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Troubleshoot Zombie/Defunct Processes in UC Servers

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Troubleshoot Zombie

When a process terminates, it enters the defunct state for a long period. This state enables the parent process to monitor the exit status of the processes that are currently running. The kernel will not remove kernel structures associated with the process table until the parent has either examined the exit state of the child process or informed the kernel. If the parent process terminates without performing one of these actions, the system will never remove the child’s structures, and the child process will remain a dead process.

Troubleshoot/Clear the Zombies Manually

Zombie processes do not consume any system resources, except the small amount of memory necessary to store the PID, which was previously indicated. However, they do preserve their process ID. UC servers have vast amounts of memory available to them, which means that it is unlikely that the system will run out of PIDs for other processes due to the presence of Zombies on the system. Consequently, the zombies can be left on the Cisco Router, where they will be automatically deleted when the system is rebooted the following time.

The parent process is responsible for deleting zombies from the process table. When a parent exits without deleting its zombies, the operating system will try and remove them. Machine administrators may usually remove zombies from the process control block by rebooting the system. Here is the exception. Because a zombie has stopped running, putting the kill command on it has no impact. It may still need to read exit information and updates to work properly.

What is a Defunct Process?

A process can stop executing but remain in the process table for the parent to collect exit information and updates before deleting the process from the process table. Because it is no longer in operation, it just requires RAM to keep the exit status and other process-relevant information in the place where it shows in the process table, and it does not require any additional RAM.

It is crucial to understand that when a process comes to an end, it is considered a defunct process. In most cases, defunct processes are terminated by the parent process almost quickly after they are created. Thus they do not appear in the ps output. In extremely unusual conditions, zombies can be observed in the output of the ps command for extended periods. Zombies are an inherent element of every Unix operating system, but having an excessive number of them in the process table might cause problems.

Conclusion

Additionally, a defunct process is referred to as a zombie process or an orphaned process. Certain resources, such as memory, may remain connected with a deceased process and are unavailable for usage. A stopped process cannot be terminated. Apart from the minuscule RAM necessary to store the PID, Zombies Attack process consume no system resources yet keep their process ID. Owing to the enormous amount of RAM allocated to UC servers, the likelihood of the system running out of PIDs for other processes owing to the combination of Zombies is quite unlikely.

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How to tell if it’s incandescent or LED Flashlight?

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LED Flashlight

What is led light?

LED is the abbreviation of light emitting diode in English. Its basic structure is a piece of electronic light-emitting semiconductor material, which is placed on a leaded shelf, and then sealed with epoxy resin around it to protect the inner core wire. Good seismic performance. LED flashlight generally have the advantages of small size, low power consumption, long service life, high brightness, low heat, environmental protection, and durability.

What is an incandescent lamp?

Ordinary incandescent lamps are referred to as general bulbs, also known as GLS lamps, which are the most common incandescent lamps. Typical incandescent lamps have a tungsten filament in a sealed glass bulb. This light bulb has different sizes, shapes and colors, and has many advantages, such as small size for easy use, soft light and good color rendering, can effectively express the texture and texture of materials, cheap, etc. However, it also has shortcomings, such as low light efficiency leading to high cost of use, will produce heat and increase the burden of air conditioning, exposure will produce glare, etc. Incandescent lamps are generally used in ceilings and light fixtures such as desk lamps, this light is pleasant to the senses, best suited to create a warm atmosphere. Colored incandescent lamps usually use colored glass bulbs or a colored lampshade over the lamp.

What is the difference between incandescent lamps and led flashlights?

  1. Different light-emitting principle

The working principle of the incandescent lamp is that heat is generated when the current passes through the tungsten filament, and the spiral tungsten filament continuously gathers the heat, so that the temperature of the filament reaches more than 2000 degrees Celsius. When the filament is incandescent, it emits light like red-hot iron can emit light. The higher the temperature of the filament, the brighter the light emitted, so it is called an incandescent lamp. When an incandescent lamp emits light, a large amount of electrical energy is converted into heat energy, and only a very small part can be converted into useful light energy.

