--- title: "#high-availability articles | Hashnode" description: "Explore 196 articles tagged #high-availability on Hashnode. Tutorials, guides, and how-tos from the community." url: "https://hashnode.com/tag/high-availability" --- Tag # #high-availability 196 posts · 5 followers [Rajesh Ravi](https://hashnode.com/@rajeshravi) · [4d ago](https://hashnode.com/posts/zero-downtime-monitoring-in-oem-24ai-patching-your-oms-without-going-blind/6aef30394cf43edb0a6aaa3f) ### [Zero Downtime Monitoring in OEM 24ai: Patching Your OMS Without Going Blind](https://www.rajeshravi.com/zero-downtime-monitoring-in-oem-24ai-patching-your-oms-without-going-blind?utm_source=hashnode&utm_medium=feed) EM 24ai's Zero Downtime Monitoring keeps alerts and notifications live during OMS patching. Here's how it works and what your topology needs to get it. 8 min read · [rajeshravi.com](https://www.rajeshravi.com/zero-downtime-monitoring-in-oem-24ai-patching-your-oms-without-going-blind?utm_source=hashnode&utm_medium=feed) [Daanial Farrukh](https://hashnode.com/@daanial) · [Nov 4](https://hashnode.com/posts/three-data-centres-and-no-high-availability-why-a-second-site-without-a-load-balancer-is-not-redundancy/6aeb6bd0332717ffe274ce4e) ### [Three Data Centres and No High Availability — Why a Second Site Without a Load Balancer Is Not Redundancy](https://quabin.hashnode.dev/three-data-centres-and-no-high-availability-why-a-second-site-without-a-load-balancer-is-not-redundancy?utm_source=hashnode&utm_medium=feed) A second data centre is not redundancy if one load balancer sits in front of it. A presales war story, the four-layer HA check, and the fix. 15 min read · [quabin.hashnode.dev](https://quabin.hashnode.dev/three-data-centres-and-no-high-availability-why-a-second-site-without-a-load-balancer-is-not-redundancy?utm_source=hashnode&utm_medium=feed) [4](https://hashnode.com/posts/three-data-centres-and-no-high-availability-why-a-second-site-without-a-load-balancer-is-not-redundancy/6aeb6bd0332717ffe274ce4e) [Rajesh Ravi](https://hashnode.com/@rajeshravi) · [Oct 24](https://hashnode.com/posts/oem-24ai-remote-agents-stop-deploying-an-agent-on-every-host-you-monitor/6adcac6fc5f5ba96a013153e) ### [OEM 24ai Remote Agents: Stop Deploying an Agent on Every Host You Monitor](https://www.rajeshravi.com/oem-24ai-remote-agents-stop-deploying-an-agent-on-every-host-you-monitor?utm_source=hashnode&utm_medium=feed) EM 24ai's Remote Agent lets you monitor databases without an agent on every host. Here's the setup flow, RAC/Data Guard placement rules, and current limits. 9 min read · [rajeshravi.com](https://www.rajeshravi.com/oem-24ai-remote-agents-stop-deploying-an-agent-on-every-host-you-monitor?utm_source=hashnode&utm_medium=feed) [RONI DAS](https://hashnode.com/@ronidas) · [Oct 21](https://hashnode.com/posts/one-zone-in-london-lost-power-why-wasnt-that-a-small-problem/6ad8761a0778650e60148b8f) ### [One zone in London lost power. Why wasn't that a small problem?](https://systemdesignacademy.hashnode.dev/one-zone-in-london-lost-power-why-wasnt-that-a-small-problem?utm_source=hashnode&utm_medium=feed) On 20 Oct a power event took out one zone of Google Cloud's London region, and some services across the region had errors in an incident that lasted about 8 hours. What zones, regions and providers each protect you from, and a design that keeps worki 12 min read · [systemdesignacademy.hashnode.dev](https://systemdesignacademy.hashnode.dev/one-zone-in-london-lost-power-why-wasnt-that-a-small-problem?utm_source=hashnode&utm_medium=feed) [Onlive Server](https://hashnode.com/@onliveserver) · [Oct 17](https://hashnode.com/posts/building-a-zero-license-private-cloud-step-by-step-proxmox-ve-8-high-availability-cluster-deployment/6ad35fc7f4630cf57973f071) ### [Building a Zero-License Private Cloud: Step-by-Step Proxmox VE 8 High-Availability Cluster Deployment](https://onliveinfotech.hashnode.dev/building-a-zero-license-private-cloud-step-by-step-proxmox-ve-8-high-availability-cluster-deployment?utm_source=hashnode&utm_medium=feed) Learn how to configure a Proxmox VE 8 HA cluster with Corosync quorum, Ceph distributed storage, VM failover, and backup best practices. 