Mailslot Monitor

Mailslot Monitoring, Debugging and Analysis

OS: Windows only.

Purchase

All-in-one subscription

A subscription unlocks all IO Ninja capabilities including everything needed for Mailslot Monitor —
for as low as ~$5/month!

Individual capabilities

As an alternative, you can purchase capabilities
needed for Mailslot Monitor individually.

Required:

org.jancy.io.devmon

$55

Enables monitoring app-to-kernel interactions, required to monitor mailslot communications.

In Microsoft Windows, applications, services, and drivers often rely on mailslots for inter-process communication (IPC). However, developers and IT professionals face a significant challenge: the absence of well-known tools to sniff or monitor mailslot communications. This lack of visibility makes debugging mailslot-based IPC systems cumbersome and time-consuming. Without a dedicated tool, it’s difficult to track down issues, analyze communication patterns, or validate data being sent and received through mailslots.

The Mailslot Monitor plugin provides a comprehensive solution to this problem by enabling users to view the data messages being delivered to mailslots in real-time. Designed specifically for debugging and monitoring mailslot communications, the plugin fills the critical gap in IPC tools.

What Makes Mailslot Monitor so Great?

Real-Time Capture

Gain immediate insights into IPC with live monitoring of data flowing through mailslots. The plugin captures reads and writes from all nodes in a single log sheet, limited only by disk space.

Advanced Filtering Options

Stay focused on what matters with powerful filtering features:

Capture Filter: Control what data is logged by specifying criteria like file name, process, or file ID.
View Filter: Refine your view to focus on specific data streams without altering the underlying log data.

Powerful & Beautiful Logging Engine

The Ninja Scroll logging engine is the heart of IO Ninja! It offers many unique and useful features you won't find in other mailslot monitors, such as interleaving binary data with informational messages for a clear timeline of events, switching between hex-view and plain-text view of binary data, a regex markup engine for highlighting data based on regular expressions, and many others!

Built on the Device Monitor Service

Mailslot Monitor uses the Device Monitor (aka tdevmon) service, consisting of a kernel-mode module intercepting requests from applications to the specified devices and a user-mode configuration utility.

Installation and proper configuration of the Device Monitor service are sometimes stumbling points for users. Please follow these knowledge base articles for more information:

Getting Started

Step 1. Start a Monitoring Session

Begin by launching a Mailslot Monitor session.

Ensure you have Device Monitor installed before starting this step, please refer to our knowledge base.

Step 2. Start Capturing

Click the "Capture" button on the far right of the filter bar.

If you encounter an "Access is denied" error, please refer to our knowledge base.

Step 3. Apply a Filter

Type a wildcard to filter your results and click the green check button to apply them.

Documentation

Resource
Mailslot Monitor Documentation in the IO Ninja User Manual

Plugin	Relevance
Mailslot Terminal	Create a server-side maillsot, which clients can send messages to.
File Stream Terminal	Used as a client-side of mailslot communications.