tt_dispatch_prefetch_blocked_count
Name
Prometheus Metric Name
tt_dispatch_prefetch_blocked_count
Metric Path (tt-telemetry)
Schema:
{hostname}/tray{tray}/chip{chip}/cq{cq}/tt_dispatch_prefetch_blocked_count
Example path:
bh-glx-c09u02/tray1/chip2/cq0/tt_dispatch_prefetch_blocked_count
Description
The number of times the prefetch core for this command queue (CQ) became blocked waiting on its upstream (the host) during the last telemetry collection interval. Whereas tt_dispatch_prefetch_waiting_on_upstream is an instantaneous flag, this counts stall events: a rising value means the prefetcher is being starved repeatedly. Correlate the two to distinguish many brief stalls (high count) from one long stall (flag set, low count).
This is a per-interval delta, not a monotonic total. The device-side counter is reset each time
telemetry is read, so each sample reports only the events that occurred since the previous
collection cycle. Do not apply Prometheus rate()/increase() as you would to a cumulative
counter.
A separate metric is emitted for every command queue the chip can support (cq0, cq1, …). CQs
absent from a given read, and chips whose firmware bundle is below version 19.12.0, report the
default value of 0.
Values
Type: Unsigned Integer
Units: None
Allowable values:
A non-negative integer count of prefetch stall events in the last interval. For example, 12 means
the prefetch core blocked on the host 12 times since the previous read.
Prometheus Labels
Label Name |
Value |
|---|---|
hostname |
The host from which the metric was collected. |
hall |
The datacenter hall where the host is located. Sourced from the Factory System Descriptor (FSD). |
aisle |
The datacenter aisle where the host is located. Sourced from the Factory System Descriptor (FSD). |
rack |
The rack number where the host is located. Sourced from the Factory System Descriptor (FSD). |
shelf_u |
The shelf U position in the rack where the host is located. Sourced from the Factory System Descriptor (FSD). |
tray |
The tray (UBB) that the device is located on. |
chip |
The ASIC location within the tray. |
cq |
The hardware command queue index ( |