CTS 4743 Final

Message Queuing

Asynchronous communication between two processes with guaranteed delivery:

task manager

CPU uptime:

Network segmentation

Can be used to restrict the network level access of guests:

Which of the following emerging industry trends affect most Enterprise IT organizatioins today?

Cloud Computing DevOps Software Defined Infrastructure

NAT

Converts a private IP address to a public IP address and vice versa

Match technology to the description

DHCP DNS Framework Instrumentation SAN NAT ARP

Which of the following statements are considered IT Troubleshooting goals?

Determining root cause Getting user(s) working again Saving evidence for root cause determination

Match the OSI layer(s) to the type of communication.

Device to Device: Layer 2 Host to Host: Layer 3 Process to Process: Layer 4 Application to Application: Layers 5-7

Business to business

Focus is on addressing three key elements of integration (type of access, type of connectivity and method of authentication):

Match the Cloud term to its definition

Fog Computing SaaS EC2 MultiCloud Hybrid Cloud Iaas PaaS

Load balancing

Front-ending multiple servers/processes that perform the same function, but only sending traffic to the healthy ones:

Number of CPUs:

Iscpu

Terminal Emulation

Legacy character-based applications that can be deployed on 2, 3 or n-tier architectures:

tcpdump

Linux command line tool that allows you to perform a packet capture:

Cloud Native

Only utilize PaaS services without needing to rely on accessing any underling operating system:

HybridCloud

Refers to a cloud computing model where services are offered by both third-party vendors and corporate/enterprise IT

Local load balancer

Session stickiness:

SAN

Storage infrastructure consisting of a dedicated network (typically fiber channel) and storage devices

Client error

The request contains bad syntax or cannot be fulfilled: 4xx

Informational

The request was received, continuing process: 1xx

Successful

The request was successfully received, understood, and accepted: 2xx

Server error

The server failed to fulfill an apparently valid request: 5xx

Web Proxy

Used to block users from accessing restricted web sites:

Event viewer

View application & system logs:

regedit

View/Edit Registry entries:

netstat

Which processes are listening on which ports:

Disk space used: - constraint

constraint: None

Device to Device:

layer 2

Which processes are listening on which ports:

netstat

Tunneling

- Can perform health-checking to determine which server to send work to: - Allowing direct network layer communication between devices that otherwise could not communicate:

Job scheduling

- Can start programs based on date/time, creation of a file, completion of a task, etc.: - Event-based execution on programs without user interaction:

Both *db server & web/app server*

- Concurrent requests exceeded the amount allowed causing rejections and/or delays: - Errors in logs indicate that a product patch is needed:

Web/Application server

- Lack of code instrumentation causing difficulty isolating where the problem resides: - Long waits on remote resource calls causing 5xx response codes:

Resource Manager, Perfmon

- Per process network bandwidth used: - I/O Queue Length by disk:

Perfmon

- Processor queue length: - Pages in & out per second:

Database server

- Sessions being blocked by other sessions due to acidic transactional locks: - Transaction log getting full disallowing any further writes to the database: - Poorly executing queries taking up a large amount of CPU and/or I/O: - Low Buffer cache-hit ratio causing most data to be retrieved from disk:

Web-based

3-layers and 3-tiers in its basic form, but can get complex; Solves some of the issues with the client-server architecture:

Client-server

A 2-layer and often 2-tier application architecture pattern that typically utilizes a complex front-end application communicating with a shared back-end database:

SaaS

A cloud offering whereby a fully functional application is provided to the customer with only application configuration options/customizations are available

PaaS

A cloud offering whereby a specific type of technology function (e.g. database, application server) is provided

Iaas

A cloud offering whereby virtual computing (VMs) are provided

Serverless/FaaS

A fairly new and popular subset of the Cloud Native application architecture pattern:

Which of the following statements are true about networking concepts?

