Starting with version
The batch-lines(), batch-lines(), and batch-timeout() options of the destination determine how many log messages syslog-ng PE sends in a batch. The batch-lines() option determines the maximum number of messages syslog-ng PE puts in a batch in. This can be limited based on size and time:
syslog-ng PE sends a batch every batch-timeout() seconds, even if the number of messages in the batch is less than batch-lines(). That way the destination receives every message in a timely manner even if suddenly there are no more messages.
syslog-ng PE sends the batch if the total size of the messages in the batch reaches batch-bytes() bytes.
To increase the performance of the destination, increase the number of worker threads for the destination using the workers() option, or adjust the batch-bytes(), batch-lines(), batch-timeout() options.
By default, syslog-ng PE separates the log messages of the batch with a newline character. You can specify a different delimiter by using the delimiter() option.
If the target application or server requires a special beginning or ending to recognize batches, use the body-prefix() and body-suffix() options to add a beginning and ending to the batch. For example, you can use these options to create JSON-encoded arrays as POST payloads, which is required by a number of REST APIs. The body of a batch HTTP request looks like this:
value of body-prefix() option log-line-1 (as formatted in the body() option) log-line-2 (as formatted in the body() option) .... log-line-n (the number of log lines is batch-lines(), or less if batch-timeout() has elapsed or the batch would be longer than batch-bytes()) value of body-suffix() option
The following destination sends log messages to an Elasticsearch server using the bulk API. A batch consists of 100 messages, or a maximum of 512 kilobytes, and is sent every 10 seconds (10000 milliseconds).
destination d_http { http(url("http://your-elasticsearch-server/_bulk") method("POST") batch-lines(100) batch-bytes(512Kb) batch-timeout(10000) headers("Content-Type: application/x-ndjson") body-suffix("\n") body('{ "index":{} } $(format-json --scope rfc5424 --key ISODATE)') ); };
Starting with version
|
Caution:
If you set multiple URLs in the url() option, set the persist-name() option as well to avoid data loss. |
The following destination sends log messages to an Elasticsearch server using the bulk API, to 3 different ingest nodes. Each node is assigned a separate worker thread. A batch consists of 100 messages, or a maximum of 512 kilobytes, and is sent every 10 seconds (10000 milliseconds).
destination d_http { http(url("http://your-elasticsearch-server/_bulk" "http://your-second-ingest-node/_bulk" "http://your-third-ingest-node/_bulk") method("POST") batch-lines(100) batch-bytes(512Kb) batch-timeout(10000) workers(3) headers("Content-Type: application/x-ndjson") body-suffix("\n") body('{ "index":{} } $(format-json --scope rfc5424 --key ISODATE)') persist-name("d_http-load-balance") ); };
If you are using load-balancing (that is, you have configured multiple servers in the url() option), increase the number of worker threads at least to the number of servers. For example, if you have set three URLs, set the workers() option to 3 or more.
The http destination of syslog-ng PE can directly post log messages to web services using the HTTP protocol. The http destination has the following options.
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 PE 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 PE flushes the messages only if batch-timeout() expires, or the batch reaches the limit set in batch-bytes().
Available in syslog-ng PE version
For details on how this option influences HTTP batch mode, see http: Posting messages over HTTP
Type: | number |
Default: | 1 |
Description: Specifies how many lines are flushed to a destination in one batch. 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.
For example, if you set batch-lines() to 100, syslog-ng PE waits for 100 messages.
If the batch-timeout() option is disabled, the syslog-ng PE 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 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.
Note that if the batch-timeout() option is enabled and the queue becomes empty, syslog-ng PE 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 PE 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.
For details on how this option influences HTTP batch mode, see http: Posting messages over HTTP
Type: | time in milliseconds |
Default: | 0 (disabled) |
Description: Specifies the time syslog-ng PE waits for lines to accumulate in the output buffer. The syslog-ng PE 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 PE sends messages to the destination at most once every batch-timeout() seconds.
For details on how this option influences HTTP batch mode, see http: Posting messages over HTTP
Type: | string or template |
Default: |
Description: The body of the HTTP request, for example, body("${ISODATE} ${MESSAGE}"). You can use strings, macros, and template functions in the body. If not set, it will contain the message received from the source by default.
Accepted values: | string |
Default: | none |
Description: The string syslog-ng PE puts at the beginning of the body of the HTTP request, before the log message. Available in syslog-ng PE version
For details on how this option influences HTTP batch mode, see http: Posting messages over HTTP
Accepted values: | string |
Default: | none |
Description: The string syslog-ng PE puts to the end of the body of the HTTP request, after the log message. Available in syslog-ng PE version
For details on how this option influences HTTP batch mode, see http: Posting messages over HTTP
Accepted values: | Directory name |
Default: | none |
Description: Name of a directory, that contains a set of trusted CA certificates in PEM format. The CA certificate files have to be named after the 32-bit hash of the subject's name. This naming can be created using the c_rehash utility in openssl. For an example, see Configuring TLS on the syslog-ng clients. The syslog-ng PE application uses the CA certificates in this directory to validate the certificate of the peer.