9 min read · [onliveinfotech.hashnode.dev](https://onliveinfotech.hashnode.dev/building-a-zero-license-private-cloud-step-by-step-proxmox-ve-8-high-availability-cluster-deployment?utm_source=hashnode&utm_medium=feed) [Shevchenko Ivan](https://hashnode.com/@SIA13) · [Oct 16](https://hashnode.com/posts/how-to-give-a-pfsense-ha-backup-node-access-to-networks-behind-vpn-tunnels/6ad2131fa80d2f808d30ab2e) ### [How to Give a pfSense HA BACKUP Node Access to Networks Behind VPN Tunnels](https://help.dc24.cloud/how-to-give-a-pfsense-ha-backup-node-access-to-networks-behind-vpn-tunnels?utm_source=hashnode&utm_medium=feed) Fixing a "blind" CARP backup: a role-aware static route via Cron plus LAN firewall rules 7 min read · [help.dc24.cloud](https://help.dc24.cloud/how-to-give-a-pfsense-ha-backup-node-access-to-networks-behind-vpn-tunnels?utm_source=hashnode&utm_medium=feed) [1](https://hashnode.com/posts/how-to-give-a-pfsense-ha-backup-node-access-to-networks-behind-vpn-tunnels/6ad2131fa80d2f808d30ab2e) [Atash Das](https://hashnode.com/@atashdas) · [Oct 15](https://hashnode.com/posts/sap-disaster-recovery-architecture-when-each-tool-earns-its-place/6ad0a17adb151624652751d5) ### [SAP Disaster Recovery Architecture — When Each Tool Earns Its Place](https://atashdas.hashnode.dev/sap-disaster-recovery-architecture-when-each-tool-earns-its-place?utm_source=hashnode&utm_medium=feed) Whitepaper | SAP | AWS | Cloud Architecture | Disaster Recovery 11 min read · [atashdas.hashnode.dev](https://atashdas.hashnode.dev/sap-disaster-recovery-architecture-when-each-tool-earns-its-place?utm_source=hashnode&utm_medium=feed) [Jayesh Sojitra](https://hashnode.com/@jayeshsojitra) · [Oct 13](https://hashnode.com/posts/multi-az-vs-multi-region-what-each-actually-protects-against/6acdfc73fb5da3df24ac0040) ### [Multi-AZ vs Multi-Region: What Each Actually Protects Against](https://jayesh-sojitra.hashnode.dev/multi-az-vs-multi-region-what-each-actually-protects-against?utm_source=hashnode&utm_medium=feed) "We're highly available" can mean very different things. Multi-AZ and Multi-Region protect against different failures, at very different cost and complexity. 4 min read · [jayesh-sojitra.hashnode.dev](https://jayesh-sojitra.hashnode.dev/multi-az-vs-multi-region-what-each-actually-protects-against?utm_source=hashnode&utm_medium=feed) [Usman Khan](https://hashnode.com/@usmankhan-io) · [Oct 5](https://hashnode.com/posts/advanced-system-architecture-multi-region-read-replicas/6ac370d77b92c3ef844b824d) ### [Advanced System Architecture: Designing Multi-Region Read Replicas and Global Data Consistency](https://ctousman.hashnode.dev/advanced-system-architecture-multi-region-read-replicas?utm_source=hashnode&utm_medium=feed) Multi-region read replicas, replication lag, and read-after-write consistency for global SaaS 4 min read · [ctousman.hashnode.dev](https://ctousman.hashnode.dev/advanced-system-architecture-multi-region-read-replicas?utm_source=hashnode&utm_medium=feed) [N Chandra Prakash Reddy](https://hashnode.com/@ChandraPrakash1996) · [Sep 13](https://hashnode.com/posts/aws-outage-a-digital-wake-up-call/6aa6c9760dd0506686a4f75f) ### [AWS Outage: A Digital Wake-Up Call](https://devopstour.hashnode.dev/aws-outage-a-digital-wake-up-call?utm_source=hashnode&utm_medium=feed) Learn why one cloud provider going down takes half the internet with it. 10 min read · [devopstour.hashnode.dev](https://devopstour.hashnode.dev/aws-outage-a-digital-wake-up-call?utm_source=hashnode&utm_medium=feed)