A layer 4 conversation requires five unique values (Src IP/port, Dest IP/port & protocol) A layer 3 firewall is basically a router with special software to drops packets based on definitions provided Using a VLAN, a broadcast domain (subnet) can span multiple Ethernet switches

Fog computing

A relatively new paradigm which focuses on offloading or moving processing and storage to endpoint devices consuming cloud services

SOA and microservices

A style of software design whereby you break-up the business logic portion of your application into smaller independent portions that communicate with each other:

EC2

AWS' cloud computing offering

Instrumentation

Ability to monitor or measure the level of an application's performance, to diagnose errors, and to write trace information

Proxying

Acts as a "man-in-the-middle" by transparently relaying communications between two processes:

Overview - The application is called "CCAPP". It has a web-based front-end interface and exposes several services for other applications to utilize. Web Infrastructure - All the application components are written in .NET and deployed on 2 app pools on 3 IIS servers named WIIS1.acme.com (with IP 10.20.10.101), WIIS2.acme.com (with IP 10.20.10.102), & WIIS3.acme.com (with IP 10.20.10.103) - they each listen on port 80. One app pool is for the web-based user interface and utilizes the "/ccapp" virtual directory, while the other app pool is for the web services and uses the "/ccapp-apis" virtual directory The IIS servers are part of two pools (one for each virtual directory) front-ended by a load balancer. The load balancer exposes two VIPs (ccapp.acme.com with IP 204.153.78.20 for the user interface and ccapp-apis.acme.com with IP 204.153.78.21 for the web services) to the internet. The load balancer proxies the web servers and populates the X-Forwarded-For HTTP Header for both pools Both app pools are recycled in a rolling fashion (one IIS server at a time) each night There is no "session stickiness" because the session state is stored in a database Security & Network There is a firewall in between the load balancer and the IIS servers The application's front-end interface is protected by an OAUTH cloud-based service that has a replicated copied of the company's Active Directory. For any user to authenticate to the application it needs to be defined in AD and part of the ccapp-users group. The application's web services are protected by IP-filtering (only certain IP addresses are allowed to connect to them) and application tokens (long strings) are individually shared with each client There is a firewall in between the IIS servers and the database server Database & Other external factors CCAPP utilizes a SQL Server database (IP 10.20.20.100) for its application data and its session state (only applicable to the user interface) CCAPP (UI & services) makes calls to internal web services that have their own web and database servers. The application also makes calls to web services on the Internet The application is 24x7, but also has a nightly batch job component that performs heavy updates for a couple of hours Transaction log backups occur every 30 minutes, differential backups nightly and full backups weekly on Sundays Index rebuilds and/or reorgs (depending on the state of each index) as well statistics updates are performed on a weekly basis as well The database is large (over 3TB) and replicated to another location asynchronously for disaster recovery purposes Personnel Assume you have access to a business user representative, an ITSM practitioner, server engineer, DBA, web hosting engineer, network engineer & an application developer Scenario #2 - Calls come in that one of our external partners are failing to get responses back from one of the "CCAPP" web services. Select the three most appropriate initial questions to ask/actions to take.

Ask the ITSM practitioner & business user representative if any other applications or external partners are experiencing problems Ask the business user representative to confirm that the application screens/functions are working for internal users as expected Ask the ITSM practitioner if any relevant changes were performed recently

