<@U0A71G31CDV> can I measure starrocks shared clus...
# questions-and-troubleshooting
z
@Rocky can I measure starrocks shared cluster -> object store latency and its metrics?
r
Yes, you can measure the latency and performance between a StarRocks shared-data cluster and your object storage (e.g., S3, OSS, GCS). StarRocks provides a comprehensive set of metrics specifically for this purpose, primarily categorized under the Starlet and Shared-data monitoring dashboards. Key Metrics for Object Store Latency These metrics are exported via Prometheus and can be viewed in Grafana: 1. Read Latency (S3/Object Store) *
fslib_read_io_latency
: Provides both quantile (P75, P95, P99) and average latency for reads from the object store. *
fslib_read_iops
: The number of read I/O operations per second. *
fslib_read_throughput
: The I/O throughput (bytes per second) for reads. 2. Write/Upload Latency *
fslib_s3_single_upload_latency
: Quantile latency for S3
PutObject
operations. *
fslib_s3_multi_upload_latency
: Quantile latency for S3 Multipart Upload operations. *
fslib_s3_complete_multi_upload_latency
: Latency for the final "complete" step of a multipart upload. *
fslib_write_io_latency
: Measures application-level write latency. Note that this may appear lower than actual S3 latency because it often reflects writes to an internal buffer. 3. Metadata Latency Since shared-data clusters store metadata on the object store, monitoring these is crucial: *
Get/Put Tablet Metadata Latency
: Latency for fetching or updating tablet metadata. *
Get/Put Txn Log Latency
: Latency for transaction log operations on the object store. Monitoring Tools * Prometheus/Grafana: StarRocks exposes these metrics at the
/metrics
endpoint of the FE and BE (or CN) nodes. * Dashboard Templates: StarRocks provides official Grafana dashboard templates specifically for shared-data clusters: * Shared-data Dashboard for VM * Shared-data Dashboard for K8s Data Cache Impact If you have the Data Cache enabled, some "reads" will be served from local disk/memory instead of the object store. To distinguish between them, monitor: *
fslib_cache_hit_ratio
: A high hit ratio means most reads are staying local, reducing observed query latency regardless of object store performance. *
fslib_cache_hits/misses
: The frequency of local vs. remote access-to-object-store operations. Referencesadministration/management/monitoring/metrics-shared-data.mdusing_starrocks/caching/block_cache.mdadministration/management/monitoring/metrics.mdadministration/management/monitoring/Monitor_and_Alert.md