3 ms·
Due to Amdahl's law, you surely don't get 32x write throughput from having 32 write masters however.
by tcoff91 2y ago
Due to Amdahl's law, you surely don't get 32x write throughput from having 32 write masters however.
- mike_hearn 2y agoIt depends a lot on what the query patterns are. If your writes are naturally spread out then yes you can get close because the 32x will be writing to 32 different parts of the database and there won't be cache blocks pingponging around. If all the writes are contending on the same parts of the same tables then you won't get 32x indeed because your queries will be waiting on each other to release locks etc. At least that's my understanding. I've not tuned an app that runs on such a cluster.
- yuliyp 2y agoAmdahl's law doesn't talk about throughput, but latency. You can absolutely get 32x more throughput by having 32 parallel backends. Each individual write won't be 32x faster e2e, but that's not really the point.
- tcoff91 2y agoBut what about when multiple nodes have to coordinate to do a write?