Category: Interview Questions

1. What Is Service Console?

The service console is developed based up on Redhat Linux Operating system, it is used to manage the VMKernel.

2. What Are The Basic Commands To Troubleshoot Connectivity Between Vsphere Client /vcenter To Esx Server?

• service mgmt–vmware restart  (restarts host agent(vmware–hostd) on vmware esx server)
• service vmware-vpxa restrat (restarts Vcenter agent service)
• service network restart (restarts management networks on ESX)

3. What Is Vcenter Agent?

VC agent is an agent installed on ESX server which enables communication between VC and ESX server. This Agent will be installed on ESX/ESXi will be done when you try to add the ESx host in Vcenter.

4. What Is The Command Used To Restart Ssh, Ntp & Vmware Web Access?

• Service sshd restart
• Service ntpd restart
• Service vmware–webaccess restart

5. What Are The Types Of Ports Groups In Esx/esxi?

There are 3 types of port groups in ESX:

1. Service console port group
2. VMkernel Port group
3. Virtual machine port group

There are only 2 types of port group in ESXi:

1. Vmkernel Port group
2. Virtual Machine Port group

6. What Is Vmkernel ?

VMWare Kernel is a Proprietary kernel of vmware and is not based on any of the flavors of Linux operating systems, .VMkernel requires an operating system to boot and manage the kernel. A service console is being provided when VMWare kernel is booted. Only service console is based up on Redhat Linux OS not VMkernel.

7. What Is The Use Of Service Console Port ?

Service console port group required to manage the ESX server and it acts as the management network for the ESX. vCenter/vSphere Client uses the service console IP’s to communicate with the ESX server. 

8. What Is The Use Of Vmkernel Port ?

Vmkernel port is used by ESX/ESXi for vmotion, ISCSI & NFS communications. ESXi uses Vmkernel as the management network  since it don’t have service console built with it.

9. What Is The Use Of Virtual Machine Port Group?

Virtual Machine port group is used by Virtual machine communication.

10. How Virtual Machine Communicates To Another Servers In Network ?

All the Virtual Machines which are configured in VM Port Group are able to connect to the other machines on the network. So this port group enables communication between vSwitch and Physical Switch by the use of uplink (Physical NIC) associated with the port group.

11. What Is The Default Number Of Ports Configured With The Virtual Switch?

When the time of Virtual switch created, Vswitch is created with 56 ports by default. We can extend the no of ports by editing the vswitch properties.

12. What Are The Different Types Of Partitions In Esx Server?

/ -root
Swap
/var
/Var/core
/opt
/home
/tmp

13. What Is Mac Address Changes?

All the virtual machines nics are provide with the MAC address at the time of creation and it is stored in .VMX file. If the packet  doesn’t match with the MAC address as same as in the .VMX  file , it does not allow incoming traffic to the VM by setting this option as reject.

If it is set as Accept,ESX accepts requests to change the effective MAC address to other than the MAC address save din the .VMX file.

14. What Are The Traffic Shaping Policies Available In The Vswitch?

Traffic shaping policies are disabled by default.

There are 3 different traffic shaping policy setting:

• Average Bandwidth
• Peak Bandwidth
• Burst Size

15. What Are The Load Balancing Policies Available In Vswitch?

• Route based on the originating virtual switch port ID
• Route based on source MAC hash
• Route based on IP hash
• Route based on the originating virtual switch port ID – Chooses an uplink based on the virtual port where the traffic entered the virtual switch.  The traffic will be always send with that same uplink until that particular uplink is failed and failed over to another NIC.
• Route based on source MAC hash – Choose an uplink based on a hash of the source Ethernet MAC address.The traffic will be always send with that same uplink until that particular uplink is failed and failed over to another NIC.
• Route based on IP hash – Choose an uplink based on a hash of the source and destination IP addresses of each packet.

16. What Is Forged Transmits?

Which is same as the Mac Address changes setting but it worked for the outgoing traffic but the MAC address changes setting is for incoming traffic.

17. What Is A Vlan?

A VLAN is the VIRTUAL LAN which is used to broke down the Broadcast traffic into many logical groups. Basically, one physical switch comprise of one broadcast domain. VLAN used to separate the one broadcast domain into many small pieces to separate the networks within the broadcast domain.

18. What Are The Types Of Vlan Tagging In Vsphere?

There are 3 types of VLAN tagging available in Vsphere:

1. Virtual Switch Tagging (VST)
2. External Switch Tagging (EST)
3. Virtual Guest Tagging (VGT)

19. What Are The Security Options Available For Esx Vswitch?

• Promiscuous Mode – Reject
• MAC Address changes – Accept
• Forged Transmits – Accept

20. What Is Promiscuous Mode?

If the promiscuous mode set to Accept, all the communication is visible to all the virtual machines, in other words all the packets are sent to all the ports on vSwitch. It can be useful when you are running virtual machines with network sniffers to capture packet in that network.

21. What Are The Types For Network Failover Detection Settings?

• Link Status only
• Beacon Probing

Link Status only
– Relies solely on the link status provided by the network adapter. This detects failures, such as cable pulls and physical switch power failures, but it cannot detect configuration errors, such as a physical switch port being blocked by spanning tree or misconfigured to the wrong VLAN or cable pulls on the other side of a physical switch.

Beacon Probing
–  Sends out and listens for beacon probes — Ethernet broadcast frames sent by physical adapters to detect upstream network connection failures — on all physical Ethernet adapters in the team. In addition to link status, to determine link failure. This detects many of the failures which are not detected by Link Status.

1. What Are The Advantages In Progress 4gl?

• Less development effort
• Solve more complex application
• Support multiple language
• Reusability
• Less knowledge required for platform and deployments
• Support application server and web based application
• It is used for both front-end and back-end.

