Question

1. Describe the different components founder under the Performance Tab?

2. Give several examples of using Baseline data?

3. Describe the different sources of data used by Performance Monitor.

4. What type of alert in Performance Monitor can write an event to specific log?

5. What is the default tunnel types for VPN server?

Answer 1

--> Describe the different components founder under the Performance Tab?

Ans. The Performance tab shows a flame graph of the creation time for your components. Look at longer and deeper portions of the graph for potential performance bottlenecks.

Record Performance Data

Use the Record, Clear and Show current collected buttons to gather performance data about specific user actions or collections of user actions.

1. To start gathering performance data, press .
2. Take one or more actions in the app.
3. To stop gathering performance data, press .

Hover over a component in the flame graph to see more detailed information about that component in the bottom-left corner. The component complexity and timing information can help diagnose performance issues.

This measure...	Is the time it took to complete...
Self time	The current function. It excludes the completion time for functions it invoked.
Aggregated self time	All invocations of the function across the recorded timeline. It excludes the completion time for functions it invoked.
Total time	The current function and all functions that it invoked.
Aggregated total time	All invocations of the function across the recorded timeline, including completion time for functions it invoked.

--> Give several examples of using Baseline data?

Baseline data is a measurement that is collected prior to intervention or teaching starting.
Some examples of this measure of data collection include:

• Number of words read.
• Number of times a student gets out of their seat.
• Number of times students raise their hands.

--> Describe the different sources of data used by Performance Monitor.

Category	Performance Counters	Notes
Logical Disk	Current Disk Queue Length Disk Read Bytes/sec Disk Write Bytes/sec	The number of outstanding write requests and the amount of bytes read and written to the server’s hard disk. Select these counters for the disk on which you installed Tableau Server (referred to as the instance in PerfMon).
Memory	% Committed Bytes in Use Available MBytes	The percentage of virtual memory in use, and the amount of memory available in megabytes.
Processor Information	%Processor Time % Processor Utility	The percentage of time that the processor spends active, and the percent of processing capacity being used by the processor.
Process	% Processor Time Private Bytes	The percentage of processing capacity being used by a particular process, and the amount of memory reserved for the process. Select these counters for the following processes (referred to as instances in PerfMon): run-backgrounder (Backgrounder) run-dataserver (Data server) redis-server (Cache server) hyperd (Data engine) run-vizqlserver (VizQL Server)

--> What type of alert in Performance Monitor can write an event to specific log?

Performance counter alerts enable an event to be written to the event log and a command to be run when a specified performance counter exceeds or falls below a configured value.

--> What is the default tunnel types for VPN server?

What is VPN Tunneling?

The term VPN tunneling describes a process whereby data is securely transported from one device or network to another through a non-secure environment (such as the internet) without compromising privacy. Tunneling involves protecting data by repackaging it into a different form.

In reality, no physical tunnel exists, of course; the data has to travel through the same wires as any other data passing through the public network. Rather, VPN tunneling employs the concepts known as data encapsulation and encryption to safely carry data traffic through the non-secure environment. Encapsulation insulates the packet of data from other data traveling over the same network, while encryption makes the data “invisible” (unreadable) even to surveillance agents and criminals who recognize it as encrypted information.

Types of VPN tunneling protocols

There are many types of VPN protocols that offer varying levels of security and other features. The most commonly used tunneling protocols in the VPN industry are PPTP, L2TP/IPSec, SSTP, and OpenVPN - and the world's best VPN services should offer most or all of them. Let’s take a closer look at them.

1. PPTP

Point to Point Tunneling Protocol (PPTP) is one of the oldest protocols still being used by VPNs today. Developed by Microsoft and released with Windows 95, PPTP encrypts your data in packets and sends them through a tunnel it creates over your network connection.

PPTP is one of the easiest protocols to configure, requiring only a username, password, and server address to connect to the server. It’s one of the fastest VPN protocols because of its low encryption level.

While it boasts fast connection speeds, the low level of encryption makes PPTP one of the least secure protocols you can use to protect your data. With known vulnerabilities dating as far back as 1998, and the absence of strong encryption, you’ll want to avoid using this protocol if you need solid online security and anonymity – government agencies and authorities like the NSA have been able to compromise the protocol’s encryption.

2. L2TP/IPSec

Layer 2 Tunneling Protocol (L2TP) is used in conjunction with Internet Protocol Security (IPSec) to create a more secure tunneling protocol than PPTP. L2TP encapsulates the data, but isn’t adequately encrypted until IPSec wraps the data again with its own encryption to create two layers of encryption, securing the confidentiality of the data packets going through the tunnel.

L2TP/IPSec provides AES-256 bit encryption, one of the most advanced encryption standards that can be implemented. This double encapsulation does, however, make it a little slower than PPTP. It can also struggle with bypassing restrictive firewalls because it uses fixed ports, making VPN connections with L2TP easier to block. L2TP/IPSec is nonetheless a very popular protocol given the high level of security it provides.

3. SSTP

Secure Socket Tunneling Protocol, named for its ability to transport internet data through the Secure Sockets Layer or SSL, is supported natively on Windows, making it easy for Windows users to set up this particular protocol. SSL makes internet data going through SSTP very secure, and because the port it uses isn’t fixed, it is less likely to struggle with firewalls than L2TP.

SSL is also used in conjunction with Transport Layer Security (TLS) on your web browsers to add a layer to the site you’re visiting to create a secure connection with your device. You can see this implemented whenever the website you visit starts with ‘https’ instead of ‘http’.

As a Windows-based tunneling protocol, SSTP is not available on any other operating system, and hasn’t been independently audited for potential backdoors built into the protocol.

4. OpenVPN

Saving the best for last, we have OpenVPN, a relatively recent open source tunneling protocol that uses AES 256-bit encryption to protect data packets. Because the protocol is open source, the code is vetted thoroughly and regularly by the security community, who are constantly looking for potential security flaws.

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The protocol is configurable on Windows, Mac, Android, and iOS, although third-party software is required to set up the protocol, and the protocol can be hard to configure. After configuration, however, OpenVPN provides a strong and wide range of cryptographic algorithms that will allow users to keep their internet data secure and to even bypass firewalls at fast connection speeds.