High availability is an architectural consideration often involving degrees of redundancy to insure availability in case of system or component failure. Highly available systems are commonly implemented in situations where the risk outweighs the cost. Best practices such as change control, ...
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1answer
68 views
High availability architecture for a small business
We are a small startup. In our current setup we have a dedicated server in a remote location. Our website and applications are hosted in that server. Website and some applications are in PHP and the ...
0
votes
1answer
40 views
Ganeti vs Proxmox
I'm system administrator in small software house. I'm going to virtualise our servers. The main reason for doing this is providing highest possible uptime, but probably it will also increase resources ...
6
votes
2answers
99 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 ...
-1
votes
1answer
37 views
corosync active-active with 2 virtual IPs - clone constraints task
I have DNS roundrobin on 2 virtual IP in front of service. (Among others the service tested was: apache, nginx, varnish, postfix, … It really does not matter. Let's call it just service.)
I ...
1
vote
0answers
25 views
repcached broken sync - memcached high avalaibility
I have been using repcached (memcached-1.2.8-repcached-2.2)to store php sessions in order to have a highly available memcached. Everything runs perfect, I can restart a daemon without losing sessions.
...
1
vote
0answers
11 views
Are there any advantages in SQL Server Always On vs. SQL Server 2008 R2 Mirroring with only two nodes? [migrated]
We are currently hosting a SaaS website on two Windows 2008 R2 / SQL Server 2008 R2 Servers. Would upgrading to SQL Server 2012 / Always On give us any advantages with respects to high availability?
...
3
votes
1answer
119 views
HA Setup for MySQL/mostly MyISAM Tables
I am currently using Master-Slave Replication, seperating reads from writes at the application level.
The only kind of failover currently implemented is application level detection of master failure, ...
0
votes
1answer
39 views
Office network failover? [closed]
Possible Duplicate:
What hardware do I need to add a backup internet connection?
I have a office LAN providing internet access to several workstations. Each workstation is basically ...
2
votes
1answer
30 views
Availability & Scaling : Three Tier or Two Tier
I began working on a three -Physical- tier website (UI:MVC / Application:REST / DB), I've always considered that three tier is more scalable than two (taboo for high traffic websites), but lately i ...
1
vote
0answers
39 views
What are the exact storage requirements for an AlwaysOn implementation?
We're investigating implementation options for SQL Server AlwaysOn.
AlwaysOn is dependant on Windows Clustering, and I have read several articles that state shared storage is no longer a requirement ...
1
vote
2answers
127 views
Convert HyperV Servers in to HyperV Cluster
We have 2 Hyperv Servers and a SAN. When they were configured, High Availability wasn't on the horizon. But it is now.
Can I convert the current servers in place to use Failover Clustering?
Or
...
0
votes
1answer
83 views
Simple Load Balance Architecture
We currently have a simple 3 server setup:
Cloud NGinx/Apache web server (NGinx serves static, dynamic is proxied to Apache/PHP backend)
Dedicated Database server
Cloud Outgoing email + monitoring ...
0
votes
1answer
41 views
HA set-up for hornetq
i am absolutely new in this area and we are going to set-up hornetq as a MOM in our production servers soon. after reading the documents, i was thinking that it will be good to have client side ...
1
vote
4answers
192 views
DNS Round Robin: Do browsers stick to one IP as long as it is online?
How do most browsers behave if they get multiple A-records from the DNS server? Do the stick to one IP as long as it is reachable (and only use another if the IP is down)? Or do they switch all the ...
0
votes
1answer
48 views
How to approach high availability and fail-overs when moving to a vmWare cloud server/cluster
I'm currently running a CentOS VPS with some simple web/DB/VPN servers, but I'm planning to move to a vmWare Enterprise cloud based machine in the near future to improve availability, and I need to ...
-1
votes
0answers
86 views
Strange summary in pgpool-admin
I want use pgpool 3.1 with three postgres 9.1 in replication mode. I edit pgpool.conf.sample-replication (code below). While testing all seems fine but when i install pgpool-admin in summary i have ...
0
votes
1answer
90 views
Cheap, reliable high availability solution?
We're looking for a way to improve the reliability of one of our servers (Apache/MySQL/Virtualmin setup).