The most important light-emitting structure of an LED flashlight is the lamp bead, which looks small but has a very complex structure. After we zoom in on the structure of the LED lamp bead, we will find the internal particle size chip. The complexity of the large structure of this chip is unimaginable, and it is usually divided into several layers. The longest layer is called the P-type semiconductor layer, the middle is called the light-emitting layer, and the bottom layer is called the N-type semiconductor layer. Simply put, the principle of LED lighting is mainly the use of light-emitting diodes.

2. The heat radiation generated is different

The heat of an incandescent lamp can be felt in a short period of time. The greater the power, the more heat. The electrical energy is converted partly to light and partly to heat. When people are very close, you can clearly feel the heat emitted by the incandescent lamp. LED electric energy converts light energy, which produces very little heat radiation, most directly converted into light energy, and the power of general lamps is low, coupled with the heat dissipation structure. Compared with incandescent lamps, LED flashlight cold light source of heat radiation is better.

3. The color of the light emitted is different

The light emitted by incandescent lamps is full-color light, but the composition ratio of each color light is determined by the luminescent material and temperature. The unbalanced ratio causes the color cast of the light, so the color of the object is not realistic enough under the incandescent light.

LED is a green light source. LED flashlight DC drive, no strobe, and also no infrared and ultraviolet components, no radiation pollution, high color rendering and has a very strong luminous directionality.

Not only that, LED lights also have good dimming performance, no visual error will occur when the color temperature changes, and the cold light source has low calorific value and can be touched safely. It is a healthy light source that protects eyesight and is environmentally friendly to meet people’s physical health needs.

4. How to distinguish between incandescent lamps and led flashlights

We have listed many differences between incandescent lamps and led flashlights, but it is difficult for us to distinguish them with the naked eye, so how should we simply tell between incandescent lamps and led lights?

  • The shape of the lamp: led shape more, and incandescent light only one shape is a round bulb.
  • The material of the lamp: most of the LEDs have aluminum on the lamp or inside, while the incandescent lamp will only be glass.
  • Light color: led will have a variety of colors, while the incandescent lamp only one color yellow
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Rules of Installing Rooftop Generators

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Installing Rooftop Generators

When it comes to generators, there are some important steps to consider. First is choosing the right generator. Next comes deciding whether you want to buy, rent or consider different types of generator financing options. Third, after getting the generator, you need to fix the questions regarding the generator installation.

One of the installation options for modern autonomous power supply systems is the possibility of mounting the generator on the flat roofs of buildings. This option is used in case of a shortage of free space and the impossibility of allocating a specially prepared interior space. However, in this case we are not talking about the installation of a power generator in an open design.

For installation on flat roof sections, it is necessary to reliably protect the generator from adverse weather conditions, as well as provide sufficient sound insulation, for which a container version of the generator or the installation of power generating equipment in a special casing is used.

Advantages of rooftop generators

The main advantages of rooftop generators are:

  • Space savings;
  • All issues related to air supply are solved simply and cheaply by eliminating the need to build an expensive air duct system;
  • No need for a long exhaust system;
  • With sufficient noise insulation, there is no problem of acoustic impact on nearby people.

The main disadvantages of placing the power generators on the roof are:

  • The roof structure must support the weight of the installed equipment and the fuel tank;
  • Difficulties with lifting the power generator to the required height;
  • It is necessary to obtain the approval of the relevant services;
  • The impossibility of installing a large number of fuel storage tanks.

In particular, ceilings must be especially carefully examined and calculated so that they can withstand the weight of the installed power generator and the main fuel tank. In the event that the existing ceilings do not show sufficient strength, the generator set can be installed on platforms made of structural steel with their obligatory support on the load-bearing walls of the building.

