conversations.from: human
conversations.value: Give me a description for a book titled Cloud Computing about with the genre: Computers & Technology, Networking & Cloud Computing.
conversations.from: assistant
conversations.value: This books provides in-depth coverage of cloud computing fundamentals such as security reference model, content delivery network, load balancing and compliance issues. Other additional features including review questions, notes and chapter summaries are structured to illuminate the essential theme of the concepts.
conversations.from: human
conversations.value: Give me the first five paragraphs for this book.
conversations.from: assistant
conversations.value: Cloud Computing
  The collected data are stored in the Ceilometer database. Ceilometer provides two sets of API: (1) for writing to the collector and (2) for accessing the database. As with all other components, the API server is a separate process.
  The above architecture is summarized in Figure 7.14, which shows a logical message flow. In reality, all the components are "interconnected" by a real messaging bus—that is, they read and write into the same logical "wire."81
  In order to know when to scale up (or down) a stack, the Heat engine needs feedback on the CPU utilization of the stack instances. To enable this, one can define the alarms based on the compute agent's metrics. (Of course, it is not that Ceilometer itself reads the template—only the Heat engine does. Ceilometer only needs to provide an API flexible enough for the Heat engine to express the template rules for the auto-scaling group.)
  The alarm is set on the request of the Heat engine when the stack is created. When the alarm "sounds," the Heat engine follows up by creating a new instance, connecting it to the networks, and so on. Similarly, an alarm can be set to scale down (say when the average CPU utilization falls below 40%), so when extra instances become redundant, they are eliminated. Note that this feature is not simply an exercise in efficiency by a Cloud provider—it also saves money for the customer, who typically pays the Cloud provider for each instance. A true example of elasticity!
  It is important to note that OpenStack supports integration of software configuration and management tools—specifically Chef and Puppet, which we mentioned in the previous section.
conversations.from: human
conversations.value: Add another sentence about Ceilometer, evaluated, according, template-specified, reported.
conversations.from: assistant
conversations.value: Cloud Computing
  The collected data are stored in the Ceilometer database. Ceilometer provides two sets of API: (1) for writing to the collector and (2) for accessing the database. As with all other components, the API server is a separate process. 
  The above architecture is summarized in Figure 7. 14, which shows a logical message flow. In reality, all the components are "interconnected" by a real messaging bus—that is, they read and write into the same logical "wire. "81
  In order to know when to scale up (or down) a stack, the Heat engine needs feedback on the CPU utilization of the stack instances. To enable this, one can define the alarms based on the compute agent's metrics. With the support of Ceilometer, the metrics get evaluated according to the template-specified rules, and exceptions are reported as alarm notifications. (Of course, it is not that Ceilometer itself reads the template—only the Heat engine does. Ceilometer only needs to provide an API flexible enough for the Heat engine to express the template rules for the auto-scaling group. )
  The alarm is set on the request of the Heat engine when the stack is created. When the alarm "sounds," the Heat engine follows up by creating a new instance, connecting it to the networks, and so on. Similarly, an alarm can be set to scale down (say when the average CPU utilization falls below 40%), so when extra instances become redundant, they are eliminated. Note that this feature is not simply an exercise in efficiency by a Cloud provider—it also saves money for the customer, who typically pays the Cloud provider for each instance. A true example of elasticity!
  It is important to note that OpenStack supports integration of software configuration and management tools—specifically Chef and Puppet, which we mentioned in the previous section.
conversations.from: human
conversations.value: Give me five more paragraphs.
conversations.from: assistant
conversations.value: The SNMP framework architecture is laid out in the RFC 3411,5 which is part of the Internet Standard 62. The SNMP system is realized by exchanging the SNMP protocol messages among the SNMP entities. At least one of these entities is a manager; the others are present in the devices or network elements. In its more general form, the architecture of an entity is presented in Figure A.2.
  The dispatcher supports (concurrently) multiple protocol versions but provides a single abstract interface to SNMP applications.
  COPS is specified in RFC 2748,9 but the context for this work has been set in RFC 2753,10 which provides the motivation, describes the terminology, and otherwise specifies the framework. We will introduce this context briefly.
  First of all, the objective of the framework is to describe the execution of policy-based control over the QoS admission control decisions, with the primary focus on the RSVP protocol as an example.11
  Among the goals of the framework are support for pre-emption, various policy styles, monitoring, and accounting. Pre-emption here means the ability to remove a previously granted resource so as to accommodate a new request.12 As far as the policy styles go, those to be supported include bi-lateral and multi-lateral service agreements and policies based on the notion of relative priority, as defined by the provider. Support for monitoring and accounting is effected by gathering the resource use and access data. The framework also states the requirement for fault tolerance and recovery in cases when a PDP fails or cannot be reached.
conversations.from: human
conversations.value: Give me the last five paragraphs.
conversations.from: assistant
conversations.value: When both rules are enforced, as shown in Figure A.19, information can flow only upward. But this is problematic in practice. At some point, troops have to learn from their commanders where to go. Bell and LaPadula solved this problem by exempting a special group of trusted subjects from the rules. Another assumption of the Bell–LaPadula model is that the security levels of the involved actors stay the same (which is called the tranquility property). If security levels are allowed to change, information could flow in an undesired direction. Figure A.20 shows such a case, where Subject 4 lowers its own security level after reading from Object 3 in the previous example and writes to Object 1, leaking sensitive information as a result. The tranquility property actually has two versions: strong and weak. The strong version forbids changing security levels during system operation, while the weak version allows changes as long as the established security policy (e.g., no "read up" or "write down") is not violated.
  Figure A.21 shows as an example a message flow for identity federation through the SAML HTTP Redirect binding. The assumption here is that the relying party and identity provider have a pre-established relationship. The flow is high-level and goes as follows. Upon detecting that the user (through the user agent) requesting resource access has not been authenticated, the relying party issues a SAML authentication request, which is redirected to the identity provider. Then the identity provider performs the steps to authenticate the user. Again, the steps are specific to the authentication method of choice and beyond the scope of SAML. Upon completion of the authentication steps, the identity provider sends the SAML authentication response carrying the assertion, which is redirected to the relying party. According to the authentication response, the relying party then responds.
  Building on OAuth 2.0, OIDC automatically acquires the former's virtues, including support for REST, JSON, standard signing and encryption mechanisms, and varied deployment scenarios. As a result, interoperability is improved. But user-centric features (e.g., user-defined identifiers) are gone. According to the OpenID Foundation (the organization continuing to oversee OpenID's evolution), OIDC:
  XACML follows a general policy control model, which employs the PDP and PEP described earlier for QoS support and, in addition, the constructs below:
  Figure A.24 shows how these different constructs are related to each other through an example workflow involving the following steps: