Questions tagged [high-availability]
High availability is an architectural consideration often involving degrees of redundancy to insure availability in case of system or component failure.
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3-node Pacemaker setup shows 1 node 2 times, with the same name, one online and one offline
So I've got: machine001, machine002, machine003.
machine001 has 2 resources, machine002 has 1 resource. Normally they don't go on the same host, unless machine002 goes in standby.
Recently, I saw ...
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Windows Server quorum concept and split-brain issue prevention
I saw a similar question asked here that is closely related, but the provided answer doesn't entirely address my doubts.
Assume a 3 node cluster is configured without a witness node, and all nodes are ...
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Can not start etcd cluster when setting up a HA K8S cluster
I am following this article to set up a HA k8s cluster:
Guide: Kubernetes Multi-Master HA Cluster with kubeadm
I have three master nodes(3,4,5) and four worker nodes(2,6,7,8) (one of the worker nodes ...
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How do I (automatically) re-attempt to deliver mail from a different Postfix server?
My network consists of two different locations and in both I have a Postfix server running for outgoing mail on each of them. Mail gets submitted to any of the two round-robin, based on having them ...
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HAProxy and postgres
My haproxy configuration is as below, in the backend there is pg_autoctl cluster, another VM (bunty4) hosts the monitor and haproxy is installed on it.
global
maxconn 100
defaults
log global
...
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Load balance the Load balancer
I am looking to get load balancing for my load balancer.
We are looking to create a fully HA network.
All of our servers are redundant, the databases are redundant, but above them is a single server ...
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communication failure between availability zones in one region in AWS
Is there a possibility for communication failure between availability zones in one region in AWS(assuming both AZs are up but only network communication failure)? If there is communication failure, is ...
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Getting error when stop & deallocate two VMs in an availability set to perform updates
I am trying to stop & deallocate two VMs in an availability set to perform updates,
getting this error.
Provisioning failed. Delete/Deallocate operation on VM 'ncsas-qvhapp001' failed because the ...
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Seeking Advice re. IPFS Clustering - Overhead, Performance, Design Guidance
I’m about to rebuild a server cluster - currently set up for high reliability & availability - RAID, disk mirroring, automatic failover, all that good stuff.
I’ve been thinking about replacing the ...
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What is the best way to set up Prometheus + Alertmanager with a HA
I have a monitoring solution that uses Prometheus as a scraper and a data storage, Grafana as a visualiser and Alertmanager as an alerting tool. This all is running on a single server.
However, there'...
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keydb active-replica multi-master php session storage
I'm looking to use keydb/redis for php session storage in a HA setup. Currently, I have two keydb instances running with the following config:
Instance 1 (192.168.2.10)
requirepass pass123
masterauth ...
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Pacemaker fence_drac5 agent ... cannot see where to specify password
I am setting up a pacemaker cluster with two nodes on Ubuntu Server 22.04.
Both are Dell servers with a fully licensed idrac module, so I would like to use the drac5 stonith agent to make the cluster ...
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Programmatically (SH Script) check which server is traffic routed too by HA Proxy
I have 2 HA Proxy servers with Keepalived configured with them, and have 2 backend servers to which traffic is routed by HA Proxy, am writing a shell script that will sync a directory between backend ...
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Install HA Kube
I've tried following various different guides on installing HA kube and I cant get anything to work.
My basic setup is to have 3 master nodes with Keepalived creating a virtual IP (10.10.20.30) and ...
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Will anycast failover to the next server if it encounters a 404 from an nginx server?
I know that anycast will failover for layer 3 issues but will anycast failover if a file is not present? I.E. like a 404?
It seems like it won't, like as long as nginx returns something anycast will ...
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How to have two applications accessing a shared drive without isci config or shared lun?
We have a 2-node cluster configured using red hat high availability (pacemaker) but without shared storage i.e. each of the node has its own disk /dev/sda and /dev/sdb.
We are not allowed to configure ...
