The Hydrolix stack includes Prometheus, an open-source metrics database. While the Stack runs, Hydrolix continuously updates its Prometheus instance with metrics information. You can query, view, and actively monitor this information through the use of a stack's Grafana instance or you can access it via your own monitoring platform.

Using Prometheus directly

Prometheus has its own web-based UI, available by visiting https://<YourHostname/prometheus in your web browser.

This view is far more basic than Grafana's, suitable for quickly entering queries and seeing simple, graphed results. Hydrolix does make this feature available immediately, without any additional setup.

Hydrolix's metrics

This table lists the metrics available, and which components update them.

If more than one component uses a given metric, then 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, e.g. "process_open_fds{service="stream-peer"}".

For more information about metric types, refer to Prometheus's documentation.

Streaming metrics

HTTP Stream Ingest

These metrics are specific to the use of streaming data sources.

Metric	Type	Components	Purpose
`http_source_byte_count`	Counter	Stream head	Count of bytes processed.
`http_source_request_count`	Counter	Stream head	Count of http requests.
`http_source_request_duration_ns`	Histogram	Stream head	A histogram of HTTP request durations in nanoseconds.
`http_source_request_error_count`	Counter	Stream head	Count of http request failures.
`http_source_row_count`	Counter	Stream head	Count of rows processed.
`http_source_value_count`	Counter	Stream head	Count of values processed.
`kinesis_source_byte_count`	Counter	Stream peer	Count of bytes read from Kinesis.
`kinesis_source_checkpoint_count`	Counter	Stream peer	Count of Kinesis checkpoint operations.
`kinesis_source_checkpoint_duration_ns`	Histogram	Stream peer	Duration of Kinesis checkpoint operations.
`kinesis_source_checkpoint_error_count`	Counter	Stream peer	Count of errors in Kinesis checkpoint operations.
`kinesis_source_error_count`	Counter	Stream peer	Count of errors in Kinesis source reads.
`kinesis_source_lag_ms`	Gauge	Stream peer	Measure of lag in Kinesis source.
`kinesis_source_operation_count`	Counter	Stream peer	Count of operations on Kinesis.
`kinesis_source_operation_duration_ns`	Histogram	Stream peer	Histogram of duration of operations on Kinesis.
`kinesis_source_record_count`	Counter	Stream peer	Count of records read from Kinesis.
`kinesis_source_row_count`	Counter	Stream peer	Count of rows read from Kinesis.
`kinesis_source_value_count`	Counter	Stream peer	Count of values read from Kinesis.

Indexer Metrics

Metric	Type	Components	Purpose
`indexer_rows_written`	Histogram	Stream Peer	Total rows indexed (written to partitions)
`indexer_bytes_written`	Histogram	Stream Peer	Total bytes indexed (written to partitions)
`indexer_partitions_rejected`	Histogram	Stream Peer	Histogram of partitions not able to written. If value is 0=raw data parsing failed, 1=raw data / transform schema mismatch, 3=Error writing partition file, 4= Other Error during indexing
`indexer_partitions_written`	Histogram	Stream Peer	Total partitions created
`indexer_partition_write_seconds`	Histogram	Stream Peer	Time from receiving indexing query to writing partition file (seconds)

Go environment metrics

These metrics track resources used by Hydrolix's Go environments.