2. What Is The Latest Version In Progress And In Which Are Currently Working?

• The latest version of the PROGRESS 4GL is 10.1 Open Edge
• The currently working version is progress 9.1D

3. What Are The Two Ways Of Programming In Progress?

• CUI (Procedure Editor)
• GUI (ADM-2)

4. What Is The Syntax For Message Statement?

Syntax:

Message “” view-as alert-box buttons

Message type:

•  Information
•  Question
•  Error
• Warning

Buttons:

• Ok
• Yes-No
• Yes-No-Cancel                  

Example:
Message “welcome to progress” view-as alert-box information buttons ok.

5. What Is The Syntax For Variable Declaration?

Define variable as format initial no-undo

Example:
 Define variable lv_a as integer format 999 initial 1 no-undo.

6. Why We Are Using No-undo?

Whenever we change the value of a variable, it will store the previous value into the before image file. To avoid this reason, we are using no-undo while declaring the variable.

7. How Many Date Formats Available In Progress?

Two types of date format available:

1. MDY
2. DMY

8. What Are The Types Of Looping Statement?

1. Repeat
2. Do
3. For-each
4. Do-while

9. What Is The Use Of Entry?

It is used to extract a string from the list. This function takes two parameters one is the position of the string and another one is the list.

Syntax: 
Entry ().

10. What Is The Use Of Num-entries?

NUM-ENTRIES is used to return the no of entries available in the list .

Syntax:
 Num-entries().

11. What Are The Types Of Blocks?

• Repeat, do, for-each block
• Procedure block
• Trigger block
• Editing block

12. What Is Trigger Block?

It’s a block which contains one or more statements. whenever an event occurs the corresponding trigger block will be fired.

13. What Is Editing Block?

Editing block is used to get the input from the user:

• Prompt-for
• Set 
• Update

14. What Is The Difference Between Prompt-for & Set?

Prompt-for: 
This is used to get input for both variable and database.

Set: 
This is used to get input only for variable.

15. What Are The Types Of Procedures?

1. Internal procedure
2. External procedure
3. Persistent procedure
4. Super procedure

16. What Is Persistent Procedure?

It’s the procedure which keeps the value of the external procedure using handle variable. This variable will be valid until we close the progress session.

17. How Will You Run External Procedure Persistently?

Run persistent set

18. What Is The Use Of Parameter?

The parameter is used to passing the argument to function and procedure.

19. What Are The Types Of Parameters?

1. Input
2. Output
3. Input-output

20. How Will You Define A Parameter?

Syntax:

Define parameter as no-undo.

Example:
 Define input parameter ip_a as integer no-undo.

21. What Are The Types Of Programming Models?

1. Procedure driven model (CUI)
2. Event driven model (GUI)

22. What Is Function?

Function is a sub-program like procedure but it can return only one single value.

23. What Is A Frame?

Frame is a rectangular display area with in the window. It is used to display field level widgets.

24. What Are The Types Of Frames?

• Down
• One Down

25. How Will You Track The Error In The Statement?

Using error-status function we can track the error in the statement.

26. What Are The Methods In Error-status?

• Error
• Num-Messages
• Get-Number
• Get-Message

27. How Many Primary Keys Will Be In A Single Table?

Only one primary key in a single table

28. What Are The Types Of Indexes?

• Primary key index
• Unique index
• Word index

29. How Will You Fetch Single Record & Multiple Records?

1. For-first and find-first are used to fetch a single record
2. For each statement is used to fetch the multiple records

30. What Is The Difference Between Find & Find-first?

Find:

In find statements if there are any non-primary key records which has duplication will provide ambiguous error

Find-first:

In find-first statements the ambiguous error will be overcome because which is return the first record from the buffer

31. What Is The Difference Between Find-first And For-first?

For-first:

1. Using field option for specify the field name for modification
2. Using multiple index
3. Using word index field

Find-first:

1. In find first not support the above three statements
2. In find first we use no-error and available option

32. What Is The Use Of No-error?

No-error statement which is used to suppress the progress errors.

33. What Is The Use Of Xref?

XREF is used to find out the index being used in a file

34. What Is The Syntax For Xref?

Compile save XREF

35. What Is Record Scoping?

To identify the scope of the record.

36. What Are The Types Of Scoping And Their Uses?

Weak scope .

        eg :-  
 for each loop

Strong scope

         eg :-
Do for loop

37. Tools To Develop Web Based Application?

1. Web-speed 3.0 is a software, which is used to develop web-based applications.
2. Web client is a software where client/Server applications will be accessed using browser like Netscape or Internet Explorer.

38. Can We Create A Word-index For An Array Field?

No, we can’t create a word-index for an array field.

39. What Is No-wait?

When one procedure is accessing a table in exclusive lock mode at the same time some other procedure try to access the same table it will not wait till the table is released if the no-wait option is used.

40. What Is The Use Of Delimiter?

The Delimiter is a character that is used to separate the field values. The default delimiter is space.

41. What Is The Use Of Etime & What Does It Returns?

1. It is used to find out the time taking for execution of a particular block
2. It returns milliseconds.

42. What Is Buffer-copy?

Buffer-Copy is one statement. This is used to bulk copy of a source record to a target record by copying each source field to the target field of the same name.

1. Why Is The Code Of Gmp Changing From Time To Time?

The TGA uses internationally harmonised manufacturing standards to allow manufacturers to operate in an international environment. The TGA maintains its GMP standards in line with updates issued through the PIC/S. Regular updates are necessary to maintain mutual confidence with regulators overseas and to promote quality assurance of inspections and harmonisation of technical standards and procedures with international inspection standards for the production and testing of medicinal products.

Australian manufacturers benefit from reduced regulatory burden where the TGA is able to adopt harmonised international standards and establish mutual recognition agreements and cooperation arrangements with comparable overseas regulatory authorities.

2. When Did The Current Code Of Gmp Become Mandatory?

The current Code of GMP was introduced on 29 July 2009 with a transition period up to 30 June 2010. It became mandatory from 1 July 2010.

