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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corosync + pacemaker + nginx

I have been trying to configure and implement corosync + pacemaker + nginx to my vbox to create a High-Availability set-up between web servers. But can't find an exact tutorial on how to make it work ...
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8answers
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Alternatives to Heartbeat, Pacemaker and CoroSync?

Are there any major alternatives for automatic failover on Linux besides the typical Heartbeat/Pacemaker/CoroSync combinations? In particular, I'm setting up failover on EC2 instances, which only ...
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1answer
26 views

High availability of http service

I know this has been discussed many times. I read a lot about the subject. Let's say I want to have a failover between http services (a static web server, a load-balancer..) From what I understand, ...
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2answers
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corosync fails to install

I was trying to setup cluster using corosync and pacemaker on RHEL6 (CentOS release 6.5) I have added following repo data [haclustering] name=HA Clustering type=rpm-md baseurl=http://download....
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0answers
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Why does DFSZKFailoverController kills Namenode process in hadoop?

I try to configure hadoop high availability cluster by following this tutorial: http://www.edureka.co/blog/how-to-set-up-hadoop-cluster-with-hdfs-high-availability/ When I follow that article I faces ...
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1answer
1k views

Using LVS (Linux Virtual Server) for doing DNS HA

I have been trying to create an LVS DNS HA using CentOS 6.x: Piranha GUI to configure the DNS Pulse is the HA heart of CentOS LB IPTables to configure marks on the packets since DNS uses TCP and UDP ...
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0answers
10 views

Pacemaker: disallow resource on stopped node

I have a slave-ip resource which I'd like to locate on my slave under normal operation in a 2 node PostgreSQL cluster for read-only purposes. All is fine, right till the point of failure of the ...
3
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1answer
138 views

DNS issue with Failover IP from Hetzner

Assume we have two servers A and B with 'real' and external IPs and we can switch the so called 'failover ip' (W.X.Y.Z) to point to a specific external IP of A or B. This works from the 'outside' and ...
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2answers
540 views

How to create a high-availability application server?

I am working with some hardware units which uses mobile Internet to communicate to my application server. Initially, the hardware had a hard-coded IP address (load balancer) in the hardware for ...
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1answer
22 views

System outage when only one of two HAProxy servers is down. Failover doesn't seem to be working

First of all my experience with HAProxy stack is just one day old so I hope my question makes sense. I have 2 HAProxy VMs and 2 Apache VMs (vagrant machines) as follows. 192.168.50.11 HAPROXY VM1 ...
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0answers
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Tradeoffs between cross-cloud and cross-AZ-single-cloud deployments

We have a educational system (federated microservices that are running mostly on AWS EC2, RDS MySQL and a message queue) that is already distributed across regions, primarily for latency hiding, ...
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2answers
2k views

Multi-site high availability

We have a SaaS application that we need to be highly available. We already have an expensive, well-maintained Hyper-V failover cluster, but today the datacenter where we host that cluster had a five-...
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1answer
20 views

Exchange Server 2013, Database Availability Groups, NAT, and High Availability

Dilemma here I want a high availability/failover solution for people accessing outlook anywhere or exchange from outside the network. I have 2 exchange servers (EXCH1 and EXCH2) that have Exchange ...
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1answer
24 views

Disable VM Autostart - XenServer

After running updates in XenServer 6.5 I noticed that some virtual machines that were recently turned off started turning on again automatically after the server I applied updates to restarted. When ...
2
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2answers
110 views

Linux HA Cluster: running a resource as non-root user

i'm have successfully setup the HA cluster using pacemaker and corosync on centos7, and i've also been able to add and start resources. one of the resources is an instance of tomcat, and in the ...
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7answers
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Mathematically, how to calculate an uptime percentage based on a number of nodes and their respective uptime percentage?