An alternative way to specify this option is to put it into a tls() block, together with any other TLS options. This allows you to separate these options and ensure better readability.
Make sure that you specify TLS options either using their own dedicated option (ca-dir(), ca-file(), cert-file(), cipher-suite(), key-file(), peer-verify(), and ssl-version()), or using the tls() block and inserting the relevant options within tls(). Avoid mixing the two methods. In case you do specify TLS options in both ways, the one that comes later in the configuration file will take effect.
destination d_http { http( url("http://127.0.0.1:8080") tls( ca-dir("dir") ca-file("ca") cert-file("cert") cipher-suite("cipher") key-file("key") peer-verify(yes|no) ssl-version(<the permitted SSL/TLS version>) ) ); };
Accepted values: | Filename |
Default: | none |
Description: Name of a file that contains an X.509 CA certificate (or a certificate chain) in PEM format. The syslog-ng PE application uses this certificate to validate the certificate of the HTTPS server. If the file contains a certificate chain, the file must begin with the certificate of the host, followed by the CA certificate that signed the certificate of the host, and any other signing CAs in order.
An alternative way to specify this option is to put it into a tls() block, together with any other TLS options. This allows you to separate these options and ensure better readability.
Make sure that you specify TLS options either using their own dedicated option (ca-dir(), ca-file(), cert-file(), cipher-suite(), key-file(), peer-verify(), and ssl-version()), or using the tls() block and inserting the relevant options within tls(). Avoid mixing the two methods. In case you do specify TLS options in both ways, the one that comes later in the configuration file will take effect.
destination d_http { http( url("http://127.0.0.1:8080") tls( ca-dir("dir") ca-file("ca") cert-file("cert") cipher-suite("cipher") key-file("key") peer-verify(yes|no) ssl-version(<the permitted SSL/TLS version>) ) ); };
Accepted values: | Filename |
Default: | none |
Description: Name of a file, that contains an X.509 certificate (or a certificate chain) in PEM format, suitable as a TLS certificate, matching the private key set in the key-file() option. The syslog-ng PE application uses this certificate to authenticate the syslog-ng PE client on the destination server. If the file contains a certificate chain, the file must begin with the certificate of the host, followed by the CA certificate that signed the certificate of the host, and any other signing CAs in order.
An alternative way to specify this option is to put it into a tls() block, together with any other TLS options. This allows you to separate these options and ensure better readability.
Make sure that you specify TLS options either using their own dedicated option (ca-dir(), ca-file(), cert-file(), cipher-suite(), key-file(), peer-verify(), and ssl-version()), or using the tls() block and inserting the relevant options within tls(). Avoid mixing the two methods. In case you do specify TLS options in both ways, the one that comes later in the configuration file will take effect.
destination d_http { http( url("http://127.0.0.1:8080") tls( ca-dir("dir") ca-file("ca") cert-file("cert") cipher-suite("cipher") key-file("key") peer-verify(yes|no) ssl-version(<the permitted SSL/TLS version>) ) ); };
Accepted values: | Name of a cipher, or a colon-separated list |
Default: | Depends on the OpenSSL version that syslog-ng PE uses |
Description: Specifies the cipher, hash, and key-exchange algorithms used for the encryption, for example, ECDHE-ECDSA-AES256-SHA384. The list of available algorithms depends on the version of OpenSSL used to compile syslog-ng PE. To specify multiple ciphers, separate the cipher names with a colon, and enclose the list between double-quotes, for example:
cipher-suite("ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384")
An alternative way to specify this option is to put it into a tls() block, together with any other TLS options. This allows you to separate these options and ensure better readability.
Make sure that you specify TLS options either using their own dedicated option (ca-dir(), ca-file(), cert-file(), cipher-suite(), key-file(), peer-verify(), and ssl-version()), or using the tls() block and inserting the relevant options within tls(). Avoid mixing the two methods. In case you do specify TLS options in both ways, the one that comes later in the configuration file will take effect.
destination d_http { http( url("http://127.0.0.1:8080") tls( ca-dir("dir") ca-file("ca") cert-file("cert") cipher-suite("cipher") key-file("key") peer-verify(yes|no) ssl-version(<the permitted SSL/TLS version>) ) ); };
Accepted values: | string |
Default: | newline character |
Description: By default, syslog-ng PE separates the log messages of the batch with a newline character. You can specify a different delimiter by using the delimiter() option. Available in syslog-ng PE version
For details on how this option influences HTTP batch mode, see http: Posting messages over HTTP
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 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 will be used. This provides a faster, but less reliable disk-buffer option.
|
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.
