syslog-ng Premium Edition 7.0.14 - Administration Guide

If the stats-freq() global option is higher than 0, syslog-ng PE periodically sends a log statistics message. This message contains statistics about the received messages, and about any lost messages since the last such message. It includes a processed entry for every source and destination, listing the number of messages received or sent, and a dropped entry including the IP address of the server for every destination where syslog-ng has lost messages. The center(received) entry shows the total number of messages received from every configured sources.

The following is a sample log statistics message for a configuration that has a single source (s_local) and a network and a local file destination (d_network and d_local, respectively). All incoming messages are sent to both destinations.

Log statistics;
        dropped='tcp(AF_INET(192.168.10.1:514))=6439',
        processed='center(received)=234413',
        processed='destination(d_tcp)=234413',
        processed='destination(d_local)=234413',
        processed='source(s_local)=234413'

The statistics include a list of source groups and destinations, as well as the number of processed messages for each. You can control the verbosity of the statistics using the stats-level() global option. The following is an example output.

src.internal;s_all#0;;a;processed;6445
src.internal;s_all#0;;a;stamp;1268989330
destination;df_auth;;a;processed;404
destination;df_news_dot_notice;;a;processed;0
destination;df_news_dot_err;;a;processed;0
destination;d_ssb;;a;processed;7128
destination;df_uucp;;a;processed;0
source;s_all;;a;processed;7128
destination;df_mail;;a;processed;0
destination;df_user;;a;processed;1
destination;df_daemon;;a;processed;1
destination;df_debug;;a;processed;15
destination;df_messages;;a;processed;54
destination;dp_xconsole;;a;processed;671
dst.tcp;d_network#0;10.50.0.111:514;a;dropped;5080
dst.tcp;d_network#0;10.50.0.111:514;a;processed;7128
dst.tcp;d_network#0;10.50.0.111:514;a;queued;2048
destination;df_syslog;;a;processed;6724
destination;df_facility_dot_warn;;a;processed;0
destination;df_news_dot_crit;;a;processed;0
destination;df_lpr;;a;processed;0
destination;du_all;;a;processed;0
destination;df_facility_dot_info;;a;processed;0
center;;received;a;processed;0
destination;df_kern;;a;processed;70
center;;queued;a;processed;0
destination;df_facility_dot_err;;a;processed;0

The statistics are semicolon separated: every line contains statistics for a particular object (for example source, destination, tag, and so on). The statistics have the following fields:

To reset the statistics to zero, use the following command: syslog-ng-ctl stats --reset

The monitoring() source

Monitoring statistics and metrics of syslog-ng > The monitoring() source

The monitoring() source allows you to select which statistics of syslog-ng PE you want to monitor. In addition, the statistics are available as structured name-value pairs, so you can format the output similarly to other log messages. That way, you can easily convert the statistics and metrics, for example, into JSON or WELF format. That way, you can send the statistics of your log messages into a monitoring solution.

The monitoring() source queries the statistics (counters) that syslog-ng PE collects, formats them, and optionally resets the counters. The monitoring() source emits only these messages, making it easy to route them to their appropriate destination. The stats-level() global option determines exactly which statistics syslog-ng PE collects.

Declaration

source s_monitor{
    monitoring(
        query("*")
    );};

Example: Save all statistics into a file in JSON format

The following configuration increases the stats-level() option to 3, and generates a JSON-formatted message every 10 seconds. The generated message contains every available statistics, and is saved into the /var/log/syslog-ng-statistics.log file.