3. What Is Meant By ‘marketing Authorisation’?

Marketing Authorisation is a set of regulatory requirements specified on the ARTG and any other requirements imposed by a relevant Delegate of the Secretary upon product listing or registration.

Examples of regulatory requirements include, but are not limited to, compliance with registered formulations, special storage and transportation conditions, shelf life, labelling, batch release testing requirements etc.

The Marketing Authorisation is equivalent to a Certificate of Registration or a Certificate of Listing for a medicinal product under the Therapeutic Goods Act 1989.

4. Is The Holder Of The Marketing Authorisation The Product Sponsor?

Yes

5. Can A Sponsor Perform Release For Supply?

Release for supply is defined as a manufacturing step for which a TGA licence is required. For this reason, a sponsor can only perform release for supply if the sponsor holds a TGA manufacturing licence. Refer to clause 1.1vii. of the 2009 Code.

6. Can A Manufacturer Have More Than One Authorised Person To Perform Release For Supply?

Yes – a manufacturer is allowed to have more than one authorised person to perform release for supply.

7. Do Product Quality Reviews (pqrs) Have To Be Conducted Yearly?

Yes. However, if very few batches of one product are manufactured in one year, it may also be acceptable to conduct a two yearly PQR providing a rationale is documented and scientifically justified. The justification for a reduction in the frequency of reviews should consider whether the medicines are registered, listed or complementary, the number and size of batches manufactured, whether grouping is utilised  and the method of manufacture, together with an assessment of the risk associated with the product. The approach taken by the manufacturer will be assessed on a case-by-case basis.

8. Can One Product Quality Review (pqr) Be Prepared For A Group Of Products?

Grouping (sometimes referred to as bracketing or matrixing) of products for the preparation of PQRs may be acceptable, if adequately justified. It is usually only acceptable if the amount of batches manufactured annually for each product within the group is low, the grouped products are of the same pharmaceutical form containing the same or very similar active ingredients and are manufactured using the same equipment. Acceptability will be assessed during inspections on a case-by-case basis.

9. Do All Batches For Which Manufacture Has Commenced Have To Be Included In Product Quality Reviews (pqr)s?

Yes. For example, also all batches for which the manufacture was terminated, delayed or has failed are expected to be included in the PQRs. When grouping is applied, all batches of all products in each group are expected to be included in the PQR.

10. What Are The Requirements For Product Quality Review (pqr) For Products That Are For Export Only?

The PQR requirements for products that are for export only are the same as the PQR requirements for all other products.

11. What Are Language Requirements For Personnel?

Manufacturers should define language requirements or standards and ensure personnel are proficient in the required language for their allocated tasks, particularly in relation to documenting and recording. Procedures employed to overcome identifiable deficiencies should also be documented.

12. What Is The Definition Of ‘campaign’ Manufacture?

Clause 5.19 defines campaign manufacture as being a separation in time of production. That is, manufacturing a series of batches of the same product in sequence in a given period of time and/or maximum number of batches followed by an appropriate (validated) cleaning procedure.

13. What Environment Is Required For Sampling Primary Packaging Materials For Non-sterile Products? Can They Be Sampled In The Warehouse?

Clause 3.9 also describes the physical requirements for the area being used to sample primary packaging material for non-sterile products. As product contact components, primary packaging materials should be sampled within an environment that adequately protects the packaging from contamination. The standard of air quality is optional and HVAC is not expected. However, sampling of primary packaging materials in an open warehouse would not be allowed.

14. What Are The Requirements For Label Counting And Verification?

Roll labels must be counted either on receipt or at issue. Supplier counts are not acceptable unless the supplier is specifically qualified and supplier certifies the exact count for each roll. Supplier numbering of labels is an acceptable alternative.

Cut labels must be counted and effectively verified by the manufacturer because of risks of mix-ups.

15. Is It Necessary To Conduct On-going Stability Studies At A Gmp Certified Laboratory?

No. However, the results from these studies are required to be reliable and meaningful. For that reason, other certificates may be used in lieu of a GMP certification, such as a current Good Laboratory Practice (GLP) certificate or licence issued by a regulatory authority acceptable to the TGA or a current ISO 17025 accreditation certificate. Stability test methods used by the laboratory should be appropriately validated and documented according to the requirements of the Code.

The results from the on-going stability monitoring studies must be considered as part of release for supply, which is the final step in manufacturing.

16. In The Case Of Imported Medicines, Is The Responsibility To Conduct An On-going Stability Monitoring Program With The Manufacturer Or With The Sponsor?

The responsibility is with both the manufacturer and the sponsor. The manufacturer who carries out release for supply needs to ensure that the batch meets its Marketing Authorisation, and that an on-going stability monitoring program is conducted and data is available to support the expiry date. The sponsor is responsible for the Marketing Authorisation, ensures an on-going stability testing program is performed and has access to the stability results. In the contract manufacturing agreement, the responsibility for on-going stability may be contracted out to the manufacturer or other parties.

17. Is Grouping Of Products In The On-going Stability Program Acceptable?

Grouping or bracketing could be acceptable, if appropriately scientifically justified and if the formulation is (nearly) identical. This will be assessed during inspections on a case-by-case basis.

18. Are On-going Stability Data Reviewed During Inspections?

Yes. During inspections, the operation of an appropriate on-going stability program are reviewed, including the results of on-going stability studies, where appropriate. If there are any concerns, the inspector can refer the evaluation to the regulator.

19. Should The Results Of The On-going Stability Program Be Part Of The Release For Supply Process?

Yes, the results of the on-going stability program are expected to be available to the Authorised Person who should consider those before releasing a batch for supply.

20. Is Annex 2 Applicable To The Manufacture Of Apis Used In Biological Medicinal Products?

Yes. The manufacture of APIs for biological medicinal products for human use is usually performed in immediate conjunction with the manufacture of the biological medicinal product itself. For that reason, Annex 2 is written to cover both the API and the finished product manufacturing steps of biologicals. Additionally, Part II of the Code is applicable to the manufacture of APIs for biological medicinal products.

