High Durability in the cloud refers to how resilient your data is. High Durability is a measurement of how well your cloud storage performs. High Durability is when you start seeing all of the number nines stacked together. The 11 nines is a common concept in high durability as in data storage should be 99.999999999% durable. In other words, with that level of high durability for data, a business would not lose any data at all over a very long period of time.
The ability to recover from a disaster and to prevent any loss of data is what is known as Disaster Recovery and it goes hand in hand with High Durability. Disaster recovery and high durability mandates that:
- You have a backup solution
- The backup and be restored fast
- The backup is fully operational at all times
- Live data is not corrupt
How Does Azure Offer High Durability
High durability in Azure is offered via multiple types of storage redundancy. Here are a few of them.
Primary Region Redundancy
- Locally redundant storage (LRS) copies data synchronously 3 times within a single physical location in the primary region. LRS is the least expensive replication option but is not recommended for applications requiring high availability or durability.
- Zone-redundant storage (ZRS) copies data synchronously across 3 Azure availability zones in the primary region. For applications requiring high availability one can use ZRS in the primary region while also replicating to a secondary region.
Secondary Region Redundancy
- Geo-redundant storage (GRS) copies data synchronously 3 times within a single physical location in the primary region using LRS. Data is then copied asynchronously to a single physical location in the secondary region. Within the secondary region, data is copied synchronously 3 times using LRS.
- Geo-zone-redundant storage (GZRS) copies data synchronously across 3 Azure availability zones in the primary region using ZRS. Data is then copied asynchronously to a single physical location in the secondary region. Within the secondary region, data is copied synchronously 3 times using LRS.
Learn More About Azure High Durability
- Azure Storage Common Storage Redundancy (docs.microsoft.com)
- 5 Must Know Facts About Microsoft Azure (blog.mycloudit.com)
- Azure Storage Replication Explained Lrs Zrs Grs Ra Grs (cloud.netapp.com)
- Cloud Storage Durability Vs Availability (backblaze.com)
- Cloud Storage Durability Do You Really Need 11 Nines (lunavi.com)
- Understanding Azure Storage Redundancy Offerings (techcommunity.microsoft.com)
- Durable Cloud Storage (comparethecloud.net)
- Data Durability Fault Tolerance Resilience In Azure Databricks (medium.com)