I had same error message and was unable to find any online info.
Open a case with Cisco and below is response.
%DIAG-DIAG-6-INFO : goldxr_OBFL_online_coalescer(L#1274)
Please see below for an explanation of OBFL
The OBFL feature records operating temperatures, hardware uptime, interrupts, and other important
events and messages that can assist with diagnosing problems with hardware cards (or modules) installed
in a Cisco router or switch. Data is logged to files stored in nonvolatile memory. When the onboard
hardware is started up, a first record is made for each area monitored and becomes a base value for
subsequent records. The OBFL feature provides a circular updating scheme for collecting continuous
records and archiving older (historical) records, ensuring accurate data about the system. Data is
recorded in one of two formats: continuous information that displays a snapshot of measurements and
samples in a continuous file, and summary information that provides details about the data being
collected. The data is displayed using the show logging onboard command
This message is just informational and can be ignored. This message indicates the system is coalescing (combining) OBFL records for diagnostic purposes
