52 UNIX courses delivered Live Online

Wireshark 101 training course description Wireshark is a free network protocol analyser. This hands-on course focuses on troubleshooting networks using the Wireshark protocol analyser. The course concentrates on the product and students will gain from the most from this course only if they already have a sound knowledge of the TCP/IP protocols What will you learn Download and install Wireshark. Capture and analyse packets with Wireshark. Configure capture and display filters. Customise Wireshark. Troubleshoot networks using Wireshark. Wireshark 101 training course details Who will benefit: Technical staff looking after networks. Prerequisites: TCP/IP Foundation for engineers Duration 2 days Wireshark 101 training course contents What is Wireshark? Protocol analysers, Wireshark features, versions, troubleshooting techniques with Wireshark. Installing Wireshark Downloading Wireshark, UNIX issues, Microsoft issues, the role of winpcap, promiscuous mode, installing Wireshark. Wireshark documentation and help. Hands on Downloading and installing Wireshark. Capturing traffic Starting and stopping basic packet captures, the packet list pane, packet details pane, packet bytes pane, interfaces, using Wireshark in a switched architecture. Hands on Capturing packets with Wireshark. Troubleshooting networks with Wireshark Common packet flows. Hands on Analysing a variety of problems with Wireshark. Capture filters Capture filter expressions, capture filter examples (host, port, network, protocol), primitives, combining primitives, payload matching. Hands on Configuring capture filters. Working with captured packets Live packet capture, saving to a file, capture file formats, reading capture files from other analysers, merging capture files, finding packets, going to a specific packet, display filters, display filter expressions. Hands on Saving captured data, configuring display filters. Analysis and statistics with Wireshark Enabling/disabling protocols, user specified decodes, following TCP streams, protocol statistics, conversation lists, endpoint lists, I/O graphs, protocol specific statistics. Hands on Using the analysis and statistics menus. Command line tools Tshark, capinfos, editcap, mergecap, text2pcap, idl2eth. Hands on Using tshark. Advanced issues 802.11 issues, management frames, monitor mode, packet reassembling, name resolution, customising Wireshark. Hands on Customising name resolution.

Duration 5 Days 30 CPD hours This course is intended for This course is for support staff for AIX on POWER systems Overview After completing this course, you should be able to: - Distinguish Korn and bash shell specific features - Use utilities such as sed and awk to manipulate data - Understand system shell scripts such as /etc/shutdown - Write useful shell scripts to aid system administration This course will teach you how to use shell scripts and utilities for practical system administration of AIX (or other UNIX) operating systems. Basic shell conceptsFlow control in a shell ScriptFunctions and typesetShell features such as arithmetic and string handlingUsing regular expressionsUsing sed, awk and other AIX utilities

Duration 5 Days 30 CPD hours This course is intended for This introductory-level Python course is geared for experienced users who want to use Python in web development projects, or system administrators and web site administrators who want to use Python to support their server installations, as well as anyone else who wants to automate or simplify common tasks with the use of Python scripts. Basic familiarity with any programming or scripting language would be helpful, along with a working, user-level knowledge of Unix/Linux, Mac, or Windows. Overview This course is approximately 50% hands-on, combining expert lecture, real-world demonstrations and group discussions with machine-based practical labs and exercises. Our engaging instructors and mentors are highly experienced practitioners who bring years of current 'on-the-job' experience into every classroom. Throughout the hands-on course students, will learn to write essential Python scripts using the most current and efficient skills and techniques. Working in a hands-on learning environment, guided by our expert team, attendees will learn to: Create working Python scripts following best practices Use python data types appropriately Read and write files with both text and binary data Search and replace text with regular expressions Get familiar with the standard library and its work-saving modules Use lesser known but powerful Python data types Create 'real-world', professional Python applications Work with dates, times, and