Sejumlah artikel yang terkait dengan replication akan saya rencanakan hadir dalam blog saya. Berikut adalah artikel pertama dari replication, tentang Time synchronization.
Agar replikasi dapat berlangsung secara baik, penting untuk seluruh domain controller pada suatu domain / forest untuk memiliki sistem waktu yang sama. Alasannya adalah untuk Kerberos, jika terdapat domain controller yang tidak sinkron dalam waktu lebih dari 5 menit saja, autentikasi akan gagal dilakukan.
Windows Time Service merupakan tool yang disediakan Microsoft untuk menjaga konsistensi keseluruhan domain atau forest agar tetap berada momen waktu yang sama. Windows Time Services menggunakan sistem keanggotaan yang hirarki untuk member dari domain AD DS dan forest, dengan mesin yang menjadi PDC Emulator Master role sebagai lokasi utama untuk informasi waktu. Sistem waktu yang digunakan pada top level tidak perlu disinkronisasi dari manapun- sinkronisasi hanya penting dilakukan di dalam domain, seluruh membernya memiliki kesamaan dalam persepsi waktu, tidak peduli apakah waktu yang dipakai itu waktu yang aktual atau tidak.
Dari bawah ke atas, hirarki tersebut terlihat seperti berikut:
- Workstation dan server-server yang bukan domain controllers akan mensinkronisasikan waktunya dengan domain controller saat logon ke domain.
- Domain controllers akan mengontak domain controller yang berperan sebagai PDC Emulator operation master role untuk domain mereka masing-masing untuk rujukan waktu yang digunakan (current time).
- Tiap domain dalam forest dengan multiple domains akan merujuk ke PDC emulator operations master- yang menjadi domain controller pada root forest.
Kita dapat melakukan domain controller yang menjadi PDC emulator operations master role dalam beberapa cara melalui command line. Pertama, kita harus memilih sumber waktu yang akan digunakan. Microsoft menyediakan host time.windows.com, yang disinkronisasikan ke U.S. Army's Atomic Clock, salah satu pilihan yang bagus. Begitu kita telah tentukan sumber waktunya, jalankan perintah berikut dari command line pada PDC emulator domain controller:
net time /setsntp: <TIMESOURCE>
Ganti <TIMESOURCE> dengan nama lengkap DNS dari sumber waktu yang kita gunakan. Sebagai contoh, jika kita menggunakan time.windows.com sebagai sumber waktu, perintah yang diketikkan menjadi :
net time /setsntp:time.windows.com
Dengan mengkonfigurasi sumber waktu untuk PDC emulator domain controller, komputer ini akan melakukan sinkronisasi dengan sumber waktunya, dia akan terus mencoba setiap 45 menit sampai sinkronisasi sukses dilakukan hingga 3 kali. Untuk selanjutnya, dia melakukan ping ke time server hanya sekali saja tiap 8 jam. Jika kita ingin memicu terjadinya time synchronization secara manual, jalankan:
w32tm /resync
Windows Time Service memerlukan outbound UDP port 123 dibuka pada firewall agar time synchronizations dapat terjadi.
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Seringkali di jaringan yang menggunakan dynamic DNS, dimana user terutama yang menggunakan notebook, datang ke kantor melakukan docking notebooknya ke jaringan, Server DHCP memberikan alamat IP, dan Server DNS meregistrasikan record-nya dalam zone dns database-nya, tidak lama kemudian si user melakukan undocking notebooknya dari jaringan misalkan untuk melakukan tugas-tugas mobile keluar kantor, record notebook si user yang sebenarnya telah expired ini di DNS tidak langsung terhapus. Kita perlu melakukan penghapusan informasi yang expired ini, agar tidak menumpuk banyak seiring dengan perkembangan waktu.
Di Windows Server 2008 (dan juga pada edisi Windows 2000 dan 2003) terdapat proses scavenging yang berfungsi untuk menemukan berbagai informasi resource record DNS dinamis yang belum di update dalam kurun waktu tertentu ini dan kemudian menghapus yang telah basi (stale resource recod) untuk memastikan informasi zone DNS yang di propagasi pada interval berikutnya berisi data-data yang terkini.
Terjemahan bebas scavenging itu sendiri berarti mengais-ngais barang, sedangkan Scavenger adalah pemulung. Proses scavenging pada DNS bertujuan untuk memilah-milah resource record yang basi untuk kemudian dihapus.
