GC Log Analysis

A GC log includes details of the entire GC process and the resources it uses.

Analyzing GC log can help troubleshoot long pause problems and optimize overall Java application performance.

Supported Format

OpenJDK 8 and 11
Serial GC, Parallel GC, CMS GC, G1 GC, ZGC

Feature List

The supported features are as follows:

Overview
Key Performance Indicators
Problem suggestion
GC Cause
Graphs over time
GC Details
Other features

Implementation Overview

Then main entrance of the feature is in GCLogAnalyzer.parse. There are 3 main steps :

GCLogParser will parse the original GC log file into GCEvents, recording direct information from the file. This is done by first recognizing the format and collector of the log, then parse each line using corresponding parsing rules.
GCModel.calculateDerivedInfo will calculate more metrics we can get from original info, such as promotion of single event and max pause time of the whole process. All these data are saved in GCModel.
Frontend pages displays information through gclog backend apis.

Sample