@version: 7.0
options{
    stats-level(3);
    keep-hostname(no);
};
source s_monitor{ monitoring(
    query("*")
    freq(10)
    message-template('$(format-json --scope nv_pairs)')
    );};
destination d_file {
    file("/var/log/syslog-ng-statistics.log");
};
log {
    source(s_monitor);
    destination(d_file);
};

The generated message is similar to this one:

[2017-04-03T14:00:31.786133] Outgoing message; message='Apr  3 14:00:31 example-hostname syslog-ng[12281]: {"src":{"severity":{"7":{"processed":"0"},"6":{"processed":"0"},"5":{"processed":"0"},"4":{"processed":"0"},"3":{"processed":"0"},"2":{"processed":"0"},"1":{"processed":"0"},"0":{"processed":"0"}},"monitoring":{"s_monitor#0":{"stamp":"0","processed":"0"}},"facility":{"other":{"processed":"0"},"9":{"processed":"0"},"8":{"processed":"0"},"7":{"processed":"0"},"6":{"processed":"0"},"5":{"processed":"0"},"4":{"processed":"0"},"3":{"processed":"0"},"23":{"processed":"0"},"22":{"processed":"0"},"21":{"processed":"0"},"20":{"processed":"0"},"2":{"processed":"0"},"19":{"processed":"0"},"18":{"processed":"0"},"17":{"processed":"0"},"16":{"processed":"0"},"15":{"processed":"0"},"14":{"processed":"0"},"13":{"processed":"0"},"12":{"processed":"0"},"11":{"processed":"0"},"10":{"processed":"0"},"1":{"processed":"0"},"0":{"processed":"0"}}},"source":{"s_monitor":{"processed":"0"}},"global":{"sdata_updates":{"processed":"0"},"payload_reallocs":{"processed":"2"},"msg_clones":{"processed":"0"}},"destination":{"d_file":{"processed":"0"}},"center":{"received":{"processed":"0"},"queued":{"processed":"0"}},"PROGRAM":"syslog-ng","PID":"12281"}\x0a'

For reference, the JSON part in a readable format is:

{
  "center" : {
      "queued" : { "processed" : "0" },
      "received" : { "processed" : "0" }
    },
  "destination" : { "d_file" : { "processed" : "0" } },
  "global" : {
      "msg_clones" : { "processed" : "0" },
      "payload_reallocs" : { "processed" : "2" },
      "sdata_updates" : { "processed" : "0" }
    },
  "PID" : "12281",
  "PROGRAM" : "syslog-ng",
  "source" : { "s_monitor" : { "processed" : "0" } },
  "src" : {
      "facility" : {
          "0" : { "processed" : "0" },
          "1" : { "processed" : "0" },
          "2" : { "processed" : "0" },
          "3" : { "processed" : "0" },
          "4" : { "processed" : "0" },
          "5" : { "processed" : "0" },
          "6" : { "processed" : "0" },
          "7" : { "processed" : "0" },
          "8" : { "processed" : "0" },
          "9" : { "processed" : "0" },
          "10" : { "processed" : "0" },
          "11" : { "processed" : "0" },
          "12" : { "processed" : "0" },
          "13" : { "processed" : "0" },
          "14" : { "processed" : "0" },
          "15" : { "processed" : "0" },
          "16" : { "processed" : "0" },
          "17" : { "processed" : "0" },
          "18" : { "processed" : "0" },
          "19" : { "processed" : "0" },
          "20" : { "processed" : "0" },
          "21" : { "processed" : "0" },
          "22" : { "processed" : "0" },
          "23" : { "processed" : "0" },
          "other" : { "processed" : "0" }
        },
      "monitoring" : { "s_monitor#0" : {
              "processed" : "0",
              "stamp" : "0"
            } },
      "severity" : {
          "0" : { "processed" : "0" },
          "1" : { "processed" : "0" },
          "2" : { "processed" : "0" },
          "3" : { "processed" : "0" },
          "4" : { "processed" : "0" },
          "5" : { "processed" : "0" },
          "6" : { "processed" : "0" },
          "7" : { "processed" : "0" }
        }
    }
}

monitoring() source options

Monitoring statistics and metrics of syslog-ng > The monitoring() source > monitoring() source options

The monitoring() driver has the following options. Only the query() option is required, other options are optional.

clear-on-read()

Type:	boolean
Default:	no

Description: Reset the counters after reading. Note that if a destination is not available, syslog-ng PE will not reset its counter even if clear-on-read() is set to yes.