Untuk mengontrol scavenging untuk seluruh zona pada server tertentu, klik-kanan nama server dari DNS Management snap-in dan pilih Set Aging/Scavenging for All Zones. Properti dari Aging/Scavenging muncul seperti pada gambar berikut.
Pada bagian pojok kanan dari gambar ini, ada pilihan untuk mengaktifkan/menon-aktifkan scavenging. Sebagai tambahan, kita juga melihat dua pilihan yang salah satunya adalah no-refresh interval, artinya adalah waktu dimana registrasi secara dinamis di set untuk read only sebelum dilakukan pemeriksaan oleh proses scavenger. Ini artinya komputer client tidak dapat melakukan registrasi ulang (re-registration) dirinya selama masa periode ini berlangsung. Pilihan lainnya adalah refresh interval, yang menyatakan jumlah waktu dari suatu record untuk tetap ada dan diizinkan untuk di refresh setelah melewati masa no-refresh interval sebelum proses scavenger menghapusnya. Secara esensial, scavenger process tidak dizinkan untuk “menyentuh” suatu record kecuali setelah kedua interval ini (no-refresh dan refresh intervals) terlewati secara penuh.
Untuk mengaktifkan scavenging, beri tanda cek pada checkbox dan klik OK. Jika kita menggunakan Active Directory-integrated zones, kita akan diminta untuk konfirmasi pilihan tersebut. Klik OK sekali lagi, dan scavenging akan diaktifkan. Seperti pada gambar berikut ini:
![clip_image002[4]](http://wss-id.org/blogs/bobby/clip_image0024_thumb_41965180.jpg "clip_image002[4]")
Satu langkah lagi, kita tetap perlu untuk mengaktifkan scavenging pada nameserver, yang dapat kita lakukan dengan cara klik-kanan nama - server dalam DNS Management, pilih Properties, dan klik tab Advanced.
Pada bagian bawah, beri tanda cek pada checkbox "Enable automatic scavenging of stale records," dan kemudian masukkan periode waktunya.
Jika kita ingin mengontrol scavenging dan intervalnya untuk tiap-tiap zone, bias kita lakukan dengan cara klik-kanan zone dalam zone dalam DNS Management dan pilih Properties. Kemudian lakukan navigasi ke tab General dan klik tombol Aging.
Kita dapat melihat timestamp dalam format yang mudah dibaca dengan cara klik-kanan suatu record dalam DNS Management snap-in dan pilih Properties. Field timestamp record tersebut menunjukkan tanggal dan waktu record tersebut dibuat dalam DNS.
Untuk melihat record timestamp, pilih Advanced dari menu View dari console.
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Folks, I have delivered a presentation on MS Windows 7 on December 14 2008 on MUGI Bandung event at IMT Telkom Bandung. In that event, I spent only about 30 minutes for introducing the “Welcome to Windows 7 Desktop” to audiences.
The agenda made some important points, such as a brief history of the Windows desktop, areas for improvement and goals, showing functionality and how to explain to our users the new features using the best practices and the “coolest” way to do it.
Thanks a lot to Mr Naren and Mr Wely for their great contributions to support me with Windows 7 build 6801 pre-beta version and some presentation on MS Power Point files from PDC which is very useful and helpful.
The What and the Why…
The philosophy for Windows products is: Early and Often. If the customer’s experience is positive even the very first time they open or try a product, they will like it. That means: Customer satisfaction.
How can we use early and often to delight our customers (users)?
Back to the Future…
It is very important to look to the past—especially when it has very cool ideas that will be very practical (resurrected).
The presentation started with Windows 1.01 (1985) which showed a very rudimentary taskbar and large icons that represented minimized windows. Each window had its own toolbar, its own identity. As the first goal since the beginning was multitasking, W7 will continue having this functionality. W1.0 was not able to overlap windows; each window had to be tiled.
After some years, Windows 3.0 (1990) was released. In this version, windows were minimized to the desktop and we were able to see them at the bottom of the screen. Overlapping windows were introduced.
At last Windows 95 (1995) gave us a real taskbar with a Start Menu and notification area. Caption controls (minimize, restore, and close buttons) and the quick launch were introduced as well.
In Windows XP (2001) we were introduced to taskbar grouping, Start Menu MFU, and balloon tips.
Finally, last year an enormous change came in the form of Windows VISTA (2007) which introduced windows switching and managing, a much better searching experience, programs in a list, thumbnails, gadgets and window grouping, etc.
