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Statistics of AxoSyslog

1: Metrics and counters

2: Log statistics from the internal() source

The AxoSyslog application collects various statistics and measures different metrics about the messages it receives and delivers. These metrics are collected into different counters, depending on the configuration of AxoSyslog. The stats-level() global option determines exactly which statistics AxoSyslog collects. You can access these statistics and metrics using the following methods.

Recommended: Structured, selective methods:

Using the monitoring() source.
Using the syslog-ng-ctl query command. For further information about using syslog-ng-ctl commands, see The syslog-ng control tool manual page.

Legacy: Unstructured, bulk methods

Using the internal() source.
Using the syslog-ng-ctl stats command.

For further information about using syslog-ng-ctl commands, see The syslog-ng control tool manual page.
Use the socat application: echo STATS | socat -vv UNIX-CONNECT:/opt/syslog-ng/var/run/syslog-ng.ctl -
If you have an OpenBSD-style netcat application installed, use the echo STATS | nc -U /opt/syslog-ng/var/run/syslog-ng.ctl command. Note that the netcat included in most Linux distributions is a GNU-style version that is not suitable to query the statistics of syslog-ng.

1 - Metrics and counters

You can list all active metrics on your AxoSyslog host using the following command (this lists the metrics, without their current values): syslog-ng-ctl query list "*"

To list the metrics and their values, use the following command: syslog-ng-ctl query get "*"

The displayed metrics have the following structure.

The type of the object (for example, dst.file, tag, src.facility)

The ID of the object used in the syslog-ng.conf configuration file, for example, d_internal or source.src_tcp. The #0 part means that this is the first destination in the destination group.

The instance ID (destination) of the object, for example, the filename of a file destination, or the name of the application for a program source or destination.

The status of the object. One of the following:

a - active. At the time of querying the statistics, the source or the destination was still alive (it continuously received statistical data).
d - dynamic. Such objects may not be continuously available, for example, like statistics based on the sender’s hostname. These counters only appear above a certain value of stats-level() global option:
- host: source host, from stats-level(2)
- program: program, from stats-level(3)
- sender: sender host, from stats-level(3)
Example: Dynamic counters

The following example contains 6 different dynamic values: a sender, a host, and four different programs.
```
    src.sender;;localhost;d;processed;4
    src.sender;;localhost;d;stamp;1509121934
    src.program;;P-18069;d;processed;1
    src.program;;P-18069;d;stamp;1509121933
    src.program;;P-21491;d;processed;1
    src.program;;P-21491;d;stamp;1509121934
    src.program;;P-9774;d;processed;1
    src.program;;P-9774;d;stamp;1509121919
    src.program;;P-14737;d;processed;1
    src.program;;P-14737;d;stamp;1509121931
    src.host;;localhost;d;processed;4
    src.host;;localhost;d;stamp;1509121934
```
To avoid performance issues or even overloading AxoSyslog, you might want to limit the number of registered dynamic counters in the message statistics. To do this, configure the stats-max-dynamics() global option.
o - This object was once active, but stopped receiving messages. (For example, a dynamic object may disappear and become orphan.)

Note The AxoSyslog application stores the statistics of the objects when AxoSyslog is reloaded. However, if the configuration of AxoSyslog was changed since the last reload, the statistics of orphaned objects are deleted.

The connections statistics counter displays the number of connections tracked by AxoSyslog for the selected source driver.

Example: sample configuration and statistics output

The following configuration will display the following syslog-ng-ctl statistics output:

Configuration:

   source s_network { 
      tcp( 
        port(8001)  
      ); 
    };

Statistics output:

   src.tcp;s_network#0;tcp,127.0.0.5;a;processed;1
    src.tcp;s_network#0;tcp,127.0.0.1;a;processed;3
    src.tcp;s_network;afsocket_sd.(stream,AF_INET(0.0.0.0:8001));a;connections;2

The type of the statistics:

batch_size_avg: When batching is enabled, then this shows the current average batch size of the given source or destination.

batch_size_max: When batching is enabled, the value of batch_size_max shows the current largest batch size of the given source or destination.

discarded: The number of messages discarded by the given parser. These are messages that the parser could not parsed, and are therefore not processed. For example:

   parser;demo_parser;;a;discarded;20

dropped: The number of dropped messages — AxoSyslog could not send the messages to the destination and the output buffer got full, so messages were dropped by the destination driver, or AxoSyslog dropped the message for some other reason (for example, a parsing error).

eps_last_1h: The EPS value of the past 1 hour.

eps_last_24h: The EPS value of the past 24 hours.

eps_since_start: The EPS value since the current AxoSyslog start.

