Frequently asked questions

What is fastThread?

fastThread is an universal thread dump analyser. It parses complex thread dumps and presents with you with insightful metrics and beautiful graphs.

Why fastThread?

In production environment we face below mentioned problems. For some applications it's few times in a day, for some applications it's few times in an hour :-).

* CPU consumption starting to spike up all of a sudden (without any recent deployment)
* Application response time degrading over a period of time
* Frequent OutOfMemoryError
* Client applications timing out on you
* Database response time starting to degrade
* Application becoming unresponsive

Under these circumstances DevOps team captures thread dumps & other artifacts from the JVM and sends it to the Vendor to identify the root cause of the problem. Vendors typically take days (or weeks) to get back to you say one of the following:

* "Please upgrade to latest version of our software".
* "Problem is not happening in our product, it's happening because of XYZ ", blame game will continue.

fastThread is born to change this game. It's born to empower the DevOps and Developers to identify the root cause of the problem *themselves*. That too entire root cause identification happens instantly in matter of seconds. We have developed highly sophisticated, intelligent thread dump analysis patterns to identify the root cause of the problems. fastThread applies these intelligent patterns on the thread dumps and instantly identifies root causes of the problem. fastThread pin points the exact class, exact method and exact line number where the problem happens.

fastThread is built with two primary focuses:

1. Simplicity
2. Universality

Tool has been architected with "simplicity" as the core focus. Analyzing thread dumps is just a one step process, which is: uploading the thread dumps to the tool. No need to register. No need to login. No need to pay (it's a free service). As it's told one picture is worth 1000 words, fastThread produces several beautiful graphs and insightful metrics. We constantly get appreciated for the simplicity of the tool.

JVM thread dump format aren't unique. They vary by the Java vendor and versions. But fastThread parses all formats of thread dumps. Thus we would like to proudly claim fastThread as the first universal thread dump analyzer. As tool operates at the JVM level, it can analyze problems in Java, Scala, Jython, JRuby, .... (Basically any language that runs on JVM).

Can you share some of the graphs & metrics generated by fastThread?

Fig: Transitive graph showing what threads are blocking what other threads?

Fig: Panel showing WAITING threads and their stack traces

Is this a free tool?

Yes, 'Public' version is free. On the other hand if you want private deployment, where tool can run with in your corporate network, you can purchase our 'Pro' version. For more details check out our pricing

Great, the tool is free. But can you clarify the licensing when it comes to reusing the reports and their graphics? Is it ok to use them in a blog post? Or a company report?

Yes, you are welcome to use the graphics and other metrics provided by the fastThread tool in your blog post or company report by specifying accreditation "Generated by" at the bottom of the graphics.

I am seeing great graphs and details, but still I am not able to solve my problems. What should I do?

You can always reach us for help: We guarantee to get to root cause of any scalability, performance, availability problems with in 24 hours. We have solved hundreds of performance problems over the years. We are only engineers. There is no sales, no marketing, no overhead, so we are highly cost effective.

How to generate thread dumps?

It's very easy. Check this article

Is fastThread project open-sourced on Github?

No. Not yet. We are planning to do so in near future.

fastThread isn't able to parse my thread dumps? What should I do?

Please report it to We will fix it.