Skip to content

Monitoring

JUICE module monitoring and metrics.
JUICE module monitoring and metrics.

JuiceFS instances expose Prometheus metrics via juicefs mount --metrics. In JUICE, metrics listen on 0.0.0.0:<port>, default port 9567.

Monitoring Architecture 

JuiceFS Mount (metrics: 0.0.0.0:<port>)
    ↓
VictoriaMetrics (scrape)
    ↓
Grafana Dashboard

If INFRA is deployed, juice_register writes scrape targets to:

/infra/targets/juice/<hostname>.yml

The current source includes the Node JuiceFS dashboard (UID: node-juice) for capacity, cache, object-storage, metadata-transaction, and client-resource metrics across JuiceFS mounts on a node.

Target File Example 

- labels: { ip: 10.10.10.10, ins: "node-jfs", cls: "jfs" }
  targets: [ 10.10.10.10:9567 ]

To register manually:

./juice.yml -l <host> -t juice_register

Key Metrics

Object Storage

Metric Type Description
juicefs_object_request_durations_histogram_seconds histogram Object storage request latency
juicefs_object_request_errors counter Object storage errors

Cache

Metric Type Description
juicefs_blockcache_hits counter Cache hits
juicefs_blockcache_miss counter Cache misses

Metadata Transactions

Metric Type Description
juicefs_transaction_durations_histogram_seconds histogram Metadata transaction latency (histogram)
juicefs_transaction_durations_histogram_seconds_count counter Metadata transaction request count

Common PromQL

Cache hit ratio:

rate(juicefs_blockcache_hits[5m]) /
(rate(juicefs_blockcache_hits[5m]) + rate(juicefs_blockcache_miss[5m]))

Object storage P99 latency:

histogram_quantile(0.99, rate(juicefs_object_request_durations_histogram_seconds_bucket[5m]))