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Pada artikel ini saya tidak akan membahas semua option yang ada pada squid.conf, saya hanya akan membahas option-option yang dirasa penting untuk menjalankan squid dan berpengaruh besar dalam optimasi squid.

http_port 3128
Option ini akan menentukan di port berapa squid akan berjalan (biasanya di port 3128 dan 8080)

icp_port 0
Option ini akan menentukan melalui port berapa squid akan mengirimkan dan menerima request ICP dari proxy cache tetangga.

cache_mem 32 MB
Option ini menentukan berapa besar memory yang akan digunakan oleh squid, defaultnya adalah 8 MB yaitu default yang cocok untuk digunakan pada
banyak sistem. Namun jika anda memiliki memory yang berlebih, maka disarankan untuk menaikkannya. Ada yang berpendapat bahwa nilai ini
didapat dari sepertiga memory bebas bagi squid.

cache_dir ufs /cache 1600 4 256
Option pada cache_dir menentukan sistem penyimpanan seperti apa yang akan digunakan (ufs), nama direktori tempat penyimpanan cache (/cache), ukuran
disk dalam megabytes yang digunakan oleh direktori tempat penyimpanan cache (1600 Mbytes), jumlah subdirektori pertama yang akan dibuat di bawah /cache (4),
dan jumlah subdirektori kedua yang akan diciptakan di bawah subdirektori pertama tadi (256).
Nilai2 pada option cache_dir tadi harus disesuaikan dengan sistem yang anda miliki, biasanya yang harus disesuaikan hanyalah tempat penyimpanan cache, ukuran disk,
dan jumlah subdirektori yang akan dibuat. Mengenai angka2 tersebut, dapat kita peroleh dari rumus yang telah disediakan oleh Mas Devshed untuk optimasi sbb:
1. Gunakan 80% atau kurang dari setiap kapasitas cache direktori yang telah kita siapkan. Jika kita mengeset ukuran cache_dir kita melebihi nilai ini,
maka kita akan dapat melihat penurunan performansi squid.
2. Untuk menentukan jumlah subdirektori pertama yang akan dibuat, dapat menggunakan rumus ini:
x=Ukuran cache dir dalam KB (misal 6GB=~6,000,000KB) y=Average object size (gunakan saja 13KB)
z= Jumlah subdirektori pertama = (((x / y) / 256) / 256) * 2 = direktori
Sebagai contoh, misal saya menggunakan 6 GB dari untuk /cache (setelah disisihkan 80% nya), maka:
6,000,000 / 13 = 461538.5 / 256 = 1802.9 / 256 = 7 * 2 = 14
maka baris cache_dir akan menjadi seperti ini: cache_dir ufs 6000 14 256

cache_store_log none
Option ini akan melog setiap aktivitas dari storage manager. Log ini akan memperlihatkan objek-objek mana saja yang dikeluarkan dari cache, dan objek-objek mana saja yang disimpan dan untuk brp lama objek tersebut disimpan. Karena biasanya tidak ada gunanya untuk menganalisis data ini, maka disarankan untuk didisable.

negative_ttl 2 minutes
Default dari option ini adalah 5 menit, tetapi Mas Moh. J. Kabir menyarankan agar direndahkan menjadi 2 dan jika mungkin menjadi 1 menit. Kenapa settingannya seperti itu? Mas Moh. J. Kabir menjelaskan bahwa kita menginginkan proxy yang kita miliki setransparan mungkin. Jika seorang user mencari halaman web yang dia yakin itu ada, maka kita pasti tidak ingin adanya waktu lag antara URL menuju dunia dan kemampuan user untuk mengaksesnya.

cache_effective_user squid
cache_effective_group squid
Jika squid cache dijalankan oleh root, maka user yang akan menjalankannya akan diubah sesuai UID/GID user yang disebutkan pada option di atas. Pada contoh option di atas jika squid dijalankan oleh root, maka squid cache akan dijalankan dengan UID/GID squid.

