> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-parallel-read-in-order-multi-part.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
> System table containing information about and status of scheduling nodes residing on the local server.
# system.scheduler
**Querying in ClickHouse Cloud**
The data in this system table is held locally on each node in ClickHouse Cloud. Obtaining a complete view of all data, therefore, requires the `clusterAllReplicas` function. See [here](/reference/system-tables/overview#system-tables-in-clickhouse-cloud) for further details.
Description
Contains information about and status of [scheduling nodes](/concepts/features/configuration/server-config/workload-scheduling#hierarchy) residing on the local server.
This table can be used for monitoring. The table contains a row for every scheduling node.
Columns
* `resource` ([String](/reference/data-types/string)) — Resource name
* `path` ([String](/reference/data-types/string)) — Path to a scheduling node within this resource scheduling hierarchy
* `type` ([String](/reference/data-types/string)) — Type of a scheduling node.
* `weight` ([Float64](/reference/data-types/float)) — Weight of a node, used by a parent node of `fair` type.
* `priority` ([Int64](/reference/data-types/int-uint)) — Priority of a node, used by a parent node of 'priority' type (Lower value means higher priority).
* `precedence` ([Int64](/reference/data-types/int-uint)) — Precedence of a node, used by space-shared (memory) parent nodes to order admission and eviction (Lower value means higher precedence).
* `is_active` ([Nullable(UInt8)](/reference/data-types/nullable)) — Whether this node is currently active - has resource requests to be dequeued and constraints satisfied.
* `active_children` ([Nullable(UInt64)](/reference/data-types/nullable)) — The number of children in active state.
* `dequeued_requests` ([Nullable(UInt64)](/reference/data-types/nullable)) — The total number of resource requests dequeued from this node.
* `canceled_requests` ([Nullable(UInt64)](/reference/data-types/nullable)) — The total number of resource requests canceled from this node.
* `rejected_requests` ([Nullable(UInt64)](/reference/data-types/nullable)) — The total number of resource requests rejected from this node.
* `dequeued_cost` ([Nullable(Int64)](/reference/data-types/nullable)) — The sum of costs (e.g. size in bytes) of all requests dequeued from this node.
* `canceled_cost` ([Nullable(Int64)](/reference/data-types/nullable)) — The sum of costs (e.g. size in bytes) of all requests canceled from this node.
* `rejected_cost` ([Nullable(Int64)](/reference/data-types/nullable)) — The sum of costs (e.g. size in bytes) of all requests rejected from this node.
* `busy_periods` ([Nullable(UInt64)](/reference/data-types/nullable)) — The total number of deactivations of this node.
* `throughput` ([Nullable(Float64)](/reference/data-types/nullable)) — Current average throughput (dequeued cost per second).
* `vruntime` ([Nullable(Float64)](/reference/data-types/nullable)) — For children of `fair` nodes only. Virtual runtime of a node used by SFQ algorithm to select the next child to process in a max-min fair manner.
* `system_vruntime` ([Nullable(Float64)](/reference/data-types/nullable)) — For `fair` nodes only. Virtual runtime showing `vruntime` of the last processed resource request. Used during child activation as the new value of `vruntime`.
* `queue_length` ([Nullable(UInt64)](/reference/data-types/nullable)) — For `request_queue` and `allocation_queue` nodes. Current number of resource requests residing in the queue.
* `queue_cost` ([Nullable(Int64)](/reference/data-types/nullable)) — For `request_queue` and `allocation_queue` nodes. Sum of costs (e.g. size in bytes) of all requests residing in the queue.
* `budget` ([Nullable(Int64)](/reference/data-types/nullable)) — For `request_queue` nodes. The number of available 'cost units' for new resource requests. Can appear in case of discrepancy of estimated and real costs of resource requests (e.g. after read/write failure)
* `is_satisfied` ([Nullable(UInt8)](/reference/data-types/nullable)) — For constraint nodes only (e.g. `inflight_limit`). Equals to `1` if all the constraint of this node are satisfied.
* `inflight_requests` ([Nullable(Int64)](/reference/data-types/nullable)) — For `inflight_limit` nodes only. The number of resource requests dequeued from this node, that are currently in consumption state.
