Exciting news! The upcoming IntelliJ IDEA 13.1 will bring you integration with Chronon Debugger (via this plugin). You can try it right away with the latest preview build. In case you’re wondering, Chronon is a new revolutionary tool keeping track of running Java programs and recording their execution process for later analysis, which can be helpful when you need to thoroughly retrace your steps when dealing with complicated bugs.
Chronon is a commercial tool and normally you would need to buy a license to use it, but the awesome news for you is that it’s completely free to use with IntelliJ IDEA 13.1 Ultimate.
In this post I will give you a quick intro into how Chronon works and how you can use it with IntelliJ IDEA 13.1 EAP.
Install Plugin
To enable Chronon, you need to go to Settings → Plugins → Install JetBrains plugin, select Chronon, and click Install plugin.
Chronon Include/Exclude Patterns
Chronon uses code instrumentation to record the data, so we need to tell it which classes it should look at. For that, open the run configuration that you’re using for your application and specify Include / Exclude Patterns on the Chronon tab. Choose the classes carefully, because tracking too many of them at the same time would have significant negative performance impact.
Let’s see how Chronon works on a simple example of the two-threaded array sorting, where one thread performs quicksort, and the other one does bubble sorting. It’s essential to understand that Chronon is not literally a debugger, as it only helps you record the execution progress and then, play it back, like a videotape.
Run with Chronon
Well, it’s time to run our app. For that we can either click the toolbar button or use the Run → Run ‘ChrononDemo’ with Chronon menu.
When the app finishes, IntelliJ IDEA unpacks the recording data and opens the Chronon tool window (which looks very similar that of Debugger.) Of course, you can open a previously recorded session and play it back via the Run → Open Chronon Recording action in the main menu.
Debug actions
Here we can step through the recorded data forward or backward by using the actions from the Run menu.
Variable history
As the current position changes, the Locals tab displays values of local variables. If you select a local variable, the History tab displays the entire history of changes made to that variable during the recorded runtime. Note that the variables data is only shown for the primitives types and the classes specified in the Include Pattern.
Double-clicking a change in the History tab will take you to the code where it has occurred.
History of changes is available for elements of local arrays and collections as well.
Switch between threads
The Threads tab lets you switch between different threads that have been recorded.
Method history
One of the tabs in the Chronon tool window is the Method history. In it you can track the execution history of a method, with the input and output data, which makes it easy to see how and where a method has been invoked.
Logging
The Logging tab lets you define custom logging statements and track their output during the program execution.
Exceptions
Chronon is especially helpful when debugging failed tests. The Exceptions tab displays all recorded exceptions and you can double-click them to see a playback of how and when they occurred.
By the way, this is exactly what we’re doing to investigate problems that are otherwise very hard to reproduce when tests fail on our Teamcity build server. TeamCity uses Chronon to run tests so we can use its recordings at any time to examine problems and spot bugs.
We hope you’ll find Chronon helpful, and as always, are waiting for your feedback in our discussion forum and issue tracker.
Develop with Pleasure!
This looks very cool! Congrats.
I wonder if the API will be open so that we could integrate the value history (and maybe method history) as I’m a plugin developer and the plugin I’m working on also includes a debugger (GDB to use for golang).
Thanks.
How does this debugger compare with the built-in debugger? Aka, what features this debugger provides that are not available in the default debugger (for a java/ee developer)?
Thanks.
As the article says Chronon is not literally a debugger. It only helps you record the execution progress and then, play it back, like a videotape. However we’d like to see Chronon UX similar to the UX of the built-in debugger as the use-cases have a lot in common (stepping back and forward, stopping at a breakpoint, evaluating an expression, etc). That’s why we ask you to give it a try and share your feedback.
Great news
What happens, if the included packages contain third party libs, *without* source code ?
Will I still see local vars etc. ?
you will see the data in 3rd party libs if they were compiled with debug info.
This simply looks incredible.
Any chance to extend this kind of functionality to web applications too? e.g. JSP support, etc.
This looks very useful. Will scala projects be supported?
Unfortunately no, but you can vote for it: http://community.chrononsystems.com/chronon_systems/topics/add_support_for_scala_and_other_jvm_based_languages_compiled_to_bytecode
Trying Chronon but it keep throwing this error. I using Mac mavericks and running latest intellij and java 8.
