Brendan Gregg

AUGUST 18, 2019

For example, iostat(1), or a monitoring agent, may tell you your average disk latency, but not the distribution of this latency. For smaller environments, it can be of more use helping eliminate latency outliers. bpftrace uses BPF (Berkeley Packet Filter), an in-kernel execution engine that processes a virtual instruction set.

Latency 68

Latency C++ Cache Programming 68

Brendan Gregg

OCTOBER 8, 2018

more capable, and built from the ground up for the modern era of the eBPF virtual machine. Screenshot: tracing read latency for PID 181: # bpftrace -e 'kprobe:vfs_read /pid == 30153/ { @start[tid] = nsecs; } kretprobe:vfs_read /@start[tid]/ { @ns = hist(nsecs - @start[tid]); delete(@start[tid]); }'. Attaching 2 probes. ^C

C++ 110

C++ Virtualization Programming Latency 110

Brendan Gregg

OCTOBER 7, 2018

more capable, and built from the ground up for the modern era of the eBPF virtual machine. Screenshot: tracing read latency for PID 181: # bpftrace -e 'kprobe:vfs_read /pid == 30153/ { @start[tid] = nsecs; } kretprobe:vfs_read /@start[tid]/ { @ns = hist(nsecs - @start[tid]); delete(@start[tid]); }'. Attaching 2 probes. ^C

C++ 40

C++ Virtualization Programming Latency 40

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. CLI tools The Cassandra systems were EC2 virtual machine (Xen) instances. Was there some other program consuming CPU, like a misbehaving Ubuntu service that wasn't in CentOS? These can be invisible to top(8). us on Ubuntu.

Speed 126

Speed Java AWS Virtualization 126

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. CLI tools The Cassandra systems were EC2 virtual machine (Xen) instances. Was there some other program consuming CPU, like a misbehaving Ubuntu service that wasn't in CentOS? These can be invisible to top(8). in total.

Speed 52

Speed Java AWS Virtualization 52

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. CLI tools The Cassandra systems were EC2 virtual machine (Xen) instances. Was there some other program consuming CPU, like a misbehaving Ubuntu service that wasn't in CentOS? These can be invisible to top(8). us on Ubuntu.

Speed 40

Speed Java AWS Virtualization 40

The Morning Paper

DECEMBER 8, 2019

On the last morning of the conference Daniel Bittman presented some of the work being done in the context of the Twizzler OS project to explore new programming models for NVM. The starting point is a set of three asumptions for an NVM-based programming model: Compared to traditional persistent media, NVM is fast.

Hardware 56

Hardware Programming Media Storage 56