Glossary: Sybase Control Center for Replication

alert – a mechanism for notifying administrators when a managed resource experiences a status change, or when a performance metric passes a user-specified threshold.

alert instance – a copy of an alert type that has been configured to generate a particular kind of alert for a specific managed resource.

alert notification – an indication that an alert has fired. Alert notifications appear in the Alert Monitor view. If e-mail notification is enabled, alert notifications are also delivered to the specified e-mail address.

alert target – the destination for an alert notification and source of an alert response.

alert type – (1) A template that defines the resource type and the key performance indicator associated with an alert instance. (2) The basis on which an alert fires: state or threshold. Some alerts are triggered by the state of their key performance indicator (for example, running or stopped), while other alerts are triggered when their KPI’s numerical value passes a specified threshold.

alert storm – the result of issuing many redundant alerts associated with a common or root occurrence. See also alert suppression.

alert storm suppression – a Sybase Control Center feature that can be configured to prevent alert storms by suppressing repeat alert notifications for a specified period of time.

availability – indicates whether a resource is accessible and responsive.

collection – a named, predefined set of key performance indicators for which values are collected from monitored servers at the same time. Collections supply the performance and availability data shown on Sybase Control Center screens and charts. Use the scheduler to view a list of collections and to control which collections run, how often they run, and the length of time for which they run.

component – A server object in a replication environment. Examples of components are connections, routes, and Replication Agent threads.

connection – A connection from a Replication Server to a database.

database – A set of related data tables and other objects that are organized and presented to serve a specific purpose.

data server – A server that provides the functionality necessary to maintain the physical representation of a replicated table in a database. An example of a data server is Sybase Adaptive Server.

Data Server Interface (DSI) – Replication Server threads corresponding to a connection between a Replication Server and replicate database. DSI threads submit transactions from the DSI outbound queue to a replicate database. They consist of a scheduler thread and one or more executor threads. The scheduler thread groups the transactions by commit order and dispatches them to the executor threads. The executor threads map functions to function strings and execute the transactions in the replicate database. DSI threads use an Open Client connection to a database. See also connection.

edge – A topology object representing a relationship between two nodes, displayed in the form of a line that connects the topology node icons. Edges are usually defined with a direction.

Enterprise Connect Data Access (ECDA) – An Open-Server-based software gateway that supports DB-Library and CT-Library application program interfaces and Open Database Connectivity (ODBC) protocols. It serves as a fundamental building block for database middleware applications that provides access to non-Sybase databases.

environment – A set of servers that interact to perform replication. It can be a subset of the replication domain identified by the ID server.

event – an activity in the system, such as a user logging in, a service starting or stopping, or a condition changing. Use the alerts feature to detect and notify you about system events.

heat chart – a graphical view of resource availability in the current perspective.

ID Server – A Replication Server in a replication system. It assigns unique ID numbers to every Replication Server and database in the system and maintains the version information for the system.

job – a task performed by the scheduler in Sybase Control Center.

key performance indicator (KPI) – a single metric used to evaluate the status or performance of a monitored resource. A KPI value can be a state (such as running, error, or stopped) or a numerical value. KPIs are grouped into collections (and also, for some product modules, into key performance areas, or KPAs). KPI values are collected by scheduled collection jobs and appear on monitoring screens and in the statistics and heat charts. Examples of KPIs are Server Availability and Number of Blocked Processes.

latency – The measure of the time it takes to distribute a data modification operation from a primary database to a replicate database. The time includes Replication Agent processing, possibly ECDA processing—if the replicate database is non-Sybase—Replication Server processing, and network overhead.

Mirror Activator – Provides an integrated, zero-loss disaster recovery solution when used in conjunction with a storage replication system. Replication Server, Mirror Replication Agent, and Enterprise Connect Data Access (ECDA) are the components of Mirror Activator.

Mirror Replication Agent – A component of a Mirror Activator disaster recovery system that reads the mirror transaction log of the primary database and sends transaction data as LTL commands for replicated tables and replicated stored procedures to the primary Replication Server, which converts the LTL commands into SQL and applies the SQL to the replicate database.

node – A topology object representing a server or other entity type, displayed visually in the form of an icon.

partition – A raw disk partition or operating system file that a Replication Server uses for stable queue storage. See also stable queue.

perspective – a named tab in Sybase Control Center that displays information related to a collection of managed resources (such as servers) and a set of views associated with those resources. The views in a perspective are chosen by users of the perspective. You can create as many perspectives as you need, and customize them to monitor and manage your resources. Perspectives allow you to group resources ways that make sense in your environment—for example by location, department, or project.

RepAgent thread – The Replication Agent for a primary Adaptive Server. It reads the transaction log and sends the transaction data as LTL commands for replicated tables and replicated stored procedures to the primary Replication server, which converts the LTL commands into SQL and applies the SQL to the replicate database.

replication – A process by which the changes to the data in one database—including creation, updating, and deletion of records—are also applied to the corresponding records in another database.

Replication Agent – Reads the transaction log of a primary, non-Sybase database, and sends transaction data as LTL commands for replicated tables and replicated stored procedures to the primary Replication Server, which converts the LTL commands into SQL and applies the SQL to the replicate database.

replication path – The set of all servers and internal components, such as threads and queues, that transactions travel through when moving from the primary to the replicate database.

repository – a database that stores information related to managed resources, along with user preference data, operational data, and performance statistics.

resource – a unique Sybase product component (such as a server) or a subcomponent.

route – A one-way message stream from a source Replication Server to a destination Replication Server. Routes carry data modification commands (including those for RSSDs) and replicated functions or stored procedures between Replication Servers.

SCC-enabled login account – a user account that has been granted privileges in Sybase Control Center by mapping appropriate Sybase Control Center roles. (Roles are typically mapped to a group to which the account belongs rather than to the account itself.) The user account and group can be native to Sybase Control Center or created in the operating system or the LDAP directory service to which Sybase Control Center authentication is delegated. You must use an SCC-enabled account to log in to Sybase Control Center.

schedule – the definition of a task (such as the collection of a set of statistics) and the time interval at which Sybase Control Center executes the task.

stable queue manager (SQM) – A thread within Replication Server that manages the stable queues. Replication Server uses one SQM thread for each stable queue, whether inbound or outbound.

stable queue – A store-and-forward queue where Replication Server stores messages destined for a route or database connection. Replication Server builds stable queues using its disk partitions.

topology – A graphical representation of how the servers in a replication environment are connected to each other. It is a network diagram that provides a visual map of the availability of the replication environment.

view – a window in a perspective that displays information about one or more managed resources. Some views also let you interact with managed resources or with Sybase Control Center itself. For example, the Perspective Resources view lists all the resources managed by the current perspective. Other views allow you to configure alerts, view the topology of a replication environment, and graph performance statistics.