Note

When using the eps_last_1h, the eps_last_24h, and the eps_since_start statistics, consider the following:

EPS stands for “event per second”, and in our case, a message received or sent counts as a single event.
The eps_last_1h, the eps_last_24h, and the eps_since_start values are only approximate values.
The eps_last_1h, the eps_last_24h, and the eps_since_start values are automatically updated every 60 seconds.

matched: The number of messages that are accepted by a given filter. Available for filters and similar objects (for example, a conditional rewrite rule). For example, if a filter matches a specific hostname, then the matched counter contains the number of messages that reached the filter from this hosts.

   filter;demo_filter;;a;matched;28

memory_usage: The memory used by the messages in the different queue types (in bytes). This includes every queue used by the object, including memory buffers (log-fifo) and disk-based buffers (both reliable and non-reliable). For example:

   dst.network;d_net#0;tcp,127.0.0.1:9999;a;memory_usage;0

Note The memory usage (size) of queues is not equal to the memory usage (size) of the log messages in AxoSyslog. A log message can be in multiple queues, thus its size is added to multiple queue sizes. To check the size of all log messages, use global.msg_allocated_bytes.value metric.

msg_size_max: The current largest message size of the given source or destination.

msg_size_avg: The current average message size of the given source or destination.

Note

When using the msg_size_avg and msg_size_max statistics, consider that message sizes are calculated as follows:

on the source side: the length of the incoming raw message
on the destination side: the length of the outgoing formatted message

not_matched: The number of messages that are filtered out by a given filter. Available for filters and similar objects (for example, a conditional rewrite rule). For example, if a filter matches a specific hostname, then the not_matched counter contains the number of messages that reached the filter from other hosts, and so the filter discarded them.

Note

Since the not_matched metric applies to filters, and filters are expected to discard messages that do not match the filter condition, not_matched messages are not included in the dropped metric of other objects.

   filter;demo_filter;;a;not_matched;0

processed: The number of messages that successfully reached their destination driver.

Note Consider that a message that has successfully reached its destination driver does not necessarily mean that the destination driver successfully delivered the messages as well. For example, a message can be written to disk or sent to a remote server after reaching the destination driver.

queued: The number of messages passed to the message queue of the destination driver, waiting to be sent to the destination.

stamp: The UNIX timestamp of the last message sent to the destination.

suppressed: The number of suppressed messages (if the suppress() feature is enabled).

written: The number of messages successfully delivered to the destination. This value is calculated from other counters: written = processed - queued - dropped. That is, the number of messages AxoSyslog passed to the destination driver (processed) minus the number of messages that are still in the output queue of the destination driver (queued) and the number of messages dropped because of an error (dropped, for example, because AxoSyslog could not deliver the message to the destination and exceeded the number of retries).

This metric is calculated from other metrics. You cannot reset this metric directly: to reset it, you have to reset the metrics it is calculated from.

Note

Consider that for AxoSyslog version 3.36, the following statistics counters are only supported for the http() destination, or the http() destination and all network() sources and destinations, and all file() sources and destinations, respectively:

msg_size_max
msg_size_avg
batch_size_max
batch_size_avg
eps_last_1h
eps_last_24h
eps_since_start

The number of such messages.

Availability of statistics

Certain statistics are available only if the stats-level() global option is set to a higher value.

Level 0 collects only statistics about the sources and destinations.
Level 1 contains details about the different connections and log files, but has a slight memory overhead.
Level 2 contains detailed statistics based on the hostname.
Level 3 contains detailed statistics based on various message parameters like facility, severity, or tags.

When receiving messages with non-standard facility values (that is, higher than 23), these messages will be listed as other facility instead of their facility number.

Aggregated statistics

Aggregated statistics are available for different sources and destinations from different levels and upwards:

	`msg_size_avg`	`msg_size_max`	`batch_size_avg`	`batch_size_max`	`eps_last_1h`	`eps_last_1h`	`eps_last_1h`
`network()` source and destination	from level 1	from level 1	counter N/A	counter N/A	from level 1	from level 1	from level 1
`file()` source and destination	from level 1	from level 1	counter N/A	counter N/A	from level 1	from level 1	from level 1
`http()` destination	from level 0	from level 0	from level 0	from level 0	from level 0	from level 0	from level 0

msg_size_avg

msg_size_max

batch_size_avg

batch_size_max

eps_last_1h

network() source and destination

from level 1

counter N/A

from level 1

file() source and destination

from level 1

counter N/A

from level 1

http() destination

from level 0

2 - Log statistics from the internal() source

If the stats-freq() global option is higher than 0, AxoSyslog 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 AxoSyslog 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

Statistics of AxoSyslog

Recommended: Structured, selective methods:

Legacy: Unstructured, bulk methods

1 - Metrics and counters

Example: Dynamic counters

Example: sample configuration and statistics output

Availability of statistics

Aggregated statistics

2 - Log statistics from the internal() source