Description of problem:
The documented default values for the following values are incorrect. Per the documentation shipped within the rsyslog-doc RPM:

/usr/share/doc/rsyslog-7.4.7/html/rsyslog_conf_global.html
<formatted>
    $ActionQueueHighWaterMark <number> [default 8000]
<snip>
    $ActionQueueLowWaterMark <number> [default 2000]
<formatted>

This is similar to the bug report below that was closed WONTFIX due to being opened against an older release not eligible for the solution described.

    Bug 922152 – Documentation states incorrect default values for certain queue related directives

When using the documented default values, the disk assisted queues will not be used. This is due to the (documented) ActionQueueLowWaterMark being higher than the default ActionQueueSize of 1000. The ActionQueueSize is hit prior to the watermark being hit, and the disk-assisted queue functionality fails.


Version-Release number of selected component (if applicable):
 rsyslog-7.4.7-16.el7

How reproducible:
 Easily

Steps to Reproduce:
1. Set a remote rsyslog target with the default configuration values.

$ActionQueueFileName fwdRule1 # unique name prefix for spool files
$ActionQueueMaxDiskSpace 1g   # 1gb space limit (use as much as possible)
$ActionQueueSaveOnShutdown on # save messages to disk on shutdown
$ActionQueueType LinkedList   # run asynchronously
$ActionResumeRetryCount -1    # infinite retries if host is down
$ActionQueueLowWaterMark 2000 # the default
$ActionQueueHighWaterMark 8000 # the default

# remote host is: name/ip:port, e.g. 192.168.0.1:514, port optional
*.* @@remote-host:514

2. Initiate a connection failure state on the remote-host system
3. Verify that there are local fwdRule1 spool files created


Actual results:
 Spool files are not created, and the local logging will stall within rsyslog until the remote action is failed entirely.


Expected results:
 Spool files are created and logging continues during intermittent connection failures to a remote rsyslog server.

Additional info:
 The actual defaults are visible in the action.c source file:

        cs.iActionQHighWtrMark = 800;                   /* high water mark for disk-assisted queues */
        cs.iActionQLowWtrMark = 200;                    /* low water mark for disk-assisted queues */