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option UseSplitVerifier; support was removed in 8.0
objc[18778]: Class JavaLaunchHelper is implemented in both /Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home/bin/java and /Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home/jre/lib/libinstrument.dylib. One of the two will be used. Which one is undefined.
java.lang.IllegalArgumentException
at java.com.chronon3.sb.recorder.custom.org.objectweb.asm.ClassReader.(SourceFile:170)
at java.com.chronon3.sb.recorder.custom.org.objectweb.asm.ClassReader.(SourceFile:153)
at java.com.chronon3.sb.recorder.instrumentors.a.e.a(SourceFile:21)
at java.com.chronon3.sb.recorder.instrumentors.a.a.b.a(SourceFile:61)
at java.com.chronon3.sb.recorder.instrumentors.a.a.a.transform(SourceFile:53)
at sun.instrument.TransformerManager.transform(TransformerManager.java:188)
Any idea what is wrong ?
jdk 8 is currently not supported due to the split verifier issue (and also because it is not officially released yet).
please use jdk 6 or 7.
Does the Chronon Intellij plugin work for remote applications? I’ve installed the plugin, but the Chronon tab is only available for Application run/debug configurations, not Remote.
It’s awesome!
But I faced with one major issue – I am unable to add classes and packages from JDK.
E.g. I’ve added “java.util.*” into Include pattern column but it doesn’t show the values of the variables from that package.
The same issue with adding particular class from jdk – java.util.Date.
Do you know anything about that? Am I doing something wrong?
the java namespace cannot be recorded. details here:
https://chronon.atlassian.net/wiki/display/DOC/Include+and+Exclude+patterns
I just quickly wanted to test it with a static main method:
int i = 3;
i *= 2;
sout(i);
The program runs with these logs:
Chronon: Shutting down…
Chronon: Please wait while runtime date is processed…
Chronon: Compressing Data …
Chronon: Saving to disk …
Chronon: Done
But I’m getting an error message saying
“Error unpacking recording: null”
Why?
IntelliJ 13.1 ultimate, Java 1.7 (51)
Hi, there should be an exception in the log, could you please post it here
Hi Egor, thank you for your reply. With log, do you mean the Run window (Alt + 4)? There is no exception listed, just the Chronon results mentioned above.
I tested the same project on Win7 and it works. Could it be possible that the plugin has issues with Win8.1 (64bit)?
Ron, I mean IDEA log, have a look at https://intellij-support.jetbrains.com/entries/23352446-Locating-IDE-log-files
This make me want to cry (for joy)
Thought I would give this a try. It looked awesome, and I love my IntelliJ IDEA. I have a web application I wanted to test this on, so I installed the Chronon Recording Server and sat that up to collect recordings from my Jetty installation. It worked just fine. Then I downloaded the recording to my laptop (it was a tar so I had to untar it first) and then tried to open it with the “Open Chronon recording…” dialog in IntelliJ. but alas, it only says “Chronon Recording not found”.
Can I only with the Chronon Plugin open recordings done by the plugin itself?
In this case you need to unpack the recording manually and then open the unpacked folder (though it will not have the chronon icon)
Another way is to create a folder structure IDEA is expecting:
top folder named as you wish and subfolder “recording” with the actual recording.
In this case IDEA will open the top folder, unpack the recording into “unpackedRecording” subfolder and open it.
Perfect! Works like a charm!
I just upgraded to IDEA 13.1. I was playing around with the new Chronon debugger when I noticed that when I stop a Java application that was launched using the “Run with Chronon” feature, I got the following error message:
Chronon Recording Not Found
And the error popup includes the path where it’s trying to look for the file.
I’m on
OS X Mavericks 10.9.2, IDEA 13.1, JDK 1.6.0_65 64 bit.What am I missing here?
Hi, in order to use chronon please use Exit action instead of Stop
Ah, thanks Egor! That worked!
Really a WOW plugin, I’m impressed.
But why F8 / Alt-F6 etc to move fwd and backward ? After all, this is not a debugger, but more og a “player”. I think the plugin would become even more useful with arrow keys, or the mouse wheel to go forward/back.
For now we mimic regular debugger “look and feel” just because people are used to it. In future we may rethink what’s the best user interface for such technology. Thanks for your feedback!
This is a great concept and I’ve followed it for a while, even before there was IntelliJ integration.
I tried the plugin and got the same outcome as one year ago. It works great for simple programs, however once you add things like Spring, JMS etc. (not for monitoring, just as part of your application), it becomes unusable. I never got it to work for our application, depending on what I try, it either blocks when instrumenting classes, spring blocks while loading, or it only records the first second or two.
This happens even when I start unit tests (so no app server or odd JVM configuration involved).
This looks awesome for applications that truly do have a static “main” method, but can it be used with applications outside of that limited range? What about web applications, launched from a servlet container? What about Maven integration?
I am working on a project that uses GWT and the Google App Engine, and a local development machine run is launched through the “gwt:run” Maven goal. When I edit the “Run/Debug Configuration” entry for this Maven goal, there is no “Chronon” tab to configure.
However, I *can* launch the Maven goal using the “Run with Chronon” icon in the top toolbar… and the “Run with Chronon” option is present when I right-click on the goal in the Maven Projects view. When execution exits, though, selecting “Run -> Open Chronon Recording” and selecting the project directory produces a “Chronon recording not found” error dialog.