Overview - The application is called "CCAPP". It has a web-based front-end interface and exposes several services for other applications to utilize. Web Infrastructure - All the application components are written in .NET and deployed on 2 app pools on 3 IIS servers named WIIS1.acme.com (with IP 10.20.10.101), WIIS2.acme.com (with IP 10.20.10.102), & WIIS3.acme.com (with IP 10.20.10.103) - they each listen on port 80. One app pool is for the web-based user interface and utilizes the "/ccapp" virtual directory, while the other app pool is for the web services and uses the "/ccapp-apis" virtual directory The IIS servers are part of two pools (one for each virtual directory) front-ended by a load balancer. The load balancer exposes two VIPs (ccapp.acme.com with IP 204.153.78.20 for the user interface and ccapp-apis.acme.com with IP 204.153.78.21 for the web services) to the internet. The load balancer proxies the web servers and populates the X-Forwarded-For HTTP Header for both pools Both app pools are recycled in a rolling fashion (one IIS server at a time) each night There is no "session stickiness" because the session state is stored in a database Security & Network There is a firewall in between the load balancer and the IIS servers The application's front-end interface is protected by an OAUTH cloud-based service that has a replicated copied of the company's Active Directory. For any user to authenticate to the application it needs to be defined in AD and part of the ccapp-users group. The application's web services are protected by IP-filtering (only certain IP addresses are allowed to connect to them) and application tokens (long strings) are individually shared with each client There is a firewall in between the IIS servers and the database server Database & Other external factors CCAPP utilizes a SQL Server database (IP 10.20.20.100) for its application data and its session state (only applicable to the user interface) CCAPP (UI & services) makes calls to internal web services that have their own web and database servers. The application also makes calls to web services on the Internet The application is 24x7, but also has a nightly batch job component that performs heavy updates for a couple of hours Transaction log backups occur every 30 minutes, differential backups nightly and full backups weekly on Sundays Index rebuilds and/or reorgs (depending on the state of each index) as well statistics updates are performed on a weekly basis as well The database is large (over 3TB) and replicated to another location asynchronously for disaster recovery purposes Personnel Assume you have access to a business user representative, an ITSM practitioner, server engineer, DBA, web hosting engineer, network engineer & an application developer Scenario #1 - Calls come in that the user interface for the "CCAPP" application is failing with a generic message on certain screens/functions. Other screens are working fine and there aren't any performance issues. The errors seem to be happening to many, potentially all users. Select the three most appropriate initial questions to ask or actions to take

Ask the ITSM practitioner if any relevant changes were performed recently Ask the business user representative which application screens/functions appear to be working and which are not Ask the ITSM practitioner & business user representative if any other applications are experiencing performance problems

Overview - The application is called "CCAPP". It has a web-based front-end interface and exposes several services for other applications to utilize. Web Infrastructure - All the application components are written in .NET and deployed on 2 app pools on 3 IIS servers named WIIS1.acme.com (with IP 10.20.10.101), WIIS2.acme.com (with IP 10.20.10.102), & WIIS3.acme.com (with IP 10.20.10.103) - they each listen on port 80. One app pool is for the web-based user interface and utilizes the "/ccapp" virtual directory, while the other app pool is for the web services and uses the "/ccapp-apis" virtual directory The IIS servers are part of two pools (one for each virtual directory) front-ended by a load balancer. The load balancer exposes two VIPs (ccapp.acme.com with IP 204.153.78.20 for the user interface and ccapp-apis.acme.com with IP 204.153.78.21 for the web services) to the internet. The load balancer proxies the web servers and populates the X-Forwarded-For HTTP Header for both pools Both app pools are recycled in a rolling fashion (one IIS server at a time) each night There is no "session stickiness" because the session state is stored in a database Security & Network There is a firewall in between the load balancer and the IIS servers The application's front-end interface is protected by an OAUTH cloud-based service that has a replicated copied of the company's Active Directory. For any user to authenticate to the application it needs to be defined in AD and part of the ccapp-users group. The application's web services are protected by IP-filtering (only certain IP addresses are allowed to connect to them) and application tokens (long strings) are individually shared with each client There is a firewall in between the IIS servers and the database server Database & Other external factors CCAPP utilizes a SQL Server database (IP 10.20.20.100) for its application data and its session state (only applicable to the user interface) CCAPP (UI & services) makes calls to internal web services that have their own web and database servers. The application also makes calls to web services on the Internet The application is 24x7, but also has a nightly batch job component that performs heavy updates for a couple of hours Transaction log backups occur every 30 minutes, differential backups nightly and full backups weekly on Sundays Index rebuilds and/or reorgs (depending on the state of each index) as well statistics updates are performed on a weekly basis as well The database is large (over 3TB) and replicated to another location asynchronously for disaster recovery purposes Personnel Assume you have access to a business user representative, an ITSM practitioner, server engineer, DBA, web hosting engineer, network engineer & an application developer Scenario #1 - Calls come in that the user interface for the "CCAPP" application is failing with a generic message on certain screens/functions. Other screens are working fine. This seems to be happening to many, potentially all users. The following are the answers provided to the above: Ask the ITSM practitioner if any relevant changes were performed recently - no relevant changes found in last two days Ask the ITSM practitioner (with access to the Helpdesk) & business user representative if any other applications are experiencing performance problems - No other applications experiencing issues Ask the business user representative if they can provide the IP address of a user with the problem - The IP address 10.4.53.5 is provided Ask the business user representative which application screens/functions appear to be working and which are not - It appears that any screens that perform updates are not responding or timing out, while read-only screens seem to be responding Ask the Web Hosting engineer to see if any of the members in the load balancer pool for this application are down - No pool members are down Ask the Server engineer if any of the IIS servers or the database server is experiencing high activity - No servers are experiencing high activity Ask the Database administrator to see if there are any blocked sessions - No blocked sessions found Ask the Network engineer to see if the firewall is experiencing high CPU - CPU activity is normal on the firewall Based on the above answers, select the three most appropriate follow-up questions/actions.

