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Questions tagged [availability]

The tag has no usage guidance.

0
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2answers
36 views

What availability is needed for an E-Mail server to not lose messages?

Setting up an E-Mail server, I wonder, what if it goes down. Do I need a redundant setup in order to not lose incoming mails? Or would it suffice to make sure it doesn't go offline for longer than, ...
1
vote
1answer
22 views

Will having 2 web app instances ensure availability incase of WPA problems?

I have an azure web app (S2 app Service plan) that is set to autoscale but has a min instance count of 1. As it mostly idles, the real instance count also is 1 almost all of the time. Last week "...
0
votes
1answer
92 views

Reliable way to check server availability

I am using scheduler/API to scan target machines for Vulnerabilities(Using Nessus). But before the scan starts, I want to check if the servers are available or not for scan. I understand from this ...
0
votes
1answer
61 views

When an ISP is DDoSed, will its NOC have Internet access?

When an ISP is hit by a huge DDoS attack and its data plane is severely congested, will its Network Operations Center (NOC) have alternative Internet access? I'm curious what would be the industry ...
0
votes
1answer
73 views

Courier IMAP server and availability

i manage a little mail server based on Ubuntu Server, with: exim4 courier imap server spamassassin clamav to serve 20 users mailbox. It works well, but i'd like to put in service a second server with ...
4
votes
3answers
359 views

Availability at risk due to one offline Domain Name Server?

A domain can have plenty of name servers registered at there domain registrar. The name servers are picked randomly and not like expected primary first, secondary second and so on. Knowing that, ...
0
votes
1answer
316 views

F5 LTM The time between a node going down and a health check failing

Simple question but I couldn't find an answer online. Suppose the following scenario plays out: The node to receive traffic next becomes unresponsive before a health check can be initiate when it ...
3
votes
1answer
2k views

EC2 Bandwidth between two instance in same availability zone

I'm using an Apache proxy on one server in front of tomcat on a different server. What is the the bandwidth between the two EC2 instances if they are in the same availability zone? Does this have ...
-1
votes
1answer
27 views

Interchanging remote hosting with computer hosting vs. displaying availability state of computer hosting on remote website [closed]

Recently, I bought a domain kkziomek.eu. The root domain is hosted on a remote hosting. I added a subdomain "komputer.kkziomek.eu" which is hosted on my computer. To do that I created a subdomain, ...
0
votes
1answer
66 views

azure availability set second VM shuts down first VM

I've got two Ubuntu VMs in one availability set. When I start the second VM it takes a few minutes and the first VM stopps. I'm a bit helpless (beginner) here. Any advice would be very apprechiated.
1
vote
1answer
2k views

Unable to configure port mapping for Azure availability set in the new portal

Where is the option to configure port mappings in the new Microsoft Azure portal (http://portal.azure.com)?
0
votes
0answers
233 views

NewRelic Availability Monitoring of Third Party Service

Background NewRelic offers availability monitoring whereby you can specify a ping URL for an application and have NewRelic send HTTP GET requests to that URL and GREP the response for selected text, ...
1
vote
0answers
36 views

Amazon EC2 instance was not available for few minutes (amazon showed that everything ok)

Few minutes ago my amazon Ec2 instance was unavailable for a few minutes. During this time neither I was able to connect to web-site with http, nor I was able to ssh to it. Also I was not able to ...
2
votes
1answer
123 views

Website not available everywhere

Today I noticed my website http://mint-nachhilfe.ch/ was down, but other people (located in different networks) said it looks up from there. When I came home, I double-checked, and I can really reach ...
1
vote
1answer
52 views

Using Dynamic DNS for server reboots

Basically, I want all the traffic to go to one server while the other reboots. Here's the environment: Two or more VPS servers. Same datacenter, but no internal ip or lan, and no shared ip. I was ...
-1
votes
1answer
158 views

Choosing a database management system to maximize availability and scalability [closed]

If I was planning on choosing a database management system and know that the data needs to be available as close to 100% as possible and that it needs to scale as well as possible, is there a "best" ...
2
votes
1answer
904 views

How to check if redis master is OK?

On the documentation, they advice the monitor command. But it has a 50% performance penalty for the whole system, and how should I do that ? Whatching the ouput using SSH until I don't see anything ? ...
0
votes
2answers
116 views

Immortal application

(TL;DR: last paragraph) I'm running an online service and have thusfar been doing offline backups and simple monitoring to achieve resilience and availability. Resilience is rather manual but I'm ...
5
votes
1answer
2k views

Determine availability zone of AWS IP address

I'm currently using Heroku (which uses AWS) and my program needs to communicate with my own EC2 instance. I've made my EC2 instance in the same Region as Herokus', however, in order to reduce costs ...
89
votes
14answers
68k views

Is Ping a reliable way to check if a server is available?

In my application I am pinging a server and waiting for a response. I am using this to determine whether the server is available and responsive or not. Is this a reliable way of determining ...
2
votes
0answers
710 views

Exchange 2003 to 2010 migration: Can I remove free/busy public folder once all users are moved?

Now that all my mailboxes are on the 2010 server, can I remove the schedule+free/busy public folder? I am having scheduling synchronization issues, and I believe it may be at fault. All clients are ...
2
votes
5answers
561 views

Check availability of my websites

How can I check the availability of websites from hosted by company? Ping the server and checking if the services for IIS or Apache/Tomcat is not enough. I want to see if the sites are responsive, if ...
4
votes
4answers
405 views

System Monitoring Redundancy

I consult in a small business environment where I have two HyperV hosts (with <10 VMs) + a couple other servers. I recently had an issue where one of the HyperV hosts had a CPU issue and it came ...
1
vote
1answer
404 views

Swapping db's to increase availability during database update

I have a SQL server database with data supplied from a 3rd party. They supply a tool to update the database data weekly. The tool is pretty old and uses ODBC. The update can take several hours. In ...
0
votes
4answers
340 views

ngnix reverse proxy [closed]

Most of the configuration and example I've seen out there, the backend server are either on the same machine or the same network network. Has any body done this with backend servers located in ...
8
votes
3answers
1k views

How to manage communication during application downtime?

I've had a lot of experiences lately with application downtime, from both vendors and my own applications. This has got me thinking and as best I can google there isn't really a good or standard way ...
0
votes
1answer
52 views

Fixing the accesibility of a webserver

I have my server, which is hosted in datacenter, and there is a website and a database installed on this server. DNS servers for the domain name are the default ones of the domain name registrator. ...
1
vote
2answers
99 views

http server connectivity puzzle

I have been seeing some strange connection issue in the production environment. The setup has two IBM Http Server's (IHS) and a network IP load-balancer in front of them (round-robin). One instance ...
1
vote
2answers
2k views

Lifetime of IIS worker process or AppDomain

I have an ASP.NET app hosted in IIS, and I have automatic worker process recycling/shutdown disabled. I'd like to have a rough idea of how long the app has been running continuously without being re-...
3
votes
6answers
4k views

uptime.exe crashing on Windows Server 2008

Can anyone get uptime.exe to run either the /s or /p:n switches on a Windows Server 2008 box without crashing? I realise it's a NT tool and no longer supported, but it worked fine on 2003. I've ...
1
vote
2answers
1k views

How can I tell which package updates will require a reboot or service restart?

One of our boxes is running Ubuntu 8.04 LTS. Most Ubuntu package upgrades are trivial and don't affect availability much. How do I tell which packages are going to cause an outage before applying them?...