Gateway Metrics Overview

Apinizer Gateway collects various metrics about API traffic, external connections, cache operations, and JVM status. These metrics are presented in Prometheus format and can be used to monitor, analyze, and optimize API performance. Metrics are collected in two formats: general and tagged, and are categorized into Counter, Gauge, Timer, and DistributionSummary types.

Metric Categories

Apinizer Gateway metrics are divided into four main categories:

API Traffic Metrics

Provides detailed information about API requests, success/error rates, response times, and sizes.

External Connection Metrics

Provides information about requests made to external services, success/error rates, and response times.

Cache Metrics

Provides information about cache operations, success/error rates, and response times.

JVM Metrics

Provides information about memory usage, GC, thread status, and processor usage.

Metric Formats

Each metric is collected in two formats:

General Metric

Total values without labels. For example, total number of all API requests.

Tagged Metric

Metrics enriched with labels for detailed analysis. For example, requests by API ID.

Prometheus Metric Types

Gateway metrics are collected using four basic metric types of Prometheus. These types are designed to best represent different data types and behaviors.

Each metric type serves different purposes depending on how you collect and analyze the data.

Counter

Counter (Counter)

It is a value that only increases. It starts from zero when the application runs and increases, and is reset only when the application is restarted. Counter type metrics are ideal for tracking continuously increasing values such as total request count, error count, or number of completed operations.

Available Operations:

• sum: The total value itself
• rate: Calculates the rate of increase over time (such as how much it increases per second)
• increase: Calculates the total increase in a specific time range

Gauge

Gauge (Gauge)

Represents an instant value. This value can increase, decrease, or remain constant. Gauge type metrics are used to monitor an instant state or level such as current memory usage, instant CPU usage, or number of active threads.

Available Operations:

• sum: Sum of Gauge values grouped by labels
• mean: Average of Gauge values grouped by labels
• min/max: Minimum or maximum of values grouped by labels

Timer

Timer (Timer)

Measures how long an operation takes (usually in milliseconds or seconds). Although technically not a special type in Prometheus, it is a metric created by libraries such as Micrometer with a combination of DistributionSummary and Counter. These metrics provide information such as average duration, maximum duration, and percentile slices.

Available Operations:

• sum: Gives the total duration
• count: Gives how many times the operation was performed in total
• mean: Calculates the average duration of the operation
• max: Gives the longest duration observed
• histogram_quantile: Calculates percentile slices

DistributionSummary

DistributionSummary (Distribution Summary)

Used to monitor the distribution of a value. It works similarly to Timer, but instead of measuring time, it measures arbitrary numerical values such as request size, file size. This metric also provides statistical information such as average, maximum, and percentile slices.

Available Operations:

• sum: Gives the total value
• count: Gives the number of observed values
• mean: Calculates the average of values
• max: Gives the largest value observed
• histogram_quantile: Calculates percentile slices

API Traffic Metrics

These metrics are used to monitor API requests passing through Apinizer and measure their performance. While total requests, success, error, and cache hit rates are tracked numerically, request processing time and data sizes are measured for performance analysis.

Some metrics are provided with api_id and api_name labels for API-based detailed examination.

General Metrics

Metric Name	Description	Type
apinizer_api_traffic_total_count	Total API traffic requests	Counter
apinizer_api_traffic_success_count	Successful API requests	Counter
apinizer_api_traffic_error_count	Failed API requests	Counter
apinizer_api_traffic_blocked_count	Blocked API requests	Counter
apinizer_api_traffic_request_pipeline_time	API request pipeline time (ms)	Timer
apinizer_api_traffic_routing_time	API routing time (ms)	Timer
apinizer_api_traffic_response_pipeline_time	API response pipeline time (ms)	Timer
apinizer_api_traffic_total_time	API total time (ms)	Timer
apinizer_api_traffic_request_size	API request size (byte)	DistributionSummary
apinizer_api_traffic_response_size	API response size (byte)	DistributionSummary
apinizer_api_traffic_cache_hits_count	API cache hit count	Counter

Tagged Metrics (api_id, api_name)

