For most businesses, organizations, and individuals, data is everything. Unfortunately, it can all be lost within a matter of seconds. This makes data replication absolutely essential for your protection. With so many options to choose from, it can difficult to determine which one is best for you. Let’s look at several of the best practices for data replication between data centers.
Synchronous Remote Replication
Falling under the category of remote replication, synchronous replication copies data to one or more secondary sites immediately as it is created. As a result, the duplicate system is guaranteed to have a copy available, eliminating any risk if accidentally lost. However, the primary system has to wait for the secondary system to confirm it has received each packet without error before it can continue. This requires low-latency communication, the bandwidth of a LAN between the servers, and leads to longer response times. As a result, synchronous replication works best when the primary and secondary system are physically close to each other. While it’s expensive, it’s considered to be bulletproof according to numerous experts.
Also in the category of remote application, asynchronous replication replicates data after the fact, or in non-real-time. You can program the duplication to occur at predefined intervals, or to occur automatically when a system update takes place. Although there’s an increased risk for lost data because of the delay in communication, it’s significantly faster than synchronous replication and can be executed on a low speed WAN. While it is less expensive than synchronous replication, it doesn’t provide the real-time recovery capabilities that make synchronous untouchable.
SAN Level Replication
SAN replication ensures your database is backed up to a different storage array at the local site, to a different location on your storage level, or to a remote storage array at a different site. This is ideal for getting a real-time, or as close to real-time as possible, backup of one or more LUNs to a different site or another array for disaster recovery and local backup. It’s required if you’re constructing a geographically distributed cluster. This gives you the opportunity to have your cluster nodes divided up between two (any more than this can be risky) different facilities. It shouldn’t be used if you’re establishing a read-only copy of the database.
Guest OS-Level Replication
This type of replication duplicates data on a block-level basis to the targeted machine. This option requires you to pay license costs as well as a source machine agent, but it does offer one-click failover. This means that you can recover your lost data with a simple click of one button.
Application Level Replication
Taking place at the transaction level, every transaction is captured and copied to multiple systems. This offers short a RTO, or time in the future in which your system will be up and running again, and RPO, or the point in time in the past to which you’ll be able to recover data. However, you must ensure your OS system is properly maintained at the time of failover. This replication works best with SQL databases.
Disaster Prevention Can Start Today
Making certain that your data is properly replicated is a necessity for businesses and organizations, as well as many individuals. Failing to do so can prove to be a disastrous decision. Fortunately, there are numerous options for data replication, such as those listed above, that can provide the protection you need.