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") ) ); };
Type: | string list |
Default: |
Description: Custom HTTP headers to include in the request, for example, headers("HEADER1: header1", "HEADER2: header2"). If not set, only the default headers are included, but no custom headers.
The following headers are included by default:
X-Syslog-Host: <host>
X-Syslog-Program: <program>
X-Syslog-Facility: <facility>
X-Syslog-Level: <loglevel/priority>
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 PE 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 PE to execute external applications. |
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. |
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. |
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") ) ); };
Type: | number |
Default: | Use global setting. |
Description: The number of messages that the output queue can store.
Accepted values: | Filename |
Default: | none |
Description: Path and name of a file that contains a private key in PEM format, suitable as a TLS key. If properly configured, the syslog-ng PE application uses this private key and the matching certificate (set in the cert-file() option) to authenticate the syslog-ng PE client on the destination server.
The http() destination supports only unencrypted key files (that is, the private key cannot be password-protected).
An alternative way to specify this option is to put it into a tls() block, together with any other TLS options. This allows you to separate these options and ensure better readability.
Make sure that you specify TLS options either using their own dedicated option (ca-dir(), ca-file(), cert-file(), cipher-suite(), key-file(), peer-verify(), and ssl-version()), or using the tls() block and inserting the relevant options within tls(). Avoid mixing the two methods. In case you do specify TLS options in both ways, the one that comes later in the configuration file will take effect.
destination d_http { http( url("http://127.0.0.1:8080") tls( ca-dir("dir") ca-file("ca") cert-file("cert") cipher-suite("cipher") key-file("key") peer-verify(yes|no) ssl-version(<the permitted SSL/TLS version>) ) ); };
Type: | POST | PUT |
Default: | POST |
Description: Specifies the HTTP method to use when sending the message to the server.
Type: | string |
Default: |
Description: The password that syslog-ng PE uses to authenticate on the server where it sends the messages.
Accepted values: | yes | no |
Default: | yes |
Description: Verification method of the peer. The following table summarizes the possible options and their results depending on the certificate of the peer.
The remote peer has: | ||||
---|---|---|---|---|
no certificate | invalid certificate | valid certificate | ||
Local peer-verify() setting | no (optional-untrusted) | TLS-encryption | TLS-encryption | TLS-encryption |
yes (required-trusted) | rejected connection | rejected connection | TLS-encryption |
For untrusted certificates only the existence of the certificate is checked, but it does not have to be valid — syslog-ng accepts the certificate even if it is expired, signed by an unknown CA, or its CN and the name of the machine mismatches.
|
Caution:
When validating a certificate, the entire certificate chain must be valid, including the CA certificate. If any certificate of the chain is invalid, syslog-ng PE will reject the connection. |
Type: | string |
Default: |
Description:If you receive the following error message during syslog-ng PE startup, set the persist-name() option of the duplicate drivers:
Error checking the uniqueness of the persist names, please override it with persist-name option. Shutting down.
This error happens if you use identical drivers in multiple sources, for example, if you configure two file sources to read from the same file. In this case, set the persist-name() of the drivers to a custom string, for example, persist-name("example-persist-name1").
Type: | number (of attempts) |
Default: | 3 |
Description: The number of times syslog-ng PE attempts to send a message to this destination. If syslog-ng PE could not send a message, it will try again until the number of attempts reaches retries, then drops the message.
To handle HTTP error responses, if the HTTP server returns 5xx codes, syslog-ng PE will attempt to resend messages until the number of attempts reaches retries. If the HTTP server returns 4xx codes, syslog-ng PE will drop the messages.
Type: | string |
Default: | None, uses the libcurl default |
Description: Specifies the permitted SSL/TLS version. Possible values: sslv2, sslv3, tlsv1, tlsv1_0, tlsv1_1, tlsv1_2.
An alternative way to specify this option is to put it into a tls() block, together with any other TLS options. This allows you to separate these options and ensure better readability.
Make sure that you specify TLS options either using their own dedicated option (ca-dir(), ca-file(), cert-file(), cipher-suite(), key-file(), peer-verify(), and ssl-version()), or using the tls() block and inserting the relevant options within tls(). Avoid mixing the two methods. In case you do specify TLS options in both ways, the one that comes later in the configuration file will take effect.
destination d_http { http( url("http://127.0.0.1:8080") tls( ca-dir("dir") ca-file("ca") cert-file("cert") cipher-suite("cipher") key-file("key") peer-verify(yes|no) ssl-version(<the permitted SSL/TLS version>) ) ); };
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.
Type: | number |
Default: | 0 |
Description: Sets the maximum number of messages sent to the destination per second. Use this output-rate-limiting functionality only when using disk-buffer as well to avoid the risk of losing messages. Specifying 0 or a lower value sets the output limit to unlimited.
