Query Metrics
Query metrics overview
Prometheus in Hydrolix
The Hydrolix stack includes Prometheus, an open-source metrics database. Hydrolix continuously updates its Prometheus instance with metrics information.
You can query, view, and actively monitor this information using a stack's Grafana instance, or you can access it with your own monitoring platform. See Prometheus Integration for more information about setting up Prometheus with an external server.
Use multiple components with a metric
If more than one component uses a given metric, querying it will return results from all relevant components. You can restrict results to a specific component by adding a service keyword to your query.
For example, "process_open_fds{service="stream-peer"}".
For a list of all Hydrolix metrics, see All Metrics.
Query metrics
These metrics track activity specific to querying.
| Metric Name | Type | Components | Purpose |
|---|---|---|---|
net_connect_attempts_total | Histogram | Head/Query peer | Histogram of TCP connection attempted to storage service |
net_connect_seconds | Histogram | Head/Query peer | Histogram of time to connect over TCP to storage service in seconds |
net_dns_resolve_seconds | Histogram | Head/Query peer | Histogram of DNS resolution time to storage service in seconds. |
net_http_response_time | Histogram | Head/Query peer | Histogram HTTP response time to storage service in seconds |
net_http_response_bytes | Histogram | Head/Query peer | Histogram of HTTP bytes downloaded from the storage service |
net_http_attempts_total | Histogram | Head/Query peer | Histogram of HTTP connection attempted to storage service |
net_http_status_code | Histogram | Head/Query peer | Histogram of HTTP status code result from storage service |
vfs_cache_hitmiss_total | Histogram | Head/Query peer | Histogram of cache status if bucket = 0 cache miss, and 1 cache hit |
vfs_cache_read_bytes | Histogram | Head/Query peer | Histogram bytes read from cache |
vfs_net_read_bytes | Histogram | Head/Query peer | Histogram bytes read from network |
vfs_cache_lru_file_eviction_total | Histogram | Head/Query peer | Histogram cache eviction of files |
epoll_cpu_seconds | Histogram | Head/Query peer | Histogram CPU used in seconds |
epoll_io_seconds | Histogram | Head/Query peer | Histogram I/O in seconds |
epoll_poll_seconds | Histogram | Head/Query peer | Histogram wait for file descriptor in seconds |
hdx_storage_r_catalog_partitions_total | Histogram | Head/Query peer | Histogram of per query catalog partition count |
hdx_storage_r_partitions_read_total | Histogram | Head/Query peer | Histogram of per query partition read count |
hdx_storage_r_partitions_per_core_total | Histogram | Head/Query peer | Histogram of per core partition used count |
hdx_storage_r_peers_used_total | Histogram | Query peer | Histogram of storage used total |
hdx_storage_r_cores_used_total | Histogram | Query peer | Histogram of Cores used total |
hdx_storage_r_catalog_timerange | Histogram | Head/Query peer | Histogram of query time range distribution |
hdx_partition_columns_read_total | Histogram | Head/Query peer | Histogram of column read |
hdx_partition_block_decode_seconds | Histogram | Head/Query peer | Histogram of time spent decoding hdx blocks in seconds |
hdx_partition_open_seconds | Histogram | Head/Query peer | Histogram of time spent opening hdx partition in seconds |
hdx_partition_read_seconds | Histogram | Head/Query peer | Histogram of time spent reading hdx partition in seconds |
hdx_partition_skipped_total | Histogram | Head/Query peer | Histogram of partition skip count due to no matching columns |
hdx_partition_blocks_read_total | Histogram | Head/Query peer | Histogram of partition read count |
hdx_partition_blocks_avail_total | Histogram | Head/Query peer | Histogram of partition blocks available |
hdx_partition_index_decision | Histogram | Head/Query peer | Histogram of partition decision if bucket = 0 fullscan, 1 partial scan and 2 no match |
hdx_partition_index_lookup_seconds | Histogram | Head/Query peer | Histogram of index lookup in seconds |
hdx_partition_index_blocks_skipped_percent | Histogram | Head/Query peer | Histogram of skipped index blocked in percentage |
hdx_partition_index_blocks_skipped_total | Histogram | Head/Query peer | Histogram of skipped index blocked in total |
hdx_partition_rd_w_err_total | Histogram | Head/Query peer | Histogram of errors if bucket = 0 read error, 1 written error and 3 error |
query_iowait_seconds | Histogram | Head/Query peer | Histogram query IO wait in seconds |
query_cpuwait_seconds | Histogram | Head/Query peer | Histogram query cpu wait in seconds |
query_hdx_ch_conv_seconds | Histogram | Head/Query peer | Histogram of time spent converting hdx blocks to clickhouse in seconds |
query_health | Histogram | Head/Query peer | Histogram of query health if bucket = 0 initiated error, 1 succeeded and 2 error |
query_peer_availability | Histogram | Head/Query peer | Histogram of query peer availability if bucket = 0 primary_peer_available, 1 secondary_peer_available and 2 no_reachable_peers |
query_attempts_total | Histogram | Head/Query peer | Histogram of query attempts total |
query_response_seconds | Histogram | Head/Query peer | Histogram of query response total in seconds |
query_rows_read_total | Histogram | Head/Query peer | Histogram of query rows read total |
query_read_bytes | Histogram | Head/Query peer | Histogram of query read bytes total |
query_rows_written_total | Histogram | Head/Query peer | Histogram of query rows written total |
For a complete list of the metrics used by Hydrolix, including Prometheus, RabbitMQ, and others, see All Metrics.
Updated 28 days ago