Andreas Ericsson's presentation on using Nagios with Merlin. The presentation was given during the Nagios World Conference North America held Sept 25-28th, 2012 in Saint Paul, MN. For more information on the conference (including photos and videos), visit: http://go.nagios.com/nwcna

1. Merlin
Redundancy for Nagios

2. op5
Agenda
About op5 and op5 Monitor
Need for distributed monitoring
Concept and implementation
Examples and scenarios
Customer cases
More Info

3. About op5

4. op5 Monitor
op5 Monitor
op5 Monitor Delivers
Delivers
 Reports & Trend analysis
Infrastructure
 Service levels
 Availability
Storage  Easy configuration
 Data status visualization
Application  SLA reports, maps, etc
 Monitor virtual, cloud and
Network
outsourced services
 Distributed and load-
balanced setups
Status
 Automated intelligent
alarms and action on
events
VM's

5. Need For Distributed Monitoring

6. Need For Distributed Monitoring
Reliability
Reliability
 24x7 SLA for Mission-Critical Services
 Availability and SLA Reporting

7. Need For Distributed Monitoring
Performance
Performance
 High Number of Active System checks
 Limitations of the Operating System
 Growth

8. Need For Distributed Monitoring
Distributed Monitoring
Distributed Monitoring
 Locations
 Combinations of Network
 IP Address Conflicts
 Security

9. Why Merlin?
 Other solutions for redundancy are clunky at best
 Redundancy is important
 Load-balancing and automatic fail-over
 Network functionality (as its users see it) is hardly ever
measurable from a single place

10. Key Features
Redundancy
– Ensure availability
– Ensure availability
Performance
– Handle larger networks
– Handle larger networks
Load balancing
– Share the workload
– Share the workload
Distributed monitoring
– Geographical coverage
– Geographical coverage
Our solution for a scalable monitoring refers to an:
 Easy to use system
 Capable of constantly changing to fit the needs of your business
 Give stability and performance

11. Concept and Setups

12. op5 Merlin Open Source Project
Merlin - Module for Effortless Redundancy
and Load balancing in Nagios
For setting up distributed Nagios
installations

13. Brief project info
 Started 2006 as a prototype for a huge installation
 First used as redundancy engine 2009
 Used in production at +800 installations
 Largest production installation has 3 masters and 14
pollers
 v2.0.0 (with Nagios 4 support) to be released officially
next week
 Current bleeding edge is v2.0.0-beta2-p10

14. Key design concepts
 Peer loadbalancing is 100% transparent
 Pollers take care of one or more hostgroups
 Pollers can be (and often are) peered
 Binary protocol for extreme performance
 32-bit and 64-bit machines can't play together :-/
 Object config of two peers must be identical
 Pollers must never know about objects they're not
responsible for

15. Merlin System Design
Database
Backlog
Backlog
dbi
Socket
Backlog
Merlin Module
Config File Merlin Daemon

16. Merlin System Design
 Peer + Peer System Design
Database Database
Backlog Backlog
dbi dbi
Socket Socket
Backlog Backlog
Merlin Module Merlin Module
Config file Config file
Merlin Daemon Merlin Daemon

17. Peered Setup
Scalability / High Availability
The backend allows a variety of Peer
high availability setups and allows
almost infinite scalability by adding Peer
more "peers"
Config
Peer
Check results
Poll/check
Monitored objects

18. Master/Poller Setup
Remote Modules
Master
Remote modules allow the
monitoring of individual services
and devices using a dedicated, but
centrally managed monitoring
system
Poller Poller Cloud Poller
Config
Check results
Poll/check
Monitored objects Monitored objects Monitored objects

19. Combined Setup
Master/Peer
Poller Peer
Poller Peer Poller Peer
Monitored objects Monitored objects Monitored objects

20. Configuration And Management

21. Configuration And Management
 Merlin automatically distributes object config
 Split and Push Config-in master / poller
configurations
 Straight-up sync for peers when needed

22. Early Adopters
 Mogul Services AB
 Hosts critical services for operators, call-centers
banking, online media and emergency broadcast
channels
 Very early implementation (beta-stage in POC-deal)
 Quite complex setup (peered masters, multiple
pollers)
 Very high availability demands

23. Examples And Scenarios

24. Performance
Peer
 Add more if needed to scale out
Peer
performance monitoring rather than to
scale up on hardware
 Growth of the monitoring system with
the requirements of the company
Peer Peer
Peer
Peer

25. Reliability
Peer
 Through dynamic distribution of
Peer
service checks the individual nodes are
peered. This setup also provides
redundancy
Peer Peer
Peer
Peer

26. Security
 Safety zones in the network
Master  Monitoring as a Service
 DMZ
 Branch offices with “one-way”
availability
Poller Poller Poller
Monitored objects Monitored objects Monitored objects
DMZ Customer Network Secure Network

27. Cloud Monitoring
Master
 Monitoring of publicly
available services
Cloud Poller
 Services outside their own Poller
network monitor
Monitored objects Monitored objects
DMZ

28. Large Organisation Setup

29. Customer case study: Merlin Ahoy!
Company
Since late 1959, the Viking Line ships sail daily from
Finland to Sweden. The shipping company Viking Line
Abp based in Mariehamn, the capital of the autonomous
Åland Islands in Finland.
Challenge: “There have been improvements in functionality
Unreliable network uplinks to the core system, the when we communicate via satellite links.
It is easier then before to have the server on
change between cable connections, wireless and board to communicate with our main servers
satellite networks, depending on the location of the ship on shore”
Jonas Lindroos, IT department at Viking Line
make it difficult to monitor all on-board IP services such
as IPTV, VoIP, WiFi hotspot and infotainment.
Solution:
On each ship an op5 Monitor instance was installed. It
allows distributed monitoring of Viking Line, monitoring
all services on all vessels and provides centrally
managed monitoring.

30. Questions?
 http://git.op5.org
 http://www.op5.org