This question is more of a math question than a server question, but it is strongly server related. If I have a server that I would be able to guarantee 95% uptime and I would put that server in a ...
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2answers
1k views

Xen Remus setup

Currently, I'm running the IT for a small organization, and we just purchased a new server to replace our aging Dell poweredge. As the Dell isn't so bad as to be junk, I was hoping to set up Xen on ...
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0answers
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HA CloudStack with storage on 2 'micro cloud' chassis

I have 2x Supermicro 5038ML-H8TRF micro clouds's (8 independent hot swappable servers in a 3u chassis). I want to setup a HA private cloud. Basically each chassis will have 1 Management & 3 VM ...
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1answer
1k views

Exchange 2010 DAG Failover Cluster DNS Issues

I am having an issues with my Exchange 2010 servers. I have two servers that have HUB/CAS/MAILBOX installed on them. They are configured to use DAG failover cluster. I expereienced an issue recently ...
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2answers
62 views

crm status : 0 nodes and 0 resources configured

I've configure corosync and then I got these issue 0 nodes and 0 resources configured. [root@sitampan2 verdana]# crm status Stack: unknown Current DC: NONE Last updated: Thu Jun 16 15:15:40 2016 ...
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1answer
36 views

Error configuring File Share Witness in a Windows 2012R2 Cluster

I'm learning how to configure a simple W2012R2 Cluster for a AlwaysOn Basic Availability Group. I have this VM scenario: - 1 DC (outside the cluster) - 2 SQL Server Standard 2016 (in a Cluster) I'...
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2answers
45 views

Load Balancing & High Availability Network Limitations

I'm in the process of coming up with a highly available Apache / MySql group of virtual servers using HAProxy Reverse Proxy & Keepalive. I'm aware that I'm going to be using a floating public ip, ...
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1answer
22 views

HA Swarm cluster with docker-machine

I have a Swarm cluster which currently only has a single master. So far the whole thing has been deployed using docker-machine. I have another node that I would like to use as another master. When I ...
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1answer
63 views

how to cache contents in HAProxy [closed]

global log /dev/log local0 log /dev/log local1 notice chroot /var/lib/haproxy stats socket /run/haproxy/admin.sock mode 660 level admin stats timeout 30s user haproxy group haproxy daemon # ...
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0answers
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AWS VPC equivalent to CARP across multiple AZs

I'm presently trying to setup a HA MySQL environment within an AWS VPC. The basic setup will involve having a MySQL server in each of the availability zones, with one acting as master and the other ...
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0answers
187 views

How to use Docker with HAProxy+Keepalived?

I want to practise in creation of high-available web-application using multiple Docker containers on one machine. I launch several web-servers within Docker containers. Say, three servers rest1, ...
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1answer
26 views

Cisco 1921, SMTP, and NAT on multiple Exchange Servers

In a LAN environment, I have 3 exchange servers that have been deployed for high availability and failover in case one of the 3 servers becomes unavailable. Currently, my NAT settings only send ...
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0answers
40 views

How can I configure a single-node cluster on RHEL 7?

For particular purposes, I'd like to know how can I configure a RHEL 7 HA cluster with only one node (of course, no HA will be available in this scenario). The following article says that single-node ...
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0answers
64 views

Zookeeper can work with Pacemaker?

As mentioned in the title, do you think Zookeeper can work with Pacemaker instead of Corosync? Is there any examination about that? Thanks for your help!
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0answers
31 views

Configure STONITH for esxi host CentOS guests

I am just doing some initial researching into STONITH and am finding that it can require Hardware to reset the failed nodes. Something called an IPMI can be used. I was wondering how something like ...
7
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2answers
20k views

How to setup STONITH in a 2-node active/passive linux HA pacemaker cluster?

I am trying to setup an active/passive (2 nodes) Linux-HA cluster with corosync and pacemaker to hold a PostgreSQL-Database up and running. It works via DRBD and a service-ip. If node1 fails, node2 ...
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1answer
66 views

Proxmox HA Cluster tiebreaker node

I want to setup a Proxmox HA Cluster using a quorum for reducing the risk for a split-brain. So I need 3 nodes. Is it possible for one of the nodes to just act as a tiebreaker node without running any ...
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2answers
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pacemaker corosynce lsb resource script( Sybase Database ASE Server and Backup Server)

I'm trying to create a lsb resource with pcs on rhel7.2 The "sybase" script is about Sybase Database ASE Server and Backup Server Startup & Stop & Restart $ status script Before [root@...
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1answer
61 views

