Ok - that makes sense, but if trying to reach the master before it's up is causing the delay - how can we fix that? This would almost always happen whenever there is activity to the database and a failure occurred.
On Apr 7, 5:56 am, Nickolas Toursky <[email protected]> wrote: > Hi Cole, > > When you first requested int-mysql-master IP address, it probably > failed to resolve and a negative response (NXDOMAIN) was cached for > 300 seconds. This could happen if you are requesting int-mysql-master > IP before it was fully initialized. > > Nick > > On Apr 7, 7:17 am, Cole <[email protected]> wrote: > > > If this is true, then what could be causing the delay? > > > Thanks, > > Cole > > > On Apr 6, 4:15 pm, Nickolas Toursky <[email protected]> wrote: > > > > Hi Cole, > > > > This value is intented to be used as the minimum possible TTL for the > > > zone as per RFC 1035, but in fact it only reflects negative caching > > > time to live. In other words, for this number of seconds NXDOMAIN > > > reponse (DNS entry not found) is returned by resolver after it has > > > failed to resolve domain name. > > > > Regards, > > > Nick > > > > On Mon, Apr 6, 2009 at 9:07 PM, Cole <[email protected]> wrote: > > > > > If you are logged into Scalr and on the Home tab, just click > > > > applications, then in your application (must be running), under > > > > options select "Edit DNS Zone". Once you have the DNS options up, you > > > > will see right at the top Minimum TTL listed as 300 -- and you can not > > > > change this value. Any ideas? > > > > > Thanks, > > > > Cole > > > > > On Apr 2, 8:08 pm, Alex Kovalyov <[email protected]> wrote: > > > >> On Thu, Apr 2, 2009 at 8:36 PM, Cole <[email protected]> wrote: > > > > >> > In Scalr's DNS I have noticed the is has a setting for Minimum TTL > > > >> > which cannot be changed, and is set at 300. > > > > >> May I ask you to point me to the place where you're seeing this value? > > > > >> > overriding the 20 ttl for the int-myswl-master. Is there anyway to > > > >> > change this so that the DNS updates quickly in case of a failure? > > > > >> > On Apr 2, 2:04 am, Cole <[email protected]> wrote: > > > >> >> Hi, > > > > >> >> Thank you so much for your response, it was very helpful. > > > > >> >> I have a few morequestionsas well. > > > >> >> I have setup a mysql farm on scalr with 3 instances, but I am having > > > >> >> trouble accessing the master through a Windows instance that is also > > > >> >> on the same AWS account. This windows instance is hosting the domain > > > >> >> name I own. > > > > >> >> The issue is that after I shut down the master mySql server (to > > > >> >> simulate a crash) and let a slave automatically promote itself to a > > > >> >> master, it takes a long time for the DNS (5 minutes at least) to be > > > >> >> correctly resolved on this windows instance. > > > > >> >> If from a cmd prompt I do: > > > >> >> nslookup int-mysql-master.db2test.mydomain.com > > > > >> >> I will get the follow response: > > > >> >> Server: ip-172-16-0-23.ec2.internal > > > >> >> Address: 172.16.0.23 > > > >> >> *** ip-172-16-0-23.ec2.internal can't find int-mysql- > > > >> >> master.db2test.forexonthego.com: Non-existent domain > > > > >> >> The odd thing though, is if I keep doing the nslookup, after a while > > > >> >> it will finally show me the correct address, at which point I can > > > >> >> then > > > >> >> login to mysql through the int-mysql-master. If I just use the > > > >> >> correct internal IP that scalr shows in the dns panel, I can log in > > > >> >> that way (long before the dns starts resolving correctly). > > > > >> >> Incase this helps, in Scalr the dns settings for the things I can > > > >> >> change are: > > > >> >> www 14400 IN CNAME db2test.mydomain.com. > > > >> >> db2test.mydomain.com. 14400 IN NS ns3.scalr.net. > > > > >> >> At godaddy (my domain registra) I added to the name servers to have > > > >> >> db2test pointing to ns1.scalr.net, ns2.scalr.net, and ns3.scalr.net > > > >> >> Any ideas for this? > > > > >> >> Thanks, > > > >> >> Cole > > > > >> >> On Apr 1, 10:03 am, Nickolas