Apple iPad Pro 10.5” review – web developer and admin perspective

Last update: 20170709

Objective: to build and operate a Fast and Responsive static website, as a habit

Tool: Apple iPad Pro 10.5” only

I have been using the new Apple iPad Pro 10.5” for nearly a month. My old iPad Air was mainly used to watch TV and to do video conferencing. It could not multi-task. It was too thick and too heavy to carry when compared to iPhone.

The new Apple iPad Pro 10.5” is more, VERY to be exact, powerful. Can do better multi-tasking with iOS11. With larger screen and Smart Keyboard, it can do somethings which are difficult to do on iPhone, such as webpage coding and cloud service management.

To build and operate a website, we need both Development Tools and Cloud Services. Since we’re using iPad only, we need to make sure the platforms provide fast and easy to use web portal. After trying many options, below are my suggestions for Cloud Services (1-3) and Development Tools (4-6) to achieve our above-mentioned objective.

1.Cloud storage: AWS S3 (upload/download and edit via Transmit)

2.CDN: AWS CloudFront, KeyCDN, ChinaCache


    • User demographics & behavior: Google Analytics
    • Real User Measurement: Soasta mPulse

    • Synthetic Performance Measurement: Uptrends

4.HTML Editor: Nitro HTML (split view to edit HTML source and visualize page at the same time)

5.FTP: Transmit (build-in editor to make small/quick modification on the fly is a bonus!)

6.Testing/checking Tools

    • VPN: VyprVPN
    • DNS checking: DIG

    • HTTP response header: WebScope

All these Cloud Services and Development Tools are good values and inexpensive, some of them are FREE!

With all these, I built and launched my revamped demo site .


How to use CDN: demos to show performance improvement

Latest update: 20170709

I am happy to tell you that my CDN demo site is relaunched today! The objectives of the new demos is to show how CDN improves website performance, and to help people visualize and understand how to make website faster.

My CDN demo site was first launched in early 2012 with the objective to show how to use different EdgeCast CDN products to improve the delivery of static, dynamic, video content and software download. Then in 2016 I made some demos to show how to use HolaCDN solutions to improve video streaming quality. All these demos before 2017 were focusing on HOW to use the CDN products to do somethings. For the new demos, I will focus on Why and What of parts of the equation.

“When you Speed Up service, people become more engaged – and when people become more engaged, they click and buy more” The Google Gospel of Speed, Jan 2012.

What is it?
The new demo webpages are constructed inline with the current Internet norms

  • using RWD to fit different screen sizes. Faster is a feature. Responsive too. [1][2]
  • the demo webpage size is about 3MB. According to HTTP Archive, 3MB is the average webpage size in June 2017. It was 1.0MB in June 2012!
  • there are 3rd party web components, usually for analytics and social networking[3]
  • in terms of #HTTP objects, 60% is image, 25% is JS, 15% is CSS/fonts/html.
  • in terms of object byte size, 90% is image, 5% JS and 2% fonts.
  • following the Google PageSpeed and Yslow guidelines of high performance website.
  • all demos are the same from coding perspective. They look the same. The only difference is the delivery arrangement of the first party content (1 HTML file and 13 images) – from which origin and with/without CDN(s). As of 20170707, I tired three CDNs: ChinaCache, AWS CloudFront and Google Cloud CDN. [4]

It looks nice, doesn’t it?

How to use the demos?
To see is to believe it. Each demo is using different Origin and CDN (if any). By clicking it and watch it, you can feel how fast your browser loads the webpage.

Besides your visual observation, there are some good online tools which provide quantitative analysis of website performance. is one of them. Below is a GTmetrix comparison of my new Demo#1 (AWS S3 Origin and no CDN) and Demo#3 (AWS Origin and ChinaCache)


Which one is faster?


  1. Besides focusing on mobile-friendly demos, I am trying to use mobile device (iPad), rather than laptop, to prepare the demos. Apple iPad Pro 10.5” with iOS11 Is a powerful content production device!
  2. RWD is cool. It is fun to develop a good-looking website as a habit. As a game. Do it anywhere, using iPad. Thank you!
  3. I am using a few 3rd party analytics tools: Google Analytics, Alexa and Soasta.
  4. AWS S3 and Google Cloud Storage are very similar. But there are many differences between CloudFront and Google Cloud CDN!

More blog posts on these topics are coming.

Please feel free to try Wish you a nice weekend:)


20170708 add a new demo – Origin: AWS S3, CDN: KeyCDN. Add a new performance analytics JS from

20170709 add e new demo – Origin: AWS S3, CDN: multi-CDN (ChinaCache for China, KeyCDN for Europe and CloudFront anywhere else)

How does a CDN work?

