So.. I've installed Logstash, and instead of using the logstash shipper (because it needs the JVM and is generally massive), I'm using rsyslogd with the following configuration.

# Use traditional timestamp format
$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
$IncludeConfig /etc/rsyslog.d/*.conf


# Provides kernel logging support (previously done by rklogd)
$ModLoad imklog
# Provides support for local system logging (e.g. via logger command)
$ModLoad imuxsock

# Log all kernel messages to the console.
# Logging much else clutters up the screen.
#kern.*                                                 /dev/console

# Log anything (except mail) of level info or higher.
# Don't log private authentication messages!
*.info;mail.none;authpriv.none;cron.none;local6.none            /var/log/messages

# The authpriv file has restricted access.
authpriv.*                                              /var/log/secure

# Log all the mail messages in one place.
mail.*                                                  -/var/log/maillog


# Log cron stuff
cron.*                                                  /var/log/cron

# Everybody gets emergency messages
*.emerg                                                 *

# Save news errors of level crit and higher in a special file.
uucp,news.crit                                          /var/log/spooler

# Save boot messages also to boot.log
local7.*                                                /var/log/boot.log

In /etc/rsyslog.d/logstash.conf there are 28 file monitor blocks using imfile

$ModLoad imfile   # Load the imfile input module
$ModLoad imklog   # for reading kernel log messages
$ModLoad imuxsock # for reading local syslog messages

$InputFileName /var/log/rabbitmq/startup_err
$InputFileTag rmq-err:
$InputFileStateFile state-rmq-err
$InputFileFacility local6
$InputRunFileMonitor
....
$InputFileName /var/log/some.other.custom.log
$InputFileTag cust-log:
$InputFileStateFile state-cust-log
$InputFileFacility local6
$InputRunFileMonitor
....
*.* @@10.90.0.110:5514

There are 28 InputFileMonitor blocks, each monitoring a different custom application logfile..

If I run

[root@secret-gm02 ~]# lsof|grep rsyslog
rsyslogd   5380        root  cwd       DIR              253,0       4096          2 /
rsyslogd   5380        root  rtd       DIR              253,0       4096          2 /
rsyslogd   5380        root  txt       REG              253,0     278976    1015955 /sbin/rsyslogd
rsyslogd   5380        root  mem       REG              253,0      58400    1868123 /lib64/libgcc_s-4.1.2-20080825.so.1
rsyslogd   5380        root  mem       REG              253,0     144776    1867778 /lib64/ld-2.5.so
rsyslogd   5380        root  mem       REG              253,0    1718232    1867780 /lib64/libc-2.5.so
rsyslogd   5380        root  mem       REG              253,0      23360    1867787 /lib64/libdl-2.5.so
rsyslogd   5380        root  mem       REG              253,0     145872    1867797 /lib64/libpthread-2.5.so
rsyslogd   5380        root  mem       REG              253,0      85544    1867815 /lib64/libz.so.1.2.3
rsyslogd   5380        root  mem       REG              253,0      53448    1867801 /lib64/librt-2.5.so
rsyslogd   5380        root  mem       REG              253,0      92816    1868016 /lib64/libresolv-2.5.so
rsyslogd   5380        root  mem       REG              253,0      20384    1867990 /lib64/rsyslog/lmnsd_ptcp.so
rsyslogd   5380        root  mem       REG              253,0      53880    1867802 /lib64/libnss_files-2.5.so
rsyslogd   5380        root  mem       REG              253,0      23736    1867800 /lib64/libnss_dns-2.5.so
rsyslogd   5380        root  mem       REG              253,0      20768    1867988 /lib64/rsyslog/lmnet.so
rsyslogd   5380        root  mem       REG              253,0      11488    1867982 /lib64/rsyslog/imfile.so
rsyslogd   5380        root  mem       REG              253,0      24040    1867983 /lib64/rsyslog/imklog.so
rsyslogd   5380        root  mem       REG              253,0      11536    1867987 /lib64/rsyslog/imuxsock.so
rsyslogd   5380        root  mem       REG              253,0      13152    1867989 /lib64/rsyslog/lmnetstrms.so
rsyslogd   5380        root  mem       REG              253,0       8400    1867992 /lib64/rsyslog/lmtcpclt.so
rsyslogd   5380        root    0r      REG                0,3          0 4026531848 /proc/kmsg
rsyslogd   5380        root    1u     IPv4         1200589517        0t0        TCP 10.10.10.90 t:40629->10.10.10.90:5514 (ESTABLISHED)
rsyslogd   5380        root    2u     IPv4         1200589527        0t0        UDP *:45801 
rsyslogd   5380        root    3w      REG              253,3   17999744    2621483 /var/log/messages
rsyslogd   5380        root    4w      REG              253,3      13383    2621484 /var/log/secure
rsyslogd   5380        root    5w      REG              253,3       7180    2621493 /var/log/maillog
rsyslogd   5380        root    6w      REG              253,3      43321    2621529 /var/log/cron
rsyslogd   5380        root    7w      REG              253,3          0    2621494 /var/log/spooler
rsyslogd   5380        root    8w      REG              253,3          0    2621495 /var/log/boot.log
rsyslogd   5380        root    9r      REG              253,3 1064271998    2621464 /var/log/custom-application.monolog.log
rsyslogd   5380        root   10u     unix 0xffff81081fad2e40        0t0 1200589511 /dev/log  

You can see that there are nowhere near 28 logfiles actually being read.

I really had to get one file monitored, so I moved it to the top, and it picked it up, but I'd like to be able to monitor all 28+ files, and not have to worry.

OS is

Centos 5.5 

Kernel 2.6.18-308.el5

rsyslogd 3.22.1, compiled with:
    FEATURE_REGEXP:             Yes
    FEATURE_LARGEFILE:          Yes
    FEATURE_NETZIP (message compression):   Yes
    GSSAPI Kerberos 5 support:      Yes
    FEATURE_DEBUG (debug build, slow code): No
    Atomic operations supported:        Yes
    Runtime Instrumentation (slow code):    No

Questions:

Why is rsyslogd only monitoring a very small subset of the files? How can I fix this so that all the files are monitored?