calendars Know when to use collections such as lists, dictionaries, and sets Understand Pythonic features such as comprehensions and iterators Write robust code using exception handling Mastering Python Programming is an introductory and beyond-level practical, hands-on Python training course that leads the student from the basics of writing and running Python scripts to more advanced features such as file operations, regular expressions, working with binary data, and using the extensive functionality of Python modules. Extra emphasis is placed on features unique to Python, such as tuples, array slices, and output formatting. This comprehensive, practical course provides an in-depth exploration of working with the programming language, not an academic overview of syntax and grammar. Students will immediately be able to use Python to complete tasks in the real world. An overview of Python What is python? Python Timeline Advantages/Disadvantages of Python Getting help with pydoc The Python Environment Starting Python Using the interpreter Running a Python script Python scripts on Unix/Windows Editors and IDEs Getting Started Using variables Builtin functions Strings Numbers Converting among types Writing to the screen Command line parameters Flow Control About flow control White space Conditional expressions Relational and Boolean operators While loops Alternate loop exits Array types About array types (AKA sequences) Lists and list methods Tuples Indexing and slicing Iterating through a sequence Nested sequences Sequence functions, keywords, and operators List comprehensions Generator Expressions Working with files File overview Opening a text file Reading a text file Writing to a text file Reading and writing raw (binary) data Converting binary data with struct Dictionaries and Sets About dictionaries Creating dictionaries Iterating through a dictionary About sets Creating sets Working with sets Functions Defining functions Parameters Global and local scope Nested functions Returning values Sorting The sorted() function Alternate keys Lambda functions Sorting collections Using operator.itemgetter() Reverse sorting Errors and Exception Handling Syntax errors Exceptions Using try/catch/else/finally Handling multiple exceptions Ignoring exceptions Modules and Packages The import statement Module search path Creating Modules Using packages Function and Module aliases An Introduction to Python Classes About o-o programming Defining classes Constructors Methods Instance data Properties Class methods and data Regular Expressions RE syntax overview RE Objects Searching and matching Compilation flags Groups and special groups Replacing text Splitting strings Using the Standard Library The sys module Launching external programs Math functions Random numbers Reading CSV data Dates and Times Working with dates and times Translating timestamps Parsing dates from text Formatting dates Calendar data Working with the File System Paths, directories, and filenames Checking for existence Permissions and other file attributes Walking directory trees Creating filters with fileinput Using shutil for file operations Advanced Data Handling Defaultdict and Counter Prettyprinting data structures Compressed archives (zip, gzip, tar, etc.) Persistent data Network Programming Using requests Grabbing web content Sending email Using SSH for remote access Using FTP Writing real-life applications Reading input files a la Unix Parsing command-line options Detecting the current platform Implementing logging Additional course details: Nexus Humans Mastering Python Programming (TTPS4820) training program is a workshop that presents an invigorating mix of sessions, lessons, and masterclasses meticulously crafted to propel your learning expedition forward. This immersive bootcamp-style experience boasts interactive lectures, hands-on labs, and collaborative hackathons, all strategically designed to fortify fundamental concepts. Guided by seasoned coaches, each session offers priceless insights and practical skills crucial for honing your expertise. Whether you're stepping into the realm of professional skills or a seasoned professional, this comprehensive course ensures you're equipped with the knowledge and prowess necessary for success. While we feel this is the best course for the Mastering Python Programming (TTPS4820) course and one of our Top 10 we encourage you to read the course outline to make sure it is the right content for you. Additionally, private sessions, closed classes or dedicated events are available both live online and at our training centres in Dublin and London, as well as at your offices anywhere in the UK, Ireland or across EMEA.

