In the current fast moving world, where time is precious and counted in terms of everything, can we imagine ourselves sitting in front of a laptop waiting for a webpage to open? How many of you reading this blog remember the days waiting to download grades report from the university site on the results day? That was an era before HA (High Availability).
Why HA and Failover Manager?
The real challenge for HA came in with the time constraint. For example, consider situations like completing a transaction where the OTP has to be keyed in less than 1 min, and the page not being able to be accessed within the allotted time.  That’s a real challenge which threw an even bigger challenge to the High Availability feature thereby resulting in adding many advanced options to High Availability. The effect of not having a HA in business process may be very detrimental to the organization. Every organization or business should use it to meet the current necessities of the modern world. The only effective solution to address this is High Availability which helps in E-vailability of the server for fast access.
Increased availability, security and speed is directly proportional to increased cost. Breaking the hassle of cost constraint, open source has provided a reliable solution to many businesses to be able to afford High Availability. One such affordable open source database which provides the high availability is EnterpriseDB Failover Manager.
More about EnterpriseDB Failover Manager:
EFM not only provides a solution for High Availability, but also monitors the HA configuration, and automates the failover. It creates a fault tolerant database clusters to minimize the downtime when a master database fails by keeping the data online in high availability.
EFM works on a replication cluster model. When the master is down, the streaming is redirected to the standby database which is in the cluster. This will not impact any activities on the application. The user will not even know the promotion of the standby server as master.
 Key features of EntepriseDB Failover Manager:

• Automatic Failover from Master to Standby node.
• Manual failover is possible.
• Email notifications when cluster status changes.
• Administrator is notified when the agents exit from the cluster.
• Configurable timeout parameters
• Witness provides protection against the “split brain” scenarios
• Can be configured on cloud technology (PPCD: Postgres Plus cloud Database)
• Supports multiple standby nodes.

Practical Challenges a Failover Manager resolves:

• Cost of downtime
• Recovery Time Objective(RTO) nearing to zero
• Data loss when one DB node crashes
• Auto failover feature
• Complements the Postgres Streaming Replication feature for setting up standby databases
• Achieves fast failover times

Advancements:
EFM has been trying to provide the better features from version to version.

• In the newest version of EFM-2.1, it can handle a controlled failover to a desired replication node for easy maintenance and disaster recovery.
• A dedicated witness is not required if the cluster has at least 2 standby nodes.

With EDB’s challenging good prices and ease to install and set up the EFM has made it a favourite to many users, assuring all routine daily activities with high operational performance and zero downtime. Having implemented EFM and other components of EDB in many of our customer sites, in addition to having all the features required for current time needs, the most liked about EDB is having no vendor lock-in and subscription model pricing.
Prathima Mulpuri I Database Solution Consultant, Ashnik

Prathima is a Database consultant with Ashnik. She is very passionate about learning new technologies and working on different database administrations. She handled the installations for our clients successfully which is her key role.In the past, she worked with the Pediatric Radiology of America, Virginia USA, as an Oracle DBA. She has experience in the field of Database administration for 4 years on Oracle 10g and Linux. She has completed her engineering in Electronics and Communications in the year 2001 from Madras University.