東大電子情報工学科の田浦先生におよるオペーレーティングシステム授業で行なった「仮想マシンにおけるメモリ管理及びExtended Page Table」についての発表のスライドです。
発表で取り扱ったのはMerrifiel(2017)の"Performance Implications of Extended Page Tables on Virtualized x86 Processors"です。
Bucket your partitions wisely - Cassandra summit 2016Markus Höfer
When we talk about bucketing we essentially talk about possibilities to split cassandra partitions in several smaller parts, rather than having only one large partition.
Bucketing of cassandra partitions can be crucial for optimizing queries, preventing large partitions or to fight TombstoneOverwhelmingException which can occur when creating too many tombstones.
In this talk I want to show how to recognize large partitions during datamodeling. I will also show different strategies we used in our projects to create, use and maintain buckets for our partitions.
Myths of Big Partitions (Robert Stupp, DataStax) | Cassandra Summit 2016DataStax
Large partitions shall no longer be a nightmare. That is the goal of CASSANDRA-11206.
100MB and 100,000 cells per partition is the recommended limit for a single partition in Cassandra up to 3.5. Exceeding these limits can cause a lot of trouble. Repairs and compactions could fail and reads cause out-of-memory failures.
This talk provides a deep-dive of the reasons for the previous limitations, why exceeding these limitations caused trouble, how the improvements in Cassandra 3.6 helps with big partitions and why you should not blindly let your partitions get huge.
About the Speaker
Robert Stupp Solution Architect, DataStax
Robert is working as a Solutions Architect at DataStax and is also a Committer to Apache Cassandra. Before joining DataStax he worked with his customers to architect and build distributed systems using Cassandra and has a long experience in building distributed backend systems mostly using Java as the preferred language of choice.
Understanding and tuning WiredTiger, the new high performance database engine...Ontico
MongoDB 3.0 introduced the concept of different storage engine. The new engine known as WiredTiger introduces document level MVCC locking, compression and a choice between Btree or LSM indexes. In this talk you will learn about the storage engine architecture and specifically WiredTiger, and how to tune and monitor it for best performance.
MongoDB 3.0 представил новый концепт движков хранения. Новый движок известен как WiredTiger и предоставляет новый уровень документов MVCC фикс, компрессию и выбор между Btree или индексами LSM. В этом докладе вы поймете, как тюнить и мониторить архитектуры движка базы данных, а точнее WiredTiger для получения максимальной производительности.
[Open Infrastructure & Cloud Native Days Korea 2019]
커뮤니티 버전의 OpenStack 과 Ceph를 활용하여 대고객서비스를 구축한 사례를 공유합니다. 유연성을 확보한 기업용 클라우드 서비스 구축 사례와 높은 수준의 보안을 요구하는 거래소 서비스를 구축, 운영한 사례를 소개합니다. 또한 이 프로젝트에 사용된 기술 스택 및 장애 해결사례와 최적화 방안을 소개합니다. 오픈스택은 역시 오픈소스컨설팅입니다.
#openstack #ceph #openinfraday #cloudnative #opensourceconsulting
The first portion of the session will cover the critical reason why PostgreSQL generates these full page writes (FPW) and how to monitor the rate of generation. Next we will demonstrate the negative effect of full page writes on performance, scale, backups and replication. Then we will cover various techniques to decrease the amount of full page writes and improve your databases performance/scale/efficiency including using new PostgreSQL versions, parameter changes, application changes and the use of specific PostgreSQL features like partitioning. The final portion of the session will look at how future architectures can eliminate the need for full page writes.
東大電子情報工学科の田浦先生におよるオペーレーティングシステム授業で行なった「仮想マシンにおけるメモリ管理及びExtended Page Table」についての発表のスライドです。
発表で取り扱ったのはMerrifiel(2017)の"Performance Implications of Extended Page Tables on Virtualized x86 Processors"です。
Bucket your partitions wisely - Cassandra summit 2016Markus Höfer
When we talk about bucketing we essentially talk about possibilities to split cassandra partitions in several smaller parts, rather than having only one large partition.
