Log Message:
Update to nagios-4.0.8. Patches applied upstream were removed. Added two
patches. From: http://nagios.sourceforge.net/docs/nagioscore/4/en/whatsnew.html

 Changes and New Features

    Performance Improvements:

    The performance improvements in Nagios Core 4 come primarily from the \ 
following areas:
        Core Workers - Core workers are lightweight processes whose only job is \ 
to perform checks. Because they are smaller they spawn much more quickly than \ 
the the old process which forked the full Nagios Core. In addition, they \ 
communicate with the main Nagios Core process using in-memory techniques, \ 
eliminating the disk I/O latencies that could previously slow things down, \ 
especially in large installations.
        Configuration Verification - Configuration verification has been \ 
improved so that each configuration item is verified only once. Previously \ 
configuration verification was an O(n2) operation.
        Event Queue - The event queue now uses a data structure that has O(log \ 
n) insertion times versus the O(n) insertion time previously. This means that \ 
inserting events into the queue uses much less CPU than in Nagios Core 3.
        Macro Resolution - Macros are now sorted on startup so macro lookup can \ 
use a binary search. In addition, frequently accessed macros $USERx$, $ARGx$, \ 
and $HOSTADDRESS$ are given special case, early lookups.
    Object Definitions:

    The following changes have been made to object definitions:
        The host address attribute is now optional. The address attribute is set \ 
to the host name when it is absent. Most configurations set the host name \ 
attribute to the DNS host name making the address attribute redundant.
        Both hosts and services now support an hourly value attribute. The \ 
hourly value attribute is intended to represent the value of a host or service \ 
to an organization and is used by the new minimum value contact attribute.
        Services now support a parents attribute. A service parent performs a \ 
function similar to host parents and can be used in place of service \ 
dependencies in simple circumstances.
        The failure_prediction_enabled flag has been removed from both host and \ 
service object definitions.
        Contacts now support a minimum value attribute. The mininum value \ 
attribute is used with the host and service hourly value attributes to determine \ 
whether to notify a contact on host and service problems.
        The host obess_over_host and the service obsess_over_service attributes \ 
can now both use the shortened attribute obsess.
    Object Behavior:
        Contact Inheritance - According to the documentation, contacts should \ 
only be inherited from host to service if the service has no other contacts \ 
whatsoever (and the same goes for escalations), but the way the code previously \ 
worked was that it handled contact_groups and contacts directives separately, \ 
meaning services with only 'contacts' specified were still eligible for \ 
inheriting 'contact_groups' from the host. This has been updated to comply with \ 
the documentation.
        Timeperiods - There were several issues processing timeperiods when both \ 
exclusions and exceptions were involved. The issues have been corrected.
    Configuration:

    The following changes have been made to the main Nagios Core configuration, \ 
nagios.cfg:
        Because there are many ways to obtain object information, the object \ 
information is no longer stored if in the object cache if the configuration \ 
variable object_cache_file equals '/dev/null'. Setting the variable to \ 
'/dev/null' will reduce the disk I/O load.
        Because there are many ways to obtain status information, the status \ 
information is no longer stored if in the status data file if the configuration \ 
variable status_file equals '/dev/null'. Setting the variable to '/dev/null' \ 
will reduce the disk I/O load.
        There is a new configuration variable, log_current_states, which \ 
determines whether current states will be logged in the log files when they are \ 
rotated. In Nagios Core 3, this was always the behavior and it is the default in \ 
Nagios Core 4. Disabling the logging of current states on log rotation can save \ 
considerable disk space for large installations.
        There is a new configuration variable, check_workers, which specifies \ 
how many worker processes are created when Nagios Core starts. If not specified, \ 
the number of worker process is determine by the number of CPUs on the system.
        There is a new configuration variable, query_socket, which specifies the \ 
location of the query handler socket. The default location is \ 
/usr/local/nagios/var/rw/nagios.qh.
        The configuration variables, check_result_reaper_frequency and \ 
max_check_result_reaper_time, have been deprecated. Because of the new worker \ 
architecture, checks are no longer reaped, but they are fed back to core by the \ 
worker processes. As a result, these variables no longer make sense.
        All file and directory configuration variables in the main nagios.cfg \ 
can now use paths that are relative to the location of nagios.cfg.
        Although rarely used in the past, creating nagios objects in the main \ 
nagios.cfg configuration file was allowed. This is now prohibited.
    Macros:
        Additions - A new macro, $CHECKSOURCE$, has been added which contains \ 
information about what process performed a check.
        Changes - If use_large_installation_tweaks is set, the \ 
$HOSTGROUPMEMBERS$ and $SERVICEGROUPMEMBERS$ macros are no longer exported \ 
because they can consume the available space for environment variables.
        Macros are normally available as environment variables when check, event \ 
handler, notification, and other commands are run. This can be rather CPU \ 
intensive in large Nagios installations, so you can disable the export of \ 
environment variables completely with the enable_environment_macros option.
        Macro information can be found here.
    Query Handler:

    The query handler is a general purpose communication mechanism that allows \ 
external entities to communicate with Nagios Core in a well-defined manner. As \ 
of this writing, all communication with the query handler takes place through a \ 
Unix-domain socket whose location is defined by the query_socket configuration \ 
variable.

