Metric Range Query Node in Pathways

Overview

The Metric Range Query node in FojiSoft Pathways is used to execute a metric query over a defined range of time. This is particularly useful for analyzing trends, generating reports, and monitoring performance over a specific duration.

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Node Properties

1. Name

• Description: A unique identifier for the metric query operation.
• Usage: Assign a descriptive name (e.g., "Retrieve Network Latency Data" or "Query CPU Usage Over Time").

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2. Query

• Description: Defines the metric query that will be executed.
• Options for Expression Type:
  1. JavaScript Statement: A direct JavaScript expression for simple queries.
  2. JavaScript Function: A function for dynamic queries.
  3. Handlebars Template: A dynamic template for injecting real-time query values.
• Example Expressions:
  • JavaScript Statement: "network_latency"
  • JavaScript Function: function getQuery() {   return "network_latency"; }
  • Handlebars Template: metric_query_variable
• Status: Required (A valid query must be provided for execution).

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3. Start Time

• Description: Defines the earliest timestamp for querying data.
• Options: Same as Query Type (JavaScript Statement, JavaScript Function, Handlebars Template).
• Example Expressions:
  • JavaScript Statement: Date.now() - 900000  // Fetch data from 15 minutes ago
  • JavaScript Function: function getStartTime() {   return Date.now() - (60 * 60 * 1000); // Fetch data from 1 hour ago }
  • Handlebars Template: start_time_variable

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4. End Time

• Description: Defines the latest timestamp for querying data.
• Options: Same as Start Time.
• Example Expressions:
  • JavaScript Statement: Date.now()  // Fetch data up to the current time
  • JavaScript Function: function getEndTime() {   return Date.now(); }
  • Handlebars Template: end_time_variable

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5. Query Step

• Description: Determines the granularity of the data points retrieved (e.g., per second, per minute).
• Default Value: 1 Minute
• Customization: Adjust based on workflow needs (e.g., seconds, minutes, hours).
• Example Use Cases:
  • High-resolution data: Set Step = 1 Second
  • Hourly summaries: Set Step = 1 Hour
  • Daily reports: Set Step = 1 Day

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6. Variable Name

• Description: The name of the output variable where the retrieved metric data will be stored.
• Status: Required (Must be defined for further use in the workflow).
• Usage: Choose a meaningful variable name (e.g., latency_trend, cpu_usage_history).

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How It Works

1. Define the Query: Specify the metric query to retrieve relevant data.
2. Set Start and End Times: Choose a time range for data retrieval.
3. Define Query Step: Controls how frequently data points are sampled.
4. Store Output in a Variable: The retrieved metric data is saved under the specified variable name.

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Example Use Cases

1. Analyzing Network Latency Trends

• Query: "network_latency"
• Start Time: Date.now() - 3600000 (1 hour ago)
• End Time: Date.now()
• Query Step: 1 Minute
• Variable Name: latency_trend
• Outcome: Retrieves network latency values over the past hour at 1-minute intervals.

2. Tracking CPU Utilization Over 24 Hours

• Query: "cpu_usage"
• Start Time: Date.now() - 86400000 (24 hours ago)
• End Time: Date.now()
• Query Step: 5 Minutes
• Variable Name: cpu_usage_history
• Outcome: Retrieves CPU utilization data for the past 24 hours in 5-minute increments.

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Best Practices

• Optimize Query Frequency: Avoid excessive data retrieval by setting appropriate step values.
• Use Meaningful Variable Names: Helps with workflow clarity and debugging.
• Leverage JavaScript Functions: For dynamic query adjustments based on system state.

The Metric Range Query node is essential for analyzing performance trends over time, providing valuable insights for monitoring and decision-making.