If you use multiple monitoring source, and you use the clear-on-read() parameter, make sure to adjust the queries appropriately. Overlapping queries that read and reset the same counters result in incorrect statistics.

freq()

Type:	integer
Default:	600 [seconds]

Description: Specifies how often does syslog-ng PE execute the query and send a statistics message.

message-template()

Type:	string
Default:	N/A

Description: Specifies how the message containing the queried statistics is formatted. You can use macros and template functions in the format string. For example, you can format the message as a JSON object:

source s_monitor{ monitoring(
    query("*")
    freq(10)
    message-template('$(format-json --scope nv_pairs)')
    );};

Note that here you can only format the payload of the message (that is the, ${MESSAGE} part). You can format the headers or other parts of the outgoing message in the destination driver.

query()

Type:	string
Default:	N/A

Description: Specifies which statistical counters will be included in the messages. Note that the list of available counters depends on your syslog-ng PE configuration (mainly the configured sources and destinations) and on the stats-level() global option. The * string includes every available counters. The syntax of the query option is identical to the syslog-ng-ctl query get <query> command.

source s_monitor{ monitoring(
    query("*")
    );};

For example, the "destination*" query lists the configured destinations, and the metrics related to each destination. An example output:

destination.java.d_elastic#0.java_dst(ElasticSearch,elasticsearch-syslog-ng-test,t7cde889529c034aea9ec_micek).stats.dropped: 0
destination.java.d_elastic#0.java_dst(ElasticSearch,elasticsearch-syslog-ng-test,t7cde889529c034aea9ec_micek).stats.processed: 0
destination.java.d_elastic#0.java_dst(ElasticSearch,elasticsearch-syslog-ng-test,t7cde889529c034aea9ec_micek).stats.stored: 0
destination.d_elastic.stats.processed: 0

The monitoring-welf() source

Monitoring statistics and metrics of syslog-ng > The monitoring() source > The monitoring-welf() source

This source is actually preconfigured monitoring() source that generates statistics messages in WELF format. Starting with syslog-ng PE version 7.0.2, syslog-ng PE uses this driver for new installations to generate statistics. By default, a message is sent every 10 minutes (600 seconds).

@version: 7.0
@include 'scl.conf'
options {
    stats_level(3);
};
source s_monitoring_welf {
    monitoring-welf(freq(10) query('*'));
};
destination d_file {
    file("/tmp/output.txt");
};
log {
    source(s_monitoring_welf);
    destination(d_file);
};

The output is similar to the following:

Apr 3 14:03:26 example-host syslog-ng[12363]: PID=12363 PROGRAM=syslog-ng center.queued.processed=0 center.received.processed=0 destination.d_file.processed=0 global.msg_clones.processed=0 global.payload_reallocs.processed=2 global.sdata_updates.processed=0 source.s_monitoring_welf.processed=0 src.facility.0.processed=0 src.facility.1.processed=0 src.facility.10.processed=0 src.facility.11.processed=0 src.facility.12.processed=0 src.facility.13.processed=0 src.facility.14.processed=0 src.facility.15.processed=0 src.facility.16.processed=0 src.facility.17.processed=0 src.facility.18.processed=0 src.facility.19.processed=0 src.facility.2.processed=0 src.facility.20.processed=0 src.facility.21.processed=0 src.facility.22.processed=0 src.facility.23.processed=0 src.facility.3.processed=0 src.facility.4.processed=0 src.facility.5.processed=0 src.facility.6.processed=0 src.facility.7.processed=0 src.facility.8.processed=0 src.facility.9.processed=0 src.facility.other.processed=0 src.monitoring.s_monitoring_welf#0.processed=0 src.monitoring.s_monitoring_welf#0.stamp=0 src.severity.0.processed=0 src.severity.1.processed=0 src.severity.2.processed=0 src.severity.3.processed=0 src.severity.4.processed=0 src.severity.5.processed=0 src.severity.6.processed=0 src.severity.7.processed=0\x0a'