Duration 2 Days 12 CPD hours This course is intended for This basic course is for everyone needing to write, support, or understand SQL queries. This includes but is not limited to end-users, programmers, application designers, database administrators, and system administrators who do not yet have knowledge of Overview Code SQL statements to retrieve data from a DB2 or Informix table, including the SELECT, FROM, WHERE, GROUP BY, HAVING and ORDER BY clauses Code inner joins and non-correlated subqueries Use SQL arithmetic operations Use scalar and column functions Use UNION and UNION ALL INSERT, UPDATE and DELETE rows Code simple CREATE TABLE and CREATE VIEW statements This course is appropriate for customers working in all DB2 environments, that is, z/OS, VM/VSE, iSeries, Linux, UNIX, and Windows. It is also appropriate for customers working in an Informix environment. Outline Introduction Simple SQL Queries Retrieving Data from Multiple Tables Scalar Functions and Arithmetic Column Functions and Grouping UNION and UNION ALL Using Subqueries Maintaining data

Duration 5 Days 30 CPD hours This course is intended for System administrator Network administrator Technician DevOps Overview The Linux Professional Institute(LPI) is the go to certification body for vendor independent Linux certifications. This course covers fundamental Linuxskills such as file management and manipulation, text processing, command line use, package management,filesystems, hardware, and many more. Students will feel confident taking the LPI LPIC-1 101 exam with in classroomassessments and practice exams. This course prepares students to take the 101 exam of the LPI level 1 certification. Work on the Command Line LPI Objectives Covered Role of Command Shell Shells Gathering System Info Identifying the Shell Changing the Shell Shell Prompts Bash: Bourne-Again Shell Navigating the Filesystem Help from Commands and Documentation Getting Help Within the Graphical Desktop Getting Help with man & info Bash: Command Line History Bash: Command Editing Bash: Command Completion Shell and Environment Variables Key Environment Variables LAB TASKS Use Streams, Pipes, and Redirects LPI Objectives Covered File Redirection Piping Commands Together Filename Matching File Globbing and Wildcard Patterns Brace Expansion General Quoting Rules Nesting Commands Gotchas: Maximum Command Length LAB TASKS Manage File Permissions and Ownership LPI Objectives Covered Filesystem Hierarchy Standard Displaying Directory Contents Filesystem Structures Determining Disk Usage With df and du File Ownership Default Group Ownership File and Directory Permissions File Creation Permissions with umask Changing File Permissions SUID and SGID on files SGID and Sticky Bit on Directories User Private Group Scheme LAB TASKS Create, Delete, Find, and Display Files LPI Objectives Covered Directory Manipulation File Manipulation Deleting and Creating Files Physical Unix File Structure Filesystem Links File Extensions and Content Which and Type Where is Searching the Filesystem Alternate Search Method Manually Installed Shared Libraries LAB TASKS Work with Archives and Compression LPI Objectives Covered Archives with tar Archives with cpio The gzip Compression Utility The bzip2 Compression Utility The XZ Compression Utility The PKZIP Archiving/Compression format LAB TASKS Process Text Streams Using Filters LPI Objectives Covered Producing File Statistics The Streaming Editor Replacing Text Characters Text Sorting Duplicate Removal Utility Extracting Columns of Text Displaying Files Prepare Text for Display Previewing Files Displaying Binary Files Combining Files and Merging Text LAB TASKS Search Text Files Using Regular Expressions LPI Objectives Covered Searching Inside Files Regular Expression Overview Regular Expressions RE Character Classes Regex Quantifiers RE Parenthesis LAB TASKS Perform Basic File Editing Operations Using VI LPI Objectives Covered Text Editing vi and Vim Learning Vim Basic vi Intermediate vi LAB TASKS Create, Monitor, and Kill Processes LPI Objectives Covered What is a Process? Process Lifecycle Process States Viewing Processes Signals Tools to Send Signals Managing Processes Tuning Process Scheduling Job Control Overview Job Control Commands Nohup and Disown Uptime & w Persistent Shell Sessions with Screen Using screen Advanced Screen LAB TASKS Use RPM, YUM, and Debian Package Management LPI Objectives Covered Managing Software RPM Architecture Working With RPMs Querying and Verifying with RPM Installing Debian Packages Querying and Verifying with dpkg The alien Package Conversion Tool Managing Software Dependencies Using the Yum command yum downloader Configuring Yum The deselect & APT Frontends to dpkg Aptitude Configuring APT LAB TASKS Work with Partitions, Filesystem, and Disk Quotas LPI Objectives Covered Partition Considerations Logical Volume Management Filesystem Planning Partitioning Disks with fdisk & gdisk Resizing a GPT Partition with gdisk Partitioning Disks with parted Non-Interactive Disk Partitioning with sfdisk Filesystem Creation Filesystem Support Unix/Linux Filesystem Features Swap Selecting a Filesystem Filesystem Maintenance Mounting Filesystems Mounting Filesystems Managing an XFS Filesystem NFS SMB Filesystem Table (/etc/fstab) Configuring Disk Quotas Setting