maximum_object_size 1024 KB
Dengan option ini, ukuran file maksimum yang disimpan oleh squid cache bisa dibatasi. Dengan kata lain objek yang lebih besar dari bilangan ini tidak akan disaved ke dalam disk yang sudah disisihkan buat cache (misal /cache).

minimum_object_size 4 KB
Dengan option ini maka objek yang lebih kecil dari bilangan yang disebutkan tidak akan disaved ke dalam disk yang sudah disisihkan buat cache. Ada tambahan dari artikel yang ditulis Mas Jay bahwa ukuran file minimum yang dicache bertujuan mengefektifkan filesystem di mana biasanya ext2 diformat dengan 4 KB inode.

ftp_user hari@huhui.comThis email address is being protected from spam bots, you need Javascript enabled to view it
Dengan option ini, maka ketika klien mengakses situs ftp anonymous, email address di atas akan dikirim sebagai password bagi ftp server anonymous.

reference_age 1 month
Dengan option ini, maka file cache yang tidak pernah diakses lagi selama nilai parameter di atas, akan dihapus secara otomatis oleh squid.

acl PazzNET src 192.168.1.0/255.255.255.0
http_access allow PazzNET
http_access deny all
Option-option tersebut menentukan subnet mana yang boleh mengakses proxy squid. Jika ada beberapa subnet, kita bisa menambahkan definisi acl nya.

cache_mgr hari@huhui.comThis email address is being protected from spam bots, you need Javascript enabled to view it
Email-address dari local cache manager yang akan menerima email jika cache mati.Email ini pulalah yang akan muncul pada browser klien jika terjadi suatu kesalahan ketika mengakses suatu web via proxy squid.

visible_hostname hari.huhui.com
Informasi ini dikirim sebagai footer pada saat pesan error tampil di layar browser klien.

half_closed_clients off
Beberapa klien dapat membatalkan koneksi TCP nya, dengan membiarkan bagian penerimaaannya terbuka. Kadang-kadang squid tidak dapat membedakan antara koneksi TCP yang half-closed dan full-closed. Defaultnya, koneksi half-closed tetap terbuka sampai pembacaan dan penulisan pada soket memunculkan pesan error. Ubahlah nilai ini ke off, maka squid dengan serta merta akan menutup koneksi client jika tidak ada data yang dibaca lagi.

Saran Mas Devshed yang lain untuk meningkatkan performance:
cache_swap_high 100%
cache_swap_low 80%

Setelah semua selesai dilakukan, cobalah start squid anda dan rasakanlah perbedaannya 
/etc/rc.d/init.d/squid start

Jika ada error, jangan panik, carilah letak kesalahan dengan selalu memonitor log
tail -f /var/log/messages

The IRR is the interest rate (also known as the discount rate) that will bring a series of cash flows (positive and negative) to a net present value (NPV) of zero (or to the current value of cash invested). Using IRR to obtain net present value is known as the discounted cash flow method of financial analysis. Read on to learn more about how this method is used. (For more insight, read the Discounted Cash Flow Analysis tutorial.)

IRR Uses
As we mentioned above, one of the uses of IRR is by corporations that wish to compare capital projects. For example, a corporation will evaluate an investment in a new plant versus an extension of an existing plant based on the IRR of each project. In such a case, each new capital project must produce an IRR that is higher than the company’s cost of capital. Once this hurdle is surpassed, the project with the highest IRR would be the wiser investment, all other things being equal (including risk).

IRR is also useful for corporations in evaluating stock buyback programs. Clearly, if a company allocates a substantial amount to a stock buyback, the analysis must show that the company’s own stock is a better investment (has a higher IRR) than any other use of the funds for other capital projects, or than any acquisition candidate at current market prices. (For more insight on this process, read A Breakdown Of Stock Buybacks.)

Calculation Complexities
The IRR formula can be very complex depending on the timing and variances in cash flow amounts. Without a computer or financial calculator, IRR can only be computed by trial and error. One of the disadvantages of using IRR is that all cash flows are assumed to be reinvested at the same discount rate, although in the real world these rates will fluctuate, particularly with longer term projects. IRR can be useful, however, when comparing projects of equal risk, rather than as a fixed return projection.