Areas for Improvement
Currently there are too many launch surfaces, too much redundancy, too much noise, and arranging windows involves acrobatics. Some pools showed that just the 0.21 percent of users use the taskbar on the right side of the screen!
Key Goals
The top goals are to make it easier to get to the programs and destinations we use all the time, and being able to switch to the right window quickly, without mistakes. Also, personalizing and organizing the desktop and choosing what is important should be key features. We all want to make sure that our environment is organized and comfortable.
- Large, more beautiful, and dynamics Icons:
Now we can enjoy large icons of the applications we want to use. We just drag the program to the toolbar and now we can open it from this point. We can switch and launch from the icon.
- Thumbnails are much better. They are bigger and we cannot just see them, but “touch them.” We can see a group of documents we have open from a program in a horizontal way and switch from the same thumbnail. We can peak at the one we want and even close from this very place. The programs from the toolbar can be rearranged as we prefer.
- UI tabs in IE as TDI/MDI are now normal windows and we just go to the taskbar, one place, to launch and switch.
- Jump list: We have a mini Start Menu for each application. At the bottom of the thumbnail of the Media Player is a toolbar. We just have to go to one place.
Some of Windows 7 new exciting features:
Icon
Are you excited with these beautiful icons?
Task Bar changes
There are many changes in taskbar of Windows 7. We can pin programs in task bar for easy launch, and there are no more redundant buttons from taskbar that launch applications.
The “Side Bar” is gone
Do you love sidebar? It comes in Windows Vista. Sidebar displays on right side of the desktop and carries different gadgets. The sidebar is gone in windows 7, but for anyone who loves gadgets, you can have them and they roam free across the desktop.
Calculator, WordPad and Paint are better
Calculator is equipped with some options that are useful in real life, it has several exciting features:
- New user interface
- Calculation history
- Unit conversion
- Calculation templates
- Date calculations
- Controls that are optimized for touch
In Windows 7 Wordpad and Paint have got office ribbons installed….
Pinning
You can still pin programs to the taskbar by dragging them or via a context menu, just like you have always done with Quick Launch. Destinations can also be pinned via a drag/drop, but they are designed to be surfaced differently as we’ll see under the Jump List section.
Jump Lists
Jump List is another feature that is also part of both the new Windows Taskbar (also in the Start Menu). Every program in Windows 7 has a jump list. It's a quick way to access files and recently opened documents or Web sites. To get a “Jump List” we can use right-click on an application on the new Windows Taskbar in Windows 7. In the pre-beta Build 6801, this feature can be found as follow, look at the picture below:
Overall a “Jump List” :
- Mini Start Menu for your program
- Surface key destinations and tasks
- Customizable
- Accessible via right-click and via drag
Thumbnail Toolbars
The new taskbar exposes a feature called Thumbnail Toolbars that surface up to seven window controls right in context of taskbar buttons. Unlike a Jump List that applies globally to a program, this toolbar is contextual to just a specific window. By embracing this new feature, Media Player can now reach a majority of people. Thumbnail Toolbars leave the taskbar uncluttered and allow relevant tasks to be conveniently accessible directly from a taskbar thumbnail. Surfacing tasks reduces the need to switch to a window.
Unfortunately, this feature is not for pre-beta build 6801, at least with toolbar thumbnail, we can use it as Remote-control for a window.
Taskbar's New Look
Opened programs reside on the Taskbar as graphic thumbnails. This feature is also not found on pre-beta version Win7 build 6801.
- Remote-control for a window
- Surface key commands
- Up to seven buttons
- Accessible from taskbar thumbnail
Custom Switchers
Automatic Arrangement
Two windows can be viewed side-by-side by dragging each window to the far left or far right of the desktop. Dragging a window to the top auto-maximizes it. This feature is also not found on this pre-beta version Win7.
New Look For Devices
Devices are now represented by photo icons.
Libraries
Libraries can be used to store and search across a variety of data. Windows explorer has a new feature of libraries. These are virtual folders that remain across different folders and even multiple networks PCs. Default libraries are for music, videos, pictures etc. So if you’re on your work laptop and you bring it home, you can play music that lives on a home PC’s drive from the laptop.
Conclusion
Windows Seven offers many improvements such as icons, jump lists, and thumbnail toolbars. Quick launch has been removed (so it will not be necessary to add shortcuts), notification icons will not be visible by default, and gadgets may be programmatically launched.
References:
- “Welcome to the Windows 7 Desktop”, PDC 2008, Chaitanya Sareen, Senior Program Manager Microsoft Corporation