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FlameGraph Htop — Benchmarking CPU— Linux

< MEDIUM: https://raaki-88.medium.com/flamegraph-htop-benchmarking-cpu-linux-e0b8a8bb6a94 >

I have written a small post on what happens at a Process-Level, now let’s throw some flame into it with flame-graphs

Am a fan of Brendan Gregg’s work and his writings and flame graph tool are his contribution to the open-source community —

https://www.brendangregg.com/flamegraphs.html

Before moving into Flamegraph, let’s understand some Benchmarking concepts.

Benchmarking in general is a methodology to test resource limits and regressions in a controlled environment. Now there are two types of benchmarking

• Micro-Benchmarking — Uses small and artificial workloads
• Macro-Benchmarking — Simulates client in part or total client workloads

Most Benchmarking scenario results boil down to the price/performance ratio. It can slowly start with an intention to provide proof-of-concept testing to test application/system load to identify bottlenecks in the system for troubleshooting or enhancing the system or to know about the maximum stress system simply is capable of taking.

Enterprise / On-premises Benchmarking: let’s take a simple scenario to build out a data centre which has huge racks of networking and computing equipment. As Data-centre builds are mostly identical and mirrored, benchmarking before going for Purchase-order is critical.

Cloud-based Benchmarking: This is a really in-expensive setup. While Continue reading

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BGP Unnumbered Duct Tape

Every time I mention unnumbered BGP sessions in a webinar, someone inevitably asks “and how exactly does that work?” I always replied “gee, that’s a blog post I should write one of these days,” and although some readers might find it long overdue, here it is ;)

We’ll work with a simple two-router lab with two parallel unnumbered links between them. Both devices will be running Cumulus VX 4.4.0 (FRR 8.4.0 container generates almost identical printouts).

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BGP Unnumbered Duct Tape

Every time I mention unnumbered BGP sessions in a webinar, someone inevitably asks “and how exactly does that work?” I always replied “gee, that’s a blog post I should write one of these days,” and although some readers might find it long overdue, here it is ;)

We’ll work with a simple two-router lab with two parallel unnumbered links between them. Both devices will be running Cumulus VX 4.4.0 (FRR 8.4.0 container generates almost identical printouts).

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HBM Gives Xeon SPs A Big Boost On Bandwidth Bound Work

If there is one bright spot in the Xeon SP server chip line from Intel, it is the version of the “Sapphire Rapids” Xeon SP processor that has HBM memory welded to it. …

HBM Gives Xeon SPs A Big Boost On Bandwidth Bound Work was written by Timothy Prickett Morgan at The Next Platform.

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Dell Wants To Put HPC And Quantum Into More Hands

The need for high-powered computing isn’t going away. Enterprises trying to corral the massive amounts of data they’re generating and adopting emerging technologies like machine learning are demanding the sort of HPC capabilities that not too long ago were reserved for research and educational institutions. …

Dell Wants To Put HPC And Quantum Into More Hands was written by Jeffrey Burt at The Next Platform.

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Terminator 1 is the best Terminator movie

And now for something completely different.

I’ve off and on thought about this for years, so it needed to be written down.

Terminator 1 is the best Terminator movie

Obviously SPOILERS, for basically all Terminator movies.

Summary of reasons

• The robot is really not human.
• It’s a proper time loop, with a bonus that none of the players in the movie know it.

I’m aware of The Terminator Wiki, but I don’t care about it. My opinions are on the movies as movies.

The behavior of the terminator

In Terminator 1 (T1) Arnold is clearly a robot in human skin. At no point do you believe it’s a human. The only reason people don’t stop and scream and point, is that “I’m being silly, that’s clearly impossible”. But Arnold spends the whole movie in the uncanny valley, the kind in 2022 reserved for realistically generated CGI characters.

It’s very nearly a perfect movie. Just take his first dialog. “Nice night for a walk”, the punks say. They are saying this to a machine that has never talked to a human before, so its response is complete nonsense. It just repeats the words back to them.