Last update: 20170628

Last Friday I was asked “how does a CDN work?” The first time I was asked the same question was year 1999. I acquired a lot of CDN knowledge and experience since I join the industry in 2012. CDN is not yet an everyday business in Asia nowadays. I want to help. An one page brief explanation. Hope you like it.

What is a CDN?

A Content Delivery Network (CDN) is a collection of web servers distributed among multiple locations to deliver content to users more efficiently.[1]

What is the job to be done by CDN?

To send web content to enduser faster. How? By moving data close to the endusers to reduce round trips and network.

Ilya Grigorik, web performance engineer at Google, says [2]:

  • Latency, not bandwidth, is the performance bottleneck for most websites.
  • Four major latency types: propagation delay, transmission delay, process delay, queuing delay
  • To improve performance of our applications… we need to reduce round trips, move the data closer to the client.

Centralized Server vs CDN [3]

How does a CDN work?

In essence, CDN puts your content in many places at once, providing superior coverage to your users. For example, when someone in London accesses your US-hosted website, it is done through a local UK CDN server. This is much quicker than having the visitor’s requests, and your responses, travel the full width of the Atlantic and back.[4]


By connecting users who request your website content to CDN, instead of connecting directly to your web server.

Using traditional centralized server model, a website, say www, will usually have a “A Record” in the DNS configuration (of to inform people to connect to the web server with the specific IP address, say We call this Customer Origin. When a user John in Beijing browses www the following (behind the scene) steps will happen:

  1. John’s computer will ask the its local DNS resolver to figure out the IP address of www
  2. the resolver will then ask the root DNS server what is the authoritative DNS server of
  3. The resolver will then ask the authoritative DNS sever of what is the IP address of www and will get the answer of
  4. John’s computer will then connect to to get the web content of www

With CDN, www will have a “CNAME Record” in the DNS configuration to inform people to connect to the server with the specific hostname, say provided by the CDN provider. When John browses the website www, we will have the same first two steps above-mentioned, but subsequent steps will become:

  1. The resolver will then ask the authoritative DNS server of what is the IP address of www and will get the answer of
  2. The resolver will then ask the authoritative DNS server of what is the IP address of The authorization DNS server of will, based on the IP address of John’s local DNS resolver and the CDN provider’s routing algorithm, provide the answer, say, which is the IP address of the CDN cache server located in/near Beijing and is the best machine to deliver the content of www to John
  3. John’s computer will then connect to to retrieve the web content of www

Say there is another user Mary in Singapore going to browse www, we will have the similar four steps, but the CDN provider will use, say, which is the IP address of the CDN cache server located in/near Singapore which can serve Mary most efficiently.

Do I need to upload my website content to CDN?

Not necessary. In most cases, CDN will on-demand fetch content from the Customer Origin.

When the CDN cache serve receives the HTTP GET request of www from an enduser, the cache server will check if the requested content of www is already stored in its storage:

  • If yes, then the cache server will send the content stored on it to the enduser. We call this “Cache Hit”
  • If no, then the cache server will fetch the content from the Customer Origin, then store it and send it to the enduser. We call the situation of missed content “Cache Miss”, and the process of fetching content from Customer Origin “Cache Fill”. CDN will Cache Fill when it needs to update the stored content.

The higher the Cache Hit rate, the faster the content delivery. High Cache Hit rate better utilizes CDN and reduces Customer Origin loading.

How long will the CDN keep my web content?

CDN provider will usually honor the Cache-Control header setting in Customer Origin. During the Cache Fill process, the CDN cache server will cache both the web content and the HTTP header information, including the Cache-Control header attributes. CDN provider will keep the content according to the Cache-Control setting or based on the customer CDN configuration.

What else?

CDN nowadays offers more features and services. Below are the key benefits of using CDN:

  • Faster delivery of both cacheable and non-cacheable content
  • Higher availability by leveraging CDN’s global footprint and scale.
  • More secure by shielding the Customer Origin from public access.
  • Reduce the expense on Customer Origin resources (computer and connectivity)

That’s all.


  1. High Performance Web Sites, Steve Souders
  2. High Performance Browser Networking, Ilya Grigorik
  3. CDN, Wikipedia
  4. Essential Guide to CDN, Incapsula
  5. Cache-Control header,


I prepare this blogpost on the new iPad Pro 10.5” with Smart Keyboard. It is GREAT. Looking forward to iOS 11!


[Update: 20170628] Apple iPad Pro 10.5” with iOS 11 beta


ASUS Zenfone 3 Review – an iPhone user perspective on Android 7.0

Published: 20170527

Truth be told, ASUS Zenfone 3 (model number: ZE520KL) is not new. It was launched almost one year ago in July 2016. There was many good product reviews. My review is a bit different, I am focusing on how it works differently from Apple iPhone.