Ways to reduce the vibration load on the building

To reduce vibration from a running generator, several methods have been developed and are actively used:

  • For power generators up to 1 MW, it’s often enough to use built-in vibration protection devices that reduce its level by 75-80%, as well as use additional solutions, such as installing additional vibration isolators between the base (chassis) of the power generator and the roof, which will reduce vibration to 98% of entry level;
  • For power generators with a capacity of more than 1 MW, built-in vibration damping may not be enough. In this case, the generator is installed on a specially prepared concrete base, which, in turn, is elastically attached to the roof, which makes it possible to significantly reduce the level of vibration exposure from the operation of power generating equipment.

It should be noted that these methods of reducing vibration noise are actively used, showing very good indicators of protecting buildings and structures from emerging vibration loads.

Ways to reduce the noise level

In addition to protecting the structure of buildings from vibration caused by a running generator set, the problem of reducing the level of noise load to regulated limits is important when placing a power generator on the roof. As a primary measure to reduce noise, special containers or noise protection casings are used, in which the generator set itself is mounted directly. These solutions make it possible to reduce the noise level by 20-30 dB.

In general, noise standards for a running generator set, designed for placement of equipment near places of people’s permanent residence or work, are as follows: the noise level of a running generator is considered to be within 75 dB at a distance of 1 m from the power generator.

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You should know these features before considering buying a phone

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features before considering buying a phone

Samsung has a wide range of phones available to its customers. If you want the best phone for your needs, read on and find out which one should be your choice.

Samsung’s Galaxy S7 edge is the latest model on offer, with an elegant curved screen that adds extra space for notifications and other functions so you can get more done in less time. It comes with its own virtual assistant, Siri-style, called Bixby.

For a phone that’s really eye-catching and has great processing power, the S7 edge should be your first choice.

DESIGN AND DISPLAY

Samsung phone prices in Singapore included a larger display in their flagship smartphone, which is now 5.5 inches in size compared to the Galaxy S6’s 5.1-inch screen. The screen’s resolution is Quad HD (1440 x 2560) at 534 ppi for amazing detail and bright colors with every image that you view on it. Images and videos will look better than on a Full HD display.

The phone’s exterior is made from metal and glass to ensure durability. The S7 Edge doesn’t have a removable battery but has fast charging and is one of the fastest phones currently available with 4 gigs of RAM. It comes with a 12-megapixel main camera, 5-megapixel selfie camera, and 32 or 64 gigabytes of internal memory, depending on the model that you purchase. Bixby (which Samsung introduced as an assistant) is integrated into the device so you can ask questions about weather, movie times for nearby theaters, translation, or request directions to your destination.

PERFORMANCE

The S7 Edge’s 4GB of RAM makes this phone one of the best available for multi-tasking. It has a fingerprint sensor for added security and syncs easily with other devices on the market. The S7 Edge performs at a high level in all categories making this a great device for any user.

BATTERY LIFE AND CONNECTIVITY

The battery life on this smartphone is excellent, so you don’t need to charge it frequently, even if you use it heavily and at full brightness. Check out the battery life on various models of the S7 Edge.

It also has Cat 9 LTE capabilities, meaning it can download and send photos, videos and other data over a faster network. If your phone is compatible with it, you can expect Bluetooth 4.2 technology to maintain your connection throughout your day.

PRICE

You can get the S7 Edge for under $400 from different retailers, depending on what network you purchase it from but there are great prices if you shop around for a deal. So if you want a top-of-the-line Samsung Galaxy S phone, choose this one. It’s durable, sharp looking and offers amazing processing power thanks to its Quad HD display resolution.

Samsung has a wide range of phones available to its customers. If you want the best phone for your needs, read on and find out which one should be your choice.

Samsung’s Galaxy S7 edge is the latest model on offer, with an elegant curved screen that adds extra space for notifications and other functions so you can get more done in less time. It comes with its own virtual assistant, Siri-style, called Bixby.

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