Foglight 7.3.0 - Performance Tuning Field Guide

Store and forward processing refers to collecting and storing data on the Foglight® Agent Manager, followed by forwarding the stored data to the server. This type of processing is required when the communication between the Foglight® Agent Manager and the Foglight Management Server is disrupted.

Any data with older timestamps that is successfully forwarded to the server triggers data-driven rules and derived metrics. Time-driven rules do not re-evaluate data with older timestamps, even if that data meets their conditions and would cause them to fire if collected in real-time, as indicated in the table below. For complete information about rule triggers or derived metrics, see the Administration and Configuration Help.

Table 1. Entities and observations
Trigger	Current Observation	Forwarded Observation
Time-driven rule	Alarms and actions occur as expected. Alarm counts are correct.	Alarms and actions do not occur as expected. Alarm counts can be incorrect.
Data-driven rule		Alarms and actions occur as expected. Alarm counts are correct.
Event-driven rule
Derived metric (including SLA	Data-driven derived metrics are calculated as expected. Time-driven derived metrics, such as the Service Level Agreement (SLA) are not re-calculated and as such can be incorrect.

Store and Forward Processing and the Foglight Management Server

Foglight® Management Server has a configurable time window for accepting and processing the forwarded data. When the store and forward processing occurs as a result of a network disruption, the Foglight Agent Manager only stores the data on the host during that time window, enabling you to control the amount of data being stored on the monitored host for optimal performance.

By default, the Foglight Management Server accepts only the data that is collected within one hour from the moment it is received. This time window can be increased using a virtual machine (VM) option,
-Dfoglight.data_service.max_past_timestamp_delta, in the configuration file <foglight_home>/config/server.config:

server.vm.option<x>="-Dfoglight.data_service.max_past_timestamp_delta=<value_in_milliseconds>";

Where:

•

x is the number associated with the first available server.vm.option in server.config.

•

value_in_milliseconds specifies the duration of the store and forward period.

Increasing the length of store and forward time window is useful in case there is a longer-term network outage.

For complete information on how to increase the length of the time window reserved for store and forward processing, see the section Enabling the Collection of Data with Older Timestamps in Chapter 8 of the Administration and Configuration Guide.


	IMPORTANT: Any data with older timestamps that is accepted on the Foglight Management Server triggers data-driven rules and derived metrics. Time-driven rules and derived metrics do not re-evaluate data with older timestamps, even if that data meets their conditions and would cause them to fire if collected in real-time. For more information about this behavior, see About Store and Forward Processing in Foglight .