So is Chronon meant to support recording of Maven-launched executions, or not? Unless I’m missing something, it looks the integration is there but in a half-completed state.
This is essentially a http://youtrack.jetbrains.com/issue/IJCP-20 : Chronon controls are available for not supported configurations, and do nothing.
Creating a Chronon support for Maven and / or GWT is another question. Feature request to http://youtrack.jetbrains.com/issues/IJCP is welcome.
I’m getting “Chronon recording not found in /home/jyrki/.IntelliJIdea13/system/chronon-recordings/2014_03_21_Runner5”. There’s some files there
Running Unittest works and if I start a Java App end use the exit button to stop the app everything works fine as well.
But starting a Webapp on JBoss I don’t have an exit button end pressing the stop button results in the the “Chronon recording not found” because the recording ist not unpacked when using stop button to shut down the webserver.
There should be a way to trigger the unpacking manually.
Addition:
Trying to unpack the recording manually ended up in:
Error: no meta data found
This means:
– Your recording has not been finished properly and is corrupt.
It is very easy to start chronon recording when an app is started from IDEA. How to enable the recording of the app running on a remote server?
Thank you!
This looks great but I can’t get my server to run with it. I’m getting an error saying: “recorderagent64-3.0.7.dll is not a valid Win32 application”
The full output looks like:
"C:\Program Files (x86)\IBM\WebSphere\AppServer\profiles\AppSrv04\bin\generated_websphere_server_start_script.cmd"
"C:\Program Files (x86)\IBM\WebSphere\AppServer\java\bin\java" -Dfile.encoding=windows-1252 -classpath "C:\Program Files (x86)\IBM\WebSphere\AppServer\runtimes\com.ibm.ws.admin.client_7.0.0.jar;C:\Program Files (x86)\IBM\WebSphere\AppServer\plugins\com.ibm.ws.security.crypto.jar;C:\Program Files (x86)\JetBrains\IntelliJ IDEA 13.1.1\plugins\webSphereIntegration\lib\webSphereIntegration.jar;C:\Program Files (x86)\JetBrains\IntelliJ IDEA 13.1.1\plugins\JavaEE\lib\javaee-impl.jar;C:\Program Files (x86)\JetBrains\IntelliJ IDEA 13.1.1\lib\openapi.jar;C:\Program Files (x86)\JetBrains\IntelliJ IDEA 13.1.1\plugins\webSphereIntegration\lib\specifics\webSphereClientImpl.jar" com.intellij.javaee.oss.process.JavaeeProcess 55991 com.intellij.j2ee.webSphere.agent.WebSphereAgent
JVMJ9TI001E Agent library C:\Users\MCDIARR\.IntelliJIdea13\config\plugins\chronon\lib\recorder\native\recorderagent64-3.0.7.dll could not be opened (C:\Users\MCDIARR\.IntelliJIdea13\config\plugins\chronon\lib\recorder\native\recorderagent64-3.0.7.dll is not a valid Win32 application. )
[2014-04-10 05:05:25,839] Artifact com.otpp.tim.enterpriseApp.ear: Server is not connected. Deploy is not available.
JVMJ9VM015W Initialization error for library j9jvmti24(-3): JVMJ9VM009E J9VMDllMain failed
Detected server admin port: 8880
Could not create the Java virtual machine.
Detected server http port: 9081
Disconnected from server
If I run the same build config without chrono there are no problems. Any idea what could be causing this?
Thanks!
A work around was posted here: http://youtrack.jetbrains.com/issue/IJCP-85
INVOKEDYNAMIC instruction is not supported (((
Does not work with Groovy / Grails. You get tons of errors. Seems that closures of any kind are not supported.
“TeamCity uses Chronon to run tests so we can use its recordings at any time to examine problems and spot bugs.”
How have you configured TeamCity that it runs tests with Chronon logging? Could you please explain?
Hi, there is no special TeamCity setup required, just set up a configuration that do recording outside the IDE: https://chronon.atlassian.net/wiki/display/DOC/Recording+outside+Eclipse
Is this plugin still maintained or is it abandoned? I see no new posts anywhere, and for something this innovative, that’s awkward, to say the least.
It is maintained. The most recent tutorial is available at https://www.jetbrains.com/idea/help/debugging-with-chronon.html
Ah, good to see new material! Thanks!
Oh… Seems like it’s impossible to debug a Maven project with Chronon as there is no Chronon tab. It this true? I’m guessing a relatively small number of Java projects are stand-alone apps.
Calling this a debugger is misleading. It only records variable and field values. You can’t evaluate expressions or navigate object hierarchies. The logging feature only outputs toString() on the variable value.