I need an Android phone to work with my customers. I want to learn more about Android as well. It will be nice to have a second phone when I travel aboard, using domestic SIM card to make low cost local phone calls and to use it as a hotspot. It is not my main smartphone but a secondary device for testing and traveling.
My key requirements are:

  • a device which is running the latest Android 7.0 Nougat
  • the hardware is good/fast enough for 2017 and 2018
  • small size, light-weight
  • good battery life
  • good customer reviews
  • costs about US$200

It is challenging to find a device meeting all six requirements! Luckily I found the ASUS Zenfone 3 ZE520KL. Below are its key hardware specifications:

  • CPU: Qualcomm Snapdragon 625
  • RAM: 3GB
  • Storage: 32GB (8GB reserved for OS)
  • Display: 5.2“ Super IPS, 1080×1920 pixels (424 ppi)
  • Dimension: 146.9 x 74 x 7.7 mm
  • Weight: 144g
  • Battery: 2650mAh

Even though it is almost an one-year old device, it is still one of the top ten Best Selling smartphones listed at popular Taiwan website! Its list price is about USD220 (TWD6641)!

After using the ASUS Zenfone 3  ZE520KL on a daily basis for more than two months, I can say I am very happy with it:

  • It is fast, but not as fast as iPhone 7 Plus (not as expensive and heavy too)
  • comfortable to use it with a single hand
  • easy to carry in pocket
  • the battery life is good! Can work the whole day (8am-10pm) on a single full charge. Can usually function as a hotspot for 10hrs!
  • The fingerprint sensor is fast! (But I find it is more user-friendly to have the senor on the front side. The iPhone fingerprint implementation is better)
  • It supports dual SIM cards and hence I can put my two most frequently used overseas SIM cards in it.

The two minor drawbacks I find are the slow camera (comparing to iPhone) and the necessary evil USB Type-C interface (I have to buy some more charging cable…).

I find Nougat is very close to the performance/experience/stability of iOS 10.3. Nougat can do somethings which iOS cannot. Multi-window View is useful when you want to use two apps simultaneously on your phone. Quick Settings, the customizable version of iOS Control Center, reduces the friction to do frequent tasks.  A few other mentionable unique Android features:

  1. Google Assistant. Its voice recognition is much better than Siri! I don‘t speak to my smartphone very often, but the Google Assistant ”please tell me my day“ is very useful in the morning.
  2. Android provides user more network visibility. The app WiFi Analyzer helps me to figure the WiFi signal strength in my home. As we use more and more ”smart“ home appliances (such as TV, iRobot and smartplug), we need better WiFi coverage across the home. WiFi Analyzer helps me to put the Wifi repeater at the right place. (We move from a single powerful router to a Wifi network system like Eero. Apple Airport products are not good enough.)The app Internet Speed Meter Lite shows at the toolbar how fast the device is retrieving data from the Internet. 
  3. Android provides user more network manageability. The app WiFi Prioritizer can monitor different network connectivity performance (WiFi vs WiFI, WiFI vs LTE, etc) and will use dynamically the more reliable and faster network. No more unusable WiFi connection! Android also allows to share the smartphone WiFi connection with laptop via USB tethering!
  4. Automation. The app MacroDroid execute behavior (such as change device configuration, launch an app, etc.) based on trigger (such as time, location, power charging status). Below is the my macro to use radio as morning alarm:


One more thing: there are not many good accessories purpose-built for Android smartphone. I find one – Lamicall iPhone Stand T1. The stand is adjustable, it works great with ASUS Zenfone 3, especially if you want to charge it and use it in portrait mode at the same time.

I am sorry, the stand is designed for iPhone:P

Apple Watch Review – two year after

Published: 20170507

Time flies. Thanks.

I was lucky to get the Apple Watch Series 0 on the launch day two years ago. One major change after wearing it is now I run more and regularly. Several 5km runs per week. I am a healthier person now too.

Activity level indicators remind me to move or exercise more. They draw my attention. They are the triggers. 

Habit = trigger, behavior, reward

The most challenging job to run is to get out of the door before it was too late in the day. Will it rain? How many days from my last run? To see the sunset when running along the harbourfront? The Activity, Weather Conditions, RunKeeper, Sunrise / Sunset, Pedometer++ complications all help!

Tsukudani Yanagibashi Komatsuya at 1 Chome-2-1 Yanagibashi, Taitō-ku, Tōkyō-to 111-0052, Japan

It is great to take photos if you see beautiful scene or interesting thing when you are running, isn’t it? However it is not very easy to get the iPhone out of the armband in general. With iPhone 7 IP76 water resistance, I don’t have to put it inside any armband to protect it from rain /splash. I can carry iPhone 7 outside and let it more accessible. Quad Lock Run Kit helps me to do so. It just takes a second or two to detach/attach your iPhone to the armband. And it changes things!