Ask the ITSM practitioner if there have been any similar issues in the past Ask the Database administrator to see if there are any conditions preventing write activity to the database Ask the Database administrator to check the diskspace on the server where the transaction log resides

Overview - The application is called "CCAPP". It has a web-based front-end interface and exposes several services for other applications to utilize. Web Infrastructure - All the application components are written in .NET and deployed on 2 app pools on 3 IIS servers named WIIS1.acme.com (with IP 10.20.10.101), WIIS2.acme.com (with IP 10.20.10.102), & WIIS3.acme.com (with IP 10.20.10.103) - they each listen on port 80. One app pool is for the web-based user interface and utilizes the "/ccapp" virtual directory, while the other app pool is for the web services and uses the "/ccapp-apis" virtual directory The IIS servers are part of two pools (one for each virtual directory) front-ended by a load balancer. The load balancer exposes two VIPs (ccapp.acme.com with IP 204.153.78.20 for the user interface and ccapp-apis.acme.com with IP 204.153.78.21 for the web services) to the internet. The load balancer proxies the web servers and populates the X-Forwarded-For HTTP Header for both pools Both app pools are recycled in a rolling fashion (one IIS server at a time) each night There is no "session stickiness" because the session state is stored in a database Security & Network There is a firewall in between the load balancer and the IIS servers The application's front-end interface is protected by an OAUTH cloud-based service that has a replicated copied of the company's Active Directory. For any user to authenticate to the application it needs to be defined in AD and part of the ccapp-users group. The application's web services are protected by IP-filtering (only certain IP addresses are allowed to connect to them) and application tokens (long strings) are individually shared with each client There is a firewall in between the IIS servers and the database server Database & Other external factors CCAPP utilizes a SQL Server database (IP 10.20.20.100) for its application data and its session state (only applicable to the user interface) CCAPP (UI & services) makes calls to internal web services that have their own web and database servers. The application also makes calls to web services on the Internet The application is 24x7, but also has a nightly batch job component that performs heavy updates for a couple of hours Transaction log backups occur every 30 minutes, differential backups nightly and full backups weekly on Sundays Index rebuilds and/or reorgs (depending on the state of each index) as well statistics updates are performed on a weekly basis as well The database is large (over 3TB) and replicated to another location asynchronously for disaster recovery purposes Personnel Assume you have access to a business user representative, an ITSM practitioner, server engineer, DBA, web hosting engineer, network engineer & an application developer Scenario #2 - Calls come in that one of our external partners are failing to get responses back from one of the "CCAPP" web services. The following are the answers provided to the above: Ask the ITSM practitioner if any relevant changes were performed recently - no relevant changes found in last two days Ask the ITSM practitioner (with access to the Helpdesk) & business user representative if any other applications or external partners are experiencing problems - No other applications or external partners experiencing issues Ask the business user representative to confirm that the application screens/functions are working for internal users as expected - Internal users are working as expected Ask the business user representative to acquire the IP address of the external partner experiencing the problem - The IP address of the external partner is 153.23.24.11 Ask the Web Hosting engineer to see if any of the members in the load balancer pool for this application are down - No members are down Ask the Server engineer if any of the IIS servers or the database server is experiencing high activity - No servers are experiencing high activity Ask the Database administrator to see if there are any blocked sessions - No blocked sessions found Ask the Network engineer to see if the firewall is experiencing high CPU - CPU activity is normal on the firewall Based on the above answers, select the three most appropriate follow-up questions/actions.