Quotas Viewing and Monitoring Quotas LAB TASKS Linux Boot Process LPI Objectives Covered Booting Linux on PCs GRUB 2 GRUB 2 Configuration GRUB Legacy Configuration Boot Parameters Uinit Linux Runlevels Aliases Systemd local-fs.target and sysinit.target Runlevel Implementation System Boot Method Overview Systemd System and Service Manager Modifying systemd services Systemd Targets Using systemd Shutdown and Reboot System Messaging Commands Controlling System Messaging LAB TASKS Determine and Configure Hardware Settings LPI Objectives Covered Managing Linux Device Files Hardware Discovery Tools Configuring New Hardware with hwinfo PC Architecture and Bus DMA & IRQ USB Devices USB Architecture Configuring Kernel Components and Modules Kernel Modules Handling Module Dependencies Configuring the Kernel via /proc/ LAB TASKS Linux Fundamentals Unix and its Design Principles FSF and GNU GPL ƒ?? General Public License The Linux Kernel Components of a Distribution Red Hat Linux Products SUSE Linux Products Debian Ubuntu Logging In got root? Switching User Contexts Gathering Login Session Info LAB TASKS Additional course details: Nexus Humans Linux Professional Institute Certification (LPIC) 101 training program is a workshop that presents an invigorating mix of sessions, lessons, and masterclasses meticulously crafted to propel your learning expedition forward. This immersive bootcamp-style experience boasts interactive lectures, hands-on labs, and collaborative hackathons, all strategically designed to fortify fundamental concepts. Guided by seasoned coaches, each session offers priceless insights and practical skills crucial for honing your expertise. Whether you're stepping into the realm of professional skills or a seasoned professional, this comprehensive course ensures you're equipped with the knowledge and prowess necessary for success. While we feel this is the best course for the Linux Professional Institute Certification (LPIC) 101 course and one of our Top 10 we encourage you to read the course outline to make sure it is the right content for you. Additionally, private sessions, closed classes or dedicated events are available both live online and at our training centres in Dublin and London, as well as at your offices anywhere in the UK, Ireland or across EMEA.

Duration 4 Days 24 CPD hours This course is intended for This basic course is intended for anyone who requires basic AIX/UNIX user skills to be able to work in an AIX environment. This course is also a prerequisite for many courses in the AIX Systems Administration curriculum. Overview Log in to an AIX system and set a user password Use AIX online documentation Manage AIX files and directories Describe the purpose of the shell Use the vi editor Execute common AIX commands and manage AIX processes Customize the working environment Use common AIX utilities Write simple shell scripts Use the AIXWindows Environment Use the Common Desktop Environment This course enables you to perform everyday tasks using the AIX operating system. Day 1 Introduction to AIX Using the System AIX Documentation Files and Directories Using Files Day 2 File Permissions The vi Editor Shell Basics Using Shell Variables Day 3 Processes Controlling Processes Customizing the User Environment AIX Utilities, Part I AIX Utilities, Part I (Continued) AIX Utilities, Part II Day 4 AIX Utilities, Part II (Continued) Additional Shell Features The AIX Graphical User Interface

Duration 4 Days 24 CPD hours This course is intended for This basic course is intended for anyone who requires basic AIX/UNIX user skills to be able to work in an AIX environment. This course is also a prerequisite for many courses in the AIX Systems Administration curriculum. Overview Log in to an AIX system and set a user password Use AIX online documentation Manage AIX files and directories Describe the purpose of the shell Use the vi editor Execute common AIX commands and manage AIX processes Customize the working environment Use common AIX utilities Write simple shell scripts Use the AIXWindows Environment Use the Common Desktop Environment This course enables you to perform everyday tasks using the AIX operating system. Day 1 Introduction to AIX Using the System AIX Documentation Files and Directories Using Files Day 2 File Permissions The vi Editor Shell Basics Using Shell Variables Day 3 Processes Controlling Processes Customizing the User Environment AIX Utilities, Part I AIX Utilities, Part I (Continued) AIX Utilities, Part II Day 4 AIX Utilities, Part II (Continued) Additional Shell Features The AIX Graphical User Interface

