Memory Usage

This page gives some information about memory usage and performance and how to affect memory usage.

• Introduction
• Increase or reduce allocated memory
• Running out of memory

Introduction

There are a few reasons Chatty may use a considerable greater amount of memory compared to other IRC clients:

• Java prefers to allocate more memory than absolutely needed, so it can reduce the work going into Garbage Collection, which reduces CPU usage.
• Java management and ressources it has to have loaded add some overhead that other programs may not have.
• Chatty stores a lot of information for all it's features to work, such as emoticons, badges, stream info, user data - some of which can increase over time as the program is running.
• Memory and CPU usage may increase depending on how many channels you are in and their activity, as more data is created and deleted in busy chats, requiring either more memory or (if Java is not allowed to allocate more) more Garbage Collection work to be performed.

You can use the /appinfo command in Chatty to get some information about current memory usage. Note that these values can be somewhat different from what is shown in e.g. Task Manager.

Increase or reduce allocated memory

When you start a Java program there is some default maximum amount of memory it is allowed to use, which can vary on a case-by-case basis.

• If the default size is too small you can experience performance issues (or even errors) and you may want to allow Java to allocate more memory.
• If you're not experiencing performance issues you can decrease memory usage, although be careful to not set it too low.

You can tell Java the maximum amount heap memory it can use by using the launch option -Xmx400M. In this example it allows a maximum heap of 400MB, which is recommended for good performance. You should normally never set it below 200MB or you may experience issues.

JAR Version

Create a shortcut (you may already have created one with the installer). When editing the shortcut change the target and add the launch option after Java but before the -jar part (you may have to add the javaw and -jar parts). It should end up looking similiar to:

javaw -Xmx400M -jar "D:\Chatty\Chatty.jar"

Standalone Version

The Chatty.exe of the Windows Standalone version will look for launch options in the file Chatty.cfg in the app folder, so you can add the -Xmx400M there, after [JVMOptions] (should already be there by default, so you can just change the number).

Running out of memory

If Java cannot clean up enough memory to make space for new data to be stored, an OutOfMemory exception will occur.

• This can be a sign that you should increase the amount of memory Java is allowed to use. For example if the maximum heap is 50MB there simply won't be enough space to even start Chatty, if it is 100MB it may still start but you'll likely run into issues a bit later. Use /appinfo to find out current and max usage.
• The longer Chatty is running at a time and the more active channels you have joined, the more data it will accumulate that are necessary for features such as displaying Stream Info History or messages that users have sent in the User Dialog. If you run into issues after leaving Chatty running for several days, then a simple restart may be helpful.
• There may be a bug, either in Chatty or some Java library, preventing memory from being cleaned up properly, resulting in a memory leak.

Short of analyzing a heap dump, basicially a full copy of the programs memory, it is hard to tell what exactly takes up the memory. Such analysis is often performed duing development and testing, but if an issue can not be reproduced then finding the exact cause can be difficult.

Reducing memory usage

The following settings can be adjusted to reduce memory usage:

Moderation - Clear message history of inactive users

Long running instances will accumulate more and more messages stored for display in the User Dialog. Setting this to a lower value can reduce memory usage.