> On Mar 1, 2024, at 11:36 AM, normandavis1990 <normandavis1...@proton.me> > wrote: > > > On Thursday, February 29th, 2024 at 11:38 PM, Israel Brewster > > <ijbrews...@alaska.edu> wrote: >>> On Feb 29, 2024, at 10:15 AM, David G. Johnston >>> <david.g.johns...@gmail.com> wrote: >>> >>> >>> >>> On Thursday, February 29, 2024, normandavis1990 <normandavis1...@proton.me >>> <mailto:normandavis1...@proton.me>> wrote: >>>> >>>> What is the difference between High Availability and Replication? >>> >>> The former is a goal, the later is a technique. >> >> Perhaps more specifically: Replication is simply Replicating - or copying - >> the “master” database to one or more “slave” databases, generally in >> real-time such that the slave database clusters are replicas of the master. >> This is good when the master goes down, because you’ll still have one or >> more copies of it available, but by itself it doesn’t keep there from being >> an outage if/when the master goes down. >> >> High Availability layers on top of replication to provide some means of >> ensuring that the database is HIGHLY available, such as an automatic >> failover system or load balancer. Many different options that work in many >> different ways are available to help meet this goal. >> --- >> Israel Brewster >> Software Engineer >> Alaska Volcano Observatory >> Geophysical Institute - UAF >> 2156 Koyukuk Drive >> Fairbanks AK 99775-7320 >> Work: 907-474-5172 >> cell: 907-328-9145 >> >>> >>> David J. >>> >> > > > Hi, > You said "This is good when the master goes down, because you’ll still have > one or more copies of it available, but by itself it doesn’t keep there from > being an outage if/when the master goes down.". What does "goes down" mean?
Exactly what I said - it goes down. Not functioning. Offline. Inaccessible. It is not up and running, therefore, it is down. > In Replication mode, if the primary server is shut down, then the data will > also be lost? No. As I said - and you quoted - “When the master goes down…you’ll still have one or more copies of it available”. So no, the data will NOT be lost. --- Israel Brewster Software Engineer Alaska Volcano Observatory Geophysical Institute - UAF 2156 Koyukuk Drive Fairbanks AK 99775-7320 Work: 907-474-5172 cell: 907-328-9145
