51
| SMSEagle MHD-8100
| User’s Manual
Failover (HA-cluster) feature
"High-availability clusters (also known as HA clusters or fail over clusters) are groups of computers (...) that can be
reliably utilized with a minimum of down-time. They operate by using high availability software to harness
redundant computers in groups or clusters that provide continued service when system components fail. Without
clustering, if a server running a particular application crashes, the application will be unavailable until the crashed
server is fixed. HA clustering remedies this situation by detecting hardware/software faults, and immediately
restarting the application on another system or whole node without requiring administrative intervention, a process
known as failover."
(source: Wikipedia)
SMSEagle NXS-family devices have their own failover mechanism based on HA-cluster. This feature allows
you to assure high availability of SMSEagle devices in critical environments. To enable failover (HA-cluster)
you need 2 devices ('aka' nodes). The failover feature monitors devices working in the cluster, and detects
faults with the following services:
1.
Apache2 WWW server
2.
PostgreSQL database
3.
SNMP agent
4.
Modem software (Gammu-SMSD daemon)
5.
Accessibility (response to ping) of whole node.
Every node in a cluster can have one of three states:
•
Master:
main healthy node in a cluster, by default accessible through Virtual IP
•
Backup:
second healthy node in a cluster, ready and waiting for replacing Master when needed
•
Fault:
node with detected service fault
Summary of Contents for MHD-8100-3G
Page 1: ...SMSEAGLE MHD 8100 3G MHD 8100 4G User s Manual ...
Page 9: ...9 SMSEagle NXS 9700 3G User s Manual GET READY TO START I ...
Page 21: ...21 SMSEagle MHD 8100 User s Manual USING OF SMSEAGLE II ...
Page 76: ...76 SMSEagle MHD 8100 User s Manual Screenshot from Blacklist Define STOP word feature ...
Page 207: ...207 SMSEagle MHD 8100 User s Manual TROUBLESHOOTING I I I I I I ...
Page 210: ...210 SMSEagle MHD 8100 User s Manual SERVICE REPAIR IV I ...
Page 212: ...212 SMSEagle MHD 8100 User s Manual TECH SPECS SAFETY INFORMATION V I ...