Expose NDC doc #2915
Expose NDC doc #2915
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| 1. version in the domain belongs to this data center, i.e. | ||
| `(vesion in domain) % (shared version increment) == (this data centers' initial version)` | ||
| 2. the version of this workflow's last event is not less then version in domain, i.e. | ||
| `(last event's version) <= (version in domain)` |
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if 1 is satisfied, what is the case that can lead to last event's version > version in domain?
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all replication tasks are handled asynchronously, meaning that domain replication (change of version) can experience delay.
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| T = 3: domain failover triggered, domain version is now 2 |
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Does it matter whether this is active or passive? Or are they the same (eventually)?
Maybe worth calling out explicitly.
docs/design/2290-cadence-ndc.md
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| Since run 2 appears in data center B first, run 1 cannot be replicated as runnable due to rule `at most one run open` (see above), thus, `zombie` workflow state is introduced. Zombie state indicates a workflow which cannot be actively mutated by a data center (assuming corresponding domain is active in this data center). A zombie workflow can only be changed by replication task. | ||
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| Run 1 will be replicated similar as run 2, except run 1's workflow state will be zombie before run 1 reaches completion. |
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Just curious, where do we keep this state? In DB?
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all persisted to database.
a workflow can potentially turn from a zombie workflow to current running workflow (in this data center), if say there is a data center which only has run 1 (no run 2) & the run 1 is running with a higher version.
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