What's New in Nagios Core 4

Eric Stanley

estanley@nagios.com

Nagios Core 4 - Overview

Released Sep 20, 2013

In development since about June, 2012

Primary developer Andreas Ericsson

Nagios Core 4 - Performance

Core Workers lightweight processes which perform simple tasks

Configuration Verification each configuration item only checked once

Event Queue Insertions now O(log n)

Macro ResolutionSorted on start-up

$ARGx$, $USERx$, $HOSTADDRESS$

Nagios Core 4 Query Handler

External interface to main Nagios Core process

Uses Unix-domain socket/usr/local/nagios/var/rw/nagios.qh

Simple protocol

Nagios Core 4 Query Handler

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

Nagios Core 4 Core Workers

Nagios CoreInitialization

Scheduling

Initiate Host/Service Checks

Retrieve Host/Service Check Results

Handle Downtime

Send Notifications

Process External Commands

Nagios Core 4 Core Workers

Nagios Core 3Entire process forked twice for each check

Check results written to and read from disk

Nagios Core 4 Core Workers

Nagios Core 4Core workers forked at Nagios start

Core workers only contain code needed to perform their tasks

Only need to fork for actual check when check is complex

Check results passed to main Nagios process in memory

Nagios Core 4 Core Workers

Workers register using query handler interface

Workers can register for specific checksSpecialized workers

Future possibilitiesRemote workers

Workers for specific hosts

Nagios Core 4 Object Changes

Hourly Value (hosts and services)Intended to convey value of the host or service to the organization

Integer value

Example: development server would have low value but e-commerce web server would have high value

Nagios Core 4 Object Changes

Minimum Value (contacts)If hourly value of host or service is less than contact's minimum value, contact is NOT notified of problems

Value of host is host's hourly value plus hourly values of all host's services

Example: sysadmin might have low minimum value, but CIO might have a high minimum value

Nagios Core 4 Object Changes

Service parentsAnalogous to host parents

Can be used in place of service dependencies for most cases

Example: check_by_ssh checks could have check_ssh as parent

Host address attribute is now optionalSet to host name when missing

Nagios Core 4 Object Changes

obsess_over_host and obsess_over_service now support shorter attribute obsess

failure_prediction_enabled has been removed

Nagios Core Object Behavior

Contact InheritanceContacts only inherited by services from hosts if service has no contacts or contact groups in its definition

Time PeriodsProblems resolved where time periods contained both exclusions and exceptions

Nagios Core 4 Configuration

status_file and object_cache_file can be set to /dev/nullCGIs still need these files

log_current_states determines whether current states are logged when logs are rotated

check_workers specifies number of core workers forked at Nagios startWhen unspecified, number of workers is calculated based on number of CPU cores

Nagios Core 4 - Configuration

query_socket location of query handler socket

enable_environment_macros determines whether macros are exported to environment when commands are run

All paths in nagios.cfg can now be relative to location of nagios.cfg

check_result_reaper_frequency and max_check_result_reaper_time deprecated

Object definitions in nagios.cfg prohibited

Nagios Core 4 - Macros

$CHECKSOURCE$ - new macro containing name of worker that performed check

When use_large_installation_tweaks set, $HOSTGROUPMEMBERS$ and $SERVICEGROUPMEMBERS$ no longer exported

enable_environment_macros configuration option (discussed earlier)

Macro-related performance enhancements

Nagios Core 4 - Miscellaneous

libnagios contains code to support worker development

Documentation some doxygen formatted docs now available (make dox)

Test Suite significantly updated

nagios.spec overhauled to bring up to current standards

Object IDs each object has a unique now has a unique ID, but it is not persistent

Nagios Core 4 Deprecated Features

Extended Host and Service Information now available in host and service definitions

-x/--dont-verify-paths command line option Don't check for circular object paths

Configuration variablescheck_result_reaper_frequency

max_check_result_reaper_time

sleep_time

external_command_buffer_slots

command_check_interval

Nagios Core 4 Obsoleted Features

Embedded PerlMost problematic part of Nagios Core

Speed improvement obviates need for embedded perl

Is possible to write embedded perl core worker

Failure predictionNever implemented

Would have broken Nagios Core paradigm

-o/--dont-verify-objects command line option

Nagios Core 4 More Information

Nagios Core Documentationhttp://nagios.sourceforge.net/docs/nagioscore/4/en/

What's New page

Doxygen Documentationmake dox

nagios-*.tar.gzUse the Source, Luke

Nagios Core 4 Experience

One person's experience2300 hosts, 4500 services

Nagios Core 3.4.0 to 4.0.0

24 core system, 32 GB RAM

Nagios Core 4 - Thanks

Andreas Ericsson

Robin Sonefors

Eric Stanley

Max Sikstrm

Dan Wittenberg

Ricardo Maraschini

Anton Lfgren

many others

Nagios Core 4 - Questions

Questions?

Click to edit the outline text format

Second Outline Level

Third Outline Level

Fourth Outline Level

Fifth Outline Level

Sixth Outline Level

Seventh Outline Level

Eighth Outline Level

Ninth Outline Level

Click to edit the title text format

Click to edit the title text format

Click to edit the outline text formatSecond Outline LevelThird Outline LevelFourth Outline LevelFifth Outline LevelSixth Outline LevelSeventh Outline LevelEighth Outline LevelNinth Outline Level