# Availability Tracking

## Availabilities by system

Each system has specific checks that inform whether Avantra considers the system to be available or not.

### Server Availability

A Physical Server is considered available (or Up) as long as the Avantra Agent installed on it is running. In cases when the agent was down, but the server itself was still running, the Avantra Agent determines (during the startup phase) since when a Physical Server was running by reading the server’s uptime parameter. It then generates availability data back in the past. For time periods the Avantra Agent cannot determine the system is running the availability is considered Unknown.

### Virtual Cluster Server Availability

A Virtual Cluster Server is considered available as long as there is an Avantra Agent running on the Physical Server the Virtual Cluster Server is active on (see above).

### SAP System Availability

An SAP System is considered available if the SystemAlive check is Ok. Unlike other Availability Data, the data for an SAP system is collected constantly in the background and is updated immediately.

### SAP Instance Availability

An SAP Instance is considered available if the following checks are Ok:

Instance Type | Check
Central or Dialog | RFCConnect
Central+Java or Dialog+Java | RFCConnect and J2EECONNECT
Java | J2EECONNECT
Java_Scs | SCS_MSGSRV
Abap_Scs | ASCS_MSGSRV
Trex | {_TREX Connect}
Web Dispatcher | WD_Connect

In other words, an SAP Instance is considered UP as long as the Avantra Agent can log in. If the login attempt fails, the SAP Instance is considered DOWN.

### Database Availability

A database is considered available if the DBConnect check is Ok.

### SAP Business Objects Availability

An SAP Business Objects System is considered available, as long as the BO_Alive check status is Ok.

### Cloud Service Availability

A cloud service is considered available, as long as the SO_Connect check status is Ok.

### End Point Availability

In the context of End-to-End Application Monitoring, there is also the so-called End Point Availability. Its availability corresponds to the check status of the E2E check record.