We have all heard about data center failure in many large enterprises, and the reason can be anything. For example, a permanent deadlock in a data transferring channel or natural or human-made disasters can cause issues. Therefore, all enterprises need a reliable database solution that can set them free from such data center disaster-related worries. CockroachDB comes into the picture to save data centers from falling apart in certain extreme failure situations. CockroachDB is a commercial cloud-based SQL database. It offers agility and continuity features for better data storing and accessing experiences. Data administrators can deploy multiple symmetric nodes in a Kubernetes cluster comprising many machines, storage disks, and centers.

Since Kubernetes also contains scalability and node failure survival capabilities. They are the best fit for each other. Another reason is that Kubernetes offers a simplified approach to managing cluster performance and makes its data highly available by creating replicas across all individual nodes. Furthermore, this discussion leads us to the OpenEBS LocalPV devices, which can help maintain CockroachDB clusters in the Kubernetes ecosystem.

A Glance At Distributed and Scalable Databases:

The increasing demands for continuous top-notch resilience, performance, and agility with usage simplification have made developers find more options in this vast open-source database field and accomplish such needs. Whenever we think of databases, either SQL or NoSQL comes first to our mind, but why? The answer is considerably more manageable. SQL guarantees consistency by offering variants like PostgreSQL and MariaDB, which contain ACID (Atomic, Consistent, Isolated, Durable) properties. NoSQL databases also provide the agility that users need. ACID or SQL properties are not considered compatible solutions.

Recently distributed and scalable databases platforms have committed to stopping this trade-off between SQL and NoSQL and trying their best to make the NoSQL database compatible with all its required properties, including ACID. Then they introduced CockroachDB, a new distributed database, and an extended version of RocksDB that contains both ACID transactional and key-value stores with graphical (vertical and horizontal) scalability-related properties. It can even control latency problems or any storage entity-related failures in wide geographically distributed networks.

The Working of CockroachDB:

Mostly, CockroachDB is placed in multi-node clusters. Into five layers, each node is further distributed which are:

• The SQL Layer: First, it parses all client queries by comparing them with the YACC file and converts them into key-value entities by making their abstract syntax tree. After that, this tree structure establishes a network of nodes with key-value code. This will create a communication channel in the network transaction layer at the execution time.
• The Transaction Layer: Further, it implements ACID transactions' semantics using two commits executed within the cluster nodes. Simultaneously, this commit process writes transactional records and extents to proceed with reading operations.
• The Distribution Layer: The transaction layer's nodes then send further process requests to this layer. Once it receives the recommendations, it instantly analyzes the requests' destination nodes to transfer them to the replication layer.
• The Replication Layer: The main work of these layers is to create copies of cluster nodes' data and then ensure their accords with other similar nodes using the Raft algorithm.
• The Storage Layer: Finally, this layer stores all nodes' key-value pairs with the help of RocksDB.
• CockroachDB supports almost every operating system, including Mac, Windows, and Linux. However, its production instances can only run reliably on Linux VMs. CockroachDB is compatible with both cloud and on-premises environments. You can't run on both. Therefore, Kubernetes is the best deployment choice, especially for stateful applications.
• Before deploying CockroachDB on the Kubernetes platform, it is essential to understand Kubernetes' imperative terminologies for workloads and stateful applications.

Kubernetes Deployment Terminologies:

• StatefulSet: Kubernetes uses a Stateful Set, a collection of its PODs. It can be visualized as the one stabilized unit containing individual network integrity. It can also be viewed as a stable object that gathers identical continuous storage systems whenever it restarts.
• Persistent Volume: One kind of block-based storage system is integrated into a POD form. It is not bound by the data volume limit. Persistent Volume is a perfect compatible option for CockroachDB.
• Certificate Signing Request: This type of request can be placed by TLS certificate using clients, which Kubernetes's Certificate Authority approves.
• Role-Based Access Control: Also known as RBAC – it is a system provided by Kubernetes. You receive the permit to cluster access authorization on a user priority (access-level) basis.

You can use all data files stored in the Kubernetes. It is necessary to have at least an installed Kubernetes version 1.15. Kubernetes's above versions are recommended to run CockroachDB clusters in it seamlessly. The best thing about Kubernetes is that there is no specific space to deploy databases, which means they can be installed in any Kubernetes distribution, for example, Local clusters, Google GKE & GCE, AWS, or any other ones. Regardless of those distributions' features and functionalities, CockroachDB always chooses to depend on OpenEBS LocalPV as it maintains the external persistency volume of data and its replications reliably.

How OpenEBS LocalPV Helps CockroachDB in Deployment?

When you use OpenEBS to help CockroachDB, it provisions its LocalPV on the nod where CockroachDB's cluster PODs are stored. It uses independent block devices to store the data of CockroachDB in scale and creates persistent data storage systems. This system is known as OpenEBS LocalPV Device volumes. It provides the following benefits over Kubernetes Local Persistent Volumes.

• More Dynamic
• Provides Better block devices' management. Further you can build LocalPVs through its NDM. Which can help identify block devices' properties, orchestrate device filters, and metrics management across platform nodes.

Once OpenEBS LocalPV volume connects with a block device, then work for only this system until it releases them. Therefore, other applications have to claim other block devices present in nodes, and node selectors help them discover ideal ones. You can reliably run CockroachDB operation in an OpenEBS LocalPV Device volume. Keep one block device or Local SSD in a node ideal among four.

How CloudStakes Technology Pvt. Ltd. can help you?

We hope that this brief guide has helped you at certain levels. If you need any guidance regarding Kubernetes deployments or other cloud computing solutions, write us all your queries at sales@cloudstakes.com. We will try our best to reach out to you with our proposed solutions within 24-48 hours.