Archive for the ‘visualizations’ Category
Revealing Hidden Latency Patterns
Latency Heat Map Response time – or latency – is crucial to understand in detail, but many of the common presentations of this data hide important details and patterns. Latency heat maps are an effective way to reveal these. I often use tools that provide heat maps directly, but sometimes I have separate trace output [...]
In: heatmaps, latency, performance, visualizations
USENIX LISA 2010: Visualizations for Performance Analysis
My USENIX LISA talk from 2010 is now available on youtube, also embedded below. The title is Visualizations for Performance Analysis (and more), and showed how the full distribution of data could be presented as a heat map. This is especially useful for latency analysis, as fast-path and slow-path differences can be studied, as well [...]
In: performance, slides, video, visualizations
dtrace.conf 2012 videos
Last month was dtrace.conf 2012, the 2nd DTrace unconference. This is a meetup of DTrace practitioners and developers, where we discuss the latest uses, developments and future directions of the technology. It was great to see old friends of DTrace, and to put new faces to names. See the video list for the sessions, which, [...]
In: DTrace, video, visualizations
Subsecond Offset Heat Maps
“Wow, that’s weird!”. My subsecond offset visualization type looked great, but others found it weird and unfamiliar. I developed it for inclusion in Joyent’s Cloud Analytics tool for the purposes of workload characterization. Given that it was so unfamiliar, I had some explaining to do. Voxer, a company that makes a walkie-talkie application for smart [...]
In: cloud analytics, DTrace, performance, subsecond, visualizations
Linux Kernel Performance: Flame Graphs
To get the most out of your systems, you want detailed insight into what the operating system kernel is doing. A typical approach is to sample stack traces; however, the data collected can be time consuming to read or navigate. Flame Graphs are a new way to visualize sampled stack traces, and can be applied [...]
In: flamegraphs, Linux, performance, perf_events, systemtap, visualizations
Visualizing Process Execution
In Visualizing Process Snapshots I showed processes and their parent-child hierarchy over time, using snapshots of process information. This approach misses short-lived processes that occur between the snapshots. Here I’ll fill in the gaps using system tracing, visualizing all processes that occurred. Snapshots vs Tracing 1 second snapshots (eg, top) [...]
In: Cloud, DTrace, experimental, performance, visualizations
Visualizing Process Snapshots
In Visualizing the Cloud I showed processes and their parent-child hierarchy, across a cloud environment, exploring patterns at different scales. Here I’ll take this a little further and look at processes over time. These are experimental visualizations shared to explore ideas. It’s Alive! Many who have seen this have described it as “creepy” — looking [...]
In: Cloud, experimental, performance, visualizations
Visualizing Device Utilization
Device utilization is a key metric for performance analysis and capacity planning. In this post, I’ll illustrate different ways to visualize device utilization across multiple devices, and how that utilization is changing over time. As a system to study, I’ll examine a production cloud environment that contains over 5,000 virtual CPUs (over 600 physical processors). [...]
In: cpu, heatmaps, performance, visualizations
Flame Graphs
MySQL Flame Graph Determining why CPUs are busy is a routine task for performance analysis, which often involves profiling stack traces. Profiling by sampling at a fixed rate is a coarse but effective way to see which code-paths are hot (busy on-CPU). It usually works by creating a timed interrupt that collects the current program [...]
In: DTrace, performance, profiling, visualizations
Visualizing the Cloud
I’ve worked on visualizations for a while, most recently with heatmaps for Joyent’s Cloud Analytics. While we’re using and enhancing these right now, we are also in a great position to continue developing new visualizations for cloud computing, given: Easy observability into all nodes via zones, and deeper analysis using DTrace. JavaScript and node.js to [...]
In: Cloud, joyent, visualizations