21. What Are The Implications Of The New Code For Manufacturers Of Radiopharmaceuticals?

The implications for radiopharmaceuticals manufacturers are similar to those for other medicines manufacturers. The Guide to interpretation of the 2002 Code for manufacturing the PET radiopharmaceutical Fludeoxyglucose [18F] Injection has been revised to reflect the 2009 Code.

22. Are Radiopharmaceuticals Supplied In A Hospital Situation Required To Be Entered In The Artg?

Yes, except for radiopharmaceutical cold kits to which a radioisotope is to be added immediately before injection into patients. Registration is not required if the cold kit is manufactured in a public or private hospital for a patient of that hospital or a patient of another public or private hospital in the same State or Territory.

23. What Is Gmp?

Good manufacturing practice (GMP) is a system for ensuring that products are consistently produced and controlled according to quality standards. It is designed to minimize the risks involved in any pharmaceutical production that cannot be eliminated through testing the final product.

The main risks are:
unexpected contamination of products, causing damage to health or even death; incorrect labels on containers, which could mean that patients receive the wrong medicine; insufficient or too much active ingredient, resulting in ineffective treatment or adverse effects.

24. Why Is Gmp Important?

Poor quality medicines are not only a health hazard, but a waste of money for both governments and individual consumers.

25. Is Gmp Necessary If There Is A Quality Control Laboratory?

Yes. Good quality must be built in during the manufacturing process; it cannot be tested into the product afterwards. GMP prevents errors that cannot be eliminated through quality control of the finished product. Without GMP it is impossible to be sure that every unit of a medicine is of the same quality as the units of medicine tested in the laboratory.

26. Can Manufacturers Afford To Implement Gmp?

Yes. Making poor quality products does not save money. In the long run, it is more expensive finding mistakes after they have been made than preventing them in the first place. GMP is designed to ensure that mistakes do not occur. Implementation of GMP is an investment in good quality medicines. This will improve the health of the individual patient and the community, as well as benefiting the pharmaceutical industry and health professionals. Making and distributing poor quality medicines leads to loss of credibility for everyone: both public and private health care and the manufacturer.

27. Should The Scope And Extent Of Validation Be Based On Risk?

Yes, the scope and extent of validation should be based on risk according to the manufacturer’s quality risk management procedures. Qualification and validation work is required to control the critical aspects of the particular operation and a common sense approach should be applied.

28. Poor Quality Medicines Can Damage Health?

A poor quality medicine may contain toxic substances that have been unintentionally added. 

A medicine that contains little or none of the claimed ingredient will not have the intended therapeutic effect.

1. What Is Phalcon ?

Phalcon is an open source, full stack framework for PHP written as a C-extension, optimized for high performance. You don’t need to learn or use the C language, since the functionality is exposed as PHP classes ready for you to use.

2. Explain Dependency Injection In Phalcon ?

PhalconDi is a component implementing Dependency Injection and Location of services and it’s itself a container for them.

Since Phalcon is highly decoupled, PhalconDi is essential to integrate the different components of the framework. The developer can also use this component to inject dependencies and manage global instances of the different classes used in the application.

Basically, this component implements the Inversion of Control pattern. Applying this, the objects do not receive their dependencies using setters or constructors, but requesting a service dependency injector. This reduces the overall complexity since there is only one way to get the required dependencies within a component.

Additionally, this pattern increases testability in the code, thus making it less prone to errors.

3. List Basic Features Provided By Phalcon ?

First of all Phalcon is not like any other php framework because it’s a php extension written in C. Php extension are .so files like extension=phalcon.so

Since it’s a php extension it’s always loaded if the extension is enabled in php.ini file, even with nothing build. And this going to make this perform fast.

The framework have no defined directory structure, so you can build your application in different pattern like multi-module, HMVC etc

4. Explain Directory Structure Of Phalcon Framework?

• app/config holds configuration files that are used for the app. I use YAML for all static configuration that I don’t want to keep in the database, usually registering them as services in the bootstrap.
• app/utilities is where I put helper classes for my app. It has a dedicated namespace (“Utilities”) which makes all of them easy to use.

5. How To Register Namespaces, Prefixes, Directories Or Classes In Phalcon ?

Registering Namespaces:

If you’re organizing your code using namespaces, or using external libraries which do, the registerNamespaces() method provides the autoloading mechanism. It takes an associative array; the keys are namespace prefixes and their values are directories where the classes are located in. The namespace separator will be replaced by the directory separator when the loader tries to find the classes. Always remember to add a trailing slash at the end of the paths.

Registering Directories:

The third option is to register directories, in which classes could be found. This option is not recommended in terms of performance, since Phalcon will need to perform a significant number of file stats on each folder, looking for the file with the same name as the class. It’s important to register the directories in relevance order. Remember always add a trailing slash at the end of the paths.

Registering Classes:

The last option is to register the class name and its path. This autoloader can be very useful when the folder convention of the project does not allow for easy retrieval of the file using the path and the class name. This is the fastest method of autoloading. However the more your application grows, the more classes/files need to be added to this autoloader, which will effectively make maintenance of the class list very cumbersome and it is not recommended.

Additional file extensions:

Some autoloading strategies such as “prefixes”, “namespaces” or “directories” automatically append the “php” extension at the end of the checked file. If you are using additional extensions you could set it with the method “setExtensions”.

6. Explain Routing In Phalcon?

The router component allows to define routes that are mapped to the controllers or handlers that should receive the request. A router parses a URI as per the information received.

Every router in the web application has two modes:

• MVC mode
• Match-only mode

The first mode is ideal for working with MVC applications. Following is the syntax to define a route in Phalcon.

$router = new Router();  
// Define a route 

$router->add( 
   “”, 
   [ 
      “controller” => “”, 
      “action”     => “”, 
   ] 
);

7. How Can You Add Validations In Phalcon?

PhalconValidation is an independent validation component that validates an arbitrary set of data. This component can be used to implement validation rules on data objects that do not belong to a model or collection.