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JBoss - JNDI Name not found on server startup
I'm deploying an app locally to an EAP 7.2 server and I'm seeing my bean being deployed and the options are available. However when the HA timer goes to start it cannot find the JNDI name.
I've tried ...
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Restrict WFCS Cluster Shared Resource to certain nodes
I have 2 CSV resources on a single WFCS cluster that spans to both Primary and DR data centers. The CSV is getting shared with all the nodes in the cluster. Ideally, I want the Primary CSV should be ...
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How to configure Keepalived Virtual IP?
I've been researching about Keepalived Virtual IP to make ProxySQL/MaxScale highly available and came across the concept of Virtual IP. All the articles that I've read just mentions a random Virtual ...
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How to create shared folder with Linux Samba Cluster that is accessible by Windows? (Two PCs in cluster with one IP)
does anyone know how to create a shared folder in any distribution of Linux that could be accessible by Windows and would be HA (high available)?
Background:
I have Windows Server cluster and it needs ...
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DRBD does not sync files even though it is UpToDate
I recently set up a DRBD replication on two nodes, did the setup, mounted the drbd disk with "create-md", "up", "connect", etc.
I, apparently, was successful when it ...
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Can enabling load balancing on a cluster jeopardise high availability?
I'm considering enabling load balancing on our data gateway clusters for Power BI, where we have two servers in a cluster, and the secondary is configured as a failover for the primary (only ...
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Can the mounted file system (NFS) be kept on another host if the VM is evacuated?
I'd like to know about OpenStack High Availability.
If the node (VM) mounts the file system (NFS) (https://docs.openstack.org/cinder/latest/admin/nfs-backend.html) and the VM is evacuated in case of ...
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Configure and connect fence device through proxy server?
I'm setting up a cluster with Pacemaker and Corosync (from Clusterlabs).
It works fine but i need to configure the fencing.
Servers run on a VMWare ESXi infrastructure.
I have a frontend server (with ...
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How can we move secondary IP address of from one NIC to other in Azure
I want to implement HA system on azure, for that I need to move secondary IP address of active vm to standby vm as soon failover happens, how can we do this?
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redundant load balancer for Tomcat
I have three Tomcat webservers in a VMWare cluster.
In the first place we thought of using Apache as a load balancer in physical server but this would be a SPOF.
I have searched around and I found ...
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How can I assign same private IP 10.3.3.51 to two azure vm having differnt MAC address? only one vm will be providing service at a time
I have two vms behind the Azure Load balancer working as High availability that is only one vm is providing service at a time, other vm will be in passive state. I want to keep same IP address 10.3.3....
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Keepalived going split brain when Firewalld is running
I'm using keepalived to provide availability between two Alma 8 Nginx servers (hosted on VMWare if that's of any relevance). When firewalld is enabled, despite a rich rule being set for VRRP, when I ...
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RabbitMQ quorum queues - have node automatically rejoin
I am exploring RabbitMQ quorum queues to improve HA for some services in a Kubernetes cluster. As I am reading, they are designed with data safety in mind.
However, the chapter "Managing Replicas&...
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Apache limits errors when scalling with many domains for Saas app
**Hello everybody ,
I making SaaS app like Shopify and ecwid ,
user create store within 10 mins , once he register he get automatic subdomain with SSL and can add products and payment methods, ...
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On Debian system, keepalived is consuming full cpu usage on both kibana nodes
I have master/slave kibana machines on Debian 10. From few days, cpu usage of keepalived daemon on both nodes are reaching to 100%. After keepalived restart it goes to normal, and this loops forever.
...
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Pacemaker/Corosync: how to emergency-shutdown all resources (VMs qemu/kvm)
Good morning everyone -
Running a 6 node Pacemaker/Corosync cluster with lots of productive qemu/kvm VMs on it, we were wondering how to best do an "emergency shutdown" of the whole lot, ie. ...
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How does hybrid unicast/anycast work for global load balancing?
