Transcript pertemuan5-performance management

performance monitoring and tuning  salah satu
tugas penting DBA
 Komputer  bagaimana mendapatkan kinerja yang
baik
 Kinerja DBMS  memiliki reputasi yang buruk
dalam hal performance
 Konten materi :
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› Performance monitoring
› Tuning
› Perbedaan monitoring dan performance management
Organisasi pengguna IT  monitor dan tune
performa IT infrastruktur
 Infrastruktur IT meliputi
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Server
Jaringan
Aplikasi
Database
Performance management yang digunakan masih
reaktif
 Contoh : tablespace yang sudah penuh
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Apa database performance ? Efisiensi ?
 Konsep db performance  konsep supply and
demand
 User request informasi dari db
 Dbms  supply informasi
 Db performance  tingkat dimana DBMS
mensupply informasi untuk permintaan users
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workload,
 throughput,
 resources,
 optimization,
 and contention
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Kombinasi dari  transaksi online, batch jobs,
adhoc query, analisa data warehousing, dan
perintah sistem dalam satu waktu
 Dapat fluktuatif dari hari ke hari, jam ke jam,
menit ke menit
 terkadang dapat diprediksi (contoh : penggunaan
internet paling banyak pada waktu istirahat)
 Lebih sering tidak dapat diprediksi
 Memiliki dampak besar pada performa db
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Kemampuan seluruh komputer untuk
memproses data
 Gabungan kecepatan I/O, CPU dan kemampuan
paralel komputer, efisiensi OS dan system
software
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Hardware dan software sebagai tempat untuk
penampungan data sistem
 Meliputi
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› Db kernel
› Disk storage
› RAM chips
› Cache control
› microcode
 Semua sistem dapat dilakukan optimasi
 DBMS perlu optimasi khusus  dilakukan ke
dalam internal DBMS
 Banyak faktor yang perlu dioptimalkan  SQL
query, db parameter
Permintaan yang tinggi  muncul contention
 Contention  kondisi dimana dua atau lebih
komponen dari kerja menggunakan sebuah
resource dengan bertentangan
 Contoh dua upate bersamaan pada satu data
 Contention naik, througput naik
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Butuh langkah proaktif selain langkah reaktif
 Perubahan pada kode aplikasi  belum bisa
dianggap langkah proaktif
 Langkah proaktif  memperbaiki masalah
sebelum menyelesaikan aplikasi
 Dba sering menggunakan pendekatan reaktif
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Penggunaan event-drivent tools  untuk
mendeteksi masalah kinerja secara otomatis
 Manajemen performance != monitoring
performance
 Manajemen performance  combine
monitoring performance + resolve masalah
 Meliputi 3 komponen spesifik
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› Monitoring, analisis, dan koreksi
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Monitoring  identifikasi masalah
Komponen kedua dari performance
management
 Monitoring  dapat menghasilkan ribuan
laporan masalah
 Hasil monitoring tidak dapat digunakan untuk
mengambil keputusan
 Analisa  diperlukan untuk mencari penyebab
utama dan cara mengatasi masalah
 Hanya dapat dilakukan oleh tenaga ahli, seperti
DBA
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Aplikasi db memerlukan interkasi konstan
antara beberapa resource komputer agar bekerja
sesuai spesifkasinya
 Tuning db dapat dipecah menjadi 3 komponen
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› System tuning
› Db tuning
› Aplikasi tuning
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Ketiganya berhubungan
System tuning occurs at the highest level and has
the greatest impact on the overall health of
database applications because every application
depends on the system.
 For the purposes of this discussion, we will define
the system as comprising the DBMS itself and all of
the related components on which it relies.
 No amount of tuning is going to help a database or
application when the server it is running on is short
on resources or improperly installed.
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The DBMS can and must be tuned to assure optimum
performance.
The way in which the DBMS software is installed, its memory,
disk, CPU, other resources, and any configuration options can
impact database application performance.
The other systems software with which the DBMS interacts
includes the operating system, networking software, message
queueing systems, middleware, and transaction processors.
System tuning comprises installation, configuration, and
integration issues, as well as ensuring connectivity of the
software to the DBMS and database applications.
Performance can be impacted by the physical
design of the database, including normalization,
disk storage, number of tables, index design,
and use of DDL and its associated parameters.
 The physical location of database files on disk
systems will have an impact on the performance
of applications accessing the data.
 As more data is stored on the same disk device,
the possibility of performance degradation
increases.
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However, design is not the only component of database
performance. The organization of the database will change
over time.
As data is inserted, updated, and deleted from the database,
the efficiency of the database will degrade. Moreover, the files
that hold the data may need to expand as more data is added.
Perhaps additional files, or file extents, will need to be
allocated.
Both disorganization and file growth can degrade
performance.
Indexes also need to be monitored, analyzed, and tuned to
optimize data access and to ensure that they are not having a
negative impact on data modification.
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The application itself must be designed appropriately and
monitored for efficiency.
Most experts agree that as much as 75% of performance
problems are caused by improperly coded applications.
SQL is the primary culprit; coding efficient SQL statements can
be complicated.
Developers need to be taught how to properly formulate,
monitor, and tune SQL statements.
However, not all application problems are due to improperly
coded SQL.
The host language application code in which the SQL has been
embedded may be causing the problem.
For example, Java, COBOL, C++, or Visual Basic code may be
inefficient, causing database application performance to suffer.
Tools DB  efektif membantu mengatur
performa DB
 Beberapa vendor menyertakan beberapa tools
untuk performance management
 Tapi tidak terlalu bisa menangani tipe data yang
sangat banyak
 Tools DB dapat dikatagorikan 2 tuama
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› Performance management
› Performance optimization
 Performance monitor
 Performance estimation
 Capacity planning tools
 SQL analysis dan tuning
 Advisory tools augment SQL
 System analysis dan tuning
We have defined database performance and
discussed it from a high level.
 Before we delve into the specifics of system,
database, and application performance, let's
examine some rules of thumb for achieving your
DBMS-related performance goals.
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Do not over-tune
 Remain focused
 Do not panic
 Communicate clearly
 Accept reality
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Applications that access relational databases are
only as good as the performance they achieve.
 The wise organization will implement a
comprehensive performance monitoring, tuning,
and management environment that consists of
policies, procedures, and integrated
performance management tools and utilities.
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