amazon ec2 - During hardware failure, do EBS-based EC2 instances terminate or stop? -

-

amazon's new ebs-based ec2 instances have 2 options shutdown: terminate or stop. stopped instances can later started again, automatically continuing same ebs root disk state had when stopped.

but happens when amazon datacenter has hardware failure, , ec2 instance forced shutdown. terminate or stop? if instance has been configured stop default on shutdown, can rely on being stopped in situation, , being able start again later?

an ec2 instance can terminated @ time , 1 must account indeed, mentioned in david's answer (+1). can arrange failed instance's elastic block store (ebs) remain available regardless though, see e.g. respective faq what happens data when system terminates?:

the data stored on local instance store persist long instance alive. however, data stored on amazon ebs volume persist independently of life of instance. if using amazon ebs volume root partition, you have set delete on terminate flag "n" amazon ebs volume persist outside life of instance. [emphasis mine]

this explained in more detail in section 2. delete on termination within eric hammond's recommended article three ways protect ec2 instances accidental termination , loss of data:

though ebs volumes created , attached instance @ instantiation preserved through “stop”/”start” cycle, default destroyed , lost when ec2 instance terminated. behavior can changed delete-on-termination boolean value buried in documentation --block-device-mapping option of ec2-run-instances.

he referring ec2-run-instances documentation, , meanwhile illustrated in more detail within amazon ec2 root device storage concepts well:

by default, root device volume , other volumes created when amazon ebs-backed instance launched automatically deleted when instance terminates [...]. can change default behavior setting deleteontermination flag value want when launch instance. example of how change flag @ launch time, see using amazon ec2 root device storage.


Comments

Post a Comment

Popular posts from this blog

javascript - Enclosure Memory Copies -

-
function myclass() { //lots , lots of vars , code here. this.bar = function() { //do numerous enclosed myclass vars } this.foo = function() { alert('hello'); //don't enclosed variables. } } each instance of myclass gets own copy of bar , foo, why prototyped methods use less memory. however, know more memory use of inner methods. it seems obvious me (1) below must true. agree? not distinct myclass instances have own distinct copies of bar, must have own distinct copies of myclass enclosure. (or else how bar method keep myclass variables straight on per instance basis?) now (2) question i'm after. since inner foo method doesn't use in myclass enclosure natural qustion is: javascript smart enough not keep myclass enclosure in memory use of foo? this depend entirely on implementation not language. naive implementations keep far more around others. answer true e.g. v8 (chrome's js engine) may not true spider...
Read more

php - Replacing tags in braces, even nested tags, with regex -

-
example preg_replace('/\{[a-za-z.,\(\)0-9]+\}/', 'replaced', 'lorem ipsum dolor sit {tag1({tag2()})}, consectetur adipiscing elit.'); the result: lorem ipsum dolor sit {tag1(replaced)}, consectetur adipiscing elit. question as can see "tag2" has been replaced, want replace "tag1" know how can this? (in cases might this: {tag1({tag2({tag3()})})}) , on.) btw using preg_replace_callback, easier show preg_replace here site can test code: http://www.spaweditor.com/scripts/regex/index.php you need add curly braces character set. here's pattern used: /\{[a-za-z.,\(\)\{\}0-9]+\}/ and here result: "lorem ipsum dolor sit replaced, consectetur adipiscing elit."
Read more