Bucketing of cassandra partitions can be crucial for optimizing queries, preventing large partitions or to fight TombstoneOverwhelmingException which can occur when creating too many tombstones.
In this talk I want to show how to recognize large partitions during datamodeling. I will also show different strategies we used in our projects to create, use and maintain buckets for our partitions.
Myths of Big Partitions (Robert Stupp, DataStax) | Cassandra Summit 2016DataStax
Large partitions shall no longer be a nightmare. That is the goal of CASSANDRA-11206.
100MB and 100,000 cells per partition is the recommended limit for a single partition in Cassandra up to 3.5. Exceeding these limits can cause a lot of trouble. Repairs and compactions could fail and reads cause out-of-memory failures.
This talk provides a deep-dive of the reasons for the previous limitations, why exceeding these limitations caused trouble, how the improvements in Cassandra 3.6 helps with big partitions and why you should not blindly let your partitions get huge.
About the Speaker
Robert Stupp Solution Architect, DataStax
Robert is working as a Solutions Architect at DataStax and is also a Committer to Apache Cassandra. Before joining DataStax he worked with his customers to architect and build distributed systems using Cassandra and has a long experience in building distributed backend systems mostly using Java as the preferred language of choice.
Understanding and tuning WiredTiger, the new high performance database engine...Ontico
MongoDB 3.0 introduced the concept of different storage engine. The new engine known as WiredTiger introduces document level MVCC locking, compression and a choice between Btree or LSM indexes. In this talk you will learn about the storage engine architecture and specifically WiredTiger, and how to tune and monitor it for best performance.
MongoDB 3.0 представил новый концепт движков хранения. Новый движок известен как WiredTiger и предоставляет новый уровень документов MVCC фикс, компрессию и выбор между Btree или индексами LSM. В этом докладе вы поймете, как тюнить и мониторить архитектуры движка базы данных, а точнее WiredTiger для получения максимальной производительности.
[Open Infrastructure & Cloud Native Days Korea 2019]
커뮤니티 버전의 OpenStack 과 Ceph를 활용하여 대고객서비스를 구축한 사례를 공유합니다. 유연성을 확보한 기업용 클라우드 서비스 구축 사례와 높은 수준의 보안을 요구하는 거래소 서비스를 구축, 운영한 사례를 소개합니다. 또한 이 프로젝트에 사용된 기술 스택 및 장애 해결사례와 최적화 방안을 소개합니다. 오픈스택은 역시 오픈소스컨설팅입니다.
#openstack #ceph #openinfraday #cloudnative #opensourceconsulting
The first portion of the session will cover the critical reason why PostgreSQL generates these full page writes (FPW) and how to monitor the rate of generation. Next we will demonstrate the negative effect of full page writes on performance, scale, backups and replication. Then we will cover various techniques to decrease the amount of full page writes and improve your databases performance/scale/efficiency including using new PostgreSQL versions, parameter changes, application changes and the use of specific PostgreSQL features like partitioning. The final portion of the session will look at how future architectures can eliminate the need for full page writes.
MySQL Performance Tuning. Part 1: MySQL Configuration (includes MySQL 5.7)Aurimas Mikalauskas
Is my MySQL server configured properly? Should I run Community MySQL, MariaDB, Percona or WebScaleSQL? How many innodb buffer pool instances should I run? Why should I NOT use the query cache? How do I size the innodb log file size and what IS that innodb log anyway? All answers are inside.
Aurimas Mikalauskas is a former Percona performance consultant and architect currently writing and teaching at speedemy.com. He's been involved with MySQL since 1999, scaling and optimizing MySQL backed systems since 2004 for companies such as BBC, EngineYard, famous social networks and small shops like EstanteVirtual, Pine Cove and hundreds of others.