Toursky <[email protected]> wrote: > > > > >> >> > Hi Cole, > > > > >> >> > 1. MySQL data snapshotting routine locks databases for write > > > >> >> > queries > > > >> >> > for some time, but they are still available for reads. Lock time > > > >> >> > heavily depends on data storage engine chosen. For large > > > >> >> > databases you > > > >> >> > should consider using either LVM or EBS storage. Anyway, exact > > > >> >> > lock > > > >> >> > time could only be determined experimentally for your setup. > > > > >> >> > 2. Databases backup feature uses 'mysqldump' utility with all of > > > >> >> > its > > > >> >> > dis/advantages. Backups are stored on S3. Again, backup time > > > >> >> > depends > > > >> >> > on many factors and could not be predicted in general. > > > > >> >> > 3. If EBS was chosen as data storage engine, all the EBS > > > >> >> > management > > > >> >> > will be done automatically. You don't have to setup > > > >> >> > volumes/snapshots > > > >> >> > on the EBS tab. > > > > >> >> > 4. All the availability zones in the US are placed on the east > > > >> >> > coast. > > > >> >> > If you need your instances to be in the different availability > > > >> >> > zones, > > > >> >> > you should choose 'Place in different zones' option for > > > >> >> > 'Placement' in > > > >> >> > the role settings ("Placement and type" tab). > > > > >> >> > 5. int-mysql subdomain round-robins through all the MySQL > > > >> >> > instances, > > > >> >> > this is correct. You should use int-mysql-master for write > > > >> >> > queries. > > > > >> >> > Nick > > > > >> >> > On Wed, Apr 1, 2009 at 8:01 AM, Cole <[email protected]> > > > >> >> > wrote: > > > > >> >> > > Hello, > > > > >> >> > > I've just setup Scalr so that I can get some highly available > > > >> >> > > MySQL > > > >> >> > > servers up on EC2. I am new, and looking for any documentation > > > >> >> > > or > > > >> >> > > info about Scalr, and I can't hardly find anything, so if you > > > >> >> > > know of > > > >> >> > > any, please point me in the right direction. > > > > >> >> > > In the mean time, I have a fewquestionsthat would really help > > > >> >> > > me out > > > >> >> > > if you could answer. > > > > >> >> > > 1. When setting up a mysqllvm farm, if I enable "Bundle and > > > >> >> > > save mysql > > > >> >> > > data snapshot every 48hrs" Will the database be unavailable > > > >> >> > > while the > > > >> >> > > bundle is taking place? If so, how long will it be unavailable? > > > > >> >> > > 2. If I enable "Periodically backup databases every 15 mins" > > > >> >> > > will the > > > >> >> > > backup cause any interruption to the database service? If so > > > >> >> > > how > > > >> >> > > long, and what type of backup is being performed (an export?) > > > >> >> > > and > > > >> >> > > where is it stored? > > > > >> >> > > 3. If under storage engine in the MySQL Settings tab I select > > > >> >> > > EBS, do > > > >> >> > > I need to also specify to attach an empty EBS volume under the > > > >> >> > > EBS > > > >> >> > > tab? Or will doing that create a second EBS drive? > > > > >> >> > > 4. When I build a farm I have to select an east or west coast > > > >> >> > > region. > > > >> >> > > How can I put a slave in a different zone for redundancy? > > > > >> >> > > 5. In the information I could find, Scalr uses a single master > > > >> >> > > multi > > > >> >> > > slave system for MySQL -- but DNS round robins, so that write > > > >> >> > > could go > > > >> >> > > to any of the instances, not just the master. This seems more > > > >> >> > > like a > > > >> >> > > master-master setup. Which one is it? And is there some type > > > >> >> > > of > > > >> >> > > locking mechanism that prevents errors, such as a primary key > > > >> >> > > being > > > >> >> > > issued to two different instances at the same time? > > > > >> >> > > Thanks in advance for you help, > > > >> >> > > Cole --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "scalr-discuss" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/scalr-discuss?hl=en -~----------~----~----~----~------~----~------~--~---