It’s a Continue reading

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HPE launches supercomputers for the enterprise

Supercomputers are super expensive, but Hewlett Packard Enterprise has announced plans to make supercomputing accessible for more enterprises by offering scaled down, more affordable versions of its Cray supercomputers.The new portfolio includes HPE Cray EX and HPE Cray XD supercomputers, which are based on the Frontier exascale supercomputer at Oak Ridge National Labs. These servers come with the full array of hardware, including compute, accelerated compute, interconnect, storage, software, and flexible power and cooling options.To read this article in full, please click here

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HPE launches supercomputers for the enterprise

Supercomputers are super expensive, but Hewlett Packard Enterprise has announced plans to make supercomputing accessible for more enterprises by offering scaled down, more affordable versions of its Cray supercomputers.The new portfolio includes HPE Cray EX and HPE Cray XD supercomputers, which are based on the Frontier exascale supercomputer at Oak Ridge National Labs. These servers come with the full array of hardware, including compute, accelerated compute, interconnect, storage, software, and flexible power and cooling options.To read this article in full, please click here

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Testing The Mettle Of The Top Supercomputing Iron On Earth

It’s fall, so that means it is the annual Super Computing conference that has been held in the United States by the Association for Computing Machinery and the IEEE Computer Society since 1989. …

Testing The Mettle Of The Top Supercomputing Iron On Earth was written by Timothy Prickett Morgan at The Next Platform.

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World’s fastest supercomputer is still Frontier, 2.5X faster than #2

Frontier, which became the first exascale supercomputer in June and ranked number one among the fastest in the world, retained that title in the new TOP500 semiannual list of the world’s fastest.Without any increase in its speed—1.102EFLOP/s—Frontier still managed to score 2.5 times faster that the number two finisher, Fugaku, which also came in second in the June rankings. An exascale computer is one that can perform 1018 (one quintillion) floating point operations per second (1 exaFLOP/s).Despite doubling its maximum speed since it was ranked number three in June, the Lumi supercomputer remained in third-place.There was just one new member of the top-ten list, and that was Leonardo, which came in fourth after finishing a distant 150th in the TOP500 rankings in June.To read this article in full, please click here

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World’s fastest supercomputer is still Frontier, 2.5X faster than #2

Frontier, which became the first exascale supercomputer in June and ranked number one among the fastest in the world, retained that title in the new TOP500 semiannual list of the world’s fastest.Without any increase in its speed—1.102EFLOP/s—Frontier still managed to score 2.5 times faster that the number two finisher, Fugaku, which also came in second in the June rankings. An exascale computer is one that can perform 1018 (one quintillion) floating point operations per second (1 exaFLOP/s).Despite doubling its maximum speed since it was ranked number three in June, the Lumi supercomputer remained in third-place.There was just one new member of the top-ten list, and that was Leonardo, which came in fourth after finishing a distant 150th in the TOP500 rankings in June.To read this article in full, please click here

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Network Break 407: VMware Buys Startup For SD-WAN Client; Zoom Meetings At The Movies?

This week's Network Break covers several announces from VMware Explore including a new SD-WAN client. ASIC-maker Marvell goes after industrial networks with new silicon, Cisco announces the curtain falling on several ISR router models, and SolarWinds settles with the SEC. Zoom and the AMC movie theater chain partner on an offering to hold big meetings at the movies, and Starlink announces it will slow customer speeds if they cross a 1TB cap.

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Network Break 407: VMware Buys Startup For SD-WAN Client; Zoom Meetings At The Movies?

This week's Network Break covers several announces from VMware Explore including a new SD-WAN client. ASIC-maker Marvell goes after industrial networks with new silicon, Cisco announces the curtain falling on several ISR router models, and SolarWinds settles with the SEC. Zoom and the AMC movie theater chain partner on an offering to hold big meetings at the movies, and Starlink announces it will slow customer speeds if they cross a 1TB cap.

The post Network Break 407: VMware Buys Startup For SD-WAN Client; Zoom Meetings At The Movies? appeared first on Packet Pushers.

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Mean Time to Innocence is not Enough

A long time ago, I supported a wind speed detection system consisting of an impeller, a small electric generator, a 12 gauge cable running a few miles, and a voltmeter. The entire thing was calibrated through a resistive bridge–attach an electric motor to the generator, run it at a series of fixed speed, and adjust the resistive bridge until the voltmeter, marked in knots of wind speed, read correctly.

The primary problem in this system was the several miles of 12 gauge cable. It was often damaged, requiring us to dig the cable up (shovel ready jobs!), strip the cable back, splice the correct pairs together, seal it all in a plastic container filled with goo, and bury it all again. There was one instance, however, when we could not get the wind speed system adjusted correctly, no matter how we tried to tune the resistive bridge. We pulled things apart and determined there must be a problem in one of the (many) splices in the several miles of cable.