Calculating IRR
The simplest example of computing an IRR is by using the example of a mortgage with even payments. Assume an initial mortgage amount of $200,000 and monthly payments of $1,050 for 30 years. The IRR (or implied interest rate) on this loan annually is 4.8%.

Because the a stream of payments is equal and spaced at even intervals, an alternative approach is to discount these payments at a 4.8% interest rate, which will produce a net present value of $200,000. Alternatively, if the payments are raised to, say $1,100, the IRR of that loan will rise to 5.2%.

The formula for IRR, using this example, is as follows:

• Where the initial payment (CF₁) is $200,000 (a positive inflow)
• Subsequent cash flows (CF ₂, CF ₃, CF N) are negative $1050 (negative because it is being paid out)
• Number of payments (N) is 30 years times 12 = 360 monthly payments
• Initial Investment is $200,000
• IRR is 4.8% divided by 12 (to equate to monthly payments) = 0.400%

Power of Compounding
IRR is also useful in demonstrating the power of compounding. For example, if you invest $50 every month in the stock market over a 10-year period, that money would turn into $7,764 at the end of the 10 years with a 5% IRR, which is approximately the current Treasury (risk-free) rate.

In other words, to get a future value of $7,764 with monthly payments of $50 per month for 10 years, the IRR that will bring that flow of payments to a net present value of zero is 5%.

Compare this investment strategy to investing a lump-sum amount: to get the same future value of $7,764 with an IRR of 5%, you would have to invest $4,714 today, in contrast to the $6,000 invested in the $50-per-month plan. So, one way of comparing lump-sum investments versus payments over time is to use the IRR.

Other IRR Uses
IRR analysis can be useful in dozens of ways. For example, when the lottery amounts are announced, did you know that a $100 million pot is not actually $100 million? It is a series of payments that will eventually lead to a payout of $100 million, but does not equate to a net present value of $100 million.

In some cases, advertised payouts or prizes are simply a total of $100 million over a number of years, with no assumed discount rate. In almost all cases where a prize winner is given an option of a lump-sum payment versus payments over a long period of time, the lump-sum payment will be the better alternative. (To learn more about this, read Understanding The Time Value Of Money.)

Another common use of IRR is in the computation of portfolio, mutual fund or individual stock returns. In most cases, the advertised return will include the assumption that any cash dividends are reinvested in the portfolio or stock. Therefore, it is important to scrutinize the assumptions when comparing returns of various investments.

What if you don’t want to reinvest dividends, but need them as income when paid? And if dividends are not assumed to be reinvested, are they paid out or are they left in cash? What is the assumed return on the cash? IRR and other assumptions are particularly important on instruments like whole life insurance policies and annuities, where the cash flows can become complex. Recognizing the differences in the assumptions is the only way to compare products accurately.

Conclusion
As the number of trading methodologies, mutual funds, alternative investment plans and stocks has been increasing exponentially over the last few years, it is important to be aware of IRR and how the assumed discount rate can alter results, sometimes dramatically.

Many accounting software programs now include an IRR calculator, as do Excel and other programs. A handy alternative for some is the good old HP 12c financial calculator, which will fit in a pocket or briefcase.

by Linda Grayson

Calculated as:

Also known as the Discounted Cash Flows Model.

There are many variations when it comes to what you can use for your cash flows and discount rate in a DCF analysis. Despite the complexity of the calculations involved, the purpose of DCF analysis is just to estimate the money you’d receive from an investment and to adjust for the time value of money.

Discounted cash flow models are powerful, but they do have shortcomings. DCF is merely a mechanical valuation tool, which makes it subject to the axiom “garbage in, garbage out”. Small changes in inputs can result in large changes in the value of a company. Instead of trying to project the cash flows to infinity, terminal value techniques are often used. A simple annuity is used to estimate the terminal value past 10 years, for example. This is done because it is harder to come to a realistic estimate of the cash flows as time goes on.

