Manually resets the circuit breaker for a table's maintenance operations, re-enabling operations that were automatically suspended after repeated failures.
RESET CIRCUIT BREAKER <table>## Overview RESET CIRCUIT BREAKER manually resets the circuit breaker for a Delta table's maintenance operations. The maintenance scheduler uses a circuit breaker pattern to protect the system from cascade failures. When maintenance operations (VACUUM, OPTIMIZE, ANALYZE) fail repeatedly, the circuit breaker trips to an open state, suspending further maintenance attempts for that table. ## Circuit Breaker States The circuit breaker follows a standard three-state model: - **Closed** (normal): Maintenance operations are allowed. Each failure increments a counter. When the failure count exceeds the threshold within the observation window, the breaker transitions to Open. - **Open** (suspended): No maintenance operations are attempted. After a configurable cooldown period, the breaker transitions to Half-Open. - **Half-Open** (probing): A single maintenance operation is allowed as a probe. If it succeeds, the breaker returns to Closed. If it fails, the breaker returns to Open with an increased cooldown (exponential backoff). ## When to Use RESET CIRCUIT BREAKER is used after the root cause of repeated maintenance failures has been resolved. Common scenarios include: - Storage connectivity issues that have been fixed. - Permission problems that have been corrected. - Corrupted table metadata that has been repaired (via FSCK REPAIR). - Resource exhaustion (memory, disk) that has been alleviated. After resetting, the circuit breaker returns to the Closed state, and maintenance operations can resume immediately. ## Result Set Returns a message confirming the reset and reporting the circuit breaker's new state. ## Access Control | Privilege | Object | Notes | |-----------|--------|-------| | Ownership or write | Table | Required to modify the table's maintenance state. | ## Compatibility RESET CIRCUIT BREAKER is a DeltaForge extension for managing the maintenance scheduler's circuit breaker. The circuit breaker pattern is part of the DeltaForge maintenance infrastructure and has no equivalent in the base Delta Lake protocol.
| Name | Type | Description |
|---|---|---|
table | Specifies the name or path of the Delta table whose circuit breaker should be reset. The table must be registered in the session. Fully qualified names (zone.schema.table) are supported. |
-- Reset the circuit breaker for a table
RESET CIRCUIT BREAKER orders;-- Reset after resolving an underlying storage issue
RESET CIRCUIT BREAKER warehouse.sales.transactions;-- Reset and then retry the failed maintenance operation
RESET CIRCUIT BREAKER events;
VACUUM events RETAIN 168 HOURS;