Archive for the ‘performance’ 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
Virtualization Performance: Zones, KVM, Xen
At Joyent we run a high-performance public cloud based on two different virtualization technologies: Zones and KVM. We have historically run Xen as well, but have phased it out for KVM on SmartOS. My job is to make things go fast, which often means using DTrace to analyze the kernel, applications, and those virtualization technologies. [...]
In: Cloud, DTrace, KVM, performance, xen, zones
zfsday: ZFS Performance Analysis and Tools
At zfsday 2012, I gave a talk on ZFS performance analysis and tools, discussing the role of old and new observability tools for investigating ZFS, including many based on DTrace. This was a fun talk – probably my best so far – spanning performance analysis from the application level down through the kernel and to [...]
In: performance, slides, talk, video, ZFS
The USE Method: SmartOS Performance Checklist
The USE Method provides a strategy for performing a complete check of system health, identifying common bottlenecks and errors. For each system resource, metrics for utilization, saturation and errors are identified and checked. Any issues discovered are then investigated using further strategies. In this post, I’ll provide an example of a USE-based metric list for [...]
In: illumos, omnios, performance, smartos, Solaris, usemethod, zones
USENIX LISA 2012: Performance Analysis Methodology
At USENIX LISA 2012, I gave a talk titled Performance Analysis Methodology. This covered ten performance analysis anti-methodologies and methodologies, including the USE Method. I wrote about these in the ACMQ article Thinking Methodically about Performance, which is worth reading for more detail. I’ve also posted USE Method-derived checklists for Solaris- and Linux-based systems. The [...]
In: methodology, performance, slides, talk, usemethod
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
Surge 2012: Real-time in the real world
In September, I attended and spoke at the Surge’12 conference in Baltimore. I highly recommend it for anyone interested in performance. The theme with most talks was problems encountered at scale – and as is often the case – you can learn more from failure than success. Bryan and I gave a talk titled “Real-time [...]
In: DTrace, performance, slides, video
DTracing in Anger
My Macbook has becomeso sluggish that it feels like I’m typing ove a 9600 baud modem aagn. Or 2400. It’s alo droping keystokes – which is irritatng as hll – so please forgive theapparent tyos and mistakes. It comes and goes each minute, so thiswhole post isn’t too bad. Usually I cn see what’s wrng [...]
In: DTrace, macosx, performance
Active Benchmarking
Benchmarking is often done badly: tools are run ad-hoc, without understanding what they are testing or checking that the results are valid. This can lead to poor architectural choices that haunt you later on. I previously summarized this situation as: casual benchmarking: you benchmark A, but actually measure B, and conclude you’ve measured C. In [...]
In: benchmarking, performance
FISL13: The USE Method
In July, Bryan Cantrill, Deirdré Straughan and I spoke at FISL, one of the world’s largest open software conferences, in Porto Alegre, Brazil. I had a great time. My talk introduced the USE Method: a simple strategy for performing a complete check of system performance health, identifying common bottlenecks and errors. This methodology can be [...]
In: performance, slides, usemethod, video
