Foglight 7.3.0 - Performance Tuning Field Guide

Store and Forward Processing

Store and forward processing is a way to collect and store data on a monitored host, followed by forwarding the stored data to the server.

About Store and Forward Processing in Foglight

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.

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:

Where:

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 .

Store and Forward Processing and the Foglight Agent Manager

When a Foglight Agent Manager’s connection to the Management Server is disrupted, the Agent Manager continues to store data from hosts on disk. When the connection is restored, the Agent Manager forwards the stored data to the server.

The data is stored in the form of data packages, or messages. A message typically contains data samples or information about the agents’ state. The collected data objects are serialized into messages and stored on disk. The serialized messages can be easily re-read from disk and translated back into the data objects, collected during the store and forward period.

The amount of the stored data is controlled with a set of configuration parameters. For more information, see Viewing the Settings that Control the Size of Stored Data.