High Availability For Enterprise-Grade PostgreSQL Environments
Amazon Aurora is a relational database service that combines the speed and availability of high-end commercial databases with the simplicity and cost-effectiveness of open-source databases. Aurora is fully compatible with MySQL and PostgreSQL, allowing existing applications and tools to run without requiring modification.
High Availability for Enterprise-Grade PostgreSQL environments
Amazon Aurora provides an ideal environment for moving database workloads off of commercial databases. Aurora has functional capabilities which are a close match to those of commercial database engines, and delivers the enterprise-grade performance, durability, and high availability required by most enterprise database workloads. AWS Database Migration Service (AWS DMS) can help accelerate database migrations to Amazon Aurora.
This article describes several architectures that providehigh availability (HA) for PostgreSQL deployments on Google Cloud. HA is the measure of systemresiliency in response to underlying infrastructure failure. In this document,HA refers to the availability of PostgreSQL clusters either within a singlecloud region or between multiple regions, depending on the HA architecture.
Depending on the service level objectives (SLOs) of your system, you mightrequire an architecture that provides a higher level of availability. There ismore than one way to achieve HA, but in general you provision redundantinfrastructure that you can quickly make accessible to your application.
Use an HA architecture when you want to provide increased data-tier uptime tomeet the reliability requirements for your workloads and services. If yourenvironment tolerates some amount of downtime, an HA architecture mightintroduce unnecessary cost and complexity. For example, development or testenvironments infrequently need high database tier availability.
EDB Postgres offers an integrated, open-source-based SQL relational database solution built for your enterprise-scale data needs. A rich set of extended capabilities support cost-effective, resilient production and non-production environments. Organizations can come to IBM to license, implement and get support for EDB Postgres and enjoy the tested and certified PostgreSQL for high availability, disaster recovery, and monitoring.
Azure Database for PostgreSQL - Flexible Server is a fully managed database service designed to provide more granular control and flexibility over database management functions and configuration settings. In general, the service provides more flexibility and server configuration customizations based on the user requirements. The flexible server architecture allows users to collocate database engine with the client-tier for lower latency, choose high availability within a single availability zone and across multiple availability zones. Flexible servers also provide better cost optimization controls with ability to stop/start your server and burstable compute tier that is ideal for workloads that do not need full compute capacity continuously. The service currently supports community version of PostgreSQL 11, 12, 13, and 14. The service is currently available in wide variety of Azure regions.
The flexible server deployment model is designed to support high availability within a single availability zone and across multiple availability zones. The architecture separates compute and storage. The database engine runs on a container inside a Linux virtual machine, while data files reside on Azure storage. The storage maintains three locally redundant synchronous copies of the database files ensuring data durability.
If zone redundant high availability is configured, the service provisions and maintains a warm standby server across availability zone within the same Azure region. The data changes on the source server are synchronously replicated to the standby server to ensure zero data loss. With zone redundant high availability, once the planned or unplanned failover event is triggered, the standby server comes online immediately and is available to process incoming transactions. This allows the service resiliency from availability zone failure within an Azure region that supports multiple availability zones as shown in the picture below.
** Zone-redundant high availability can now be deployed when you provision new servers in these regions. Any existing servers deployed in AZ with no preference (which you can check on the Azure portal) prior to the region started to support AZ, even when you enable zone-redundant HA, the standby will be provisioned in the same AZ (same-zone HA) as the primary server. To enable zone-redundant high availability, follow the steps..
Testing showed that OpenShift Data Foundation can achieve good performance while still maintaining 3x data replication, even when the application and the storage are replicated across multiple AWS Availability Zones for high availability and business continuity.
PostgreSQL is ACID-compliant (referring to fundamental properties of atomicity, consistency, isolation, and durability). It also has many built-in features to help with the ongoing operational management and durability of a database cluster. However, the core PostgreSQL database server leaves high-availability implementations to external applications.
From an enterprise user perspective, the Crunchy PostgreSQL Operator lets organizations confidently deploy PostgreSQL clusters that address common enterprise requirements such as auto-provisioning, high-availability, disaster recovery, monitoring, and management. The Crunchy PostgreSQL Operator automates and simplifies deploying and managing open source PostgreSQL clusters on Kubernetes and other Kubernetes-enabled platforms with features that include:
In the database context, high availability implies the ability to access a database without interruption. Certain events could cause a database to become unavailable during normal operations, including:
The Crunchy PostgreSQL Operator addresses these needs by integrating trusted and tested open source components that provide a high-availability environment complete with disaster recovery features. These components build on core Kubernetes and PostgreSQL capabilities to perform the following functions:
The Crunchy PostgreSQL Operator provides safe and automated failover to support enterprise high-availability requirements, backed by a distributed consensus-based high-availability solution. As a result, users can easily add or remove nodes, providing automatic failover and resiliency. Figure 2 provides a high-level perspective showing how Kubernetes interacts with the Crunchy PostgreSQL Operator to provide database replication and disaster recovery.
Each PostgreSQL database replica node has its container backed by its copy of the data in a persistent volume claim (PVC). Replica nodes in PostgreSQL can function as read-only nodes as well as failover targets for high availability. Any hardware or network failure event affecting the PostgreSQL primary node will cause failover to one of the available replicas, and that replica is then promoted to the primary node.
There are certain scenarios where read-only replicas are not necessary. In those cases, OpenShift Data Foundation can be an effective solution for providing storage replication and high availability for PostgreSQL. OpenShift Data Foundation features built-in replication for block, file, and object data. This ability allows PostgreSQL to be deployed as a standalone node with OpenShift Data Foundation providing storage replication (default 3x). In the event of a node failure or any other failure, the PostgreSQL pod will be rescheduled quickly to another node. The pod will bond to another OpenShift Data Foundation node with the persistent data intact.
In instances where additional read-only database replicas are not required, resilience and data redundancy can be achieved by using OpenShift Data Foundation along with the Crunchy PostgreSQL Operator. Internal OpenShift Data Foundation data replication provides highly available PostgreSQL. That replication can be easily extended across multiple AWS availability zones with little or no performance penalty to the application in terms of both TPS and latency, even during failover events. As a common storage services layer for Red Hat OpenShift, OpenShift Data Foundation can also provide this same data protection to other applications running in the same Red Hat OpenShift cluster.
Replication is the heart of high availability, to ensure that a complete copy of the Conjur data is present on each machine. Specifically, data is transferred from the active Master to the Standbys and Followers using PostgreSQL streaming replication. Streaming replication uses a continuous connection between the 'upstream' Master and each 'downstream' Standby or Follower. In the absence of any network problems, transfer from the Master to the downstreams is virtually instantaneous.
This article dives into topics like PostgreSQL, High Availability, and Clusters. You will learn the steps to set up a PostgreSQL cluster and the multiple options available to create a high availability environment in PostgreSQL.
This article presents several designs for PostgreSQL deployments on Google Cloud that enable high availability (HA). The measure of system durability in the face of underlying infrastructure failure is known as HA.
Citus is a PostgreSQL substitute that includes high-availability features like auto-sharding and replication. Citus partitions your database and replicate multiple copies of each shard among commodity machines in a cluster. It seamlessly sends any writes or queries to one of the other nodes, which houses a replica of the impacted shard, if any node in the cluster becomes unavailable.
You can improve the uptime of your PostgreSQL-powered real-time applications and reduce the impact of hardware failures on performance. This can be accomplished using built-in high availability tools, which reduce the need for costly and error-prone manual intervention.