Metric	Type	Components	Purpose
`go_gc_duration_seconds`	Summary	Batch peer, Stream head, Stream peer	A summary of the pause duration of garbage collection cycles.
`go_goroutines`	Gauge	Batch peer, Stream head, Stream peer	Number of goroutines that currently exist.
`go_info`	Gauge	Batch peer, Stream head, Stream peer	Information about the Go environment.
`go_memstats_alloc_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes allocated and still in use.
`go_memstats_alloc_bytes_total`	Counter	Batch peer, Stream head, Stream peer	Total number of bytes allocated, even if freed.
`go_memstats_buck_hash_sys_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes used by the profiling bucket hash table.
`go_memstats_frees_total`	Counter	Batch peer, Stream head, Stream peer	Total number of frees.
`go_memstats_gc_cpu_fraction`	Gauge	Batch peer, Stream head, Stream peer	The fraction of this program's available CPU time used by the GC since the program started.
`go_memstats_gc_sys_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes used for garbage collection system metadata.
`go_memstats_heap_alloc_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of heap bytes allocated and still in use.
`go_memstats_heap_idle_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of heap bytes waiting to be used.
`go_memstats_heap_inuse_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of heap bytes that are in use.
`go_memstats_heap_objects`	Gauge	Batch peer, Stream head, Stream peer	Number of allocated objects.
`go_memstats_heap_released_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of heap bytes released to OS.
`go_memstats_heap_sys_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of heap bytes obtained from system.
`go_memstats_last_gc_time_seconds`	Gauge	Batch peer, Stream head, Stream peer	Number of seconds since 1970 of last garbage collection.
`go_memstats_lookups_total`	Counter	Batch peer, Stream head, Stream peer	Total number of pointer lookups.
`go_memstats_mallocs_total`	Counter	Batch peer, Stream head, Stream peer	Total number of mallocs.
`go_memstats_mcache_inuse_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes in use by mcache structures.
`go_memstats_mcache_sys_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes used for mcache structures obtained from system.
`go_memstats_mspan_inuse_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes in use by mspan structures.
`go_memstats_mspan_sys_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes used for mspan structures obtained from system.
`go_memstats_next_gc_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of heap bytes when next garbage collection will take place.
`go_memstats_other_sys_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes used for other system allocations.
`go_memstats_stack_inuse_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes in use by the stack allocator.
`go_memstats_stack_sys_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes obtained from system for stack allocator.
`go_memstats_sys_bytes`	Gauge	Batch peer, Stream head, Stream peer	Number of bytes obtained from system.
`go_threads`	Gauge	Batch peer, Stream head, Stream peer	Number of OS threads created.

Kafka Ingest

These metrics are specific to the use of Kafka data sources.

Metric	Type	Components	Purpose
`kafka_source_byte_count`	Counter	Stream peer	Count of bytes read from Kafka.
`kafka_source_commit_duration_ns`	Histogram	Stream peer	Kafka commit duration.
`kafka_source_read_count`	Counter	Stream peer	Count of Kafka reads.
`kafka_source_read_duration_ns`	Histogram	Stream peer	Kafka read duration.
`kafka_source_read_error_count`	Counter	Stream peer	Count of Kafka errors.
`kafka_source_row_count`	Counter	Stream peer	Count of rows processed.
`kafka_source_value_count`	Counter	Stream peer	Count of values processed.

General metrics

These metrics track various counters and statistics regarding data ingestion.

Metric	Type	Components	Purpose
`bytes_written`	Counter	Batch peer, Stream peer	Bytes written to the indexer.
`partitions_created`	Counter	Batch peer, Stream peer	Count of partitions created.
`process_cpu_seconds_total`	Counter	Batch peer, Stream head, Stream peer	Total user and system CPU time spent in seconds.
`process_max_fds`	Gauge	Batch peer, Stream head, Stream peer	Maximum number of open file descriptors.
`process_open_fds`	Gauge	Batch peer, Stream head, Stream peer	Number of open file descriptors.
`process_resident_memory_bytes`	Gauge	Batch peer, Stream head, Stream peer	Resident memory size in bytes.
`process_start_time_seconds`	Gauge	Batch peer, Stream head, Stream peer	Start time of the process since unix epoch in seconds.
`process_virtual_memory_bytes`	Gauge	Batch peer, Stream head, Stream peer	Virtual memory size in bytes.
`process_virtual_memory_max_bytes`	Gauge	Batch peer, Stream head, Stream peer	Maximum amount of virtual memory available in bytes.
`promhttp_metric_handler_requests_in_flight`	Gauge	Batch peer, Stream head, Stream peer	Current number of scrapes being served.
`promhttp_metric_handler_requests_total`	Counter	Batch peer, Stream head, Stream peer	Total number of scrapes by HTTP status code.