[mod-security-users] Failed deleting collection error

[Nick H. <dar...@gm...>]

I'm in the process of setting up mod_security for the first time. Things
seem to be working OK so far, but I'm periodically getting a strange
message in the audit_log:

Message: Failed deleting collection (name "ip", key "123.123.123.123"):
Internal error
Apache-Handler: php5-script
Stopwatch: 1366821230906385 183614 (- - -)
Stopwatch2: 1366821230906385 183614; combined=39557, p1=106, p2=1166, p3=0,
p4=0, p5=19164, sr=28, sw=49, l=0, gc=19072
Producer: ModSecurity for Apache/2.6.8 (http://www.modsecurity.org/);
OWASP_CRS/2.2.5.
Server: Apache

I am running mod_security 2.6.8 (installed on RedHat EL5 via EPEL) and
using the CRS version 2.2.5. I'm
using modsecurity_crs_11_dos_protection.conf which I believe to be the
origin of this message.

The message seems to appear upon a request from a totally different IP
address, and happens an hour after the IP address referred to in the error
message made a request. The IP address in the error message never got
flagged for something by mod_security.

Without knowing much about mod_security's code, I'm guessing that as
mod_security records the IP addresses of who is requesting into its
collection, it must expire them out an hour later. I'm just not sure why it
is sometimes failing to delete them out, as most of the time it must be
successful because this log doesn't happen very often. Or am I supposed to
ignore this error? Thanks.