Hot answers tagged

57

Anyone who has a cached copy of the domain record will not bother updating it for 24 hours, so yes if your intent is to have at most a 5 minute window of unavailability you should wait until all of the outstanding caches have updated to live no more than 5 minutes.


37

It's (potentially) even worse than that -- you have to wait 24 hours after all of your authoritative servers have updated. The normal way for updates to happen is that you make a change to the zone on the primary server, and then each of the secondaries transfer the new zone data the next time they happen to check in with the primary. The check in frequency ...


23

Yes, you should wait. Even then of course it's not guaranteed that everyone will respect the TTL.


13

Roaming user profiles are going to be painful to use via the Internet. Any significant number of files in folders (which the AppData folder is notorious for having) is going to cause painful delays in profile synchronization during logon and logoff. Due to the way profiles are copied (file for file) latency will impact this, though as long as you're using ...


10

The big deal with cloud is flexibility, and you pay a slight premium for it. If you need 5 TB all the time, buying your own hardware is more cost efficient (though you still need to factor in maintenance, warranties, replacement, etc). If you need 5 TB for a short amount of time, renting it through the cloud would be much cheaper than buying all that ...


10

You might take a look if you have not come across this site yet (http://www.datacenterknowledge.com/). A ton of white papers across the topics. Some are "marketie," but still good starting points at the very least.


10

Start with the power. It will pretty easily show you how much of everything else you need. Get a number, maybe ask the electricians, of how many KW or KVA the project is. If it's less than say 12 KW, you are talking a medium size build out. Few racks, say five, a hundred or so servers. 100 * (1 amperes) * (120 volts) = 12 000 watts = 12KW Account for ...


8

Cloud computing of the type popularized by Amazon and Rackspace is not a direct replacement to colocation, or even VPSs. A good breakdown can be found here: http://serverfault.com/a/278547/ Cloud systems help you if you're looking for an elastic infrastructure. If your infrastructure is static, you have X servers and that number doesn't change for months ...


8

In the Advanced TCP/IP settings for the IPv4 and IPv6 configuration of the external adapters, uncheck Register this connection's address in DNS in the DNS tab.


7

You can use the domain name as usual but override the resolver like so: curl -v --resolve subdomain.example.com:443:x.x.x.x https://subdomain.example.com/ It might be awkward to maintain a lot of such mappings though. You might prefer to just ignore the cert mismatch: curl --insecure https://subdomain.example.com/ IF you want, you could use --insecure ...


6

Multicast isn't currently allowed on Rackspace Cloud Servers. The traffic volume of multicast traffic ends up overloading the switching layer and it degrades network performance for all traffic.


6

You need to combine your issued certificate and unencrypted private key into a .pfx file (PKCS#12 format) in order to import it into IIS. Use the following OpenSSL command: openssl pkcs12 -export -out "output.pfx" -inkey "Unencrypted_Private_Key.pem" -in "Issued_Certificate.cer" -certfile CACert.crt The certificate and key files are just text files with ...


6

You should let Google handle the mail reception / sending if your cloud should not take care of it. The MX DNS type is specific to mail and conveniently indicates (with priorities) which server will actually handle mail reception for a given domain. Thus avoiding the need to specify a mail server / subdomain. But it may work also without the mail. prefix, ...


6

It's necessary to do offsite backups at all times, regardless of any guarantees, assuming you care about your data. The ideal solution is to have backups on-site for quick recovery, and backups off-site for disaster recovery, and both backups should preferably be situated on RAID-6 storage.


6

The answer to your question is probably lying in the manufacturer's data sheets: Short answer is that if the gear meets the Cat6 spec's requirements it's a "Cat6 panel" - One manufacturer may just barely meet those requirements, another may meet them with a bit of a margin, and a third may have a wide margin of performance above the requirements of the Cat6 ...


6

Some security defenses: OSSEC IPtables firewall (white list instead of blacklist) SSL for phpmyadmin and certain other pages where you use login data Virus scanner like ClamAV update your machines daily The first one is a well documented Intrusion Detection System the second one is a tool to make firewall rules, it runs on top of netfilter. Backups ...


6

After contacting support, this is the answer they gave: RXTX Factor Aggregate outbound bandwidth, in megabits per second, across all attached network interfaces (PublicNet, ServiceNet, and Cloud Networks). Outbound public Internet bandwidth can be up to 40% of the aggregate limit. Host networking is redundant, and bandwidth is delivered over two ...


5

Very likely. And no - you should not see a difference in ONE string.find method call. The limiting factor on most virutalization platforms is CPU and memory - you only can have that much memory and that much CPU power in one box. So, you have to keep them "aligned" by basically assuming every slice of memory comes with a slice of CPU. As such, a 2gb server ...


5

Amazon allows for static IP's to allocated to its EC2 instances. It is actually a pretty interesting concept that allows you to get a static IP address assigned to your account which you can then point to any particular EC2 instance you have running. So if you take a server down, you point the Elastic IP to a new instance and the outside world still uses ...


5

We use dnsmadeeasy for exact same thing. DNS monitoring and failover would help you with this. For mysql, you can setup 2 way or one way replication; two-way replication is better as you don't have to worry about replicating data back when you switch back. And everything can be completely automated failrly easily.


5

You can do this. Were I you, I would only do this if : You had no need for local servers, at all. Your internet connection was rock-solid.


5

That's completely up to your provider, and ultimately, your selection of a provider. Any shared platform carries risks of your neighbors on the platform causing problems for you. In the case of a DDoS, the shared network infrastructure they're using was probably overrun. Ideally, they would work with their upstream ISPs to drop the traffic before it ...


5

You can use a Cloud Load Balancer to access your Cloud Database over public internet. Here is a link to the documentation Here is a link to the documentation if you want to use SSL Note: Do not add additional nodes behind the load balancer. If you require HA or replication you can create an HA group, or add a replica in your Cloud Control Panel.


5

In addition to the other answers, you can use https://www.whatsmydns.net/ to check how your DNS record is propagating in almost real time.


4

Have you looked at libcloud? http://incubator.apache.org/libcloud/


4

Did you read http://www.rackspacecloud.com/cloud_hosting_products/servers/compare? I'm using Rackspace Cloud Servers and Files for 4 months, and there wasn't any downtime and service outages for this time. Support is great. One thing is valuable: Amazon offers his cloud services in Europe too (Ireland), when Rackspace is based USA only. UPDATE: Now ...


4

I'm not with Rackspace, but having worked for a hosting provider I can give you one general piece of advice: If your provider says something to the effect of "We can't guarantee that X will work" and you elect to do it anyway you are outside of anyone's ability to support you. If it works, "Hey that's great! We're really happy for you!" If it stops ...


4

Almost a year to the day after the original question, I think I have a good procedure set up for downloading Rackspace images and running them locally, under Xen running on Ubuntu Precise. I'll write down the steps here so there's an easy recipe for you to follow if you want to try it out. The steps work for linux/Ubuntu domU's at least, for others YMMV. (...


4

I can see this happening depending on the method Innodb flushes data. Please look into innodb_flush_method used by your MySQL installation. Depending on the value set (O_DSYNC or O_DIRECT), InnoDB could either double buffer to the OS and the InnoDB buffer pool or just the InnoDB buffer pool. If the variable is set to cache to the buffer pool only, I can ...


4

OK, I figured it out. I went one screen too far. On GoDaddy on the main page for the domain, click the "select nameservers" link under the Nameservers heading. I went into the "DNS manager" which is only relevant if you're using GoDaddy's DNS servers.



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