[HN Gopher] Cell-Based Architecture Explained, with Zombies
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       Cell-Based Architecture Explained, with Zombies
        
       Author : madflojo
       Score  : 33 points
       Date   : 2025-02-06 12:52 UTC (3 days ago)
        
 (HTM) web link (bencane.com)
 (TXT) w3m dump (bencane.com)
        
       | ji_reilly wrote:
       | " A cell router is responsible for detecting failure within a
       | cell (Zombie outbreak) and rerouting requests (Citizens) to other
       | neighborhoods."
       | 
       | Misleading. The difference between a pure horizontally-scaled
       | cluster and cell-based architecture is that traffic destined for
       | a compromised cell does not get routed to a healthy cell. Fault
       | isolation (preventing noisy neighbors and poison pills from
       | spilling over to progressively more cells) is a primary tenet of
       | cell-based architecture.
        
         | HumanOstrich wrote:
         | How would you maintain high availability? I assume something
         | like what AWS proposes[1] where you have an independent routing
         | layer and each cell still has a gateway, but cells do not re-
         | route requests to other cells.
         | 
         | [1]: https://aws.amazon.com/solutions/guidance/cell-based-
         | archite...
        
           | withinboredom wrote:
           | If a cell dies, oh well. You then run a "rebalance" job to
           | move users off the dead cell. If the cell has downtime, that
           | doesn't apply to your overall downtime. In other words, maybe
           | all central-us customers cannot use your service; but it
           | eventually comes back up. If it is dead-dead (ie, nuke or
           | catastrophic failure), then you would migrate those users to
           | a new cell -- at the expense of latency for those users.
        
           | bpicolo wrote:
           | If failed cells cause immediate re-routing to other cells,
           | you get a lot of fun new cascading failure scenarios to think
           | about.
        
           | alienchow wrote:
           | It would be part of your architecture design trade off.
           | Disregarding whatever AWS peddles, you can have a cellular
           | infrastructure (like Google), but have non-cellular systems
           | architecture built on top of it (still deployed across
           | different cells but the dependent services in the critical
           | path residing in different cells or regions depending on
           | resource availability and/or use case). The reroutes can
           | occur at the global load balancer level, or it can happen at
           | your own FE service. Or you could just drain the cell from
           | the load balancer and the client retries go to a separate
           | cell. Or you could have the load balancer not failover at all
           | in case, which is generally the recommendation to prevent
           | cascading failure.
           | 
           | It's down to your own design and acceptable business
           | decisions, and what your business deems as availability.
        
       | HumanOstrich wrote:
       | I'm sure this will come in handy for me at some point. I've led a
       | team through moving parts of their terraform/aws monolith to
       | cells. Some people are able to grasp what cell-based architecture
       | is and when it's useful pretty easily, but for a few it just
       | doesn't click.
        
       | nsbk wrote:
       | I came here for Cell Broadband Engine Architecture and was very
       | excited about the whole zombie idea -_-
        
       | shae wrote:
       | I'd play this tower defense game where I have to organize my city
       | to resist zombies.
        
         | pithanyChan wrote:
         | i can't understand how there hasn't been a single game for the
         | CLI. RTS tower defense, rogue-like & dota, infocom games/caves
         | of qud.
         | 
         | should run on old ThinkPads. uh, maybe you can makes it one of
         | those Challenges @ lewd game weekend hacksaton or something!!!
         | uuuuuh, exciting!
        
       | pithanyChan wrote:
       | what's the refractory period doin in neighboring cells and
       | infected cells? what happens to that mechanism?
        
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       (page generated 2025-02-09 23:01 UTC)