At first, we ran a Time Domain Reflectometer (TDR) across the cable to see if we could find the problem. The TDR turned up a couple of hot spots, Continue reading

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Looking at user login time with the ac command

While not a very well known Linux command, ac can provide very useful stats on user login time. In its simplest form, it will show you how much time users have spent on the system in the time period covered by the wtmp file. All you have to type is “ac” to get a figure showing overall login time for all users.$ ac total 8360.60 The figure above indicates that users spent a total of 8,360.6 hours on the system. Looking at the wtmp file with the who command, we can see that the saved logins started on June 6th – a little more than 6 months earlier.$ who /var/log/wtmp | head -2 shs tty2 2022-06-06 16:00 (tty2) shs pts/1 2022-06-06 16:23 (192.168.0.12) To look at the times by user, add the -p (people) argument.To read this article in full, please click here

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Looking at user login time with the ac command

While not a very well known Linux command, ac can provide very useful stats on user login time. In its simplest form, it will show you how much time users have spent on the system in the time period covered by the wtmp file. All you have to type is “ac” to get a figure showing overall login time for all users.$ ac total 8360.60 The figure above indicates that users spent a total of 8,360.6 hours on the system. Looking at the wtmp file with the who command, we can see that the saved logins started on June 6th – a little more than 6 months earlier.$ who /var/log/wtmp | head -2 shs tty2 2022-06-06 16:00 (tty2) shs pts/1 2022-06-06 16:23 (192.168.0.12) To look at the times by user, add the -p (people) argument.To read this article in full, please click here

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Play To Your Team Strengths

This past weekend I went to a training course for an event that I’m participating in next year. One of the quotes that came up during the course was about picking the team that will help you during the event. The quote sounded something like this:

Get the right people on the right bus in the right seats and figure out where you want to go.

Sounds simple, right? Right people, right bus, right seats. Not everyone is going to be a good fit for your team and even if they are they may not be in the right position to do their best work. But how do you know what they’re good at?

Not-So-Well Rounded

Last night, I listened to this excellent Art of Network Engineering episode. The guest was a friend of mine in the industry, Mike Bushong (@MBushong). He’s a very talented person and he knows how to lead people. He’s one of the people that would love to work for given the opportunity. He’s also very astute and he has learned a lot of lessons about enabling people on a team.

One of the things he discussed in the episode was about people’s strengths. Continue reading

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Technology Management is the Foundation for Successful Digital Transformation

Proper IT asset management is the secret to overcoming the complexity and scaling pitfalls of a digital transformation.

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Welcome to the Supercloud (and Developer Week 2022)

In Cloudflare’s S-1 document there’s a section that begins: “The Internet was not built for what it has become”.

That sentence expresses the idea that the Internet, which started as an experiment, has blossomed into something we all need to rely upon for our daily lives and work. And that more is needed than just the Internet as was designed; it needed security and performance and privacy.

Something similar can be said about the cloud: the cloud was not designed for what it must become.

The introduction of services like Amazon EC2 was undoubtedly a huge improvement on the old way of buying and installing racks and racks of servers and storage systems, and then maintaining them.

But by its nature the cloud was a virtualization of the older real world infrastructure and not a radical rethink of what computing should look like to meet the demands of Internet-scale businesses. It’s as if steam locomotives were replaced with efficient electric engines but still required a chimney on top and stopped to take on water every two hundred miles.

The cloud replaced the rituals of buying servers and installing operating systems with new and now familiar rituals of choosing regions, and Continue reading

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Assessing Red Hat Ansible Automation Platform vulnerabilities

What your security scanner isn’t telling you

 

Security, more than ever, needs to move with speed, and we hear much about “shifting security left” and DevSecOps as methods to help achieve this. As this new paradigm gains momentum, so does the reliance on automated security tools to identify and mitigate software vulnerabilities at scale.

But what if these security tools aren’t telling you the full story?

Often, our customers reach out to us saying their security scanners flag Red Hat Ansible Automation Platform as insecure, or that it contains unpatched vulnerabilities. Rest assured, our products are security-hardened and battle-tested. Red Hat's long-standing track record of upstream contributions extends to improving upstream projects' security and contributing to industry standards. The real culprit here is your security scanner!

In this blog, we’ll cover:

• Red Hat’s approach to product security, including Ansible Automation Platform.
• Why security scanners generate false positives for Red Hat products.
• Available resources you can use to make informed product security decisions.

Note

Several links in this blog point you to resources in the Red Hat Customer Portal, which requires a user account. You and members of your team can register online or reach out to your Continue reading