TDA - Thread Dump Analyzer

I just observed if I send a kill -3 to a VM to request a thread dump and the VM Option -XX:+PrintClassHistogram is set to also dump the class histogram of the objects currently in memory this leads to a Full GC. It looks like this is to clean up ... [More] memory before dumping the class histogram. I tested it with JDK 5 and 6, both show the same behaviour. So it is better to be careful with setting this option on production environments otherwise this would lead to unwanted cleanups of the memory (think of soft-references in a cache) when just a thread dump is requested. [Less]

InfoQ has a link to a nice interview held with Tony Printezis at the JavaOne 2008 about the new garbage collector "Garbage First (G1)" which will be introduced with JavaSE 7 as alternative for the Concurrent Mark Sweep Collecto (CMS). It is also ... [More] planned to release it as update for JavaSE 6. Garbage First is just like CMS optimized for throughput but in contrast to it avoids the fragmenation of the heap and offers constant pause times. Unlike all existing Garbage Collectors it doesn't divide the heap into young and old generation which only exist logically. The implementation of the collector is based on a white paper published by SUN back in 2004. Tony Printezis has also set up an interesting garbage collection visualizer on dev.java.net: GChisto. There currently is nothing available for download, but a working development version can be checked out from CVS. A plugin for VisualVM is also planned. [Less]

InfoQ has a link to a nice interview held with Tony Printezis at the JavaOne 2008 about the new garbage collector "Garbage First (G1)" which will be introduced with JavaSE 7 as alternative for the Concurrent Mark Sweep Collecto (CMS). It is also ... [More] planned to release it as update for JavaSE 6. Garbage First is just like CMS optimized for throughput but in contrast to it avoids the fragmenation of the heap and offers constant pause times. Unlike all existing Garbage Collectors it doesn't divide the heap into young and old generation which only exist logically. The implementation of the collector is based on a white paper published by SUN back in 2004. Tony Printezis has also set up an interesting garbage collection visualizer on dev.java.net: GChisto. There currently is nothing available for download, but a working development version can be checked out from CVS. A plugin for VisualVM is also planned. [Less]

InfoQ has a link to a nice interview held with Tony Printezis at the JavaOne 2008 about the new garbage collector "Garbage First (G1)" which will be introduced with JavaSE 7 as alternative for the Concurrent Mark Sweep Collecto (CMS). It is also ... [More] planned to release it as update for JavaSE 6. Garbage First is just like CMS optimized for throughput but in contrast to it avoids the fragmenation of the heap and offers constant pause times. Unlike all existing Garbage Collectors it doesn't divide the heap into young and old generation which only exist logically. The implementation of the collector is based on a white paper published by SUN back in 2004. Tony Printezis has also set up an interesting garbage collection visualizer on dev.java.net: GChisto. There currently is nothing available for download, but a working development version can be checked out from CVS. A plugin for VisualVM is also planned. [Less]

There now is a beta version of the TDA Plugin for the just released Release Candidate of VisualVM available. It offers an enhanced integration into VisualVM compared to the quite basic plugin previews. In the beta logfiles and running applications ... [More] (remote and local) can be analyzed. It bundles the current development version of TDA, which offers customizable categories as new feature. Fig 1. VisualVM Release Candidate with TDA Plugin Figure 1 shows the plugin tab for remote and locally connected applications. It attaches itself to every connected application and offers to request them using JMX. This might change for the final release though, as VisualVM has its own mechanism for requesting thread dumps. If used with local applications VisualVM's mechanism offers the same thread dump information as if kill -3 is used. The JMX Dumps are a bit limited compared to this. The plugin beta now also offers a possibility to open and parse thread dumps found in logfiles just like the standalone version of TDA does. Fig 2. Logfile view The screenshot above shows the parsed thread dumps from a logfile. All options, filter settings and the customizable categories can be found in the VisualVM Options. The plugin is available via the VisualVM Update Center for the Release Candidate. In VisualVM just go to Tools->Plugin->Available Plugins and choose the VisualVM TDA Module. Or download the plugin from the TDA Website. Comments are welcome! [Less]