The following example shows its basic usage:

use PhalconValidation;
use PhalconValidationValidatorEmail;
use PhalconValidationValidatorPresenceOf;
$validation = new Validation();
$validation->add(
    “name”,
    new PresenceOf(
        [
            “message” => “The name is required”,
        ]
    )
);
$validation->add(
    “email”,
    new PresenceOf(
        [
            “message” => “The e-mail is required”,
        ]
    )
);
$validation->add(
    “email”,
    new Email(
        [
            “message” => “The e-mail is not valid”,
        ]
    )
);
$messages = $validation->validate($_POST);
if (count($messages)) {
    foreach ($messages as $message) {
        echo $message, “
“;
    }
}

8. List Some Database Related Functions In Phalcon?

Phalcon encapsulates the specific details of each database engine in dialects. Those provide common functions and SQL generator to the adapters.

Class—Description

PhalconDbDialectMysql–SQL specific dialect for MySQL database system

PhalconDbDialectPostgresql–SQL specific dialect for PostgreSQL database system

PhalconDbDialectSqlite–SQL specific dialect for SQLite database system

9. How To Read , Write And Delete Sessions In Phalcon?

Starting the Session:
Some applications are session-intensive, almost any action that performs requires access to session data. There are others who access session data casually. Thanks to the service container, we can ensure that the session is accessed only when it’s clearly needed:

$di->setShared(
    “session”,
    function () {
        $session = new Session();

        $session->start();

        return $session;
    }
);

Storing/Retrieving data in Session: 
From a controller, a view or any other component that extends PhalconDiInjectable you can access the session service and store items and retrieve them in the following way:

{
    public function indexAction()
    {
        // Set a session variable
        $this->session->set(“user-name”, “Michael”);
    }

    public function welcomeAction()
    {
        // Check if the variable is defined
        if ($this->session->has(“user-name”)) {
            // Retrieve its value
            $name = $this->session->get(“user-name”);
        }
    }

}

Removing/Destroying Sessions: 
It’s also possible remove specific variables or destroy the whole session:

use PhalconMvcController;

class UserController extends Controller
{
    public function removeAction()
    {
        // Remove a session variable
        $this->session->remove(“user-name”);
    }

    public function logoutAction()
    {
        // Destroy the whole session
        $this->session->destroy();
    }
}

10. How To Increase Csrf Timeout In Phalcon ?

tokens use sessions, so if you increate your session it will increase the totken time aswell.

11. Explain Mvc In Phalcon ?

Phalcon offers the object-oriented classes, necessary to implement the Model, View, Controller architecture (often referred to as MVC) in your application. This design pattern is widely used by other web frameworks and desktop applications.

MVC benefits include:

• Isolation of business logic from the user interface and the database layer
• Making it clear where different types of code belong for easier maintenance

If you decide to use MVC, every request to your application resources will be managed by the MVC architecture. Phalcon classes are written in C language, offering a high performance approach of this pattern in a PHP based application.

Models:
A model represents the information (data) of the application and the rules to manipulate that data. Models are primarily used for managing the rules of interaction with a corresponding database table. In most cases, each table in your database will correspond to one model in your application. The bulk of your application’s business logic will be concentrated in the models. Learn more

Views:
Views represent the user interface of your application. Views are often HTML files with embedded PHP code that perform tasks related solely to the presentation of the data. Views handle the job of providing data to the web browser or other tool that is used to make requests from your application. Learn more

Controllers:
The controllers provide the “flow” between models and views. Controllers are responsible for processing the incoming requests from the web browser, interrogating the models for data, and passing that data on to the views for presentation. 

12. What Is Zephir In Phalcon ?

Zephir – Ze(nd Engine) Ph(p) I(nt)r(mediate) – is a high level language that eases the creation and maintainability of extensions for PHP. Zephir extensions are exported to C code that can be compiled and optimized by major C compilers such as gcc/clang/vc++. Functionality is exposed to the PHP language

13. How To Pass Data From Controller To View In Phalcon?

The setVar() method is used to pass data from controller to view template in Phalcon.

Usage:- $this->view->setVar(“username”, $user->username);

14. Which Template Engine Phalcon Use ?

Phalcon uses a powerful and fast templating engine called Volt.

Volt is an ultra-fast and designer friendly templating language written in C for PHP. It provides you a set of helpers to write views in an easy way. Volt is highly integrated with other components of Phalcon, just as you can use it as a stand-alone component in your applications.

15. How Can You Inject Services Into A Volt Template?

If a service container (DI) is available for Volt, you can use the services by only accessing the name of the service in the template:

{# Inject the ‘flash’ service #}

{# Inject the ‘security’ service #}

16. Explain Odm In Phalcon?

ODM (Object-Document Mapper) offers a CRUD functionality, events, validations among other services in Phalcon.

17. Single Or Multi Module Applications In Phalcon?

Single Module Application:
Single MVC applications consist of one module only. Namespaces can be used but are not necessary.

Multi Module Application:
A multi-module application uses the same document root for more than one module.

18. List Various Type Of Application Events In Phalcon?

Below are the list of Application Events in Phalcon:

• Event Name–Triggered
• boot–Executed when the application handles its first request
• beforeStartModule–Before initialize a module, only when modules are registered
• afterStartModule–After initialize a module, only when modules are registered
• beforeHandleRequest–Before execute the dispatch loop
• afterHandleRequest– After execute the dispatch loop

1. What Do You Know About Gail?

Gas (India) Limited (GAIL) (formerly known as Gas Authority India Limited) is the largest state-owned natural gas processing and distribution company in India. It is headquartered in New Delhi. It has the following business segments: natural gas, liquid hydrocarbon, liquefied petroleum gas transmission, petrochemical, city gas distribution, exploration and production, GAILTEL and electricity generation. GAIL was conferred with the Maharatna status on 1 Feb 2013, by the Government of India. Only six other Public Sector Enterprises enjoy this coveted status amongst all central CPSEs.