Additional content mentioned in the presentation can be found here: http://speedemy.com/17
【DLゼミ】XFeat: Accelerated Features for Lightweight Image Matchingharmonylab
公開URL:https://arxiv.org/pdf/2404.19174
出典:Guilherme Potje, Felipe Cadar, Andre Araujo, Renato Martins, Erickson R. ascimento: XFeat: Accelerated Features for Lightweight Image Matching, Proceedings of the 2024 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR) (2023)
概要:リソース効率に優れた特徴点マッチングのための軽量なアーキテクチャ「XFeat(Accelerated Features)」を提案します。手法は、局所的な特徴点の検出、抽出、マッチングのための畳み込みニューラルネットワークの基本的な設計を再検討します。特に、リソースが限られたデバイス向けに迅速かつ堅牢なアルゴリズムが必要とされるため、解像度を可能な限り高く保ちながら、ネットワークのチャネル数を制限します。さらに、スパース下でのマッチングを選択できる設計となっており、ナビゲーションやARなどのアプリケーションに適しています。XFeatは、高速かつ同等以上の精度を実現し、一般的なラップトップのCPU上でリアルタイムで動作します。
セル生産方式におけるロボットの活用には様々な問題があるが,その一つとして 3 体以上の物体の組み立てが挙げられる.一般に,複数物体を同時に組み立てる際は,対象の部品をそれぞれロボットアームまたは治具でそれぞれ独立に保持することで組み立てを遂行すると考えられる.ただし,この方法ではロボットアームや治具を部品数と同じ数だけ必要とし,部品数が多いほどコスト面や設置スペースの関係で無駄が多くなる.この課題に対して音𣷓らは組み立て対象物に働く接触力等の解析により,治具等で固定されていない対象物が組み立て作業中に運動しにくい状態となる条件を求めた.すなわち,環境中の非把持対象物のロバスト性を考慮して,組み立て作業条件を検討している.本研究ではこの方策に基づいて,複数物体の組み立て作業を単腕マニピュレータで実行することを目的とする.このとき,対象物のロバスト性を考慮することで,仮組状態の複数物体を同時に扱う手法を提案する.作業対象としてパイプジョイントの組み立てを挙げ,簡易な道具を用いることで単腕マニピュレータで複数物体を同時に把持できることを示す.さらに,作業成功率の向上のために RGB-D カメラを用いた物体の位置検出に基づくロボット制御及び動作計画を実装する.
This paper discusses assembly operations using a single manipulator and a parallel gripper to simultaneously
grasp multiple objects and hold the group of temporarily assembled objects. Multiple robots and jigs generally operate
assembly tasks by constraining the target objects mechanically or geometrically to prevent them from moving. It is
necessary to analyze the physical interaction between the objects for such constraints to achieve the tasks with a single
gripper. In this paper, we focus on assembling pipe joints as an example and discuss constraining the motion of the
objects. Our demonstration shows that a simple tool can facilitate holding multiple objects with a single gripper.
25. key_buffer_size の調整
• SHOW STATUS LIKE 'Key_read%';
– Key_read_requests / Key_reads = 150 以上になる
ように key_buffer_size を調整
• SHOW STATUS LIKE 'Key_blocks%';
– Key_blocks_unused が数百など少ない場合
key_buffer_size を増やす必要がある。
26. 最大接続数とスレッド数の確認
• SHOW STATUS LIKE '%connection%';
– Max_used_connections
• これまでに記録された同時接続数の最大値
• SHOW STATUS LIKE 'Threads%';
– Threads_connected
• 現在開いている接続の数
– Threads_created
• 接続を処理するために生成されたスレッド数
– Threads_running
• スリープ状態になっていないスレッド数
27. table_open_cache の調整
• SHOW STATUS LIKE 'Open_tables';
– Open_tables
• 現在開かれているテーブル数を確認
– Opened_tables
• たとえ多くの FLUSH TABLES を実行していない場合でも、
この値が非常に大きい場合や急速に大きくなる場合
は、テーブルキャッシュサイズを拡張する