So far, we've had every possible kind of clusterfuck with that server in the past six months ...
3
votes
1answer
71 views
MySQL on VMware for High Availability
Given a choice between the current database-level HA options for MySQL, like Master-Master, Cluster, or Galera, and vSphere HA for the machine running the MySQL master, which would you use or combine ...
0
votes
0answers
31 views
Failover clustering without losing client connections
I need to deploy an FTP server in a high-availability configuration.
So far I've used Windows Failover clustering (using Win 2k8 Enterprise) and DRBD in Linux. Both do enable me to develop a failover ...
0
votes
1answer
103 views
Cisco Switch connected to 2 routers
I have following setup:
The router on the left is a router on a stick to route traffic within the LAN that has different VLANS.
The left switch is the root switch for our LAN and works as the VTP ...
3
votes
3answers
207 views
How can I load-balance a load balancer?
I'm about to convert a single-server single-database web application into a physically distributed high-available configuration with servers on two physical locations (for now). Now, obviously, I need ...
0
votes
1answer
80 views
Network GURUs - IP failover combined with load-balancing… Is there such software? Is it possible?
I've been playing around with high-availability solutions for a few days and so far I find UCARP very useful for IP fail-overing.
It's dead simple and does the job.
I was thinking about taking it a ...
1
vote
1answer
137 views
How do I load balance between two Linux machines?
Inspired by the Stack Overflow network, I am now obsessed with HAProxy and trying to use it myself.
At the moment, each HAProxy box has got two network cards (well, two configured, I can have a ...
1
vote
1answer
140 views
Keepalived for more than 20 virtual addresses
I have set up keepalived on two Debian machines for high availability, but I've run into the maximum number of virtual IP's I can assign to my vrrp_instance. How would I go about configuring and ...
0
votes
2answers
76 views
heartbeat: find out machine's status within a cluster?
I'm trying to do some heartbeat debugging.
Is there a simple way to ask a machine whether it thinks it's part of a cluster, and whether it's the master or the slave?
I've tried
$ heartbeat -s
...
2
votes
1answer
101 views
heartbeat: Bad nodename in /etc/ha.d//haresources [node1]
I'm trying to start heartbeat on Ubuntu 10.04 with service heartbeat start, but getting the following errors:
heartbeat[24829]: 2011/11/22_19:31:07 ERROR: Bad nodename in /etc/ha.d//haresources ...
0
votes
1answer
118 views
Heartbeat (without ldirectord etc) for a floating IP address?
I have two load-balancing servers running mod_proxy_balancer. Each server balances between two web servers.
Now I'd like to find a way to share a single IP address between those two load-balancing ...
5
votes
2answers
93 views
Insufficient channel capacity of 1GBit
There is a Caching Server (Varnish): it receives data from Amazon S3 on request, saves it for some time and gives it to the client. We have encountered the problem of insufficient channel capacity of ...
-1
votes
1answer
59 views
How to use AppScale
There are some wiki which explain how to install and setup AppScale.
But I didn't find anything related to the extensive use of AppScale. I mean, what to do in case of major outage ?
If the node ...
1
vote
0answers
106 views
Kerberos high availability failover, Apache Mod_auth_kerb, Using the Kerberos slave is slow
We host our own Redmine rails web application internally with Apache using Mod_auth_kerb and our internal Kerberos for authentication.
We have 2 internal Kerberos servers KDC1 and KDC2. KDC1 is ...
1
vote
2answers
151 views
High Availability and Load Balancing for MySQL and Jetty
I'm about to deploy two distinct systems: A MySQL cluster and a cluster of Jetty web-servers.
1. SOFTWARE
I can get more linux servers for the HA/LB, but which software should I use? I'm with ...
1
vote
2answers
57 views
Configuring high-availability with snapshots
I wanted to know if it is possible to configure HA in VMware vSphere to start virtual servers using snapshots.
For example, if one of my physical server fails, the virtual machine would start on ...
0
votes
1answer
75 views
Solid failover for IIS and ASP.NET MVC?
Our team is currently planning our next big project which looks to be an exciting one!
We our product will be an ASP.NET MVC site which can either be deployed on a customers own server or they can ...
3
votes
3answers
244 views
What is the difference between Anycast and GeoDNS / GeoIP wrt HA?
