SQL Server Disaster is an instance of serious Server disruption or data loss. To get rid of the situation, it requires detecting the actual reason(s) that is causing technical disturbance or interruption. There are a number of causes that lead to SQL Server corruption and this includes natural disaster, power failure, human errors, hardware failure, software malfunction and much more.
SQL disaster can occur anytime; Therefore, every administrator must plan a good and efficient recovery plan in advance. One major responsibility of the SQL administrator is to keep the Server in running mode and recover as much data as possible after failure takes place. Disaster Recovery Plan (DRP) must be strategized and documented for preventing severe data loss and its instance. It can be structured in some ways that includes:
➔ Effective communication plan
➔ Through hardware acquisition
➔ By contacting a list of people
➔ Keeping information of the admin plan
➔ Instruct to contact people involved in the disaster response
➔ Prepare a checklist for every recovery scenario
➔ Record time details whenever a task is initialized and when it is accomplished
Ensure Maximum Productivity & High Availability
For maximum productivity, the Server environment must be highly accessible and highly available. High availability is referred to as the attribute of a system that aims towards ensuring a higher operational performance in comparison to routine period. A system that is constantly operational or available for a longer duration of time.
The performance of Server solely depends upon the environment; in some cases, it accelerates to 99.999% whereas in some environments it shows average downtime of 5.26 minutes each year.
Build an Effective SQL Disaster Recovery Plan
There are a number of factors that must be considered while planning an effective disaster recovery plan. These factors include level of sensitivity of data, required availability, failure tolerance and many more. The effective recovery plan must include any of the following solutions.
➔ Failure Clustering
➔ Database Mirroring
➔ Log Shipping
➔ Backup & Restore
Every solution involves implementation cost and has its own advantages over one another. A reliable SQL Server Disaster Recovery plan must include at least one or more available recovery solutions.
✔ Failover Clustering
A group of autonomous or independent computers working together for increasing the scalability or availability of the clustered roles is referred to as Failover Clustering.
Note: Clustered roles was previously known as services and clustered applications.
Clustered Servers or nodes are connected through software and physical cables. If any of the servers fail another server takes the lead and begins to provide service(s). This process is referred to as failover. The clustered roles are monitored regularly to verify the appropriate functionality of each role. If the improper functionality of any of the node is monitored, it is restarted or moved to another server in the group.
✔ Database Mirroring
SQL Server database mirroring is a high availability disaster recovery technique with two server instance on same or different machines. One SQL instance is known as Principal and acts as a primary instance whereas other known as Mirror is a mirrored instance. In several cases, there is third instance that acts as a Witness. It is a simple strategy that offers a number of benefits such as increased availability of databases, increased data protection, improved availability of production database while upgrading process.
Set of technologies to distribute, copy data, database objects from one database to another and, later synchronize between the databases to maintain the consistency is referred to as Replication. Data can be distributed to different locations as well as remote users over local area network, wide area network, wireless connections, internet and the dial up connections using Replication. Consistency can be attained through synchronization. There are several benefits of replication such as, offline processing, redundancy and load balancing. It consists of two different components:
➔ Publishers: Database that contains data and replication can have one or more publishers.
➔ Subscribers: Databases that collect data from publishers through replication. Whenever the publisher data is modified, the Subscriber data is updated.
✔ Log Shipping
Log shipping technique allows sending transaction log backups automatically from a primary database to one or more secondary databases. Transaction log backups are send to primary server instance to secondary database on secondary server instances.
The monitor Server (third Server optional instance) records the status of backup & restore operation along with its history. In addition, the monitor Server raises alerts in case any of the operation fails to take place as per schedule, but this functionality is optional.
✔ Backup and Restore
Backup and Restore is considered as a basic alternate when it is about SQL Server Disaster Recovery. The process involves two major steps
➔ Backing up SQL Server data
➔ Restoring SQL Server data
There are a number of backup techniques in SQL, each of them is better over one another. The backup strategy that SQL Administrators employ solely depends on the environment, the volume of data that needs to backup, preferences and other factors.
Different backup strategies include: full backup, incremental backup, differential backup, partial backup and transaction log backup. The backup strategy is a way to define the frequency, testing techniques, how and where the backup media is stored. It also defines who is responsible for restore operation and how the restore operation must be performed for meeting the goals of data availability.
However, if you fail to implement the above mentioned SQL Disaster Recovery plan successfully, or the plan is initiated but failed to recover data; you can utilize a professional SQL DB repair solution.
Third Party Approach to Recover & Restore SQL Database Efficiently
SQL Database administrators are bound with the task to recover data with utmost consideration to ensure smooth business operations. Stellar Phoenix SQL Database Repair tool is developed to recover data efficiently. It helps fixing all kind of SQL Server DB corruptions and recovers primary and secondary database files.
Integrated with latest recovery algorithms, the tool takes care of integrity parameters during the entire MDF as well as NDF recovery procedure. SQL Server database errors such as 5171, 3414 and 8942 can be resolved. Tables, indexes, rules, triggers, keys and other components of the database can be recovered.
One major benefit of the tool is that it can restore the recovered database objects to HTML, CSV, XLS and MS SQL file formats. Microsoft SQL Server 2016\ 2014\ 2012 and all previous versions are supported. If due to any reason the procedure is disrupted, the tool automatically connects to MS SQL Server and the recovery process is initiated thereafter.