As I mentioned in my last blog, the capacity and performance of today’s NVMe® solid state drives (SSDs) have exploded and are now far more than a single compute node can consume. So, sharing these SSDs over the network is an urgent need. Traditional networked storage technology has been either slow (iSCSI) or expensive (Fibre Channel), or both – until now. With NVMe-over-Fabric™ (NVMe-oF™) technology, cloud data centers no longer need to stick with a direct-attached storage (DAS) model. The KumoScale™ software suite implements a fast, networked block storage service based on the NVMe-oF standard using existing Ethernet data center networks. A KumoScale storage node solution delivers the efficiency and flexibility of a shared storage pool with the performance capabilities of NVMe flash – what we call “NVMe flash as a service.”
Retaining native DAS-like (in-server) performance, while getting maximum utilization of disaggregated storage and server resources, is critical for the next generation of cloud infrastructure. But what about data resiliency? Let’s dig into this a bit. So-called “cloud-native” applications differ from traditional enterprise applications in terms of how they handle data resiliency. Enterprise apps – including most SQL databases – typically require their associated storage systems to provide resilience against individual drive failures and across various failure domains, including racks or entire data centers. Conventional storage arrays provide this capability but usually at a very high premium above flash media. In contrast, cloud-native applications (or those essentially born in the cloud such as NoSQL databases like Cassandra®, MongoDB® and Aerospike®) typically offer data protection by replicating shards at the database layer. In this case, the networked storage systems are expected to deliver fast, simple volumes at a very low cost – just like in the DAS model.
The reality is that modern cloud infrastructure with networked storage must be able to handle a mix of both cloud-native application and legacy enterprise apps. Few customers are 100% cloud-native, and there are always some legacy applications that depend on the storage layer to provide data protection. Data protection must be available, and easy to deploy, for legacy applications that need it – but should not be forced on those that don’t. The latest KumoScale software release (v3.11) introduces a resilient, efficient cross-domain volume replication for legacy applications and supports simple volumes for cloud-native apps. KumoScale cross-domain volume replication provides this flexibility without forcing a one-size-fits-all solution. It takes a data center-wide approach to resilience against drive failure or network partition, allowing users to specify arbitrary failure domains using tags. When provisioning volumes, KumoScale software can create volume replicas across multiple storage nodes located in different failure domains for rack-level resiliency. This addresses both equipment failure and maintenance downtime scenarios and can be provided to only those applications that require it. With this approach, the KumoScale solution significantly lowers costs compared to conventional arrays that implement data protection locally and uniformly for all users.
The KumoScale data resiliency solution was designed with performance in mind using an architecture that places the replication layer in the host, as opposed to conventional resiliency solutions where the replication is done in the storage layer. There are a few performance benefits of this approach, including lower latency, as the replication is done in parallel as opposed to sequentially. In addition, the replication bandwidth does not consume the KumoScale networking bandwidth. Further, the KumoScale data resiliency solution is fully integrated with existing monitoring and alert systems used by data center administrations. It supports alerts on various events, including a replicated volume entering a degraded state, initiating reconstruction of a replica, replica rebuilt status, and replica rebuild completed. Alerts can be customized per the data center administrator's requirements. For example, an email to the storage administrator may be generated upon certain trigger events, or an API call with information about the nature of the trigger event may be initiated to an alert system.
With the addition of cross domain volume replication, KumoScale software is a safe, fast and easy-to-manage network storage solution for modern cloud data center infrastructures.
For more information please visit kumoscale.kioxia.com.
NVMe-oF is a trademark and NVMe and NVM Express are registered trademarks of NVM Express, Inc.
Cassandra is a registered trademark of The Apache Software Foundation.
Mongodb is a registered trademark of Mongodb, Inc.
Aerospike is a registered trademark of Aerospike, Inc.
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