There now is a beta version of the TDA Plugin for the just released Release Candidate of VisualVM available. It offers an enhanced integration into VisualVM compared to the quite basic plugin previews. In the beta logfiles and running applications ... [More] (remote and local) can be analyzed. It bundles the current development version of TDA, which offers customizable categories as new feature. Fig 1. VisualVM Release Candidate with TDA Plugin Figure 1 shows the plugin tab for remote and locally connected applications. It attaches itself to every connected application and offers to request them using JMX. This might change for the final release though, as VisualVM has its own mechanism for requesting thread dumps. If used with local applications VisualVM's mechanism offers the same thread dump information as if kill -3 is used. The JMX Dumps are a bit limited compared to this. The plugin beta now also offers a possibility to open and parse thread dumps found in logfiles just like the standalone version of TDA does. Fig 2. Logfile view The screenshot above shows the parsed thread dumps from a logfile. All options, filter settings and the customizable categories can be found in the VisualVM Options. The plugin is available via the VisualVM Update Center for the Release Candidate. In VisualVM just go to Tools->Plugin->Available Plugins and choose the VisualVM TDA Module. Or download the plugin from the TDA Website. Comments are welcome! [Less]

The former SAP Memory Analyzer now is an official Eclipse project. It is now called Eclipse Memory Analyzer. No final release is available at the moment but there are nightly builds available either as download or as Update Site for Eclipse. Fig ... [More] 1. Eclipse Memory Analyzer Nightly Build The screenshot shows the overview tab of a just parsed heap dump. It gives you a quick glance of the biggest objects in the heap dump and how much memory they consume. The nightly builds can either be downloaded as bundled application or added to Eclispe using this Update Site: http://download.eclipse.org/technology/mat/0.7/update-site/ [Less]

The former SAP Memory Analyzer now is an official Eclipse project. It is now called Eclipse Memory Analyzer. No final release is available at the moment but there are nightly builds available either as download or as Update Site for Eclipse. Fig ... [More] 1. Eclipse Memory Analyzer Nightly Build The screenshot shows the overview tab of a just parsed heap dump. It gives you a quick glance of the biggest objects in the heap dump and how much memory they consume. The nightly builds can either be downloaded as bundled application or added to Eclispe using this Update Site: http://download.eclipse.org/technology/mat/0.7/update-site/ [Less]

I just updated the TDA Plugin Preview for VisualVM to work with the just released beta2. It offers quite the same as the previous preview releases. But I hope to provide a better integrated version of the plugin for the release candidate of VisualVM ... [More] which is planned to be ready for JavaOne. If everything works a planned there will be a TDA 2.0 release with a finished VisualVM Plugin ready around the beginning of july. Fig 1. VisualVM Beta2 with TDA Plugin Preview Because of a reworked welcome screen, the link for requesting a dump is currently missing and you have to use the left-most button in the toolbar for this. The Plugin again consists of two files, the library component, which contains TDA itself and the file with plugin wrapper. Everything can be downloaded on the TDA site. [Less]

I just updated the TDA Plugin Preview for VisualVM to work with the just released beta2. It offers quite the same as the previous preview releases. But I hope to provide a better integrated version of the plugin for the release candidate of VisualVM ... [More] which is planned to be ready for JavaOne. If everything works a planned there will be a TDA 2.0 release with a finished VisualVM Plugin ready around the beginning of july. Fig 1. VisualVM Beta2 with TDA Plugin Preview Because of a reworked welcome screen, the link for requesting a dump is currently missing and you have to use the left-most button in the toolbar for this. The Plugin again consists of two files, the library component, which contains TDA itself and the file with plugin wrapper. Everything can be downloaded on the TDA site. [Less]