Source : Investopedia

What Does Net Present Value – NPV Mean?

he difference between the present value of cash inflows and the present value of cash outflows. NPV is used in capital budgeting to analyze the profitability of an investment or project.

NPV analysis is sensitive to the reliability of future cash inflows that an investment or project will yield.

Formula:

In addition to the formula, net present value can often be calculated using tables, and spreadsheets such as Microsoft Excel.

Investopedia explains Net Present Value – NPV
NPV compares the value of a dollar today to the value of that same dollar in the future, taking inflation and returns into account. If the NPV of a prospective project is positive, it should be accepted. However, if NPV is negative, the project should probably be rejected because cash flows will also be negative.

For example, if a retail clothing business wants to purchase an existing store, it would first estimate the future cash flows that store would generate, and then discount those cash flows into one lump-sum present value amount, say $565,000. If the owner of the store was willing to sell his business for less than $565,000, the purchasing company would likely accept the offer as it presents a positive NPV investment. Conversely, if the owner would not sell for less than $565,000, the purchaser would not buy the store, as the investment would present a negative NPV at that time and would, therefore, reduce the overall value of the clothing company.

(Source)

Mining Business Process

1. boil the noodles in a pot with water.
2. once the noodles is cooked,  take out the noodles and throw away the water which now contains the wax from the noodles.
3. boil another pot of water till boiling and put the noodles into the hot boiling water, then shut the fire.
4. only at  this stage when the fire is off, and while the water is very hot you put the powder-ingredient into the water, to make the noodle soup.
5. however, if you need dry noodles (like Indomee Goreng), take out the noodles after step 3, and then add the powder-ingredient to the noodles to get mee goreng.

This piece of information is of important to your health where eating instant noodles is concerned. Please apply this cooking method as it doesn’t take much longer that the normal unhealthy method!

The main causes of liver damage are:

1. Sleeping too late and waking up too late are main cause.

2. Not urinating in the morning.

3. Too much eating.

4. Skipping breakfast.

5. Consuming too much medication.

6. Consuming too much preservatives, additives, food coloring , and artificial sweetener.

7. Consuming unhealthy cooking oil. As much as possible reduce cooking oil use when frying, which includes even the best cooking oils like olive oil. Do not consume fried foods when you are tired, except if the body is very fit.

8. Consuming raw (overly done) foods also add to the burden of liver. Veggies should be eaten raw or cooked 3-5 parts. Fried veggies should be finished in one sitting, do not store. We should prevent this without necessarily spending more. We just have to adopt a good daily lifestyle and eating habits.

Maintaining good eating habits and time condition are very important for our bodies to absorb and get rid of unnecessary chemicals according to “schedule.” Because :
Evening at 9 – 11 PM : is the time for eliminating unnecessary/toxic chemicals (detoxification) from the antibody system (lymph nodes). This time duration should be spent by relaxing or listening to music. If during this time a housewife is still in an unrelaxed state such as washing the dishes or monitoring children doing their homework, this will have a negative impact on health.

Evening at 11pm – 1 am : is the detoxification process in the liver, and ideally should be done in a deep sleep state.

Early morning 1 – 3 am : detoxification process in the gall, also ideally done in a deep sleep state.

Early morning 3 – 5 am : detoxification in the lungs. Therefore there will sometimes be a severe cough for cough sufferers during this time. Since the detoxification process had reached the respiratory tract, there is no need to take cough medicine so as not to interfere with toxin removal process.

Morning 5 – 7am : detoxification in the colon, you should empty your bowel.

Morning 7 – 9 am : absorption of nutrients in the small intestine, you should be having breakfast at this time. Breakfast should be earlier, before 6:30 am , for those who are sick. Breakfast before 7:30 am is very beneficial to those wanting to stay fit. Those who always skip breakfast, they should change their habits, and it is still better to eat breakfast late until 9 – 10 am rather than no meal at all. Sleeping so late and waking up too late will disrupt the process of removing unnecessary chemicals. Aside from that, midnight to 4:00 am is the time when the bone marrow produces blood.

Therefore, have a good sleep and don’t sleep late.