The company was initially given the responsibility of construction, operation & maintenance of the Hazira – Vijaypur -Jagdishpur (HVJ) pipeline Project. It was one of the largest cross-country natural gas pipeline projects in the world. Originally this 1800 Km long pipeline was built at a cost of Rs 1700 Crores and it laid the foundation for development of market for natural Gas in India. GAIL has formed subsidiaries and joint venture companies for city gas distribution and petrochemicals. GAIL is one of the pioneers to introduce city gas projects in India for gas supplies to households, commercial users and for the transport sector by forming subsidiaries/ joint venture companies.

2. Where Is The Company Headquartered?

GAIL is headquartered in New Delhi. Properly addressed at Bhikaji Cama Place, New Delhi India.

3. When This Company Was Established?

GAIL Limited was incorporated in August 1984 as a Central Public Sector Undertaking. The company was formerly known as Gas Authority of India Limited. It is India’s principal gas transmission and marketing company.

4. Who Is Current Md/chairman Of This Company?

Shri B.C. Tripathi was appointed as the chairman and managing director of GAIL (India) Limited, India in 2014.

5. What Was The Company Revenue And Profit Last Year?

The total revenue of GAIL in the financial year 2014-15 was ₹516.14 billion (US$8.0 billion). And the profits was ₹22.99 billion (US$360 million).

6. What Are The Products/services Offered By This Company?

The services offered by GAIL are natural gas, liquid hydrocarbon, liquefied petroleum gas transmission, petrochemical, city gas distribution, exploration and production, GAILTEL and electricity generation.

7. Under Which Ministry Of Central Government This Company Function?

GAIL was incorporated in August 1984 as a Central Public Sector under the Ministry of Petroleum & Natural Gas.

8. Who Are Competitors Of This Company?

The following are the competitors of GAIL:

1. ONGC
2. Cairn India
3. Petronet LNG
4. Oil India
5. Gujarat Gas.
6. Guj State Petro, etc.

9. Where Are The Manufacturing Units Of This Company Located?

• GAIL has its subsidiaries in: 
  GAIL GAS is providing natural gas to approximately 350 industrial consumers in TTZ area (Agra and Firozabad) in Uttar Pradesh India. GAIL GAS has also started the CGD work in Bengaluru Karnataka recently.
• Brahmaputra Cracker and Polymer Limited (BCPL):
  GAIL has 70% equity share in BCPL, a subsidiary, with Oil India Limited (OIL), Numaligarh Refinery Limited (NRL), and Govt. of Assam.
• GAIL Global (Singapore) Pte Limited:
  AIL has a wholly owned subsidiary, namely, GAIL Global (Singapore) Pet Ltd., to manage investments abroad.

10. Why Was This Company In News In Recent Times?

GAIL was in recent economic news for laying work contracts in Kerala. In order to strengthen natural gas pipeline network in Kerala, GAIL (India) Limited, a Maharatna enterprise, has awarded contracts for pipeline laying work of the Kochi–Kootenai–Mangalore pipeline for another 131 km.The remaining 111 km stretch in Malappuram, Kannur and Kasargod districts will be awarded by July 2017.

11. You Can See, We Have Compression Station At Different Location, Why Don’t We Use Pump Station?

We are dealing with the conveying of the gases. Compressors are meant for conveying of gases while pumps deal with liquids. Hence, we have compression stations.

12. What Is Difference Between Reciprocating Compressor And Rotating Compressor?

In reciprocating compressor the energy transfer is due to the volume changes while in rotating compressor energy transfer is due to dynamic action (velocity). Also, reciprocating compressor are meant for high head and also does not have continued mass flow rate whereas rotating compressor are meant for low head and high mass flow rate.

13. Do You Know Rankine Cycle? What Are The Four Components In It And The Purpose Of Each?

• Pump – Work input.
• Boiler- Heat addition.
• Turbine- Work output.
• Condenser- Heat rejection.

14. Why Don’t We Use Compressor And Send It To Boiler?

The work input for the compressor is more as compared to pump. So the net work output is less in case of compressor.

15. What Is The Property Of Fluid That Is The Cause For More Work Input In Compressor Than In Pumps?

Bulk density.  The density of gas is low and hence has high specific volume than liquid. So, we require handling more volume. Also gases are more susceptible to expansion and the gases are moving in adverse pressure gradient. So we require more work input.

16. Which Is Your Dream Company? Why?

GAIL, because here I will get an opportunity to learn latest technology and machines. Also it is a budding company and I will get to explore a lot by working in different domains.

17. Which Domain Do You Prefer?

I prefer maintenance for my initial duration of my job and then will prefer operation and maintenance or design. Since maintenance will get me to acquire knowledge of the different equipment residing in the plant and also help to get familiar with process flow. So it helps in designing of new plant.

Also, I would like to work where the company thinks I suits best and will give my best for the benefit of company.

18. What You Have Done In Training? ( I Did My Second Year Training In Gail).

Then, I said about the breakdown maintenance of centrifugal pumps, learn hot tapping, heat exchanger, and extruder.

19. What Is Hot Tapping?

It is to give a new pipeline in a charged line.

20. How Is C2+ Separated From Natural Gas?

There is unit GPU unit, in which there is a demethanizer column (fractional distillation) which separates methane from natural gas and we get C2+. Then they asked is it heating process or cooling. It is a cooling process since temperature goes upto -180 C. Then he refined it so it is a chilling process.

21. Who Is More Imps: Team Or You? Why?

Team, because if team succeed I will also get appreciation and prospers.

22. What Is Most Important For A Team To Get Success?

Communication- easy flow of information among people and cooperation. If there is no communication, it will be very difficult to take wise and good decisions.

23. Define Entropy?

It is measure of randomness. Then they say to give an example from general life.(This can be understandable by a general person). Then I said, if we have a group of people closed in a park then suddenly some minister or actress comes, there will be a lot of excitation and “shor gulla and people will rush to see them. So, in this randomness increases and hence entropy increases.