Based on the Wikipedia description of Anycast, it includes both the distribution of a domain-name-to-many-IP-mapping across many DNS servers as well as replying to clients with the most geographically ...
6
votes
1answer
112 views
Stretched datacenter between cities
We're planning to implement a stretched datacenter between our two sites. The connectivity between them is a single 100mbit QinQ connection. We have about 500 users at site A and 200 users at site B. ...
1
vote
0answers
110 views
xen cluster multiple nodes
I'm looking for information on how to build a Xen HA cluster with multiple nodes. I find lots of information on how to build clusters with two nodes, but that is really not enough. I've built one with ...
0
votes
1answer
86 views
MSSQL: High-Availability, Witness and Principal down case
The Setup is as follows:
1x Principal
1x Secondary
1x Witness
If the Witness and Principal are gone (Hardware- or networkfailure), the secondary DB stays offline. I know this is by design. But if ...
-1
votes
1answer
46 views
remote gateway and web servers down [closed]
I was asked this challenging question, which was quite tricky.
It goes like this.
Say there is a clustered environment of 40 web servers and the website is unfortunately down. You are in a remote ...
0
votes
4answers
134 views
How to build a redundant linux system? [closed]
What's the best path to build a FOSS rock solid redundant cluster with a bunch of atom servers?
Looking at beowulf, heartbeat, linux-ha they haven't evolved much lately, or am I wrong?
regards,
//t
0
votes
0answers
63 views
VPS hosting with IP failover across datacenters
Is there any VPS hosting that would allow IP failover (or remapping) across different datacenters ? The only one I aware of is EC2 with their Elastic IP.
What I'm trying to achieve is to have servers ...
0
votes
1answer
38 views
MySQL Replication with “same value wins” conflict resolution for updates
I have set up normal (non-clustered, ndb) two server Mysql Master-Master replication for high availability. Each server has an application that can update the local database, the changes propagate to ...
0
votes
2answers
77 views
loadBalancing/clustering on IIS/ASP.Net/SQL Server
I've to create an offer for a future ASP.NET application. They wants an high availability(99.9%+).
So I'm searching the best solutions with .Net technologies(asp.net mvc 3, IIS 7, SQL Server 2008 R2) ...
2
votes
2answers
103 views
VMware High availability, does it protects from unexpected OS crashes ?
We have an legacy but very important app running on windows server 2003. App itself doesn't support any kind of HA and it's not the most reliable piece of software.
Last week we had a special ...
0
votes
2answers
152 views
How can I make a high available tomcat cluster with no single point of failure?
I've surfed the web and tried to find a way in order to make a tomcat cluster with no single point of failure , and all what I have found is that I need something called dispatcher which will be ...
1
vote
1answer
54 views
Tomcat7 parallel deployment feature: experiences using it on production servers?
We are looking into Tomcat 7's feature to allow multiple versions of the same webapp deployed at the same time:
http://www.tomcatexpert.com/blog/2011/05/31/parallel-deployment-tomcat-7
...
1
vote
1answer
147 views
Heartbeat is giving me a heartache
I have 2 Ubuntu 11.04 VM's on which i have installed Heartbeat + apache2 to achieve a "high availability" setup. Heartbeat is up and running on both but im not able to ping the Virtual IP (cluster ip)
...
3
votes
3answers
126 views
Should redundant servers have exactly the same configuration, or slightly different?
If you provide a service on two servers to ensure high-availability, is it better to configure them in exactly the same way, of instead should you introduce slight differences to prevent "freak ...
0
votes
0answers
33 views
Networking -Geographically separated N-M failover node cluster with Pacemaker
I am trying to use Pacemaker and create a multi-node cluster which is geographically separated nodes. I have the following questions..
. Is it possible without a shared data resources?
Each of ...
0
votes
0answers
92 views
Glusterfs for mirrorring Postfix directories
I am trying to create a mail server setup with 1 main server and 1 or more mirrored slave servers. I mounted /var/vmail as glusterfs with data (in gluster terms posix storage) in /data/export. This ...
5
votes
3answers
460 views
What exactly does Gluster do?
I've been playing with gluster for the last 2 days and been asking questions here and on their questions system.
I really don't understand some of the stuff. I see people saying stuff like
Set up ...