In the Dropbox Edge network write up, the author mentions that they have taken a hybrid approach by announcing both unicast and anycast ip of PoP.
One can enable this hybrid GSLB by announcing both ...
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How to improve my current HA design
I am trying to create high availability application. My current design has two VMs, both have public IPs, both are running in same subnet and both VMs have same web application running in docker. ssl ...
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HA in k8s cluster in case of node failure pointed by A record of domain
I've got a question of "what if" kind
Suppose there is a Kubernetes cluster with 4 nodes and some domain which points to IP of node no 1 and web app using this domain having 1 pod per node. ...
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Generic high availability abstraction for application possible? [closed]
I am currently examining the possibilities to make our existing server application highly available. The software handles messages that come via UDP resp. some higher level railway-specific protocols.
...
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Configuring STONITH on non-shared disk cluster
I have configured a 2 node (VMs) cluster with SUSE High Availability Extension.
The cluster doesn't use shared disk. So Stonith is not really required. But the cluster keeps on asking for Stonith.
So ...
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High availability with round robin - rsync and DB replication or a cluster?
I have one machine (centos7) with Apache, PHP, MariaDB and Nginx, Nodejs, MongoDB installed and being used by many different domains.
I'd like to create a working mirror and can't decide between 2 ...
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How to deploy multi master Microsoft SQL database as IaaS or AWS RDS
We have a vendor product, which support only relational databases (Oracle and MS SQL). Due to operational efficiency and cost, we are planning to use MS SQL. However, we have a challenge to deploy the ...
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2 Different Public Address for High Availability
this is my first time asking a question here, and I was wondering is it possible to have two different ISP public IPs connected to a single system for high availability?
for example, if our ISP 1 ...
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Best practices for updates
We have a lot of Linux servers (Red Hat Enterprise Linux Server 7.9 running vmware) and most of the services are in containers docker. We want to implement a policy of updating our systems with ...
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What exactly is a floating IP and how does it work?
I am setting up a high availability load balancer. I found this tutorial from Digital Ocean which says that two load balancers can share a common floating IP.
https://docs.digitalocean.com/products/...
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NFS instance in availability zone - AWS
My team has the task to build a plan in case the AZ that has the NFS instance fails. This NFS instance shares files with others machines (NFS clients) in others AZ (we use North of California).
We ...
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Using (dual) ATS for dual PSU server?
There's two parts to my question:
Does it make sense to hook up a dual PSU server to an ATS to speed up failover to the secondary circuit?
If yes, does it make sense to use two separate ATSes to ...
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Mirroring Traffic with Nginx(to increase avaliablity and decrease latency )
I need to duplicate/mirror the traffic comming to my server.
I mean, I have N backend servers A1 A2 ... An(n>=2) and a nginx as reverse-proxy&load-balancer.
All the traffic comming to Nginx ...
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Data consistency in SQL AlwaysOn Availability Group
I have an AlwaysOn cluster of SQL Server 2019, containing an Availability Group of 3 replicas in Synchronous mode.
According to Microsoft documentation:
The secondary replica hardens the log and ...
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Need a simple High Availability file share
I am looking for the simplest way to share a single file in a high availability way between a pair of linux servers. (Version and distribution are unimportant, I'm looking for a generic solution.)
I ...
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load balance for kubernetes master on different subnet
I'm trying to build an architecture for new k8s cluster with master HA on different sites (different subnets).
The issue I'm facing is finding an open source Software Load Balance (there is no ...
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VLAN - Network Redundancy With Same 2nd Switch?
Is it possible to set up the same VLANs on two different switches with same IPs, but different MACs on dual port network cards of servers? In case switch 1 is down or needs maintenance I would like ...
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Centos 7, HA postgresql12, patroni with etcd v3.4
I followed this document but dont know how to enable v2 so that patroni can work with, can anyone help?
https://computingforgeeks.com/setup-etcd-cluster-on-centos-debian-ubuntu/
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