one specified. To preserve the original properties of an existing file, use the option without specifying an attribute: owner().
pad-size()
| Type: | number |
| Default: | 0 |
Description: If set, syslog-ng PE will pad output messages to the specified size (in bytes). Some operating systems (such as HP-UX) pad all messages to block boundary. This option can be used to specify the block size. (HP-UX uses 2048 bytes).
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Caution:
Hazard of data loss! If the size of the incoming message is larger than the previously set pad-size() value, syslog-ng will truncate the message to the specified size. Therefore, all message content above that size will be lost. |
perm()
| Type: | number |
| Default: | Use the global settings |
Description: The permission mask of the file if it is created by syslog-ng. For octal numbers prefix the number with 0, for example, use 0755 for rwxr-xr-x.
To preserve the original properties of an existing file, use the option without specifying an attribute: perm().
suppress()
| Type: | seconds |
| Default: | 0 (disabled) |
Description: If several identical log messages would be sent to the destination without any other messages between the identical messages (for example, an application repeated an error message ten times), syslog-ng can suppress the repeated messages and send the message only once, followed by the Last message repeated n times. message. The parameter of this option specifies the number of seconds syslog-ng waits for identical messages.
template()
| Type: | string |
| Default: | A format conforming to the default logfile format. |
Description: Specifies a template defining the logformat to be used in the destination. Macros are described in Macros of syslog-ng PE. Please note that for network destinations it might not be appropriate to change the template as it changes the on-wire format of the syslog protocol which might not be tolerated by stock syslog receivers (like syslogd or syslog-ng itself). For network destinations make sure the receiver can cope with the custom format defined.
template-escape()
| Type: | yes or no |
| Default: | no |
Description: Turns on escaping for the ', ", and backspace characters in templated output files. This is useful for generating SQL statements and quoting string contents so that parts of the log message are not interpreted as commands to the SQL server.
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 as using the name of the (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.
ts-format()
| Type: | rfc3164, bsd, rfc3339, iso |
| Default: | rfc3164 |
Description: Override the global timestamp format (set in the global ts-format() parameter) for the specific destination. For details, see ts-format().