Type: | number [seconds] |
Default: | 0 |
Description: The value (in seconds) to wait for an operation to complete, and attempt to reconnect the server if exceeded. By default, the timeout value is 0, meaning that there is no timeout. Available in version
Type: | URL or list of URLs |
Default: | http://localhost/ |
Description: Specifies the hostname or IP address and optionally the port number of the web service that can receive log data via HTTP. Use a colon (:) after the address to specify the port number of the server. For example: http://127.0.0.1:8000
In case the server on the specified URL returns a redirect request, syslog-ng PE automatically follows maximum 3 redirects. Only HTTP and HTTPS based redirections are supported.
Starting with version
|
Caution:
If you set multiple URLs in the url() option, set the persist-name() option as well to avoid data loss. |
Type: | string |
Default: | syslog-ng [version]/libcurl[version] |
Description: The value of the USER-AGENT header in the messages sent to the server.
Type: | string |
Default: |
Description: The username that syslog-ng PE uses to authenticate on the server where it sends the messages.
Type: | yes | no |
Default: | no |
Description: Use the certificate store of the system for verifying HTTPS certificates. For details, see the curl documentation.
Type: | integer |
Default: | 1 |
Description: Specifies the number of worker threads (at least 1) that syslog-ng PE uses to send messages to the server. Increasing the number of worker threads can drastically improve the performance of the destination.
|
Caution:
Hazard of data loss. When you use more than one worker threads together with disk-based buffering, syslog-ng PE creates a separate disk buffer for each worker thread. This means that decreasing the number of workers can result in losing data currently stored in the disk buffer files. Do not decrease the number of workers when the disk buffer files are in use. |
If you are using load-balancing (that is, you have configured multiple servers in the url() option), increase the number of worker threads at least to the number of servers. For example, if you have set three URLs, set the workers() option to 3 or more.
Starting with version
|
NOTE:
In order to use this destination, syslog-ng Premium Edition must run in server mode. Typically, only the central syslog-ng Premium Edition server uses this destination. For details on the server mode, see Server mode. |
This destination is only supported on the Linux platforms that use the linux glibc2.11 installer, including: Debian 7 (wheezy), Red Hat ES 7, Ubuntu 12.04 (Precise Pangolin), Ubuntu 14.04 (Trusty Tahr).
Since syslog-ng PE uses the official Java Kafka producer, the kafka destination has significant memory usage.
The log messages of the underlying client libraries are available in the internal() source of syslog-ng PE.
@module mod-java @include "scl.conf" kafka( client-lib-dir("/opt/syslog-ng/lib/syslog-ng/java-modules/:<path-to-preinstalled-kafka-libraries>") kafka-bootstrap-servers("1.2.3.4:9092,192.168.0.2:9092") topic("${HOST}") );
The following example defines a kafka destination, using only the required parameters.
@module mod-java @include "scl.conf" destination d_kafka { kafka( client-lib-dir(/opt/syslog-ng/lib/syslog-ng/java-modules/KafkaDestination.jar:/usr/share/kafka/lib/) kafka-bootstrap-servers("1.2.3.4:9092,192.168.0.2:9092") topic("${HOST}") ); };
To install the software required for the kafka destination, see Prerequisites.
For details on how the kafka destination works, see How syslog-ng PE interacts with Apache Kafka.
For the list of options, see Kafka destination options.
|
NOTE:
If you delete all Java destinations from your configuration and reload syslog-ng, the JVM is not used anymore, but it is still running. If you want to stop JVM, stop syslog-ng and then start syslog-ng again. |
The following describes how to publish messages from syslog-ng PE to Apache Kafka.
To publish messages from syslog-ng PE to Apache Kafka
If you want to use the Java-based modules of syslog-ng PE (for example, the Elasticsearch, HDFS, or Kafka destinations), download and install the Java Runtime Environment (JRE), 1.7 (or newer).
Download the latest stable binary release of the Apache Kafka libraries (version 0.9 or newer) from http://kafka.apache.org/downloads.html.
Extract the Apache Kafka libraries into a single directory. If needed, collect the various .jar files into a single directory (for example, /opt/kafka/lib/) where syslog-ng PE can access them. You must specify this directory in the syslog-ng PE configuration file.
Check if the following files in the Kafka libraries have the same version number: slf4j-api-<version-number>.jar, slf4j-log4j12-<version-number>.jar. If the version number of these files is different, complete the following steps:
Delete one of the files (for example, slf4j-log4j12-<version-number>.jar).
Download a version that matches the version number of the other file (for example, 1.7.6) from the official SLF4J distribution.
Copy the downloaded file into the directory of your Kafka library files (for example, /opt/kafka/lib/).
© 2023 One Identity LLC. ALL RIGHTS RESERVED. Feedback Terms of Use Privacy