Passing SAN Storage to Virtual Machine in active/passive HA Cluster

I need to attach a fibre channel SAN disk to one virtual machine that resides on an active/passive cluster (pacemaker, corosync). As it is the backup storage, corruption has to be strongly avoided. ...
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0answers
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PowerHA 7 for AIX 6.1: Modifying the IP source for outgoing packages

I've clusterized a server which has ip address 10.10.10.10/24 (example ip) For that I added two new nodes with ips 10.10.10.11 and 10.10.10.12 and changed the ip 10.10.10.10 to the service IP address....
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1answer
124 views

How does systemd decide if a service is ok or not

This question is related to: reliable systemd service for autossh I have a service which uses type=simple. Here the systemd docs: Type=simple (default): systemd considers the service to be ...
0
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1answer
31 views

How to calculate SLA Availability

Imagine that we have an API service with 99,9% of Availability. So this API can be down just 1m 26.4s daily. So how do I measure if an API is down? IMO, i need a sampling rate, in the SLA contract ...
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0answers
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Can we make a cpp application as HA using keepalived? [closed]

I have 2 servers running the same c++ application, but the application in master server recieves the calls. Once the application goes down in master, slave becomes master and recieves the calls. This ...
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0answers
14 views

Auto Power On Xenserver 6.5

After applying updates to my xenservers I noticed VM's that were turned off turned themselves on after the server I applied updates to rebooted. I do not have any vApps configured and I did not ...
0
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0answers
53 views

How can I configure Consul to health check connectivity from a client node to service nodes?

I'm a Consul and HA newbie and trying to evaluate how I could go about configuring certain requirements in this tool. I want to have a service configured on multiple nodes allowing client nodes to ...
0
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1answer
82 views

Can't start VM OpenNebula

I have 3 nodes with CephRBD + OpenNebula + Corosync + Pacemaker + Galera + crmsh. Software: OpenNebula 4.14.2, CentOS 7.1 All works, but when I instantiate VM, a get an error and VM in PENDING ...
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0answers
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Can I run Tomcat with mod_proxy_ajp and rolling upgrade automatically?

I have 4 Tomcat servers and 1 Apache HTTPD server and run mod_proxy_ajp: <Proxy balancer://cluster> BalancerMember ajp://10.27.1.21:8009 BalancerMember ajp://10.27.1.21:9009 ...
0
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1answer
365 views

Windows 10 Offline Files will not Sync

Brand new domain using Windows 10 workstations and Server 2012 R2 Domain Controllers. Standard folder redirection GPO Picture of the issue: Files are being redirected to a windows 2012 r2 high ...
3
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2answers
103 views

Hyper-v failover or replication in 2 node cluster

I'm trying to setup some form of a failover cluster between 2 hosts. I want to be able to have high availability on 2 of my VMs. It seems that some form of shared storage is required for this to work ...
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2answers
38 views

Using a load balancer in front of many sites

Is there any reason not to use a software load balancer / proxy in front of many small websites for admin purposes. I work for a web design agency where we have maybe 30-40 small to medium websites ...
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4answers
534 views

How can I create a “fail whale” for my website?

I have a website that we load-balance across a few machines. The load-balancer (a Brocade ServerIron ADX) is on the local network. I know it has the capability to configure a "backup" ip address to ...
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1answer
332 views

Docker Swarm and Consul production setup recommendation

I'd like to set up a production HA Docker Swarm cluster. Docker Swarm needs a Key Value store as a precondition, consul in this case. Now I'm asking what a clever setup would be: Consul should run ...
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0answers
64 views

Why Redis Sentinel can't manage 2 master servers?

I'm trying to configure Redis to have a master in each of our two main data centers. But the second Redis master keeps being demoted to slave of the first sentinel array. My version is 3.0.5. In each ...
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5answers
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Setup for high availability virtualized environment

For a project I have the task of planning a high availability setup for a web shop and CMS system. However, of course the project is on a tight budget. So a high end solution might not be in the ...
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2answers
341 views

Is it not possible to use keepalived in EC2

The problem is two of my EC2 instances (ha proxy) need to bind a single virtual IP if I want to use keepalived, but they are not possible in EC2 as only a single instance can use a elastic IP at a ...