Ask the ITSM practitioner if there have been any similar issues in the past Ask the Network engineer to perform a packet capture on the external firewall to capture any packets to and from 153.23.24.11 Ask the Web Hosting engineer to look in the logs for access attempts from the external partner's IP address (153.23.24.11) in the X-Forwarded-For HTTP Header to see what HTTP response codes are being sent back to them

None *db server & web/app server*

Browser incompatibility causing application to "look funny":

Which of the following are dimensions of problems/constraints that should be considered when trying to isolate a problem?

CPU vs. I/O vs. RAM vs. Network Constraints Sporadic vs. Persistent Single system vs. Multiple systems vs. System interaction Hard vs. Soft Constraints

openssl

Command line program available on Linux (most common), Windows & MacOS that you can use to display certificates, convert certificate formats, create private/public key pairs, etc:

wget

Command line tool available on Linux or Windows that allows you to make an HTTP GET requests w/o user interaction:

curl

Command line utility available for Linux, Windows & MacOS to access all sorts of protocols (not just HTTP) without user intervention - can test POST cmds:

Which of the following statements are considered IT Troubleshooting steps?

Devise the best approach to address the problem Verify that a problem actually exists Ensure a clear understanding of the problem and its history Isolate the cause of the problem

Match the application architecture technique to its description:

Front-ending multiple servers/processes that perform the same function, but only sending traffic to the healthy ones: Load Balancing Allowing direct network layer communication between devices that otherwise could not communicate: Tunneling Asynchronous communication between two processes with guaranteed delivery: Message Queuing Acts as a "man-in-the-middle" by transparently relaying communications between two processes: Proxying Event-based execution on programs without user interaction: Job Scheduling

redirection

Further action needs to be taken in order to complete the request: 3xx

postman

GUI that allows you to format any kind of HTTP request and save it for future use as well as to share with others - can test POST cmds:

wireshark

GUI-based packet capture analysis tool:

Fiddler

GUI-based proxy that can intercept all HTTP/HTTPS traffic and analyze it:

ARP

IP to MAC Address matching for local network communications

Which of the following is true about application architecture patterns?

Latency & "Cold starts" are common problems with some of cloud native services, especially if lightly used With a Microservices application architecture, it is often simpler to focus on the tiers & layers of similarly deployed services, while also documenting the relationship between the services Application layering influences, but does not dictate, application tiering Database server proximity is typically important for client-server applications as well as the application server of web-based applications

Which of the following disciplines are technically considered "IT Infrastructure Support"?

Network Engineering Server Engineering Storage Engineering

system information

Number & type of physical CPUs:

You use the ping command with my.fiu.edu. Assuming no domain search list, place the steps that occur to find the IP address to use.

OS looks in local hosts file for "my.fiu.edu"; If found then use IP address(es): Step 1 OS looks in local DNS cache for "my.fiu.edu"; If found and TTL has not expired, uses IP address(es): Step 2 OS makes request to local DNS server(s) for "my.fiu.edu": Step 3 Local DNS server looks in local DNS cache for "my.fiu.edu"; If found and TTL has not expired, uses IP address(es): Step 4 If not found, local DNS server then looks for "fiu.edu" authoritative servers in local cache; If found and TTL has not expired, then uses IP address(es) to request IP address(es) for "my.fiu.edu" to those servers: Step 5 If "fiu.edu" authoritative servers are not in cache, then local DNS server makes request to ".edu" root domain servers for IP address(es) of "fiu.edu" authoritative DNS server(s): Step 6 Local DNS Server makes request to ".edu" root domain server(s) for "fiu.edu" authoritative DNS server(s): Step 7 Once known, local DNS Server makes request to "fiu.edu" authoritative server(s) for "my.fiu.edu": Step 9 ".edu" root server looks in its database for "fiu.edu" and returns IP address(es) if found or "name not found" if not: Step 10

Which of the following statements are true?

On both Windows & Linux, many utilities require administrative privileges Hypervisors contain a "Hardware Abstraction Layer" while containers do not ITIM (IT Infrastructure Monitoring) tools allow you to review the statistics of many servers through one interface and provide historical trend reporting Having baseline metrics for comparison when performance is acceptable is a great way to determine if you have a problem

Match the application architecture pattern with a key element unique to it.