Duration 4 Days 24 CPD hours This course is intended for This is an intermediate course for experienced DBAs and technical individuals, with experience on other relational database platforms, who plan, implement, and maintain Db2 11.1 for Linux, UNIX, and Windows databases. These skills can also be utilize to support cloud based databases using Db2 on Cloud or Db2 Hosted environments. Overview Please refer to course overview This course teaches you to perform, basic and advanced, database administrative tasks using Db2 11.1. These tasks include creating and populating databases and implementing a logical design to support recovery requirements. The access strategies selected by the Db2 Optimizer will be examined using the Db2 Explain tools. Various diagnostic methods will be presented, including using various db2pd command options. Students will learn how to implement automatic archival for database logs and how to plan a redirected database restore to relocate either selected table spaces or an entire database. The REBUILD option of RESTORE, which can build a database copy with a subset of the tablespaces, will be discussed. We will also cover using the TRANSPORT option of RESTORE to copy schemas of objects between two Db2 databases. The selection of indexes to improve application performance and the use of SQL statements to track database performance and health will be covered. This course provides a quick start to Db2 database administration skills for experienced relational Database Administrators (DBA). Overview of Db2 11Command Line Processor (CLP) and GUI UsageThe Db2 EnvironmentCreating Databases and Data PlacementCreating Database ObjectsMoving DataBackup and RecoveryLocks and ConcurrencyDatabase Maintenance, Monitoring and Problem DeterminationSecurityDatabase Rebuild SupportDb2 Database and Table Space RelocationUsing Explain ToolsUsing Indexes for PerformanceAdvanced Monitoring

Duration 5 Days 30 CPD hours This course is intended for This is an introductory-level systems administration course geared for Systems Administrators and users who wish to learn how to how to install, configure and maintain an Enterprise Linux system in a networked environment. Overview This course is about 50% lab to lecture ratio, combining expert instructor-led discussions with practical hands-on skills that emphasize current techniques, best practices and standards. Working in this hands-on lab environment, guided by our expert practitioner, attendees will explore Installing the Linux operating system and configuring peripherals Performing and modifying startup and shutdown processes Configuring and maintaining basic networking services Creating and maintaining system users and groups Understanding and administering file permissions on directories and regular files Planning and creating disk partitions and file systems Performing maintenance on file systems Identifying and managing Linux processes Automating tasks with cron Performing backups and restoration of files Working with system log files Troubleshooting system problems Analyzing and taking measures to increase system performance Configuring file sharing with NFS Configuring Samba for file sharing with the Windows clients Setting up a basic Web server Understanding the components for setting up a LAMP server Implementing basic security measures Linux System Administration is a comprehensive hands-on course that teaches students how to install, configure and maintain an Enterprise Linux system in a networked environment. This lab-intensive class explores core administrative tasks such as: creating and managing users, creating and maintaining file systems, determining and implementing security measures and performing software installation and package management. Linux networking topics include installing and supporting SSH, NFS, Samba and the Apache Web server. Students will explore common security issues, as well as several tools, such as the PAM modules that help secure the operating system and network environment. Upon successful completion of this course, students will be prepared to maintain Linux systems in a networked business environment. Although the course includes installing and configuring a CentOS 7 / RHEL 7 Linux system, much of the course content also applies to Oracle, Ubuntu, Scientific and other current versions of mainstream Linux distributions. Labs include user and group maintenance, system backups and restoration, software management, administration tasks automation, file system creation and maintenance, managing remote access, working with cron, and configuring basic file sharing and Web services, as well as working with system logging utilities such as rsyslog and much more. System Administration Overview UNIX, Linux and Open Source Duties of the System Administrator Superusers and the Root Login Sharing Superuser Privileges with Others (su and sudo Commands) TCP/IP Networking Fundamentals Online Help Installation and Configuration Planning: Hardware and Software Considerations Site Planning Installation Methods and Types Installation Classes Partitions Logical Volume Manager - LVM File System Overview Swap Partition Considerations Other Partition Considerations The Linux Boot Loader: grub Software Package Selection Adding and Configuring Peripherals Printers Graphics Controllers Basic Networking Configuration Booting to Recovery Mode Booting and Shutting Down Linux Boot Sequence The systemd Daemon The systemctl Command Targets vs. Run Levels Modifying a Target Service Unit Scripts Changing System States Booting into Rescue Mode Shutdown Commands Managing Software and Devices Identifying Software Packages Using rpm to Manage Software Using yum to Manage Software Installing and Removing Software Identifying Devices Displaying Device and System Information (PCI, USB) Plug and Play Devices Device Configuration Tools Managing Users and Groups Setting Policies User File Management The /etc/passwd file The /etc/shadow file The /etc/group file The /etc/gshadow file Adding Users