Slow writes on Upstash Global: every write goes to the primary region first

TL;DR: Write-heavy workloads stay slow on Global databases because every write goes to the primary region first. Use regional for writes. Check which region is primary in the console. Measure write latency from your app region versus from the primary region.

The fix

1. Check which region is primary in the console.
2. Measure write latency from your app region versus from the primary region. If primary-region writes are fast and yours are slow, it is distance, not load.
3. Check your write/read ratio. Above roughly 30% writes, you are in write-heavy territory for this architecture.
4. Move the primary region to where most writes originate.
5. Split the workload: a regional database for the write-heavy parts, Global for the read-heavy parts.
6. If writes must be fast globally and consistent, Upstash Global is the wrong tool. Say so early rather than tuning around it.
7. This covers exactly what the title says: Slow writes on Upstash Global.
8. You are setting this up for the first time, or auditing an existing setup.
9. You want the key gotchas in one place before you start.
10. You are doing a different workflow with Slow; these steps are specific to the title above.
11. You need the full reference docs; this is the short path, not the manual.
12. Not pinned to a specific version; follows current Slow behavior.

When to use this

• This covers exactly what the title says: Slow writes on Upstash Global.
• You are setting this up for the first time, or auditing an existing setup.
• You want the key gotchas in one place before you start.

When not to use this

• You are doing a different workflow with Slow; these steps are specific to the title above.
• You need the full reference docs; this is the short path, not the manual.

Verified against Upstash global database docs: writes are sent to and processed at the primary region then replicated; the design optimizes READ latency and may not suit WRITE-heavy use cases; pick the primary region where writes happen. Source: https://upstash.com/docs/redis/features/globaldatabase