Only utilize PaaS services without needing to rely on accessing any underling operating system: Cloud Native Focus is on addressing three key elements of integration (type of access, type of connectivity and method of authentication): Business to Business Legacy character-based applications that can be deployed on 2, 3 or n-tier architectures: Terminal Emulation 3-layers and 3-tiers in its basic form, but can get complex; Solves some of the issues with the client-server architecture: Web-based A style of software design whereby you break-up the business logic portion of your application into smaller independent portions that communicate with each other: SOA & Microservices A fairly new and popular subset of the Cloud Native application architecture pattern: Serverless/FaaS A 2-layer and often 2-tier application architecture pattern that typically utilizes a complex front-end application communicating with a shared back-end database: Client-Server

Task Manager, Resource Manager, Perfmon

Per process CPU utilization:

Which concepts are NOT considered a core feature/expectation of cloud computing?

Physically isolated Capital expense heavy Dedicated resources

Match the key statistic to the type to constraint it should be used to identify (there will be multiple matches):

Processor queue length divided by number of processors: CPU I/O Queue Length: I/O CPU I/O Wait %: I/O Disk space used: None Network bandwidth used: Network CPU utilization %: CPU Paging swap rate: Memory

Match the key statistic to the tool on Linux which would be most appropriate to help you measure it (there will be multiple matches):

Processor queue length of runnable tasks: vmstat Per process CPU utilization: top I/O Queue Length by disk: iostat Paging swap rate: vmstat Disk space used: df Per process network bandwidth used: iftop CPU uptime: top Which processes are listening on which ports: netstat Number of CPUs: Iscpu

Match the key statistic to the tool on Windows which would be most appropriate to help you measure it (there will be multiple matches):

Processor queue length: perfmon Per process CPU utilization: Task Manager, Resource Manager, Perfmon I/O Queue Length by disk: Resource Manager, Perfmon Pages in & out per second: Perfmon View/Edit Registry entries: Regedit Per process network bandwidth used: Resource Manager, Perfmon CPU uptime: Task Manager Which processes are listening on which ports: netstat Number & type of physical CPUs: System Information View application & system logs: Event Viewer

Match the HTTP response code number to its category.

Redirection: Further action needs to be taken in order to complete the request: 3xx Client Error: The request contains bad syntax or cannot be fulfilled: 4xx Informational: The request was received, continuing process: 1xx Successful: The request was successfully received, understood, and accepted: 2xx Server Error: The server failed to fulfill an apparently valid request: 5xx

MultiCloud

Refers to a cloud computing model where services are offered by third-party vendors independently of corporate/enterprise IT

Match the potential problem to the type of platform it relates to:

Sessions being blocked by other sessions due to acidic transactional locks: Database server Concurrent requests exceeded the amount allowed causing rejections and/or delays: Both Lack of code instrumentation causing difficulty isolating where the problem resides: Web/Application server Transaction log getting full disallowing any further writes to the database: Database server Long waits on remote resource calls causing 5xx response codes: Web/Application server Poorly executing queries taking up a large amount of CPU and/or I/O: Database server Low Buffer cache-hit ratio causing most data to be retrieved from disk: Database server Browser incompatibility causing application to "look funny": None Errors in logs indicate that a product patch is needed: Both

Which of the following is true about hosting platforms?

Since HTML, JavaScript and CSS can execute on the browser, your code could be impacted by a different browser or even version of a browser Most often, application servers also include at least a thin HTTP (web) server All requests to a web or application server are typically logged and can include the IP of the client, the HTTP request method, the HTTP response code, URI, etc. Poorly executing database queries can be solved by updating statistics and/or adding an appropriate index

Framework

Software providing generic functionality to ease the burden of common programming tasks

Which of the following statements are true about application architecture techniques?

There could be multiple consumers and/or producers for any given message queue Content Delivery Networks have evolved into full reverse proxies that automatically pull updates, support dynamic content retrieval from backend servers, and can even include security features like DDoS prevention and WAF functionality Due its unattended nature, job scheduling requires thoughtful error checking and notification There are two common methods of employing "session stickiness" on a load balancer (session cookie-based or client IP-based)

Which of the following are true about networking?