So here my running gears:
-iPhone 7S Plus
-Quad Lock Run Kit
-ASICS Tiger GT-2000 running shoes

My Apple Watch Series 0 is 2-year-old and it works great (Notes a). If I buy a new one, below is wish list for my next Apple Watch:

1.three-day battery life, and I don’t have to carry the charging cable during short trip
2.built-in thermometer to measure body temperature, good info when running
3.Watch OS can launch app automatically/programmatically when it detach some motion/behavior patterns
4.Watch app which can measure sleep pattern/quality automatically (Notes b)
5.more useful complications

Gadget is very powerful computationally today. It will be great if it can be programmed to do things automatically and unattended. Let’s talk more next time.


a.My sister told me recently that her Nintendo Game & Watch Octopus handheld was still working! It is 35-year-old!
b.Pillow tracks sleeping using Apple Watch
c.A.D. Bible Continues is on air at every Sat 11pm Taipei Time. Chinese subtitle is available.

Thank you.

I left my iPad on a JAL flight

Published: 20170325
I left my iPad on JAL flight when I travelled to Japan recently.
“I left my iPad on JAL flight” I googled the phrase to look for ways to get back my iPad. I didn’t think my situation was radically uncommon. Luckily I found some relevant JAL FAQ page. My friend helped me to phone the JAL Henada Airport hotline the next day morning, they questioned us for details. They did find my iPad and verified I was the owner! We went to the airport in the afternoon and collected my precious iPad! Thank JAL!

Regarding iPad, one common complaint from the Apple community is the lack of software advancement. iOS cannot empower iPad more useful that iPhone! User cannot make the best use of the bigger screen! For example, one cannot use Flipboard (to find stuff) and Amazon (to shop) at the same time in landscape mode. Many popular apps do not support Split View on iPad.

As Android matures and hardware improves, Android devices can do somethings better than iPad and iPhone! Below is a multi-window session on ASUS Zenfone 3 5.2″. This smartphone is smaller and less powerful when compare to recent iPads but it does a better multi-window job!

By the way, I find Flipboard works better on Android. The Android version will usually return to the last article I was reading when I resume using Flipboard, while the iOS version will almost restart every time. In order to completely read an article if you switch between Flipboard and other apps frequently, you’re better using the Flipboard Read Later feature or Liking the article to remark it. Both requires additional steps.

Google Translate in any app is another useful and convenient feature. Use the Amazon app again example, as shown in the left-hand-side of the picture below, select the text and then tap the Translate option. Right-hand-side shows the translation inside the Amazon app. 

iOS does not provide similar feature. However, the powerful Workflow does! Translate Selection in Conrad’s collection can do translation in any app supporting App Extension.

Hope Apple’s acquisition of Workflow will make iOS more powerful soon!

Drive Thru History: The Gospels

Published: 20170110
Update: 20170527, 20180811

It is a good news!

If you want to know more about Jesus Christ then Drive Thru History: The Gospels is something for you.

What is Drive Thru History: The Gospel?
A TV program series with 18 action-packed episodes delve into the history, archaeology, geography, and art surrounding the birth, ministry, death, and resurrection of Jesus. Like you’ve come to expect from Drive Thru History®, these shows are fun, adventurous, and family-friendly. However, we think there is no better educational coverage of the Gospels available today! As a bonus, Dave takes you and your family on a unique driving tour of Israel to experience the actual places where Jesus traveled and taught.

Each episode lasts about 27 minutes. The whole series is less than 9 hours. It is a great show. Thanks Dave.

I learnt about this TV program series from a friend. It is one of the Drive Thru History with Dave Stotts series produced by ColderWater Media. It maybe available on TV channel in your region. The series is also available in DVDs at

You can watch it by browsing the Trinity Broadcasting Network website at The series can be found by clicking Program and then Educational, or by searching Drive Thru History. TBN uses CDN to stream the videos and the quality is good. Thanks TBN.

With a donation of US$40 or more, TBN will send you a gift – the 18-part DVD series The Gospels!

Please find below the list of the 18 episodes:

Episode 1: The Historical Landscape
Episode 2: The Announcements
Episode 3: Jesus is Born
Episode 4: Jesus Grows Up
Episode 5: Jesus Starts His Ministry
Episode 6: Jesus Returns to Galilee
Episode 7: Jesus Begins His Miracles
Episode 8: Jesus Teaches with Authority
Episode 9: The Sermon on the Mount
Episode 10: Jesus Travels the Sea of Galilee
Episode 11: Jesus Travels North
Episode 12: A Final Trip to Jerusalem
Episode 13: Jesus Arrives in Jerusalem
Episode 14: The Last Supper
Episode 15: The Trial of Jesus
Episode 16: The Crucifixion of Jesus
Episode 17: The Resurrection of Jesus
Episode 18: Who is Jesus?

Thanks God!