Because then you run into an issue when you 'n' changes. Plus, where are you increasing it on? This will require a single fault-tolerant ticker (some do that btw).
Once you encode shard number into ID, you got:
- instantly* know which shard to query
- each shard has its own ticker
* programatically, maybe visually as well depending on implementation
I had IDs that encode: entity type (IIRC 4 bit?), timestamp, shard, sequence per shard. We even had a admin page wher you can paste ID and it will decode it.
id % n is fine for cache because you can just throw whole thing away and repopulate or when 'n' never changes, but it usually does.
alt Hacker News
Because then you run into an issue when you 'n' changes. Plus, where are you increasing it on? This will require a single fault-tolerant ticker (some do that btw).
Once you encode shard number into ID, you got:
- instantly* know which shard to query
- each shard has its own ticker
* programatically, maybe visually as well depending on implementation
I had IDs that encode: entity type (IIRC 4 bit?), timestamp, shard, sequence per shard. We even had a admin page wher you can paste ID and it will decode it.
id % n is fine for cache because you can just throw whole thing away and repopulate or when 'n' never changes, but it usually does.