* `inflight_cost` ([Nullable(Int64)](/reference/data-types/nullable)) — For `inflight_limit` nodes only. The sum of costs (e.g. bytes) of all resource requests dequeued from this node, that are currently in consumption state.
* `max_requests` ([Nullable(Int64)](/reference/data-types/nullable)) — For `inflight_limit` nodes only. Upper limit for inflight\_requests leading to constraint violation.
* `max_cost` ([Nullable(Int64)](/reference/data-types/nullable)) — For `inflight_limit` nodes only. Upper limit for inflight\_cost leading to constraint violation.
* `max_speed` ([Nullable(Float64)](/reference/data-types/nullable)) — For `bandwidth_limit` nodes only. Upper limit for bandwidth in tokens per second.
* `max_burst` ([Nullable(Float64)](/reference/data-types/nullable)) — For `bandwidth_limit` nodes only. Upper limit for tokens available in token-bucket throttler.
* `throttling_us` ([Nullable(Int64)](/reference/data-types/nullable)) — For `bandwidth_limit` nodes only. Total number of microseconds this node was in throttling state.
* `tokens` ([Nullable(Float64)](/reference/data-types/nullable)) — For `bandwidth_limit` nodes only. Number of tokens currently available in token-bucket throttler.
* `allocated` ([Nullable(Int64)](/reference/data-types/nullable)) — For space-shared nodes only. The currently allocated amount of resource under this node.
* `allocations` ([Nullable(UInt64)](/reference/data-types/nullable)) — For space-shared nodes only. The current number of running resource allocations under this node.
* `updates` ([Nullable(UInt64)](/reference/data-types/nullable)) — For space-shared nodes only. The total number of updates propagated through this node.
* `increases` ([Nullable(UInt64)](/reference/data-types/nullable)) — For space-shared nodes only. The total number of increase requests approved by this node.
* `decreases` ([Nullable(UInt64)](/reference/data-types/nullable)) — For space-shared nodes only. The total number of decrease requests approved by this node.
* `admits` ([Nullable(UInt64)](/reference/data-types/nullable)) — For space-shared nodes only. The total number of allocations admitted by this node.
* `removes` ([Nullable(UInt64)](/reference/data-types/nullable)) — For space-shared nodes only. The total number of allocations removed from this node.
* `killers` ([Nullable(UInt64)](/reference/data-types/nullable)) — For space-shared nodes only. The total number of evictions initiated due to increase requests by this node.
* `victims` ([Nullable(UInt64)](/reference/data-types/nullable)) — For space-shared nodes only. The total number of allocations that were evicted from this node.
* `rejects` ([Nullable(UInt64)](/reference/data-types/nullable)) — For `allocation_queue` nodes only. The total number of resource allocations rejected from this node.
* `pending` ([Nullable(UInt64)](/reference/data-types/nullable)) — For `allocation_queue` nodes only. The current number of pending resource allocations in this node.
Examples
```sql theme={null}
SELECT *
FROM system.scheduler
WHERE resource = 'network_read' AND path = '/prio/fair/prod'
FORMAT Vertical
```
```text theme={null}
Row 1:
──────
resource: network_read
path: /prio/fair/prod
type: request_queue
weight: 5
priority: 0
is_active: 0
active_children: 0
dequeued_requests: 67
canceled_requests: 0
dequeued_cost: 4692272
canceled_cost: 0
busy_periods: 63
vruntime: 938454.1999999989
system_vruntime: ᴺᵁᴸᴸ
queue_length: 0
queue_cost: 0
budget: -60524
is_satisfied: ᴺᵁᴸᴸ
inflight_requests: ᴺᵁᴸᴸ
inflight_cost: ᴺᵁᴸᴸ
max_requests: ᴺᵁᴸᴸ
max_cost: ᴺᵁᴸᴸ
max_speed: ᴺᵁᴸᴸ
max_burst: ᴺᵁᴸᴸ
throttling_us: ᴺᵁᴸᴸ
tokens: ᴺᵁᴸᴸ
```