Scenario is to receive all incoming messages and store all of those messages in /app/syslog-ng/custom/output/all_devices.log, but forward only certain messages(by filtering).

filter tag is used to filter incoming messages to Syslog-NG, which is not the right usage, in this scenario. For example: filter f_warn { level(warn); };


My current configuration is:

@version: 3.17

source s_network {

destination d_all_logs {


log {

After storing all messages in all_devices.log, Does Syslog-NG provide syntax(configuration) to forward only certain messages(after filtering) to remote log server?


You can combine multiple directives in your configuration file.

As an example, based on your code, you define a filter:

filter f_warn { level(warn); };

then a destination:

destination remote_log_server {
 udp("" port(25214));

and put them all together with something like:

log { source(src); filter(f_warn); destination(remote_log_server); };

Obviously, you have to configure your source, filter and destination based on your needs.

I suggest you take a good read at the official manual, as there are lots of options to customize your logging.

  • Perhaps also take a look at rsyslog as an alternative to syslog-ng – wurtel Sep 6 '18 at 19:53
  • Does filter tag not stop rest of incoming messages to syslog-ng? Because we want all messages to be stored in local file... – overexchange Sep 7 '18 at 1:10
  • 1
    No, because by default every log path receives every message of the source. (You can use the flags(final) option to change this, see syslog-ng.com/technical-documents/doc/… and syslog-ng.com/technical-documents/doc/…) – Robert Fekete Sep 7 '18 at 7:19
  • @RobertFekete I mean, Do I need to add one more log statement, to my existing configuration? Given in query... – overexchange Sep 7 '18 at 9:56
  • 2
    Yes, so you'll have two, like: log { source(src); destination(local_file); }; log { source(src); filter(f_warn) destination(remote_log_server); }; – Robert Fekete Sep 7 '18 at 13:31

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