Computer Security
- 1. Nizwa College of Technology Assignment 2 26s1368 Submitted to: Ms. Kalivani Submitted from: Hajer Mohamed Said Alriyami Submitted date: 16/3/2017 Computer security And Session management
- 2. Nizwa College of Technology Assignment 2 26s1368 INTRODUCTION What is Computer Security? Computer Security is the protection of computing systems and the data that they store or access. Why is Computer Security Important? Computer Security allows the University to carry out its mission by: Enabling people to carry out their jobs, education, and research Supporting critical business process Protecting personal and sensitive information Why do I need to learn about Computer Security? Isn't this just an I.T. problem? Good Security Standards follow the "90 / 10" Rule: 10% of security safeguards are technical. 90% of security safeguards rely on the computer user ("YOU") to adhere to good computing practices Example: The lock on the door is the 10%. You remembering to lock the lock, checking to see if the door is closed, ensuring others do not prop the door open, keeping control of the keys, etc. is the 90%. You need both parts for effective security What Does This Mean for Me? This means that everyone who uses a computer or mobile device needs to understand how to keep their computer, device and data secure. o --> Information Technology Security is everyone's responsibility! Members of the UCSC community are also responsible for familiarizing themselves and complying with all University policies, procedures and standards relating to information security --
- 3. Nizwa College of Technology Assignment 2 26s1368 Security Objectives Learn "good computing security practices." Incorporate these practices into your everyday routine. Encourage others to do so as well. Report anything unusual - Notify your supervisor and the ITS Support Center if you become aware of a suspected security incident Sessionsand SessionManagement Access Manager sessionmanagement refers to the process ofmanaging the lifecycle requirements of a session, and notification of sessionevents to enable global logout. Administrators can configure Access Manager session lifecycle settings using the Oracle Access Management Console. Here, we will look at several different tools and techniques for managing sessions in the database. Users are very important to a DBA in many ways, but first they are the reason why there is need for a DBA. Users (either real or their electronic counterparts) are what keep the database in motion. Managing sessions means the DBA must monitor, tune and troubleshoot the entire outstanding user's activity in the oracle instance. We have different faces of database activity throughout the day, and over weeks, months, and years. It looks like the same data behaving differently throughout a given period, so there will be moments when the database is reported to be slow, there will be times when the database apparently will hang, and there will be other times when the database's performance will look normalfrom the user's perspective. What is the reason why the database's performance changes? Monitoring, diagnosing, and troubleshooting sessions involve several tools and techniques; specific sections of Enterprise Manager are focused on session management, as we will see throughout this report. The exposed tools behave the same on Unix like and Windows environments; except the troubleshooting last resource, killing the session, which has specific behaviors on Windows platforms due to the specific architecture implementation, and we will have to deal with it by using the oracle tool. In this context the user sessioncan either be a session generated by a real user or by a program directed to perform some activity against the
- 4. Nizwa College of Technology Assignment 2 26s1368 database. This session can be connected either in dedicated or shared mode. User sessions in a dedicated server architecture When a user requests a remote connection to the database it must first contact the listener. The listener redirects the request to the Oracle Instance. This will spawn a new Oracle Server Process, which from now on will be the process who will interface the user with the database; if the connection to the database is local to the machine, it may be established across the network or by Inter-Process Communication(IPC) , and the Oracle server process will be spawned too. This Oracle server process will be assigned to the user for the whole time the user remains attached to the database. The new user sessionwill be assigned a Serial Number and a SessionId. These are the numbers used to uniquely identify a user connected to the database. The serial number guarantees that session- level commands are applied to the correct sessionobjects in case a new session is started with the same SID. A user session can be initially monitored with the V$SESSION dynamic view. The PMON background process registers the Oracle instance against the Listener (in a self registration configuration), PMON registers information about dedicated server processeswith the Listener. A User Processstarts a connection against the Oracle instance by looking for the Listener, the Listener redirects the user process to the oracle Server Processand the dialog will be conducted from now on between the oracle server process and the user process. Foreach active connection in
- 5. Nizwa College of Technology Assignment 2 26s1368 a DedicatedServerArchitecture there will be one oracle Server Processonthe hostmachine. The connection through a dedicated server is the most widely used connection mode in most Oracle databases. Blocking sessions When two or more different sessions compete for the same row simultaneously, Oracle will immediately raise the lock enqueue mechanism, which lets one process at a time modify the row. The lock will be released once the transaction is finished (after a commit or rollback command is issued). The first process that takes the row locks it, meanwhile the other processes will have to wait. If this wait time is visible to the user then it can be misinterpreted as a slow performance problem. Blocking sessions are issues that should be solved at the program level, but in the mean time it is the DBA's responsibility to detect them and fix them. A blocking sessionmay be normal during productiontime, this is not the real problem. Oracle is prepared to queue sessions, the real problem begins when a session hangs and leaves the other session indefinitely waiting for the row lock to be released. Code use: Create sessionmangers limit Create usermanger1 identified by 123; Grant create sessionto manger1 identified by 123; Alter user manger1 sessionmangers; alter sessionmangers limit password_life_time 10/1440 password_grace_time 2/1440;
- 6. Nizwa College of Technology Assignment 2 26s1368 create tablespaceschool_ts datafile 'c:tempschool.dbf' size 100M extent management localautoallocate segmentspace management; create temporary tablespace schooltemp_ts tempfile 'c:tempschooltmp.dbf' size 20M reuse extent management local uniform size 10M; alter user manger1 quota 500 on school_ts; Reference: https://www.safaribooksonline.com http://its.ucsc.edu/policies/index.html its.ucsc.edu/security/training/intro.html https://docs.oracle.com/cd/E27559_01/admin.1112/.../session.htm