Monthly Archives: November 2017

矢志不渝 Never Give Up

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Same wisdom from different languages:

竹子的故事

在中国的最东边生长着一种竹子,名叫“毛竹”。那里的农民到处播种,每天精心培养

等待着种子萌芽,即使农民几年来一直精心照顾,毛竹4年也只不过长3CM。别的地方的人看到这种情景,摇着头表示完全不能理解。会这样想:花这么长时间种它做什么,浪费时间和精力。

但是,竹子5年后以每天足足30CM的速度生长着。这样只用6周就可以长到15米,这里瞬时间就可以变成郁郁葱葱的竹林。虽然4年间只长了3CM,但从第5年开始了暴风成长,6周时间好像发生了不可思议的变化。

但之前的4年间,毛竹将根在土壤里延伸了数百平米。

我们身边也有这样的人,即使拼了命去努力也看不到成果或者即使不被人知道也坚持到底的人们。

当我们看到他们的时候,也许会认为他们很不幸或认为他们是傻子,但他们并不是不在成长,而是在扎根,很深很结实的根。等到时机成熟,他们会登上别人遥不可及的巅峰。

也许你现在做的事情看不到成果,但不要害怕--你并不是没有成长,而是在扎根。

 

One Day I Decided To Quit……

I quit my job, my relationship, my spirituality… I wanted to quit my life.

I went to the woods to have one last talk with god

“God”, I asked,

“Can you give me one good reason not to quit?”.

His answer surprised me…

“Look around”, He said. “Do you see the fern and the bamboo ?

“Yes”, I replied.

“When I planted the fern and the bamboo seeds, I took very good care of them.

I gave them light.I gave them water.The fern quickly grew from the earth.

Its brilliant green covered the floor.Yet nothing came from the bamboo seed. But I did not quit on the bamboo.In the second year the Fern grew more vibrant and plentiful.

And again, nothing came from the bamboo seed. But I did not quit on the bamboo. He said.

“In year three there was still nothing from the bamboo seed.But I would not quit.

In year four, again, there was nothing from the bamboo seed. I would not quit.” He said.

“Then in the fifth year a tiny sprout emerged from the earth. Compared to the fern it was seemingly small and insignificant…But just 6 months later the bamboo rose to over 100 feet tall.

It had spent the five years growing roots. Those roots made it strong and gave it what it needed to survive.I would not give any of my creations a challenge it could not handle.”

He asked me. “Did you know, my child, that all this time you have been struggling, you have actually been growing roots”.

“I would not quit on the bamboo.I will never quit on you.”

“Don’t compare yourself to others.” He said.”The bamboo had a different Purpose than the fern.

Yet they both make the forest beautiful.””Your time will come”, God said to me.

“You will rise high”.

“How high should I rise?” I asked.

“How high will the bamboo rise?” He asked in return.

“As high as it can?” I questioned.”Yes.” He said, “Give Me glory by rising as high as you can.”

I left the forest and brought back this story.I hope these words can help you see that God will never give up on
you.Never, Never, Never, Give up.

Don’t tell the Lord how big the problem is, tell the problem how Great the Lord is!

 

Copied from the following links:
https://weibo.com/p/230418852db83e0102vulj

One Day I Decided To Quit……

Abnormal amount of hardware Interrupts caused high CPU issue

Published / by Chen Ye / 1 Comment on Abnormal amount of hardware Interrupts caused high CPU issue

Starter:

Interrupts are the signals userland process want to take ownership of CPU for a while(time is very short about milliseconds) to work on its requests via a system call. When this happens, in the single core situation, CPU based on priority and scheduling algorithm to determine whether put the process to the ready queue or keep it running.

There are software interrupts and hardware interrupts to differentiate this interrupts triggered by which components. But too many interrupts will significantly degrade the performance without a doubt. Some time hardware interrupts even got worse if it kept at a high rate. Let’s do a real case review as an example, but before doing that, first, we will review some knowledge about interrupts.
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Two types of three way handshake (Connection Setup and Close)

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Starter:

I still remember four years ago, one of our internal instructor Barry from Seattle to deliver training session, he mentioned three-way handshake is used as one of the technical questions to judge the technical skills of the interviewee in the most technical job interview.

Also, as an IT professional guy, I cannot emphasize enough how important it is to remember and understand these two processes as common sense in your mind since other people use this question to judge your IT skills.

The three-way handshake as one of the fundamental knowledge you should know and understand. Your solid technical skills are built on the fundamental knowledge, with the time go on, the simple technical knowledge will merge together to put you to an upper layer and form a better you.

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Application killed by oom-killer repeatedly because insufficient swap space

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Starter:

We know the disk is an extension of the memory when the computer goes into insufficient memory, it will page out some pages to the disk, but do you know where it usually stored? In the Windows world, it will be dumped to the pagefile.sys which located to your default root path of your C drive, in the Linux world, there is a special partition named swap, it will send pages out there.

Why we need to page out inactive or unused pages because we don’t have enough memory to load all the application to the memory and it is unrealistic and doesn’t make sense to purchase the same size memory like your hard disk. In OS spec, there is a virtual memory (virtual space) and page table to make application itself believe all the data is loaded into the memory, actually it is not. When pages were not stored in the memory, the OS will send out interruptions of page fault to load the data from hard disk to memory, same time if the computer in memory low status it will replace some of the inactive pages to the swap space.

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How to calculate the Isilon protection overhead

Published / by Chen Ye / 2 Comments on How to calculate the Isilon protection overhead

 

This article is for Isilon administrators or who have the experience of Isilon product.

Isilon is a scale-out NAS storage doing an excellent work of scale out the ingesting data across the nodes within the single namespace(a very very large Peta bytes partition).

For the protection mechanism, Isilon used the RAIN(redundancy node) instead of the RAID(redundancy disk) to enhance the data protection to the next level protection.

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Python: How to print out AM/PM time format every 3 mins throughout the day

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First, let’s warm up with some functions about time/date.

The purpose for doing such kind of boring things is for implementation requirements of the scheduler I will use in Windows environment.

 

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Windows: cwRsync to replicate data from source to target

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Today since the network restriction policies, I can’t map a network drive from a Windows client via SMB protocol to copy my file to a Linux host. It really worries me a lot to build up my project.

There is an ideal come across my mind and I timely captured it. How about using a classical way in Nix environment to rsync to replicate data from source to target.

Benefits are obviously seen:

  1. Only Modified contents are replicated
  2. The tunnel between two hosts are encrypted using OpenSSL key infrastructure.
  3. I can run a scheduler to periodically run to sync the contents.

So I do the following things to set it up:

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PowerShell: Image-downloader improved and function reuse version

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Another improvement makes to the Image-downloader code.

  • Introduced function “Inputchecker” to validate user input
    • vaguely match the strings user inputs and try to match with the strings, if not match ask the user to re-type the number
    • precisely matching the version number user input using regex
    • separately handling onefs and insightiq image name and url path
    • get the list of filename from URL path and dump to help the user choose insightiq version to download

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