Y74. Chapter IV Prometheus large factory monitoring system and practice -- Introduction to promql and monitoring pod resources (V)

4.PromQL brief introduction

Prometheus Provide a functional expression language PromQL (Prometheus Query Language), It enables users to find and aggregate time series data in real time , The result of expression calculation can be shown in the chart , It can also be in Prometheus In the expression browser, it is displayed in tabular form , Or as a data source , With HTTP API The method is provided to the external system .

4.1 PromQL The basic query

# Inquire about node Total memory size of node 
# HELP node_memory_MemTotal_bytes Memory information field MemTotal_bytes.
# TYPE node_memory_MemTotal_bytes gauge
node_memory_MemTotal_bytes 2.047315968e+09

# Query the total memory of the specified node 
node_memory_MemTotal_bytes{ 
    instance="172.31.7.111:9110"}

# Inquire about node The remaining available memory of the node 
# HELP no