    There are currently 5 built-in query handlers.
        core - provides Nagios Core management and information
        wproc - provides worker process registration, management and information
        nerd - provides a subscription service to the Nagios Event Radio \ 
Dispatcher (NERD)
        help - provides help for the query handler
        echo - implements a basic query handler that simply echoes back the \ 
queries sent to it

    More information about the query handler interface, including an \ 
introduction to creating a custom query handler, can be found in the \ 
source-supplied documentation.
    Core Workers:

    Previously, all host and service checks were performed by the full Nagios \ 
Core process. This required forking the Nagios Core process for every check. The \ 
full Nagios Core process includes a lot of things that are not required to \ 
actually perform the check, including check scheduling, downtime handling, \ 
processing external commands, etc. As a result, forking the Nagios Core process \ 
was much slower than was necessary. When the actual check was run, the forked \ 
process again forked a shell to run the check and the shell forked to run the \ 
plugin.

    In addition, disk files were used as the inter-process communication (IPC) \ 
mechanism between the forked Nagios process doing the checking and the main \ 
Nagios process handling the check results.

    In Nagios Core 4, the process of performing host and service checks is now \ 
accomplished using a lightweight worker processes. Standard worker processes \ 
start up with the main Nagios Core process and additional, special-purpose \ 
workers, can be started at any time after Nagios Core starts. If the check \ 
command is "simple" (no shell escapes), the worker process can run the \ 
command directly, avoiding the 2 additional forks previously required.

    Also in Nagios Core 4, the worker processes report the check results to the \ 
main Nagios Core process using in-memory IPC mechanisms (the query handler \ 
interface), eliminating the disk I/O bottleneck that used to be an issue in \ 
large installations.

    When a worker process registers with the main Nagios Core process, it tells \ 
Nagios Core what checks it will handle. This feature allows external authors to \ 
create special-purpose workers which are optimized to perform certain checks. A \ 
sample special-purpose ping check worker is included with the Nagios Core source \ 
code in the worker/ping subdirectory.

    More information about workers, including an introduction to creating custom \ 
workers can be found in the source-supplied documentation.
    Nagios Event Radio Dispatcher (NERD):

    The Nagios Event Radio Dispatcher (NERD) is a query handler based service \ 
that streams Nagios Core events to the subscriber. Currently, there are three \ 
channels that can be subscribed to: hostchecks, servicechecks and opathchecks.
    libnagios:

    libnagios is a library of functions that can be used by developers of query \ 
handlers and worker processes. libnagios currently contains the following \ 
components.
        bitmap - bitmap library for calculating dependency graphs
        dkhash - dual-keyed hash api
        fanout - sparsely populated array used for downtime, comments, and \ 
worker jobs
        iobroker - I/O broker library for multiplexing between running tasks and \ 
the master nagios process.
        iocache - I/O caching libary for bulk-reading requests and parsing them
        kvvec - key/value library for parsing requests and building responses
        nsock - socket library for connecting to and communicating through the \ 
qh socket
        nspath - general purpose path library for converting between relative \ 
and absolute paths
        nsutils - small library with worker related utilities
        pqueue - pqueue library written by Volkan Yazici
        runcmd - for spawning and reaping commands
        skiplist - skiplist library used within Nagios Core
        squeue - for maintaining a queue of the running job's timeouts
        worker - for utils and stuff nifty to have if you're a worker
    Documentation:

    Documentation of Nagios Core internals is now provided as part of the source \ 
distribution. To create an HTML version of this documentation run 'make dox' \ 
from the root of the source distribution tree. The doxygen utilities must be \ 
installed to make this documentation.
    Tests:

    A much more complete test suite is now incuded with the Nagios Core source \ 
distribution.
    RPM Spec File:

    The RPM spec file has been completely overhauled to support more current \ 
standards.
    Deprecated Features:
        Extended Host and Service Information - The hostextinfo and \ 
serviceextinfo objects are now deprecated and should not be used. Support for \ 
them will be removed in a future version. The same information specified in the \ 
hostextinfo and serviceextinfo objects can be specified in the host and service \ 
object respectively.
        -x/--dont-verify-paths command line option (Don't check for circular \ 
object paths) - Because configuration checking is now so much faster, the option \ 
to skip checking for circular object paths has been deprecated.
        The following configuration variables have been deprecated: \ 
check_result_reaper_frequency, max_check_result_reaper_time, sleep_time, \ 
external_command_buffer_slots, command_check_interval
    Obsoleted Features:
        Failure Prediction - As noted above, the failure_prediction_enabled flag \ 
has been removed from both host and service object definitions. Failure \ 
predition was never fully implemented and would require breaking the paradigm \ 
that Nagios Core knows nothing about the performance data returned by plugins. \ 
Failure prediction is much more approprately handled by an add-on than by Nagios \ 
Core.
        -o/--dont-verify-objects command line option - This option, while \ 
accepted in Nagios Core 3, has neither been advertized nor has had any effect \ 
for quite some time. The option has been removed in Nagios Core 4.
        Embedded Perl - Embedded Perl has historically been the least tested and \ 
the most problem prone part of Nagios Core. A significant part of the issue is \ 
that there are so many versions of Perl available. The performance enhancements \ 
provided by the new worker process architecture make up for any performance loss \ 
due to the removal of embeddd Perl. In addition, the worker process architecture \ 
makes possible the implementation of a special purpose worker to persistently \ 
load and run Perl plugins. The following configuration variables that were \ 
related to embedded Perl have been obsoleted: use_embedded_perl_implicitly, \ 
enable_embedded_perl, p1_file.
    Miscellaneous:
        Object IDs - Primarily only of interest to developers, all of the \ 
first-class objects now have object IDs. First-class objects are timeperiod, \ 
command, contact, host, service, escalations, dependencies and all kinds of \ 
groups. Object IDs are not persistent and are recreated on each restart.