> # Planning Monitoring and Event Tracing

> SequeLink monitoring allows the SequeLink administrator to see what is currently happening in the SequeLink environment. SequeLink event tracing allows SequeLink administrators to store information about events that occur in an event trace file, allowing them, for example, to check on events that happened overnight.

> To enable monitoring and event tracing for SequeLink services, you must have a monitoring profile and an event trace profile configured for each service you want to monitor. On Linux, UNIX, and Windows, both a monitoring and an event trace profile are enabled when you install SequeLink Server. On z/OS, the monitoring and event trace profile can be enabled during configuration.

> ### Monitoring

> SequeLink provides the following levels of monitoring for SequeLink data access services, listed here from highest-level to lowest-level. Some of the monitoring levels are also supported for the SequeLink Agent service.

> - Service monitoring monitors these activities by service:
> - Statistics of received packets and sent packets
> - Sessions started and statements opened
> - Active statements and sessions
> - Fetched rows and affected rows
> - Transactions
> - Session monitoring monitors these activities by session within a service:
> - Statistics of received packets and sent packets
> - Statements opened and active statements
> - Fetched rows and affected rows
> - Transactions
> - Information about each session, such as start time, client information (network address, data source used by the client, and type of client), native database session identification, and database user
> - Statement monitoring monitors these activities by statement within a session:
> - Fetched rows and affected rows
> - SQL statements issued

> ### Event Tracing

> Event tracing provides a method for the SequeLink administrator to store persisted information about an event. Events are generated when a client application accesses data and when certain server activities take place, such as when a service starts or an error occurs. SequeLink can trace the following types of events:

> Service Session Network Error | Statement Transaction Others

> To make the event trace information persistent, an event trace file is created during the installation or start-up of the SequeLink Server. The service attributes that define characteristics of the event trace file are ServiceEventTraceSize and ServiceEventTraceLocation. See "Event Handling Default Behavior" for the default settings of these two attributes.