Troubleshooting a projection Added in 1.10.0
Diagnosing a projection that is behind, stalled, or producing the wrong document — fleet triage through CritterWatch's shipped MCP tools (GetProjectionLag, ListShardHealth, GetBacklogState, ListBacklogHotspots, dead letters) and per-event drill-down with the JasperFx.Events projection-run CLI, which replays a stream, slice or tag query and shows the before/after state at every step. Covers the two altitudes and when to switch, reading a Failing shard's exceptionType (ApplyEventException, EventDeserializationFailureException, UnknownEventTypeException, ProgressionProgressOutOfOrderException, EventLoaderException, ShardStartException) and what the SkipApplyErrors defaults make a pause mean, where each store keeps projection dead letters, what restarts a paused shard under each daemon mode, reading a step timeline to find the apply that is wrong, and the schema failure that looks like a broken command.
Use when a projection is lagging, stuck, paused, stopped, or quietly producing a wrong value.
Skill details
- Skill name:
critterstack-projection-troubleshooting - Applies to:
marten,polecat,fisher,wolverine - Tags:
marten,polecat,fisher,projections,troubleshooting,critterwatch,mcp,cli,debugging,daemon,dead-letters,ApplyEventException,ProgressionProgressOutOfOrderException - Added in: 1.10.0
- License: Proprietary. Copyright JasperFx Software LLC.