Metric Name	Description	Type	Labels
apinizer_api_traffic_total_count_tagged	Total API traffic requests	Counter	api_id, api_name
apinizer_api_traffic_success_count_tagged	Successful API requests	Counter	api_id, api_name
apinizer_api_traffic_error_count_tagged	Failed API requests	Counter	api_id, api_name
apinizer_api_traffic_blocked_count_tagged	Blocked API requests	Counter	api_id, api_name
apinizer_api_traffic_request_pipeline_time_tagged	API request pipeline time (ms)	Timer	api_id, api_name
apinizer_api_traffic_routing_time_tagged	API routing time (ms)	Timer	api_id, api_name
apinizer_api_traffic_response_pipeline_time_tagged	API response pipeline time (ms)	Timer	api_id, api_name
apinizer_api_traffic_total_time_tagged	API total time (ms)	Timer	api_id, api_name
apinizer_api_traffic_request_size_tagged	API request size (byte)	DistributionSummary	api_id, api_name
apinizer_api_traffic_response_size_tagged	API response size (byte)	DistributionSummary	api_id, api_name
apinizer_api_traffic_cache_hits_count_tagged	API cache hit count	Counter	api_id, api_name

External Connection Metrics

These metrics are used to monitor external requests made through Apinizer. Performance of external services is analyzed by measuring total requests, error count, and response time.

Some metrics are provided with the url label for URL-based detailed examination.

General Metrics

Metric Name	Description	Type
apinizer_external_requests_total_count	Total external request count	Counter
apinizer_external_errors_total_count	Total external error count	Counter
apinizer_external_response_time	External response time (ms)	Timer

Tagged Metrics (url)

Metric Name	Description	Type	Labels
apinizer_external_requests_total_count_tagged	Total external request count	Counter	url
apinizer_external_errors_total_count_tagged	Total external error count	Counter	url
apinizer_external_response_time_tagged	External response time (ms)	Timer	url

Cache Metrics

These metrics are used to monitor the interaction of the worker (gateway) pod with cache. How the worker pod performs cache operations and its performance is analyzed by measuring total requests, error count, and response time.

Metric Name	Description	Type
apinizer_cache_requests_total_count	Total cache request count	Counter
apinizer_cache_errors_total_count	Total cache error count	Counter
apinizer_cache_response_time	Cache operation response time (ms)	Timer

JVM Metrics

These metrics are used to monitor JVM performance and resource usage in the worker (gateway) pod. They help analyze the system’s efficient operation by providing detailed information about memory, GC (Garbage Collection) activity, and thread status.

Metric Name	Description	Type
jvm_buffer_count_buffers	Number of buffers used by JVM	Gauge
jvm_buffer_memory_used_bytes	Total buffer memory used (byte)	Gauge
jvm_buffer_total_capacity_bytes	Buffer total capacity (byte)	Gauge
jvm_gc_live_data_size_bytes	Data size surviving after GC (byte)	Gauge
jvm_gc_max_data_size_bytes	Maximum data size for GC (byte)	Gauge
jvm_gc_memory_allocated_bytes_total	Amount of memory allocated by GC (byte)	Counter
jvm_gc_memory_promoted_bytes_total	Memory promoted by GC (byte)	Counter
jvm_gc_pause_seconds_count	Total number of GC pauses	Counter
jvm_gc_pause_seconds_max	Longest GC pause (seconds)	Gauge
jvm_gc_pause_seconds_sum	Total GC pause duration (seconds)	Gauge
jvm_memory_used_bytes	Memory usage by area (heap/non-heap)	Gauge
jvm_memory_committed_bytes	Committed memory by area	Gauge
jvm_memory_max_bytes	Maximum memory by area	Gauge
jvm_threads_live_threads	Current number of live threads	Gauge
jvm_threads_daemon_threads	Current number of daemon threads	Gauge
system_cpu_usage	CPU usage of main system	Gauge
system_cpu_count	Number of available processors	Gauge
system_load_average_1m	System load average (1 minute)	Gauge
process_cpu_usage	CPU usage of JVM process	Gauge
process_uptime_seconds	Runtime of JVM process	Gauge
process_files_open_files	Number of open file descriptors	Gauge