Brendan Gregg

JUNE 29, 2018

A co-worker introduced me to Craig Hanson and Pat Crain's performance mantras, which neatly summarize much of what we do in performance analysis and tuning. These have inspired me to summarize another performance activity: evaluating benchmark accuracy. If the benchmark reported 20k ops/sec, you should ask: why not 40k ops/sec?

Benchmarking 40

Benchmarking Latency Cache Network 40

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI. Software-based clocksources could fix those issues and provide accurate monotonically-increasing time.

Speed 126

Speed Java AWS Virtualization 126

HammerDB

OCTOBER 18, 2019

HammerDB doesn’t publish competitive database benchmarks, instead we always encourage people to be better informed by running their own. So over at Phoronix some database benchmarks were published showing PostgreSQL 12 Performance With AMD EPYC 7742 vs. Intel Xeon Platinum 8280 Benchmarks .

Benchmarking 63

Benchmarking Performance Hardware C++ 63

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI. Software-based clocksources could fix those issues and provide accurate monotonically-increasing time.

Speed 40

Speed Java AWS Virtualization 40

IO River

NOVEMBER 15, 2023

Two of them are particularly gnarly: fine-tuning rules to perfection and managing a WAF over a multi-CDN architecture. Attackers discover a previously unknown vulnerability in a software or system. Benchmarks should be established to measure the latency introduced by the WAF, ensuring it stays within acceptable limits.‍Conclusion‍In

Traffic 52

Traffic Network Logistics Architecture 52

IO River

NOVEMBER 2, 2023

Two of them are particularly gnarly: fine-tuning rules to perfection and managing a WAF over a multi-CDN architecture. They exploit unknown vulnerabilities, giving developers zero days to fix the issue—hence the name.‍Attackers discover a previously unknown vulnerability in a software or system. Let's dive deep into these challenges.‍1.

Traffic 40

Traffic Network Logistics Architecture 40

John McCalpin

JANUARY 22, 2018

Each of the two vector units can issue one FMA instruction per cycle, assuming that there are enough independent accumulators to tolerate the 6-cycle dependent-operation latency. This is an uninspiring fraction of peak performance that would normally suggest significant inefficiencies in either the hardware or software. jb.B1.8.

Latency 40

Latency Hardware Code Testing 40

HammerDB

OCTOBER 12, 2018

For anyone benchmarking MySQL with HammerDB it is important to understand the differences from sysbench workloads as HammerDB is targeted at a testing a different usage model from sysbench. CPUs which need to have their frequency coordinated by software: 0 . maximum transition latency: Cannot determine or is not supported. .

Best Practices 40

Best Practices Scalability Performance C++ 40

SQL Server According to Bob

JANUARY 11, 2020

Many high-end disk subsystems provide high-speed cache facilities to reduce the latency of read and write operations. For specific information on I/O tuning and balancing, you will find more details in the following document. Mirroring can be implemented at a software or hardware level.

Servers 40

Servers Cache Media Hardware 40

SQL Server According to Bob

JANUARY 11, 2020

The caching of data pages and grouping of log records helps remove much, if not all, of the command latency associated with a write operation. Action Description Manual Checkpoint – Target Specified I/O latency target set to ​​ the default ​​ of ​​ 20ms.

Servers 40

Servers Cache Database Media 40