LogJoint is a log viewer and visualizer tool. It’s designed to simplify analysis of logs from multi-component multi-threaded systems.
High-level features:
- Rich log viewing and navigation functionality.
- Log data can be retrieved from different textual or non-textual sources.
- Multiple logs can be dynamically joined into single flat view.
- Extensibility through domain-specific plugins enable advanced visualizations and custom log retrieval methods.
Rich log viewing functionality is made possible by lightweight on-the-fly log parsing that extracts basic information for each log message: timestamp, thread, severity, text message. This information enables features that plain-text tools can not offer.
Features:
- Search features allow you to find next/previous match as well as all occurrences. Matching can be done by text, severity or threads criteria. Additionally:
- Multiple search results are combined on one view.
- User can define and save named sets of favorite filtering rules.
- Previous searches are saved in the history list.
- Bookmarks you set in a log are saved and are available next time you open the log. All current bookmarks are listed on separate view. Screenshot.
- Support of huge logs by loading only small fixed part at a time.
- Logs history list helps you recall recently open logs.
- Open logs’ time ranges and gaps are visualized. Screenshot.
- Live logs monitoring with the option to see the tail.
- Messages from different threads and log sources have different background colors.
- With highlighting rules you can colorize the log custom way.
- Multiple views have current time indicator that help you understand relative position of currently selected logline. Screenshot.
Typically logs are stored as text files, either plain text or structured (XML). LogJoint is not limited to any specific log file format. Instead, it can be taught to parse any format by defining the format in a config file. LogJoint ships with a set of configs for several common formats (Log4j XML, Log4j2 XML, log4net XML, TextWriterTraceListener). LogJoint has wizards that automatically generate parser configs from logger configs (currently supported: NLog CSV, JSON and simple layouts, log4net patterns). Finally, you can use custom format wizard that will guide you through the process of creation the config file for your custom plain-text or XML log format.
Some logs are not stored in text files. Viewing these need programmatic support, embedded or provided by a plugin. Out-of-box the following non-textual sources are supported:
- (win only) LogJoint can listen to OutputDebugString()
- (win only) Windows Event Log
- (win only) Azure Diagnostics Log
Additionally:
- The tool supports adding new log sources by drag&drop from Finder/Windows Explorer or from a web browser
- Archives are extracted on the fly
- Dragging an URL makes the tool download the linked contents. If required by the host, authentication information is taken from user and cached securely.
- Text log can have any encoding, including multibyte ones such as UTF8.
When you open multiple logs at the same time in the same LogJoint process the logs are dynamically merged into flat list ordered by timestamps. This is useful for tracing transactions that span multiple log files. If logs are from different machines and their clocks are out of sync you can manually set time shifts for individual logs.
Another feature is the option to monitor a folder for parts of rotated log. The parts discovered are dynamically joined and represented as single logical list.
Plugins extend different parts of LogJoint.
- Domain-specific plugin can define the way to extract visualizable information from certain types of logs. Visualizations are:
- Timeline - displays activities such as network requests, lengthy procedures, lifespans on a Gantt chart.
- Time series - depicts the change of numeric metrics over time
- StateInspector - displays the state of logged objects at certain moment in time.
- Sequence Diagram - useful for visualization of network messages.
- Plugin can implement custom log extraction methods. For example Azure plugin reads logs from Azure Storage.
- Plugin can define a set of domain-specific rules for automatic fixing of clock skew in the logs recorded on different machines.
WebRTC plugin lets LogJoint view and visualize Chrome Debug Log (https://webrtc.org/web-apis/chrome/) and webrtc_internals_dump.txt (produced by chrome://webrtc-internals/).