24. What Is The Difference Between Impulse Turbine And Reaction Turbine?

In impulse turbine, pressure changes take place outside the rotor. Hence degree of reaction is zero whereas in reaction turbine pressure changes in rotor only. Hence degree of reaction is one.

25. Tell Me One Thing, In India, 40% People Are Below The Poverty Line Also We Are Investing In Aerospace Programs. Is It Justified According To You?

We have different schemes for the betterment of poor people like Rajiv Gandhi scheme, Indira Gandhi scheme. And we are working on them. But at the same time, we have to stand globally so we require investing in aerospace programs. Then he said you have not given the answer of my question “Is it justified”. Yes sir, It is justified as it will help in increasing employment and attract foreign investment which can be used for the poor people.

26. Are You Willing To Work Anywhere In India? Is There Any Problem?

There is absolutely (more sophisticated word can be used here. absolutely sounds some weird. Since there is no absolute satisfaction) no problem.

1. How Openvz Different From Other Virtualization Technologies?

• OpenVZ is not flexible to provide the services that are being provided by other virtualization platforms.
• OpenVZ is partial virtualization and act as a containerization, whereas other virtualization technologies are either type1 or type2 Hypervisors.
• OpenVZ uses kernel patches to run only Linux operating system, whereas other virtualization platforms can run more than one operating systems. 
• OpenVZ is fast and efficient compared to other virtualization technologies.

2. What Is The Main Function And Use Of Openvz?

OpenVZ is also known as Open virtualization is an operating system level platform that is based on Linux kernel and can run system that is based on Linux architecture. It can run multiple Linux system instances in what is called as containers. It contains Linux base operating system and gives very high performance compared to standalone servers. OpenVZ is free to use and imply. It provides custom level kernel to provide the support for its containers and user level tools.

3. What Are The Containers That Are Involved In Virtualization And Isolation?

The container consists of:

• Files that consist of system libraries and applications that provides programmers to write the code without looking further. It provides virtualized files as well that keeps the virtualization for the user. 
• Users and groups: it consists of isolated root user that allow user to group other users and set the permissions individually or either as groups. 
• Process tree: consists of processes that contain other processes under it. The level start from init and it goes as the each process is added. 
• Network: consists of the configuration for virtual network devices and the entire container to have its own IP addresses for communication with other devices. 
• Devices: consists of access permissions that are used to connect it with the real devices like network interfaces, serial ports, parallel ports, etc.
• IPC objects: consists of the files that are used for inter process communication like shared memory, semaphore, etc

4. What Are The Different Features Of Openvz?

OpenVZ is a operating system level virtualization platform and provides features like:

• Scalability: this consists of configuration related to hardware like CPU, RAM etc. 
• Performance: this consists of performance related issues that are very few in OpenVZ and it reduces the overhead that is being associated with other virtualization platforms
• Density: provides the decrease of overhead that is required by the container and doesn’t allow the demands to exceed the physical availability of the resources.
• Mass management: provides administrator rights to use the physical server of OpenVZ so that user can see all the processes that are running on the system and the containers that are consisting inside the OpenVZ

5. What Are The Required Steps To Improve The Efficiency Of Services In Openvz?

OpenVZ utilizes the processing power to reduce the overhead by decreasing the load that is given on a system. It provides better methods to improve the handling of peak loads. It also reduces the complexity by providing standardized and centralized management of the server from one place. It provides a way to isolate the servers from the actual hardware. It uses high-end servers by isolating the server from hardware and with the servers bring added advantages like reliability, longer lifespan, etc.

6. How To Setup The Tun/tap Network For A Container?

OpenVZ uses tun/tap network module to configure a container. To setup the container using tun/tap device: 

• Check your system and see that tun/tap module is already being installed. Use the command to find out:

  |smod| grep tun

•  If not present then use the command to load the tun module:

  modprobe tun

• Edit the modules.conf that is inside /etc/ to allow the tun module to run automatically during the start of the system. 
• Set the permission for the container to use the tun/tap module
• The following command allows the container to be set with the permission for the use of tun/tap networking module:

  vzctl set 101 –devnodes net/tun:rw –save

7. What Are The Commands That Are Required To Manage Openvz Virtual Machine?

The commands that are required to manage OpenVZ are as follows:

To show a list of all running VPSs we require a command named vzlist that list the containers and its parameters.The command that is used with it is:

vzlist -a

The commands can have many parameters like -o that displays only specified parameters with the name.

To calculate the usage for each container’s resources a command named vzcalc is used that show all the shared host system resources that is used by a particular container.-v is the parameter that is used to show only the valid containers that are currently in use.

8. How To Over-commit The Memory In Openvz?

To over-commit the memory in OpenVZ few pages has to be modified like vmguarpages and oomguarpages that provides the resource management configuration files. Out of these vmguarpages provides the maxium memory a container can have and oomguarpages provides the maximum memory that is being consumed by the processes. These are used to set the limit. Limit also has some files like privvmpages that puts an upper limit on container memory. It is also used for non-swappable kernel memory. By using these functions over-commitment of the memory can be done by using OpenVZ.

9. What Is The Function Of Veth In Openvz?

Veth stands for virtual ethernet device and it is used as an ethernet device in OpenVZ. It is used inside a container and veth consists of MAC address. Veth uses bridged connection configurations with other devices to setup the networking between the two parties for the communication. It includes IPs and gateways to successfully setup the networking interface. This ethernet device contains two ports one is called as CT0 and another is CT. they are connected with each other and they work as interconnected device such that one’s input is another’s output.

10. What Is The Use Of Virtual Environment In Virtuozzo?

Virtuozzo is an operating system that provides virtualization platform just like any other virtualization platform. It works well with the OpenVZ. It has it own containers that has the functionalities to provide the user with easiness and provide the environment in which management tools, recovery, etc can be incorporated. It provides the automation solution and built on top of OpenVZ.

