All Things Distributed

OCTOBER 2, 2017

percent availability in the event of a server, a rack of servers, or an Availability Zone failure. DynamoDB automatically re-distributes your data to healthy servers to ensure there are always multiple replicas of your data without you needing to intervene. Auto Scaling is on by default for all new tables and indexes.

Internet 111

Internet Internet AWS Performance 111

Percona

AUGUST 8, 2023

Unfortunately, this topic is more of an art than a science, given that there is really no foolproof algorithm or approach that can tell you exactly where you might hit a bottleneck with server performance. Global memory caches are static in size as they are defined solely by the configuration of the database itself.

Traffic 98

Traffic Cache Monitoring Database 98

All Things Distributed

NOVEMBER 21, 2017

Redis's microsecond latency has made it a de facto choice for caching. However, the slots must be moved manually on the server side. 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 96

Games Retail Latency Education 96

SQL Performance

OCTOBER 20, 2022

When SQL Server reads data under locking read committed isolation (the default for non-cloud offerings) and chooses row-level locking granularity, it normally only locks one row at a time. SQL Server solves this problem using lock classes. SQL Server needs to hold locks in this case to ensure the by-reference LOB pointers remain valid.

Testing 91

Testing Servers Cache Engineering 91

SQL Performance

JANUARY 11, 2021

So when their compiled application sends ad hoc queries to SQL Server, particularly as a prepared statement, and when we don't have the freedom to add or change indexes, several tuning opportunities are immediately off the table. You won't be able to check the plan cache for these results, because of the recompile.

Cache 59

Cache Tuning Database Performance 59

SQL Server According to Bob

JANUARY 26, 2017

My goal is to resolve mysteries about SQL Server I encounter but do this without going straight the source code first. The first case that helped me start this journey was asked by a MVP within the SQL Server community (his first name starts with Joey<g>). The question went something like this….

Servers 40

Servers Database Azure Cache 40

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 47

Benchmarking Latency Cache Network 47

HammerDB

APRIL 19, 2023

Instead, focus on understanding what the workloads exercise to help us determine how to best use them to aid our performance assessment. For the network, we can use Iperf to assess the network bandwidth between the client and the database server to ensure it will be enough to meet our peak requirement.

Performance 55

Performance Benchmarking Cache Storage 55

SQL Performance

NOVEMBER 30, 2021

SQL Server has a cost-based optimizer that uses knowledge about the various tables involved in a query to produce what it decides is the most optimal plan in the time available to it during compilation. However, nothing easily allows SQL Server to determine what percentage of the leaf level for each index of a table is already in memory.

Efficiency 54

Efficiency Servers Database Cache 54

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