SQL Performance

JANUARY 11, 2021

all_columns ; The prepared statement from the application looked like this (as seen in the plan cache): ( @P0 varchar ( 8000 ) ) SELECT * FROM dbo.TheThings WHERE TypeID = @P0. And if the query is truly observing the RECOMPILE hint I'm passing in to the plan guide, how could I ever see any evidence in the plan cache anyway?

Cache 59

Cache Tuning Database Performance 59

The Morning Paper

SEPTEMBER 24, 2019

The apps are driven using Android’s Application Exerciser Monkey which injects a pseudo-random stream of simulated user input events into the app (a UI fuzzer). The OpenX SDK was found to be using the ARP cache side channel, and the code makes it clear the authors knew what they were doing.

Systems 74

Systems Traffic Network Google 74

Sutter's Mill

JANUARY 25, 2021

Not only is the integer comparison operation cheap, but min and max are already being accessed by this function and so they’re already “hot” in registers or cache. Because we realistically can’t write and exercise them all, though, we could be observing a secondary effect from a bug that happened earlier.

C++ 45

C++ Programming Cache Testing 45

SQL Performance

OCTOBER 20, 2022

The test is a little contrived for compactness, but it’s extremely common for plans to apply predicate tests outside the original locking operator, for example after a join, aggregation, or row numbering exercise. The test procedure includes extra statements to prevent plan caching in another attempt to make the tests more repeatable.

Testing 91

Testing Servers Cache Engineering 91

Percona

AUGUST 8, 2023

Global caches like the InnoDB buffer pool and MyISAM key cache and session-level caches like the sort buffer, join buffer, random read buffer, etc. Global memory caches are static in size as they are defined solely by the configuration of the database itself. Do these queries use more caches?

Traffic 89

Traffic Cache Monitoring Database 89

CSS - Tricks

APRIL 1, 2021

With all of this in mind, I thought improving the speed of my own version of a slow site would be a fun exercise. Compressing, minifying and caching assets. We can compress our assets, minify our styles and scripts, and cache things responsibly so we’re serving what the user needs in the most efficient way possible.

Cache 92

Cache Social Media Media Website 92

SQL Server According to Bob

JANUARY 26, 2017

Note: Be sure to set your ‘max server memory’ back to 0 when you are done with this fun exercise. c:public_symbols is a symbol cache and a folder I created on my laptop. Now let;’s run the query and use show statistics to see if a spill occurs. set statistics xml on go select * from yourtable order by col2 go.

Servers 40

Servers Database Azure Cache 40

Dynatrace

APRIL 21, 2022

Once you have and understand this data, you can identify issues, find opportunities for improvement, and eliminate risks before you go through a costly migration exercise. Missing caching layers. To make an informed decision on what to optimize within your application, you must first collect baseline performance data.

Azure 188

Azure Monitoring Virtualization Metrics 188

The Morning Paper

JANUARY 23, 2020

The process tracing exercise included: Examning IRC transcripts from multiple channels. With only an hour or so of degraded performance in the end, it’s not the worst incident you can imagine, but it was clearly taken as very serious given the time of year. Gathering timestapms of changes made to application code during the outage.

Internet 53

Internet Internet Cache Engineering 53

Brendan Gregg

JUNE 30, 2018

sounds like a homework exercise of purely academic value. In some cases, a benchmark may appear to exceed network bandwidth because it returns from a local memory cache instead of the remote target. If the benchmark reported 20k ops/sec, you should ask: why not 40k ops/sec? This is really asking "what's the limiter?" Does it reproduce?

Benchmarking 54

Benchmarking Latency Cache Network 54

The Morning Paper

DECEMBER 8, 2019

The beauty of persistent memory is that we can use memory layouts for persistent data (with some considerations for volatile caches etc. This is left as an exercise for the application developer at present. in front of that memory , as we saw last week). The Twizzler programming model. What about security?

Hardware 56

Hardware Programming Media Storage 56

All Things Distributed

NOVEMBER 21, 2017

Redis's microsecond latency has made it a de facto choice for caching. With over 200 million users and seven billion language exercises completed each month, the company's mission is to make education free, fun, and accessible to all.

Games 113

Games Retail Latency Education 113

Brendan Gregg

JUNE 29, 2018

sounds like a homework exercise of purely academic value. In some cases, a benchmark may appear to exceed network bandwidth because it returns from a local memory cache instead of the remote target. If the benchmark reported 20k ops/sec, you should ask: why not 40k ops/sec? This is really asking "what's the limiter?" Does it reproduce?

Benchmarking 40

Benchmarking Latency Cache Network 40

SQL Performance

NOVEMBER 30, 2021

Although in our thought exercise, the optimizer can use buffer pool knowledge to compile the most efficient query at a single instant, it would be a dangerous way to drive plan compilation because of the potential volatility of the buffer pool contents, making the future efficiency of the cached plan highly unreliable.

Efficiency 54

Efficiency Servers Database Cache 54

The Morning Paper

NOVEMBER 14, 2019

Sharing is caring caching. Therefore friend groups all end up accessing similar content, a fact that can be exploited in the backend to improve cache utilisation. This safety guard ensures larger changes happen in stages, giving caching systems etc. We looked at this before when we studied Facebook’s Social Hashing algorithm.

Traffic 42

Traffic Internet Internet Latency 42

Percona

JULY 6, 2023

Next is the table definition. I included a sequence creation statement for the id column since one best practice is always to have a primary key column, but for the specific examples we will go through, we don’t need it.

Best Practices 89

Best Practices Tuning Database Testing 89

All Things Distributed

OCTOBER 2, 2017

In addition, DynamoDB Accelerator (DAX) a fully managed, highly available, in-memory cache further speeds up DynamoDB response times from milliseconds to microseconds and can continue to do so at millions of requests per second. Auto Scaling is on by default for all new tables and indexes.

Internet 130

Internet Internet AWS Performance 130

John McCalpin

AUGUST 1, 2018

This is an intellectually challenging and labor-intensive exercise, requiring detailed review of the published details of each of the components of the system, and usually requiring significant “detective work” (using customized microbenchmarks, hardware performance counter analysis, and creative thinking) to fill in the gaps.

Hardware 40

Hardware Transportation Performance Latency 40

The Netflix TechBlog

MARCH 6, 2019

Disk Caching? — ? MezzFS can be configured to cache objects on the local disk. Regional caching? —?Netflix If an application in region A is using MezzFS to read from an object stored in region B, MezzFS will cache the object in region A. we only pay the transfer costs for one worker, and the rest use the cached object.

Media 214

Media Storage Processing Cache 214