There could be multiple processes listening on the same port on a server In order for two devices to share a VIP for failover purposes, the two devices must be available on the same broadcast domain Wireshark can track UDP communications or TCP conversations such that they can be graphed (for throughput, roundtrip time, etc.), colorized, used as a filter, etc.

DHCP (Dynamic Host Configuration Protocol)

UDP-based broadcast protocol that provides IP addresses to hosts (typically PCs, phones, IoT devices)

DNS (Domain Name System)

UDP-based protocol used to turn names into IP addresses

Which of the following statements are true about application protocols?

Unlike SOAP, REST is not a protocol, but instead more of an architectural style of API programming In-browser developer tools have an advantage over Fiddler and Wireshark because they process information post decryption An advantage to storing the HTTP session state in an external database is that any request can go to any application server in the cluster In a large enterprise, changes to AD (Active Directory) may not instantaneously replicate to all domain controllers

Which of the following statements are considered IT Troubleshooting principles?

Use reductive problem isolation techniques Do not make things worse Ensure clarity of symptoms/evidence/actions Suppress any assumptions

Match the functionality to the application architecture technique (Answers can be used multiple times):

Used to block users from accessing restricted web sites: Web Proxy Uses DNS redirection to point the user to the VIP that should be accessed: Global Load Balancer Can perform health-checking to determine which server to send work to: Tunneling Can start programs based on date/time, creation of a file, completion of a task, etc.: Job Scheduling Session stickiness: Local load balancer Can be used to restrict the network level access of guests: Network Segmentation

Global Load Balancer

Uses DNS redirection to point the user to the VIP that should be accessed:

Which of the following are true about CPU, I/O, RAM and Network constraints?

When a system is RAM constrained, the swapping rate and kernel time on the operating system would be high CPU constraints can be addressed by tuning the application, increasing CPU power or spreading the workload Network performance issues are more likely to be rooted outside of the host experiencing the delays

Which of the following statements are true about Operating System concepts?

Windows & Linux both work with hierarchical filesystems The "Process" is the primary logical unit of an operating systema) The "Process" is the basic logical execution unit of an operating system Hardware decoupling & automatic failover are two of the primary advantages of virtualization

certmgr

Windows GUI-based tool that allows you to view all of the installed certs on a system as well as add/remove certs from a system:

Match the tool to the functionality:

Windows GUI-based tool that allows you to view all of the installed certs on a system as well as add/remove certs from a system: certmgr Command line utility available for Linux, Windows & MacOS to access all sorts of protocols (not just HTTP) without user intervention - can test POST cmds: curl Linux command line tool that allows you to perform a packet capture: tcpdump GUI-based proxy that can intercept all HTTP/HTTPS traffic and analyze it: Fiddler Command line tool available on Linux or Windows that allows you to make an HTTP GET requests w/o user interaction: wget Command line program available on Linux (most common), Windows & MacOS that you can use to display certificates, convert certificate formats, create private/public key pairs, etc: openssl GUI that allows you to format any kind of HTTP request and save it for future use as well as to share with others - can test POST cmds: Postman GUI-based packet capture analysis tool: Wireshark

Which of the following statements are true about programming & database concepts?

Within a running process, each thread maintains it's own call stack Platforms like IIS & WebSphere offer services like security, load balancing and protocol abstraction Relational databases offer durability by committed all changes to a log prior to updating the database

CPU utilization %:

constraint: CPU

Processor queue length divided by number of processors:

constraint: CPU

CPU I/O Wait %

constraint: I/O

I/O Queue Length:

constraint: I/O

Paging swap rate - constraint

constraint: Memory

Network bandwidth used:

constraint: Network

Disk space used:

df

Per process network bandwidth used:

iftop

I/O Queue Length by disk:

iostat

Host to Host:

layer 3

Process to Process:

layer 4

Application to Application:

layers 5-7

CPU uptime:

top

Per process CPU utilization:

top

Paging swap rate:

vmstat

Processor queue length of runnable tasks:

vmstat