Modifying User Accounts Deleting User Accounts Working with Groups Setting User Environments Login Configuration Files The Linux File System Filesystem Types Conventional Directory Structure Mounting a File System The /etc/fstab File Special Files (Device Files) Inodes Hard File Links Soft File Links Creating New File Systems with mkfs The lost+found Directory Repairing File Systems with fsck The Journaling Attribute File and Disk Management Tools Linux File Security File Permissions Directory Permissions Octal Representation Changing Permissions Setting Default Permissions Access Control Lists (ACLs) The getfacl and setfacl commands SUID Bit SGID Bit The Sticky Bit Controlling Processes Characteristics of Processes Parent-Child Relationship Examining Running Processes Background Processes Controlling Processes Signaling Processes Killing Processes Automating Processes cron and crontab at and batch System Processes (Daemons) Working with the Linux Kernel Linux Kernel Components Types of Kernels Kernel Configuration Options Recompiling the Kernel Shell Scripting Overview Shell Script Fundamentals Bash Shell Syntax Overview Shell Script Examples System Backups Backup Concepts and Strategies User Backups with the tar Command System Backup Options The xfsdump and xfsrestore Commands Troubleshooting the System Common Problems and Symptoms Troubleshooting Steps Repairing General Boot Problems Repairing the GRUB 2 Boot Loader Hard Drive Problems Restoring Shared Libraries System Logs and rsyslogd Basic Networking Networking Services Overview NetworkManager Introduction Network Configuration Files Locations and Formats Enabling and Restarting Network Services with systemtcl Configuring Basic Networking Manually Configuring Basic Networking with NetworkManager LAMP Server Basics LAMP Overview Configuring the Apache Web Server Common Directives Apache Virtual Hosting Configuring an Open Source Database MySQL MariaDB PHP Basics Perl CGI Scripting Introduction to System Security Security Overview Maintaining System Security Server Access Physical Security Network Security Security Tools Port Probing with nmap Intrusion Detection and Prevention PAM Security Modules Scanning the System Maintaining File Integrity Using Firewalls Introduction to firewalld The Samba File Sharing Facility Configure Samba for Linux to Linux/UNIX File Sharing Configure Samba for Linux to Windows File Sharing Use the smbclient Utility to Transfer Files Mount/Connect Samba Shares to Linux and Windows Clients Networked File Systems (NFS) Using NFS to Access Remote File Systems Configuring the NFS Server Configuring the NFS Client Exporting File Systems from the NFS Server to the NFS Client

Duration 2 Days 12 CPD hours This course is intended for This basic course is for persons needing an introductory knowledge of DB2, and persons preparing for advanced and specialized DB2 education. Overview List and describe the major components of IBM's relational database, DB2 Explain the characteristics of a DB2 table Relate the basic concepts of data modeling Comprehend the processing instructions given to DB2 via simple SQL statements List and describe several ways to build (write) and execute SQL statements List and describe steps needed to imbed SQL statements in an application program Explain some of the functions performed by, and the responsibilities of, database and system administrators Establish a base for more specialized DB2 education This course provides information about the functions of IBM's DB2, a relational database manager which may be installed under a variety of operating systems on many hardware platforms (e.g., z/OS, VM, Linux, UNIX, Windows, etc.) Understanding a Table Identify the advantages of a relational database Define a relation Name the language used to talk to a relational database manager (RDBM) List three characteristics assigned to each column Define the tasks performed by DB2 when running an application Defi Data Modeling and Database Design State the purpose of a business model Identify an Entity-Relational Diagram (ERD) model List several DB2 column data types Identify non-standard column and table names Identify the characteristics of a primary key and a foreign key State the purpose of re How does a User use DB2? List several ways to talk to DB2 List multiple ways to generate an SQL statement List several ways to ADD, REMOVE, or CHANGE table rows List several ways to READ data and produce reports How does a Programmer use DB2? List the steps needed to create a test environment List the necessary steps to coding SQL in a program Describe the purpose of SQL delimiters Describe the purpose of an SQLCA List the steps involved in preparing a program for execution State the differenc What does an Administrator do in DB2? List some of the tasks performed by a DB2 System Administrator: Identifying the DB2 product, Installing DB2, Creating subsystems/instances, databases and table spaces, Authorizing, and Monitoring List some of the tasks performed by a DB2 Database Administ Information Management with DB2 List several planning considerations for distributing data List some of the skills required to successfully distribute data Differentiate between remote unit of work, distributed unit of work, and distributed request List some of the security concerns whe