11. What Are The Benefits Of Using Virtuozzo?

The benefits of using virtuozzo are as follows:

• Higher container density: It provides better performance of the containers used in the systems and increases the memory and file sharing rate between the shared systems.
• Memory management: It is easier to manage memory segments using this as it provides lots of easy to use tools for managing the memory module.
• Management tools: It allows user to monitor, troubleshoot and administer their own virtual machines to manage the memory and other resources.
• Support and maintenance: There are lots of tools and support provided for recovery and other back up tools.

12. How To Use And Maintain Virtuozzo?

Virtuozzo is a simple operating system to be used and managed. It allows the user to customize the platform using the built in management tools. It provides consistency between different platforms that are used. It maintains the tasks of different operating system together for easy maintenance and sharing. There are management tools that allow user to patch their product and if any difficulty can just upgrade the software version.

13. What Is The Use Of Physical To Virtual Tool For Linux In Virtuozzo?

Physical to virtual tool for Linux is used while deploying virtuozzo. It is used a migration tool between physical and virtual machines. This makes it easy for the operating system to deploy all the necessary services and applications that are required by the operating system. It allows the testing processes to be migrated to ensure the performance and efficiency levels.

14. What Is The Density Level Achieved By Virtuozzo?

The density range talks about the resources of the server, content of the server and the virtual environment in which all the things are taking place. The two most important resources that are required by any virtualization platforms are CPU and RAM. The more the processing power the fewer requirements will be for the offload processing. Virtuozzo achieves a high density for example of 100 virtual environments as it has minimal content and applications when used with Linux operating system but when used with windows more resources is being taken up by windows operating system.

15. What Is The Overhead That Comes While Using Virtuozzo?

Virtuozzo allows one server that is dedicated to be split into multiple virtual servers and called as virtual environments. It doesn’t add high amount of overhead but it keeps to minimal, as it adds only the native applications and operating system. It increases the performance by decreasing the overhead.

16. What Is The Difference Between Virtuozzo And Esx Server?

• Virtuozzo containers produce the virtualization at operating system level so they are called as type-2 Hypervisors, whereas ESX server produce the virtualization at hardware level and they are called as type-1 Hypervisors. 
• Virtuozzo provides low overhead compared to ESX server due to hardware level configurations.
• Virtuozzo provides high performance and high resources at lower cost compared to ESX server. 
• Virtuozzo’s containers provide the virtualization at the same level and there is no need for hardware virtualization, whereas ESX server has to be configured at the hardware level to produce the resources.

17. What Are The Disadvantages Of Using Virtuozzo?

The disadvantages of using virtuozzo are as follows:

• Flexibility: Fexibility decreases due to operating system virtualization as all the containers uses the same operating system.
• Virtuozzo containers can’t use different operating system and have different configurations. 
• It can’t virtualize the systems at high scale as it will require more resources.
• It can’t run high end operating system or else there is a degrade in the performance of the systems. 
• The connectivity of the system is such that it can communicate only in a small range and doesn’t have very high-end tool to manage the changes.

18. How To Manage Virtual Networks?

Virtual networks allow the creation and management of one or more virtual machines. It binds the container’s virtual network adapter with the physical adapter that is associated with the network. It allows user to create virtual network on hardware node, remove an existing virtual network, and list all the networks that are present with their properties and configurations.

19. How To Enable Nat For Virtuozzo Container?

To enable the NAT services for virtuozzo container multiple servers has to be connected with the internet using the single IP address. The containers are running in host and bridged mode. NAT allows user to access the resources that are present on the internet. The command and properties combination that can be used to set the NAT for the container is

vzctl set 101 –nat on –save

This command will set the NAT for any container on the node. The 101 that is used is for a container that enables NAT for default virtual network adapter.

20. What Is Openvz And How It Compares To Virtuozzo?[

OpenVZ is a free and opensource portion of Virtuozzo. It includes core of Virtuozzo functionality, like kernel and command line management tools for creating and managing containers. Virtuozzo includes everything that OpenVZ does, plus additional features and services available with the commercial version only.

21. How Does Virtuozzo 7/openvz Pair Compares To Its Predecessor (virtuozzo Versions 4.x And 6/openvz)?

Previously, OpenVZ and Virtuozzo were built out of the same code base with some unique patches applied. That warranted the user interfaces to be similar but not identical. With Virtuozzo 7, the compatibility will be on the binary level – effectively the open source components will be the same between OpenVZ and Virtuozzo.

22. How Openvz Users Will Benefit From It?

OpenVZ components will be undergoing the same testing procedures as the commercial product. Also, some new features previously available on Virtuozzo only (notably hypervisor) will become available on the product built for OpenVZ community users.

23. What Support Options Are Available For Virtuozzo 7?

For the moment, only preview (beta) versions of Virtuozzo 7 are available. They are intended for development and testing only, not for production. Virtuozzo 7 is not yet commercially supported. For supported commercial version, please refer to Virtuozzo 6.

24. When Openvz Will Be In Upstream Kernel?

Our kernel developers work hard to merge containers functionality into the upstream Linux kernel, making OpenVZ team the biggest contributor to Linux Containers (LXC) kernel, with features such as PID and network namespaces, memory controller, checkpoint-restore and much more.

25. How Scalable Is Openvz?

OpenVZ technology scales as well as standard Linux kernel — up to thousands of CPUs and terabytes of RAM.

26. How To Install Openvz?

There are two versions of OpenVZ available:

• stable version: OpenVZ legacy (based on RHEL5 and RHEL6 kernels).
• development version: Virtuozzo Linux distribution based on RHEL7 kernel.

27. How Existing Openvz Users Can Upgrade To The New Version?

While there is no in-place upgrade, we prepared upgrade script for OpenVZ users to move their containers to the new platform. The script allows to transfer containers from old to new OpenVZ version (or from OpenVZ to Virtuozzo).